I've decided its time to make my IROC run like a Twin Turbo Camaro should. It looks like a spent way too much money on it to only go mid 12's (though it is actually a very budget oriented system). This thread is going to document my progress through-out the summer to take my IROC into roll bar territory (my goal is ~11.50 at 120+MPH on a stock turbocharged L98, preferably on street tires).

Nov 8, 2003:
I ran my best ET, which was a 12.46 at 112.9MPH on BFG Drag Radials, 1.80 60'. This was using the old JY Volvo turbochargers at 6psi and open down pipes (boost creept to 7-8psi at redline of 5500)

Nov 5, 2005:
Car is now repainted with a heavier hood and lots of sound deadner- gained ~80lbs since last drag strip pass. I have larger turbochargers, but ran the same boost- 6psi, still creeping to 7-8 at the top end. Ran 18" street tires and the my hack-job y-pipe (poor flow for sure), but I opened the electric cut-out, which is in the area of the stock cat. Ran one pass, 12.6 at 112.98 with a 1.9 60'. Tire's spun clear through 2nd gear (shifted into 3rd early), and I finally realized that 3.70 rear gear was killing me. The shift lite was on the last 200ft of the run, so the engine was spinning around 6k through the traps, which it does not like (the power is dropping off fast at 5500- you can easily feel it). All things considered, I was excited with that run and it made me realize that I may be able to get it into the 11's on 18" street tires, hence this new goal of mine.

May 5 2006:
Ran at the track again, with used 3.27 rear gears purchased from a member here (Chris, aka TPI383- Thanks man!). Still running the same boost, y-pipe bolted up with cut-out open, and the 18's. The weather was not optimal, it was quite hot and humid for May in our area. But I thought the results were semi promising. Best run was a 12.55 at 114.45 with a 2.00 60' (clean run, but bogged engine on start line). The run after, I ran a 12.58 at 114.25 (1.98 60') with the rear end drifting sideways at the top of 1st gear and most of the way through 2nd- much like this-> The tires regained grip at around 5k in second, when the power band started to run out. It was fun, but not fast. I'm kind of optomistic with these times, even though they don't look like that muck of an improvement on paper. The 3.27 gears are very neccessary for me to obtian my goal, no doubt.


Sorry for the history lesson, but I still have a few questions:
1) Obviousely I need some traction. Can I reach my goal by working with the suspension only (I like having the spiffy 18's on at the track ). Or am I shooting myself in the foot with the rubberband tires? I have a buddy who thinks I am and I should just bolt on slicks and be done with it. But I really want 11's on street tires for some reason.
2) Ok, I only had one question.

Next mod to move closer to my goal:
1)MBC of some sort to run 10psi of boost (or more if needed)
2)Alky injection to keep the 9.3:1 cast pistons happy

Any input is very welcome! I'll keep this post updated with each night at the strip, whether the results are good or bad.

 

Here a picture for those of you who may not have seen it:

 

1st off your welcome for the gears. They were collectin dust here.

Id say get some DRAG RADIALS for your 18's. or push it as far as you can with the street tires 1st. alky and more boost will deff get you to your 11's.

 

Sweet!
I'm all for trying to run what'cha brung, and looking good doing it.

10psi and alky will definitely give you enough additional power to get there. Unfortunately, it will also give you less traction, heh.

I'm no thirdgen drag-launch expert, but the things I know that should help: Lower control arm relocation brackets- Your car is lowered, right? Especially needed in this case if you don't have them already. Get them from Spohn and attach the LCA's at the lowest attachment point. That'll help to keep the tires from lifting upon power input (pro-squat).

Adjustable torque arm- I actually forgot how this helps, heh, but people have good reviews about them in the traction arena.

Adjustable shocks- Lower them to the softest setting.

All the traction you can work toward is on the launch. You want that weight transfer to happen, and it likely won't happen at all once you've started spinning. Also, the second gear shift should be helped out too by the same effects.

What size tires are you running?

 

Thanks for the reply Chris. I was just getting ready to PM you so you could see what those old gears went through this evening.

You don't think I should feel guilty spending ~$400 or so for 18" DRs? I was actually thinking about that as well. I haven't done any research yet, but who makes the best drag radials for large diameter wheels?

I think we'll start with the extra boost and alky, but then I forsee even more traction issues. I can get it out of the hole no problem, I'm not worried about that. What is really hard for me to control is 2nd gear tire spin. I mean you can't let off the throttle when your racing. Will suspension keep the street rubber hooked through 2nd gear? My rear suspension is totally stock except for 2 coils or so hacked off the springs.

 

Another thought, depending on where you're at going through the traps, 3.08's or thereabouts might help with traction even more, without slowing you down any. A twin-turbo TPI on 10 psi has got to be one very peaky son of a gun. It wouldn't hurt to hold that out a bit.

Drag radials are the way to go if you want to keep the looks and launch, but lose some handling in the process. They have nice, soft sidewalls.
I think it'd be even cooler to hit 11's with 18" street tires.

 

Thanks for your response too Steve. Are we all single or something talking about cars on the computer at 11:30pm? (well maybe its not so late for you guys, but stil l )

I like the suspension tips. Spohn is like 30 minutes from me. I should go up there and chat with them.

My tires are P275/35ZR18 Bridgestone Potenza S-03's. They grip very well on the street. If I want to cut it sidways in second going past the local import hang-out, it won't. But at the track where I want to go straight and fast, I end up counter-steering. Whats the deal?

