Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

On a 1000rwhp car, I would say a th400/3.08-3.23ish gear is nearly a no brainer. If you have the loot, maybe a 4l80e. But, while cruising I think the non lockup converter should be pretty tight, and with a 3.08 gear it would be great out on the road. A 1000 hp car can still go on the bumper with a 3 speed trans and 3.08, so there is no need for much more gear than that, which means no need for overdrive. Dont know why people get so hung up on the od?

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

X2000

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Haha, it's not so much being hung up on overdrive Dig, and although I haven't put ten thousand miles on the car this past year, I do drive the car when it does get driven. This isn't a track only car per se, I drive it, meaning from New Jersey to New York as far as Queens into Long Island, it gets driven to Atlantic City, she gets driven, and the cost of gas can get very substantial the way she sits with overdrive and even with no boost, can only imagine without it, especially when I am in New York. It's not fun constantly staring at the fuel tank when driving for over an hour in traffic, but unless you lived here, you wouldn't be able to relate. I need overdrive, I don't need to lift the front end... :)

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

3.08 and 28" tire with good tight converter is 2600 rpm at 70 mph. Somewhat high but still can be very efficient. My 3.42's does 2900 at 70. Car doesnt get bad mileage for what it is. OD gains 750 rpm down to 1950 rpm. Good savings but again the cost is abit more. Mainly converter price.

If your in traffic then you arent moving lol gear dont matter then. Sub 50 mph car is a dream to drive, as its low rpm.

A sbc car with heads cam isnt going to be the most efficient anyway but i guess you gotta decide what type of driving you want to do. Highway cruising at 60-70mph isnt my thing and i get away with it in my area.

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Wasnt singling you out with my od remark, I am thinking of steve as well not wanting to consider a th400. Gots to have that overdrive! My dads 67 442 came from the factory with a th400/3.08 combo. Drives great. They drove it across the country 7 times when he was in the navy. (Bought it new in cali)

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I hear what you guys are saying, but in my case, with the 3.42's out back and the 700R4 gearing, right now boost comes in at just under 3000-RPM in first gear, which is right when my timing comes in, and just before the stall speed kicks in, although the last check I ran my alleged 3500 stall is coupling at 2500-RPM. But anyway, the way my gearing is setup, it allows me to have a decent push off the line from every stop light without the lazy feel you would have from a bigger (lower numerically) gear out back, while not having to load up the turbo to make up for that lazy feel. It isn't the greatest setup for the track, but for a street driven vehicle, it works out pretty decently while not being too hard on me at the pump...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Few members PM'ed me asking where the GTA stands at this point awhile back, and with Dave now contemplating a part out, with Joe possibly having a startup this weekend, and with Steve getting back to work on his Iroc, it kinda inspired me to get the damn thing done. Exhaust is all that is left. Been focused on paint and interior these last few months, but got back on the exhaust not too long ago. Downpipe is still 3 inches, but only for the fist two to three feet. Once it gets down below the frame, I have it switching to 4 inches...

I'll be honest here and admit I couldn't fit a 4 inch downpipe past the headers and frame, and I refused to notch the frame. I considered cutting and re-welding the 8th primary to make a full 4 inch downpipe a reality, but I talked myself out of it. Originally I was going to run the exhaust parallel to the transmission as can be seen in the first picture, but it was way too low, so I have it running the stock routing. First pic is to reiterate where it left off a page ago, second pic was after the welding and new routing. I already welded a 4 inch v-band flange on the end of it...

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Attachment 319253

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I am reusing the Flowmaster muffler that I was originally running on the GTA, but with a few changes. For starters, I hate the way the exhaust pipes stick out below the bumper, always did and always will, so the first thing I did was cut them about ten inches to tuck them neatly underneath the body. I then cut the 3 inch inlet going into the muffler in favor for a 4 inch inlet...