The tires don't actually spin on the launch (if I get it right). They spin when boost hits on the top of first (I'm assuming this because I don't watch the boost gauge until further down the track). Then the 1-2 shift has boost and that keeps the tires from regaining control until the powerband slacks off at the very top of 2nd gear (you can feel the punch in the rear when the tires hook!).

EDIT: I wonder if a check ball MBC would actally hurt me on the strip if it makes the turbos spool faster?

 

Whta gets me now is that my car originally had 2.77 gears. I think that would be great for my current turbo system. I swapped them for 3.70's before I even knew what a turbo did. I was all anti-import until I seen a turbo Talon run 12.2 at 120 or so on a very hot and muggy night. I soon learned that a turbocharger is the best thing imports have brought us. I now know that the best combo is an American made V8 with two American made turbochargers (IMHO)

 

You're welcome.
Yeah I'm single, but I'm engaged. Too bad I'm over here on the opposite coast from her for now. It's actually 8:30 here, but I'm about to go to bed, heh.

Spohn knows drag F-bodies, but I don't know how much experience they have with standard tranny, show type cars on 18's. I'm sure they could lead you in the right direction.

I don't know about having more traction on the street. I thought that was supposed to be the other way around, haha. Maybe your track just doesn't hook well?

If they only start spinning once you build boost, it might be a bit tougher. Those things that I mentioned will still help, and maybe 10 psi will be enough enough to cause a decent weight shift after the fact, but I dunno.
See if you can build boost any quicker by honing your launch technique some. Maybe slipping the clutch on takeoff enough will 'mesh' the launch in with boost hit and keep weight back there. Of course that'll kill your clutch real quick, heh. Second gear should still be helped out by suspension work I think.

Turbo Talon running low 12's? Child's play. j/k
American cars were being turbocharged before the import companies brought them over here.
2.77's might have worked too, hehe. Your Tremec is geared similar to a stock T5, right? Those are pretty short gears, and some tall rear gears wouldn't hurt as bad off the line as they would on say, my T56 or a stock 700R4. All that TTTPI torque is going to kill traction with real short gears, as you have seen.

Edit: A check ball MBC won't make them spool faster, it'll make them spool a bit slower. That may or may not help, depending on where it happens.

 

I think you're on the right track about the traction thing. I would ditch the rear 18's for the strip, get some 17x11 ZR1's and run 315 DR's just for strip duty. Kinda stretching it, but those are still street tires right? hehe. Combine that with maybe some suspension work/tune (I dont know what your setup is), someone like Spohn would probably be the man to talk to. Beyond that I think the next thing to try would be maximizing the boost. What PSI are you launching at? My friend has been recently playing around with his turbo setup because he just went standalone ECM, now he can do all kinds of cool tricks. He can setup a window switch to spray a small nitrous shot below a certain psi (spools the turbos faster), and he also re-did his meth injection setup to begin injecting above 10psi. I think if you want to keep the L98 stock the boost will be the key. With injection and tuning you can probably run a few more pounds of boost and still control detonation, I think the limiting factor will be how much boost the heads can physically handle before the headbolts give. Maybe have the stock L98 heads studded and o-ring'd?

 

not that i'm a genius, but stock rear suspension, and 12.5 @120MPH screams "I need traction!".

LCA relocators, and cheap lca's with poly bushings. $70+$65 I think, from spohn. Cheap, easy to install (everything being relative). Try that out, i'd put money that it'd drop your ET noticeably. Have you played around with tire pressure?



I think the head studs, and o-rings (if you feel like tearing down and removing and machining the block for o-rings...) or just better head gaskets, are definately a good idea.

 

Heh, if I ever fix some of my rides so I can get to work on the toy I may start a similar thread, though I suspect that I’ll get into the low 12’s/high 11’s with the parts that I’ve accumulated before I see any boost…

1- stick foot out in front of you
2- pull out gun and start blasting off toes

I suppose that it can be done, but it’s the difficult way… but I’m pretty much anti bling… I actually bitch about the 17” tires that came on my WS6 just about every day I drive it and wish someone still made some really good 15” street/handling tires in BIG sizes.

15’s are lighter and can be made to work better under just about every situation, the only reason to go with bigger wheels on a car is if you need them to clear brakes.

Race gas when you up the boost at the track would be a lot easier then adding another variable with the alky injection. I’ve even been considering swapping over to E85 at the track (too expensive to use on the street)

To be blunt, I pretty much consider drag radials standard equipment on the back of a car like this for street use. Any kind of normal radial tends to slide around and be almost dangerous with real power being put down, and I’ve found that I actually get better mileage out of soft compound sticky tires then a harder, normal street compound just based on the lesser sliding around.

I like nitto DR’s for street use… they work great in the rain and in a pinch OK at the track (the best I’ve ever run with a stick with them was a mid 1.6 and I’ve run as fast as a 1.54 with them with an auto, but they are definitely not in the same legue as a BFG or MT radial at the track, neither of which work as well on the street)

Most people that can actually use their right foot to get out of the hole still have problems with the 1-2 shift in these cars. 90% of the problem is actually a flexible stock PHR, or even an aftermarket one with soft bushings. On the shift it actually flexes and you get a bit of an instantaneous sideways motion breaking the tires loose. A sticky tire will take care of the rest, at least in the range that you’re talking about.

I was able to spray through a 1-2 power shift with an aftermarket PHR and 275/40/17 nittos on my WS6 without any of that tire spin showing up on a prepped track.

With low profile tires… skip them. They apply more force to the tires on shifts and the launch that a low profile sidewall can’t absorb. You end up with something that feels awesome but you can’t really figure out why it doesn’t work. Video tape the car and you’ll figure it out. With the nitto 275/40/17’s, T56 and some relo brackets I was able to come out of the hole hard at 5200rpm, but within 10-15 of the line the sidewalls would actually compress as far as they could, bounce off the pavement and I’d get violent wheel spin. Did the same thing in both lower mounting positions.

If you have real drag tires with soft sidewalls it’s a different story.

Unnecessary… in a much faster car it can give you better control (more predictable ride), but the only way it’s going to improve the launch in this setup is if it’s shorter and then essentially it’s doing the same thing as the relo brackets.

I like my fronts soft and rear hard… on some of my f-bodies I even ran air bags in the rear springs with good results.

Turbo will actually extend the power band and make it less peaky, at least a normal setup, rear mount is another story usually.

Wife goes to sleep and I have time to play… probably the same for lots of people.

I’m unpopular around the suspension board for saying it but I’ll repeat it anyway… spohn stuff is overbuilt and under engineered… if you want something heavy that is probably unnecessary for what you’re doing, go for it. I own some spohn parts, including most of the rear suspension parts and they are all hanging on the wall in the garage except for my PHR and a set of relocation brackets welded onto my WS6 axle but I’m using the stock pivot points for the LCA’s anyway.

What tire pressure are you running at the track? I’m betting that it’s probably too low. With street radials I’ve found that I almost always run fastest at between 32 and 36psi.

Drag radials are a different story.

 

yep. Buick had turbos on a few of their production cars as early as 78' and i believe the first production turbocharged car was the Corvair from the early 60s

 

Go even further back than that. Turbo's and Superchargers were arround in the 30's on some cars and a lot of aircraft.

good luck on your quest, if you are ever down at Atco I'll swing over and say hi. As I live in SE PA also

 

Wow. Thanks for all the replies. I have a lot of info to work with now.

I think maybe the track is a problem. Its a very well known track, Maple Grove in Mohnton PA. I've heard they don't do much prep work for the Test'n'Tunes. I may try Cecil County MD's strip. It's a lower altitude and they are always spraying VHT (I ran my 12.5's in my turbo Z24 down there).

Please do. I love to see docmented builds, and one from someone as knowledgeable as you would be especially interesting.

Thanks for the suspension and tire tips. I do have 255/60R16 BFG Drag radials mounted on GTA wheels. Maybe I just need to bolt them up once I get to the track (I just can't stand the way they look and would hate to drive it on the street with them). I guess I can call them a street tire, and therefor meet the criteria of my self imposed goal? What do you think of trying those tires Mark?
I didn't touch the tire pressures. They were right around 30-31psi.
Yes, I know the imports weren't first, but I do believe the imports are what made the turbo mainstream in modern performance. Although guys like Ak Miller and Banks from the 70's and 80's may contradict this idea. Either way, as embarrassing as it may be, imports made me realize how awesome a turbocharger really is. I was hooked after the first turbo DSM I drove- it was stock and pretty slow, but I loved the feel of the turbo so much it brought me to where I am today. I can't even enjoy a car show any more if nothing there has a turbo.

 

Ok, maybe I don't understand how they work then. It is my understanding that the check-ball keeps boost pressure from reaching the WG actuator until the boost hits the set amount (therefore the WG won't crack open at say 4psi to be fully open at 6psi). This is said to increase the turbocharger's response.

 

You know, I think you're right, heh. I've never thought about that versus no controller at all. All I've ever compared them to is good EBC's, which help spool faster than an MBC, so I've had it in my head all along that MBC's make for slower spool.

I must say, a turbo DSM is what got me hooked on turbo's too. So much so that I had to get one then mod it, then had to get another IROC and start a TT project as soon as possible (a few years later, hehe). We think much alike in that respect.

 

Tell me if you go… I’m in the DC metro area and usually go to Capitol, but I’ve been meaning to head out to Cecil for sometime now and meet Don and a few others from the board.

If I do I’ll probably do it in a blog format, which I figure has a few advantages:
- it will let me document _everything_ in a single place and in an easily searchable and document able format
- people interested can just subscribe and see it any time I updated and comment in a format that I have some control over
- I inevitably get distracted with real life with projects like this, and I figure that when I do I could easly post pics and comment on past stuff… I literally have thousands of pictures of mosty f-body, fabrication, performance and racing related stuff from the last maybe 8 years, mosty f-body related.

I have wondered if it’s a good idea since I haven’t seen many car guys get at all involved with blogging…

I’m guessing 255/50 16’s… I think that you’ll have MUCH better luck with them, but I’m not sure to what point, and I don’t think that everyone would agree. You’ll have to remember that it’s different getting a slick, DR and street radial working off the line.

You’re well past the point where you’ll get good results with street radials, right in the range where I’ve had REALLY good luck with DR’s, but it’s also the point where a lot of people have given up on DR’s also.

I’d start with a tire pressure around 18psi and make sure you get them nice and hot (I usually do about a slow 2 count doing the burnout _after_ I start getting good smoke coming off the tires in 2nd or 3rd gear).

FWIW, I have not found anything that I can’t get to dead hook on some 275/60/15 BFG DR’s after some tweaking of the combination and technique.