The picture below was early in the process as it only shows the cuts, but I since cut the clamps on the exhaust tubes attaching to the muffler and welded them shut. I also opened the orifice on the inlet of the muffler to 4 inches after marking it, then grinding it, then welded a short 4 inch elbow leading upward over the axle housing. I still have to polish the stainless steel tail pipes as well as paint the muffler and the rest of its' tubing high temp black. All that is left is finding a 4 inch up and over pipe, as well as a 4 inch intermediate pipe leading to the downpipe. Sounds easy yes, but 4 inch tubing gets expensive, so bear with me as I finalize the exhaust lol...

Deck lid is already painted in this picture, just need to wet sand and buff. Bumper's next.

Attachment 319251

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Minor mod but I figured I would show it. Although this is a 1990 GTA that came with the Speed Density system, I put all of the stock stuff on the side and used an earlier TPI system that I ported substantially. The MAF TPI plenum is obviously not MAP bracket ready, and I wasn't about to buy another MAP bracket on ebay because most sellers feel they are so rare that they can ask a lot of money for them. So, I kept the stock one on the original system that is sitting in the garage, and I grabbed an LG4 MAP bracket that I had lying around and cut, bent, drilled and hammered it into submission to make it resemble the Speed Density one. Drilled and tapped the plenum, and it came out pretty good for little to no work involved...

Will update more as I get the rest of the exhaust finished...

Attachment 319250

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Quick update w/significant change to the setup for those following along. I pulled the turbo system off with the intentions of smoothing down the welds and to get it all ceramic coated, but I decided to go in a different direction entirely to achieve my goal once I took a solid look at everything now that I have some time. System is off, and the intake tubing to the FMIC was inverted, so now it is running the opposing way. Stainless long tube headers were ordered and are already on their way. Going Procharger, but am undecided on whether to order a D or F series, but one thing is for sure, it will be self contained...

Looking forward to the reduction in exhaust gas temps and under hood heat, as well as no more freaking oil lines either, and am also looking forward to re-installing the AC system once I get the long tube headers in. Also will be running an EBC on the cold side of the intake. Will give another update once I get the long tube headers on, right now I am just replacing the modded fuel pump block off plate with a stock one, as well as removing the oil feed line from behind the distributor, and relocating the O2 sensor back to the drivers side. Long tubes should slide right into place....

Attachment 318547

Attachment 318548

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

D1sc on small cubes will make the power easily. But gotta handle that belt slip. I dont like blower stress on stockish bottoms tho

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

What I need to do is calculate my power naturally aspirated just before the converter couples, then calculate how much boost pressure I need for a specific amount of horsepower off the line without going overboard, or having way too little to work with. It has to be just right, leaning towards an F1A. Being that the supercharger is subjected to pulley size for the when it comes in, as well as blower size itself to determine how much flow, the idea is to build a turbo curve with the supercharger by having full boost come in very early, then controlling it with the EBC on the cold side. The cast assembly is definitely a concern, it wouldn't bother me as much if I got the weight down to 3000 pounds, but not much weight was removed. I'm actually more stoked about the exhaust more than anything else, really looking forward to hearing the long tubes with Flowmaster...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

The D1SC won't put you in the 9s, especially with a TPI intake. The F1A will.
The D1SC is the same class as my T-Trim, which is maxed out at 900hp and that is on a good day :)

I had the P1SC for 1 year before I sold it to a forum member. They are the same unit, housing, etc but have different impellers. The P1SC had a straight fin impeller and was essentially a hair dryer in terms of efficiency. The D1SC flows about 200cfm better, primarily thanks to the curved impeller. The F1A is a big blower.

I had a lot of problems with bracket flex and pulley alignment, because the Fbody brackets are one of the dumbest designs on the planet. YMMV. 383backinblack has a F1A on his Camaro, you may wish to dig up his build thread and see what he used for brackets.

Did you go with the OBX stainless headers? I'm happy with mine.

I probably should have kept the Procharger and just upgraded the head unit to a D1SC, rather than that silly Turbo experiment I wasted a year of my life on. Live and learn. I think you will be quite happy with the blower. Instant power, won't worry about melting stuff or having turbos fail and be fed to the motor.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

600 whp will get you in the 9's. But i agree the tpi intake is a concern. Need to rev up to get boost without worry of to little pulley size and belt slip

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

my experience is that a large supercharger install is not as easy as most make it out to be. instead of fighting heat, you will usually fight belt slip. also much more limited on blower placement since it is belt driven..... which means all your tubing is set to a certain mounting location. mainly the inlet of the supercharger is the issue, as it will probably be right at the header. also, the radiator and fans may be in the way. and, some blowers still have oil lines, such as the vortechs. i just dont get blowers being sooooo much easier and better.