Supercharging (with all sorts of power sources for the compressor, including turbine) has been around longer then IC engines and was applied to try to increase efficiencies in IC engines at every step of the way. Yea, there were tons of assorted applications going way back all the way, but I would probably call the 60’s corvair and and Olds Jetfire (with “rocketfuel,” basically water/alchy injection) the first real, production everyday applications of turbocharging.

 

I have never seen a test that showed an increase in performance by going to a larger wheel size with the same compound. As a matter of fact I’ve never seen one that didn’t show a significant increase in performance across the board by going with a smaller diameter wheel as long as the tire is as good as the one in the bigger diameter.

What feels better has little to do with what actually works better, yes, lower profile tires feel more responsive, but we can already make 15” tires that can “respond” faster then a human can so that’s irrelevant. Assuming simlar compounds they will stick the same, the advantage comes in that with a taller side wall you can make them work at a MUCH bigger effective slip angle and like I’ve already mentioned they are MUCH lighter also.

The problem is that because of the popularity of larger wheel sizes there isn’t much available in a true high performance tire construction/compound for a smaller wheel diameter in a width/height appropriate to a car the size of an f-body.

It costs within a few cents of gas and is almost impossible to get around here.

I was running the 275/40/17’s at between 15 and 17psi depending on track conditions when this was happening and was seeing about 8-12” of tire spin on the rim on the average pass.

If anything I would expect the whole situation to get much worse as the tire profile gets lower. I’ve seen some video of a mustang with some South side bars (work basically the same way) where after the launch it would compress the sidewalls to the point that the rims would hit the track surface and actually leave 2 grooves in the pavement made by the edges of the rims.

I have no reason to believe that they would work any better with street radials or 18’s. With the same size GSC’s and the relo brackets on my WS6 I had absolutely NO traction no matter what I did, wasn’t able to run better then a 2.2 60’ in either lower location. I’ve run low 1.7 60’ times on the same tires with the LCA’s in the stock location.

My WS6 is something around 1.25” lower in the back and I get best results with the stock mounting location. With what your’e describing I’d probably try them first bolt hole and stock bolt location and see which works better, and if the first one works better then try the second, but getting conclusive results like this is going to depend on your ability to run dead consistent runs and not tainting your results with what you expect to happen
----------
it actually bleeds boost through before it reaches the opening pressure, it's not an all or nothing thing.

I really want to play with a solenoid and hobbs switch... it the set pressure of the hobbs and the solenoid valve opens and the wastegate sees full line pressure, below that pressure it slams shut. Add a small bleed between the WG and the solenoid and it will release the WG when the solenoid closes.

I’ve been told that it’s been tried and you can’t get it to work fast enough to properly control boost, but I get the feeling that part of the issue has been implementation rather then the idea. The sweet thing about that kind of setup is that you could rig an easy lower boost setting for the street and an override for a little extra instantaneous boost when you need it…

 

Mark, as of now I'm planning to go to Cecil Saturday T-n-T May 27th. I'm going to drive the car down to the track and run a few passes on the 18's, then swap to the BFG DR's (which may actually be 255/50R16s as you suggested, its been a while since I got them out). My brother will drive down to carry a jack and the DR's for me. I don't like the idea of needing a support vehicle, since I want this to be a legit 11 second street car. But, at this point this will be for research purposes. Depending on how hard up I am to make this legit, I may end up buying the Nitto 555Rs you suggested to run on the track and street (fulltime).

About the LCA relocation brackets- I was just brainstorming a bit today, and I go tto thinking they theoretically should work out for me. With my car lowered as much as it is, the LCAs angle downward from the axle to the body mounting point. When you apply forward force through the LCAs, it seems it should make the rear tires try to lift. But I do understand that the lo-pro tires may end up being more of a limiting factor for me instead of the LCA angle.

Car guys don't use blogs? I don't even know what they are....

 

Thanks for the input. I definitely agree that I'm going to need some more boost to get the job done. However, the L98 will stay together until it is time for a full build. I have no intentions of tearing into it in any way until I get to my goal, unless it breaks before I get there. Then (afte I break it or reach my goal) I'll build a motor to run high boost reliably. I still don't forsee going ***** out with it, I'll still keep a mild cam and get better heads of course. But I'll retain the TPI because I like the looks and we'll make power with boost. It'll remain VERY street oriented.

Man I wish I had kept the A/C.

 

My guess is go with the suspension mods to get the pinion angle down a bit and some drag radials (even though you would like to do it without them).

What are the IAT/MAT temps at your current (6-7PSI) boost level? Is that a reading before or after the ICs? What is the AFR under boost?

Yeah, a lot of questions. The reason I ask is because I have been tuning AFR under boost on my setup and the difference at WOT is night and day from what it started out with for HP at WOT. I went from 10 AFR to 11.6 AFR and the way the car reacts is much better (the butt meter isn't a good HP meter). That change in AFR only shows up as a 50mV difference on the stock NBO2 sensor. Also, the way it responds changes a whole bunch from a 70* F day to a 40* F night (no IC).

The VE of the stock TPI engine falls way off above 5200 RPM and the FMU will still be at a max. fuel pressure so it is going to be way rich unless the injector BPWs are tuned for it. Just as an example, putting on the log manifolds and .63 A/R T3s, I lost about 5% VE at around 5800 RPM when compared to 1 5/8" headers. I am guessing you have some more HP in that engine with the current boost levels.

With that, I would think that drag radials (I use 15" wheels, never tried 17s or 18s) would be good and easier on the rear end. Up the boost 2 PSI and spray it with windshield washer fluid if the IAT temps are high. I am guessing the tires will gain you about .3 tenths and the colder extra 2PSI will gain another .3 tenths. Close to mid-11's.

 

What do you consider too hot for the intake charge? I have an open IAT sensor w/pigtail ready to install. Just being a little slow to get it in.

Good idea on the AFR going too rich when the VE drops. I never gave that a thought. I have not installed a WB in it yet. I know it's high time to do some testing. Actually, the more I think about it, I feel guilty for trying to do what I am without doing some more R&D.

 

ZR1's are heavy and 17's don't give you a lot of sidewall to work with.

 

Well, you could just drive it on drag radials… I’ve used DR’s on daily driver’s before. For that matter I can think of a few drivers that run on slicks all the time.

Well, it’s not that simple, but I don’t realy want to get into a discussion of instant centers vs antisquat percentages… but to make my point, I’ve run low 1.8’s (power limited, the car actually couldn’t go faster) on street tires in my ’83 that was lowered a LOT more then most, even with 27” tall back tires it sat about 1” lower in the back and more then that in the front then my formula does with eibachs and 25.5” tall tires, with stock pickup points. My formula is about in the same boat right now with the eibachs, and my WS6 is lowered a little more then an inch in the back and I already told you what my experience was with relo brackets on it.

Sorta makes my point, huh?


Well, not really. VE stays the same you’re just increasing the density of air that you’re feeding it. Since in theory you’re increasing FMU ratio in proportion to the density increase you shouldn’t need a different fuel curve, at least if the FMU ratio is correct at that specific boost level (FMU’s tend not to be as proportionate to boost as the ratio suggests so usually you have a problem in the midrange being lean when you have your max boost value right…, but that is because they usually don’t react to the midrange.)

Just .3… I’d bet that it could be more like a ½-1 second in the range he’s looking at… I guess that depends on the 60’ that he’s running now… figure on about a 1.5x improvement at the quarter as what you’ll see in the 60’, so if say you’re running 2.2 60’ and knock that down to a 1.8 that should be about a .6s improvement at the big end of the track.

 

No problem. I understand that that could get very lengthy and not within the scope of this thread. So in other words, your opinion is that (at this point anyway) I don't really need them, just a track bar and maybe lower control arms?


My 60's aren't that bad. 1.9-2.0 when I get it right. The problem is 100' out or so whenever the boost hits in first and second gear. Sometimes I'm counter-steering midway through 2nd gear when the torque peaks. It doesn't really blow the tires off, just spins enogh that it starts to slide out. These 18" tires don't ever seem to completely loose control (if that makes sense?). Like I said in a previos post, the car really hooks good on the street and unless I really hammer on it, I can't get it sideways in second on the street (which pisses me off sometimes ).

 

Yes, but I was hoping to see how much the better track prep at Cecil helped my 18's hook. If they still give me problems I can switch to the DR's, then I can see exactly how much they help, back to back on the same track, same day. I thought that seemed like valuable info for me (since I'm still learning).

 

Hey glad to here your progress and goal. I had the same problem with my TT Mild 305 carbed camaro. I would not hook when my boost hit above 6 psi, and I am running 12 psi. Anyway the problem was when I would shift 2nd, the car would loose control easily.

Best thing I can recommend you is:
1. Get lakewood control arms.

2. Get a Energy Suspension polyurethane torque arm mount (this being the most important cause you probably have the stock one worn out) big and I mean bigggggg difference in straight line control.

3. Upgrade the panhard bar.

All these together will cost you less than $200.00
You will really feel a difference with these if you dont already have them.

I strongly recommend you running at least some Avgas (100LL) if you are going to up the boost. Even with the BTM it still will ping. The Avgas is a cheaper and easier thing than the Alky injection. Man, that alcohol system is a pain in the a$$ to tune with. I run now pure 100LL avgas which I get at the local airport for $4.50 a gallon, and man what a difference. Just beware, your o2 will last half as long with the lead. My wideband is uneffected so far.
Also run colder plugs if you are not doing so already. That will control you pinging and help keep the cast pistons happy.

I really think you will reach your goal soon. You can even go lower than your goal. Just get it to hook and keep it cool. I speak from experience with mine.

 

Pretty much, unless you decide to run MUCH taller, MUCH softer tires.

Sounds a lot like the only issue you have is tires…

 

Yes, I assumed that it was tuned for enough fuel with the FMU at peak torque with max. boost and not high RPM with max. boost. If it is right on at peak torque then higher RPM will be rich due to VE dropping off more than the factory settings due to the turbines and 2.5" restricting the exhaust. Like a N/A car with a restrictive exhaust, as RPM increases then VE will go down.


I was thinking a .3 drop from the loss of traction with the 1-2 shift. I was thinking he wouldn't launch much harder to ease the stress on the trans. and rear end. A harder launch will gain ET like you said though.

The thing is that going to the more efficient compressor for your setup should have gained a some ET drop due to cooler IAT. I think you could gain by tuning but it is a pain in the butt to learn and the hardware will run you about $200 or so. It brings me back to some drag radials and 2PSI more boost. I would just try the tires first or just the cheaper suspension mods. The tires and suspenion will be harder on the trans. and rear end. The 2PSI will be harder on the engine. Tuning could result in money spent and no gain. It is hard to say which is best.