900hp should EASILY put you in the 9's. if not, get to work on the rest of the car and make sure all the plug wires are hooked up.

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

True, but anything larger than a D1SC and cog is mandatory, and even with the D1SC he should go cog. I should have gone cog with my T-Trim. I'm finding myself having to shim to get alignment within a couple of hundred thou.


Cuz they sell kits for short money that "just bolt up". Both of my turbo setups were messes, and maybe I suck at turbos, but pretty much everyone elses looks like a mess too. 9 miles of hot side piping, wrapping everything in site, some cars you can't even see the plugs. The best setup I've seen is the STS because it's compact and cast, but requires oddball on-center turbos.

I'm not a fan of the procharger setup, and I had one so I'm not just talking out my rear, but I've had good luck with Vortech units on my cars and Powerdyne. The new torqstorm looks really nice too, a member has one on a 5.3 and it's a really nice clean install. On my current build I just made the blower bracket because I wanted to install the head unit on the passenger side. Was pretty easy. I don't think the 10rib is going to slip, especially at the power levels I'm looking at (600fwhp), but a cog would support 900hp no issues.

900hp Is more than possible with the F1-A, but isn't going to happen on the D1SC and especially with the TPI intake. If you follow some of my threads back from 2002-2004 I picked up a ton of power moving from a very well ported aftermarket TPI with siamesed runners to the singleplane, with no other changes. Same pulley combo, same RPM. The intake just flowed more. I think it was a 10mph increase in the quarter. That is substantial.

You might see 20psi in the plenum, but the 9 miles of runner and small diameter doesn't guarantee the flow VOLUME to the cylinder.

I vote F1-A, cog, and a good steel bracket. Should put him in to the 9s if the block can handle it.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

The tpi is a limiter...i dont see how just throwing a bigger blower at it is gonna do any different

D1's have made 800 whp on ls3's. Its looking like they are underrated.

Only problem i see is getting the boost up high enough on a 305 to get the 600+ hp level....on a cast crank standard sbc crank hub size. Turbo makes more sense here for longevity concerns.


I did one mild d1 tune, it was a 5 spd 383 tpi with afr 195 heads and a 224/230 cam. 521 whp on 8 lbs. belt kept throwing above 5500 rpm so we couldnt do much more with it

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Because the volume of air HAS to go somewhere. The F1-A will see bigger plenum boost numbers, and more flow volume to the cylinder and will help overcome the restriction of the TPI intake. But it's not the correct configuration. You are better off running a good intake, good heads and low boost (yet still the same air volume). Less heat generation, more timing, etc.

You can't "under rate" a blower. It flows X cfm at Y impeller speed, the problem is the efficiency of the impeller and volute design. Procharger's are around 65% efficient (P1), and 70% (D1).

It's not like a turbo where it's tough to predict your impeller speed at RPM. You know your pulley ratio and step ratio, and the the flow charts are established.

So yeah, I agree that a D1 could probably make 800whp on the right motor with free flowing intake and heads, aluminum heads that help dissipate heat, etc. A stock 305 TPI doesn't quite meet this description.

Maybe. I dunno. I don't think turbo is part of the debate any longer, it's what head unit he wants to use.

I ran an S-Trim with the same cam on a 355, but really crappy heads - sportsman II. Made 565 fwhp at 6,000 RPM and like 14ish lbs boost. 7" crank pulley, 3.33 s/c pulley. I believe it was around 48,000 RPM impeller speed which was pretty much max.

What was the impeller speed on your D1 combo at 5500 RPM?