 

IATs less than 100*F would be nice. In general, 10* F drop in IAT is worth 1% HP if fuel is added. Colder air also allows more boost. Keeping the engine coolant down around 180* F would be nice. Not having the coolant fan or fans on will help. Simple things like that add up. Realistically, IATs less than 130* at 7PSI would be reasonable. That is just my opinion. I am sure others will have different opinions.

One interesting thing I have found over the past few weeks is that reducing my WOT AFR from 9ish-10ish to around 11.8 AFR I have dropped about 1PSI of boost at max boost without touching the engine.

 

hey man i love you turbo setup, i would like to know if it was a kit or if you did
it your self.
one thing that will help loads is your springs. (the last i read you just cut them) while it makes your car look good it aslo takes away you cars ablity to (load) properly of the line and could also help your 2nd gear pro. for good.
solf in the front stiff in the rear- that is how you should set you shocks up.
the ajustable panhard bar will help alot to. (sins your car is lowered)
i beleave you can get to your goal on 18s.


at what rpm does your turbo spool up at
and would you be willing to change the cam.
b/c remeber you stock cam doesnt make good power above 5500.(anypower)
good luck.

 

If the FMU curve was actually linear (proportionate to the ratio) both would be pretty close to right without a change in tuning from NA. That fact that it is not linear is the big reason why it may run rich up top or lean in the middle. Yes there will be a loss of VE with a turbo exhaust… and it will be across the board. Just like there will be an apparent loss of VE with a supercharger across the board, but it’s actually the power needed to drive the supercharger that is not making it to the wheels….

 

The system is a home-brew based off stock L98 manifolds modified into turbo manifolds. The turbos are at full boost by 3k in second gear. Maybe not quite so soon in first, but the boost comes in even faster in the higher gears. I can actually get some boost under 2k in higher gears if I 'lug' the engine.

I want to reach my goal with the stock cam. Stock everything

 

how did you fab the pipes they looks nice.
and good luck again.

 

All the pipes were welded together from mandrel U-bends. The welds were ground smooth, and we used body filler to get the pipes seamless. They were then sprayed in auto base/clear metallic grey.

 

Update 5-12-06

Took the car out to another TnT at Maple Grove. Decided to just run down there with the 255/50R16 BFG DR's bolted up. First run was a 12.466 at 114.85 with a 1.937 60'. No tire spin at all, I layed the motor down under 2k on the launch. I did a long burnout in second gear in the water box. The next run, I did a similar burnout and launched even better, but still Bogged the RPMs well under 3k on the launch (since there is no boost on the launch, 3k rpm is quite weak). That run was pretty clean, until I heard a rear end noise. I backed out of it just as I got to the traps. 12.47 at 114.2 with a 1.8xx 60' (I actually don't have that slip in front of me now).

What was the noise in the rear? Well I decided not to run it again. I brought it back to my shop to have a look at the rear. I was sure something broke, as in a tooth off the ring gear or something. Turns out its all together yet. I must have goofed something in the set-up of the used gears I bought from Chris. I don't know if it was just because they were used, or if I just set them up incorrectly (I'm leaning towards the latter). In my defense, I was sick as a dog the day I put them in. But they were dead quiet driving down the road up until this evening (quieter than the 3.70s I had in before).

New question:
-What have been your experiences with the 9-bolt? Should I keep it and try to find another 3.27 gear set, or am I out of the reliabilty range of this rear (upgrade to a 12 bolt or something)?? I'm leaning towards finding another 3.27 gear for it at this point. Makes me grouchy with myself, considering I probably goofed these up

Thanks.
----------
I wish there was a smiley for kicking myself in the rear end.

Anyone else have good/bad experiences installing used gear sets? I set it up with proper backlash (.009"IIRC) and the contact pattern was dead in the center of the gear (tip to root), although it was more towards the heel on the drive side.

 

Man, you are pretty darn consistent with that thing, considering different days and conditions.

It sounds like the DR's are hooking pretty well, (obviously) you need to rev it higher and maybe slip the clutch a little more (DOH). As far as traction goes, keep running those until they start acting like the 18's when you turn up the boost (heh).

I have no experience with 9-bolts, but I'd think it should be strong enough considering all the people who are running mid-low 12's on 10-bolts.[/grain of salt]
The only time I've rebuilt a rear was in tech school 7-8 years ago and I don't remember much about it, sorry.
You said you looked it over and nothing was out of place? Is the rear still making noises?

 

Yeah, the DR's are a huge change over the 18" tires. Its been over two years since I last raced with the DR's, so I forgot how well they hooked- I just remember I had a few runs were I did spin them back then, so I was cautious at first. I now know they can take a lot more than I was giving them. I think I made longer burnouts last night than I did two years ago as well, which maybe contriduted to the stickieness. I can ride the clutch, I got good at that getting 1.9 60' on my Turbo Z24.

I've set up many rears before, this was my first used set. What bothers me is that they went from completely silent (as in zero gear noise ever) to very loud in one pass. I would think if the set-up was way out, they would have been noisy from day one (?). Maybe something moved that wasn't supposed too (although the pinion and carrier bearings are still tight). The only thing I can see wrong in the rear is that now the drive side of the ring teeth have a rough worn spot on the heel and towards the top, like the pinion is too far away (which makes me point the finger at myself). There may be a little extra backlash now too, I actually didn't measure it, but it felt like more than .009" it had when I put it together.

I think I'm going to keep the 9-bolt. I'll find another 3.27 gearset and see what happens. I'm not in favor of throwing money at it to get to my goal either. ANyone can go fast with $$$.

 

check your torque arm mount and trany mount. if any one of thoughs broke, it would allow your penion to rack up.just my two

 

89JYturbo---what are you runnin for an ecm with the turbos...how bad is it to tune? i would love to build a turbo setup for my tpi truck!! have any pics?

 

Well, I don't know if you want to copy my tuning conglomeration. They say if you are going to copy, you should copy the best Mine may not be the best but it is probably the easiest.

ECM- Stock '89 MAF ECM
MAF- I blow through the stock MAF sensor (in other words, it is mounted after the turbochargers, in the compressed air charge). Some say this doesn't work, but it has worked for me. I think what they are refering to is that the MAF maxxes out, and doesn't meter all the airflow. This may be a problem if you had no FMU (see below)
Injectors- Ford SVO 24#. These are on the small side for what I'm doing, but they allow great drivability using the stock ECM and it sets no codes. The FMU makes them act like a bigger injector because it increases the fuel pressure a lot.
Fuel Pump- Stock in-tank with a used Vortec 50/70 T-rex mounted in-line near the fuel filter
Fuel Pressure Regulator- TPIS adjustable unit mounted on rail, base fuel pressure set at 38psi IIRC.
FMU or RRFPR- This is the key to make it all work. I use a Vortec Super FMU and it works well. If I did it over again, I would get the Cartech RRFPR, which does the same thing but is cheaper and easier to tune. I don't care for the cheap eBay FMUs which don't offer much if any adjustment without disassembly to change discs. If you don't know how these units work, read up on them. They are the easiest way to tune for turbo installs on a NA car. They do have limitations, so be aware of them.
Ignition- MSD 6AL and BTM set to pull 1/2° of timing per PSI of boost. Base timing is OE at +6°

Its easy and cheap, and gets over 20MPG easily. Because of the extreme fuel pressures an FMU system produces, you are limited to about 10psi of boost on stock injectors and ECM tune. With my 24# injectors, I may have enough fuel for a little more the 10psi of boost without running past the safe fuel pressure limit (I don't know where the limit is, but I have run 120psi fuel pressure successfully in my Z24 for a long time now, even though most people say that that is not possible - but I'm not denying that 120psi FP is pushing the limit).

Most people will tell you the best route is tuning the stock ECM (converting to a MAP system first), or going stand-alone. Both these options require a lot more injector than I'm running, and the injector size will depend on your specific combo and power goals.

 

so i could run a turbo or 2 of my stock 730 ecm with say the ostrich real time tunner setup?

 

I guess it is time to play with the engine since the tires didn't help to get the ET down. I would try giving it 2PSI more of boost. BUT I would check the current injector duty cycles first to see if you have enough injector or fuel pressure left to support the boost.

IATs make a huge difference in HP. If you have an ALDL cable and a laptop computer available then do a couple of logs at WOT and see where it is at. ALDL logging at the track is great because you can look over the data later on and see why the run was good or bad. It tells all in terms of throttle lift, wheel spin, shifting RPM, how long you sat on the line, actual launch rpm, etcc.

355tpipickup,
Yes, you can run a 730 ECM with a boost device. There are various ways of using it depending on what mechanical parts you use. Start a new thread for that though. This thread is about getting a stock engined thirdgen into the mid-11's.

 

Sounds like you don’t have real numbers for it yet. You “wimped out” before you got a chance to hit it really hard off the line with the DR’s.

Well, it’s not really a used gearset problem, sometimes you’ll have a used gearset with some funny wear that that you can’t tweak all the noise out of, but it shouldn’t cause sudden changes in noise level.

Sounds to me like you have a backlash problem, or more likely, the carrier side shims are probably not packed in there tight enough to stretch the housing out enough that it doesn’t flex excessively and allow backlash to move around when you put a big load on it.

FWIW, the gears in a 9 bolt are much stronger then in a 10 bolt (I’ve broken 7 sets of gears in 10 bolts, none in 9 bolts under similar use), but the posi is weaker (worth about 35 hard passes before it needs a rebuild) and the axles are questionable (both sides are currently corkscrewed/twisted), check out this video closely, no, that is not the camera moving, the axles (both sides) are so messed up that it’s actually making the axle tubes flex

Of course, without c-clips, they are much safer.

I guess yea, they’re better in some ways but not really in others, and the fact is that you will end up hitting it really hard (well I do) if you’re going to get it to run it’s best.

Well, I still think that you have the chance to do it as you sit if you work out your launch/driving issues. Your 114mph is plenty to get into the high 11’s consistently. You’re just going to have to resign yourself to that you’re either going to break things getting there or you’re going to have to beef up the drivetrain if you don’t want to deal with breakage. For years I broke tons of parts getting cars to run at their maximum potential (and got really good at fixing them, setting up gears...), and just now I’m seriously making an attempt at building/using bullet proof parts as I replace things (we’ll see how that goes, I’ve been disappointed every time I’ve spent big money on “the right” aftermarket parts before rather then cobbling stuff together, so I’m not holding my breath).

 

That pretty much sums it up. To reach your goal you either have to launch that TPI at where it likes to run best or try to do it on HP. You run the risk of breaking trans. & rear-end parts launching it like a TPI likes to be launched. Trying to make up for a soft launch will require more boost and overall HP........harder on the engine. I am not sure which one is easier on the drivetrain.

 

FWIW, I can make anything go faster… I’m around 300# and I’ll get in someone’s car adding 100-200lbs to it’s race weight and then run a full second faster.