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Sure you can! Have you tested the wheel to see what it actually flows? Just cuz they tell you it flows X cfm at Y speed doesnt mean its actually getting X cfm lol it may be X +A or even X-A flow. Guys doing the bigger numbers are likely overdriving the blower harder than intended or it flows more than they say it does

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

The d1 already is capable of 800 whp of air in the right setup, so its more than capable of overfilling the tpi to make a measly 600 whp. You dont need 1000+ hp worth of blower to stuff tpi to make 600's.
If its got similar big tube runner stuff like the 383 i did, then it can make the power but it will just require more boost to do so. Thats where the issue is gonna be, can you pulley down enough to get boost up within the 5000-5500 rpm range? Without slip or breaking the snout off. Heads he has wont flow like the afr 195's and the cam is similar in size i believe so its gonna take some boost

I dont know what pulley was on the 383, it made 12-13 psi by 5800-6000 ish rpm but soon as you let off, the belt flopped and snapped every time so i had to stop pulls by 5500 ish and it made 8 psi

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I thought about the D1SC, but the calculation showed me that it's just a little too small for what I am shooting for. I need a larger blower (luckily the two share the same head unit) to bring in a lot more boost down low in the RPM band, allowing me to average a higher boost pressure throughout up until 6000 to 6300-RPM. The EBC will cap boost at 15-psi, and I want to put the wastegate down by the FMIC to keep the noise level from it down. The BOV I will put somewhere by the 90 degree turn by the throttle body. I put some work into the heads and intake awhile back, everything flows extremely well. Big area of concern is the cam and throttle body, overlap was easy to compensate for with the turbo, but might be a little too much for the supercharger, and the throttle body is a stock 48mm unit...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I just dont see stock block and crank lasting long if you try to drive big blower super hard at lower rpms but i do like the idea. But then why change from turbo if you want turbo like characteristics

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

This isn't really a debate, it's well published, and the efficiency is tested using SAE J-1723.

I've been doing blowers for a long time, they are very straight forward and predictable.

He's using an EBC setup, which I was tempted to do with the J-Trim, so either way he needs the larger head unit to get the low RPM flow numbers to maintain his minimum boost.

How the stock bottom end and crank survives is going to be a who-knows scenario. I've used a cast crank spinning a S-trim at full bore but that's only a 1200 cfm blower. I don't think he cares if he grenades the motor though.

What's the fastest D1 TPI car? Surely if someone was in the 9s with a TPI setup it would be well published on the forum.

Either way I'm psyched to see how it goes. Now I just need to find the time to finish mine.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

for some interesting reading, do some google searches on what the NMRA guys did with the ysi over the years.... 65,000+ rpm impellar speeds with the cast wheel. somewhere in the 900hp range, and with a pro-volute there has been some over 1,000hp combos. very cool stuff.

-edit i googled it myself and my memory is fading. they have run those blowers to 80k and made closer to 1200 at the wheels. now there is a newly redesigned billet ysi available.

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

The guy I bought my T-Trim from has a YSI now. Those are wicked blowers. I've read a little about impeller and bearing upgrades. My car can't go fast enough though. No safety stuff beyond 11.49

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

So procharger tells you that d1sc flows exactly 1400 cfm max and you believe that is 100% accurate and truthful with no margin of safety added? There is no possible way it would flow any more or less?

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Sure there is, if you have an obstruction on the intake side, or your elevation is drastically different than sea level, if you pulley it under or over the MAX stated RPM, than sure.

But they are not "underrated". Procharger goes out of their way to avoid talking about compressor efficiency because they are the worst in the industry, but they have been well tested for quite a long time now.

Unlike a custom turbo app, anything you could probably even imagine doing with these units has been done and documented. People have been putting P1 and D1 unit's on TPI cars for a very long time now.

If he wants to go 9s with his current motor, he needs an F1-A.

If he wants to build a $6k long block and go 9s, he can use the D1SC and spin the crap outta it.

If you wanna buy him a D1 to prove me wrong, have at it :)


-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I just dont understand why you think you need to spin the crap out of the d1sc to do a 9 sec pass.