I actually ran a second and a half faster in my wife’s car with her in the car with me then what she could do without me in the car at all (and she’s not a bad driver), my brother is a rather good driver with as much dragstrip experience as I have and the one time he let me make a pass in his car I went almost ½ a second faster then he was running that night, and I’m about 120# heavier then him.

That being said, I’ve never broken an engine racing (probably the worst was when I had a tranny and a motor mount let go at the same time which caused the fan to hit the shroud and crack the water pump and dent the hood) but I break drivetrains… I’ve broken more axles then I can count and auto or manual trannies, clutches… are all fairly easy game. This time around my formula is getting a 4L80e, a Moser 9” with all the good stuff… the weakest link in my drivetrain will be my custom PE converter which has a 3 disk TCC setup rated at 1600hp… If I break drivetrain parts now we’re going to know exactly which big name company is lying with the hp/torque ratings since I shouldn’t be that close to any of them

 

That is probably true. I will guess at why that happens. It is because you know how to fix stuff so you aren't afraid of breaking stuff. Most people are afraid to beat something only because they are afraid it will break and it will cost a bunch to have it fixed. You may have had that fear a long time ago, but you became wiser and the fear went away. Just a guess but I have known a few people like that. Learning/Figuring out stuff will always give you an advantage, but I think you already know that. Take that knowledge and through a bit of money with it.......well, it is tough to win when you are up against something like that.

89JYturbo,
Do you have any 8192 ALDL logs that you could post? I am curious. You say that it doesn't make boost in 1st gear at 3k RPM. I messed around with my 355ci T3 setup auto trans. by footbraking it to 1500 RPM for less than 1sec (keep exhaust temps. down..slow spool) and then slowing rolling on the throttle (due to no traction) to WOT . It makes full boost around 5000 RPM in first gear. The RPM might have been lower but I can't remember without the ALDL data in front of me. I would have thought that will your setup and a 3K RPM launch with traction that it would go to instant boost with the huge load on the engine.

 

Thanks for all the info Mark and jnkcltr.

Few things:
1) I am not afraid of breaking my car because I don't know how to fix it. I actually own an auto repair business and have been a mechanic since high school, 3 years in a dealership and 4.5 years on my own. I have set up gears before, but never used sets. I had about as much preload on the carrier bearings as possible without installing a housing spreader. I've read some info on installing used gearsets, and I learned that you should only pay attention to the wear pattern on the coast side due to the wear you will have on the drive side. IIRC, the pattern didn't quite make sense to me, and I ended up going more off the drive side which appeared OK (like I said earlier, I was very sick that day, and probably should not have been in the shop [/excuse]). HOWEVER, I am very scared of breaking the car because iit is not towable. I think we made the car too nice during ther repaint, and I am always worried about it now. Will a roll bed truck destroy my front spoiler while loading? Will my rear quarter's get chipped doing a second gear bunout in the water box? And I'm always worried when the car is in the staging lanes that somebody will walk by and scratch it. I'm not usually **** like that usually, I need to work on it, or I won't be able to enjoy this car. I think I had more fun with it in the faded black paint it used to have. Does that make any sense?

2)Awesom video of that axle. That is hard to believe!

3)I think there is a lot more left in it with the DR's alone. Those two passes did nothing but boost my confidence in the car's potential. I knew there was a little more left in it, because both were launches where the engine bogged down pretty bad. I seriousely need some practice.

4)Data logging- I have a Snap-on scan tool that I can log a run (it stores up to 20 seconds or so, maybe more). Now you won't be able to see manifold pressure on that though because it is still MAF. What else would you want to see besides MAF and IAT? Knock retard? I also plan to install a WB and get some real AFR numbers (its been a while since I checked the NB numbers, I think they were very high .8xx last I checked).

5) I'm on the look-out for another 9-bolt 3.27 gearset. Let me know if you have any laying around

 

I didn't have you in mind about the breaking & fixing thing. It was more about why 83 Crossfire TA can get something to go faster than the average person. I hear you about the nice paint on cars. The "pretty" ones I have spend more time in the garage than any where else. Too many hours of welding, sanding, painting to be out in the real world. Matching pearl colors is a pain in the butt. I love the ugly 2nd gen with the turbos though. I can drive that thing any place. Well, almost any place.....the 4.10s gotta go.

I would think that it has more left in it. I did forget about the 80 pounds you added though. Practice will help. I never had the patients for running a stick. I went to the track once with a M22 and broke stuff. A TH400 went in it the next week. I only like sticks in anything with over 10 wheels or anything with 2 or 3 wheels. I know a lot of people that love them in cars, but I don't. Probably because I am lazy.

I have no idea what format the Snap-on data would be in so I wouldn't be any help in that area. You would benefit from it though if you can play back the run. NBO2 will vary at rich AFR so I can't really say what the .8 volts would be. I read .9 volts on the narrow band with a 11.8 AFR, and .94 volts on the narrow band with a 11.0 AFR. That is just an example of the accuracy. It says nothing about your .8 volts in terms of actual AFR.
I did do a quick calc. using your 24 #/hr and 80 PSI fuel pressure with a 85% duty cycle and .60 BSFC. The FWHP didn't seem to match what the 1/4 FWHP calculator came up with using a 3550# car. My assumptions were probably wrong, but the injector calculated FWHP came up quite a bit less so maybe your %DC is close to 100% and/or your BSFC is closer to .55.

None here, the only 9-bolt I ever had lasted about 3 minutes before it blew up.