F1a flows 175 more cfm and you think thats the magic solution to make substantial more power on the same restrictive intake lol. The f1a requires 12000 more rpm to get that 175 cfm, and the d1 is the one being spun high lmao come on

Secondly 90% of the members here buy those small bolt on kits with fmus and run 7-10 psi and are happy. Nobody builds a race supercharged high power sbc anymore. Nobody had the tuning capability to make it work

And its not a good idea to make big power on unbuilt motors with blowers. Crank stress scares me.

You seem overly confident in how to build this setup with never having done a 9 sec setup before

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Why is everyone arguing? No need for that guys. I decided on the F1A because that is the biggest I can go with for that particular housing. I never implied that it is vastly superior to the D1SC, but every little bit helps at this point, and the extra 250-cfm will help down low when I pulley the system up. This is why I debated the D series with the F series, it just made sense to go a little bigger. D1SC's have been known to make more power than I would need, just not in my case though. Flow chart has the two of them close, but the F1A edges the D1SC out just enough. My goal has always been to see a 9.99 ET, or 135-mph trap speed, not to run that number every single time I visit the track or take the car for a ride, the engine simply won't last. This has always been a street car project...

This all started with Steve Kaminski, the guy who inspired me to build my GTA because of his GTA. He ran a stock bottom end (cast) GN engine, but worked the heads, intake and added a cam just like I did. I believe his best with that particular car was a 10.10 ET in the 1/4 mile before he sold it. He of course built way faster cars than that. Told him I could get the 305 in the nines building it essentially the same way as he did with his 3.8 cast GN engine, and that is how it all started. Don't argue about all this stuff guys, it's all good. Whatever happens happens, I'm just glad I am switching to the supercharger, it was something I was planning on for a long time with the EBC. The paint on the passenger strut tower is testimony as to just how hot it got under the hood with the turbo, and I drove it almost daily all summer long so far. Was also tired looking for oil spots on the floor everywhere I parked out of habit, drove me nuts. Anyway spent the day pulling the cruise control off, and also bought a new battery. It's going back in the hatch of course once the supercharger gets here, but for now I have it up front...

This was Kaminski's car that inspired me by the way, factory cast bottom end.

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I don't know why your laughing. When I don't understand something I'm humble and listen.

I explained it earlier. The D1SC can't make enough pressure to get the volume to the cylinder. The F1-A has a higher pressure potential AND it flows a larger volume. The restriction is the throttle body, the runners, etc. You need to overcome that restriction to get volume to the cylinders.

The F1-A also has a slightly more efficient impeller design, which means it's generating less heat when compressing the charge.


The tuning capability?

What do you consider high power?

Guys have been making a thousand hp for years on SBC with blowers, it just was traditionally a big investment. It's only recently with cheap chinese turbos that every goon with a toolbox is bolting on crazy horsepower.

Ahhhhh.. THAT is your understanding? Yes, I don't own a 9 second car. I've done plenty of motor work on rail cars, mud trucks, and go-fast boats.

You do understand if I wanted a 9 second car I'd build one, right? I'm not financially restrained. The only thing I can't buy is good health and more time...


-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I dont think you really know what is involved in doin a build like that but i digress

Good luck. Atleast with the f1a, when the motor goes at somepoint, it will be a good fit for a big inch built bottom end. Do a bbc snout and enjoy

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Show me the compressor maps that prove this

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

This honestly made me laugh. You are clearly making a big thing out of absolutely nothing, and I am already well versed on how to do this with a blower. I am not looking for advice, I am merely sharing a build, nothing more, which is why I asked that the arguing stop because there is no reason for it...

Already have a forged one sitting in the garage, next to many short blocks.

Attachment 318540

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I don't need to, it's in the spec sheet and the impellers are completely difference sizes.

Not to mention this has been beaten to death on just about every forum on the planet.

Welcome to the party, it's 2016, this stuff is old.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I dont see a need to argue either. But, I think what orr means is going 9s really doesnt have all that much to do with the power as it does the rest of the car and settling ng it up. Thats my experience anyway. Make somewhere around 550-600 at the wheels, get the car down to sub 3200 lb, and then manipulate your other parts and setup. Should be right around 9s with that. No need to shoot for much more hp than that, imo.

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

That I absolutely agree with Dig. Remember though, I'm just sharing updates and changes. I am in no way saying the Procharger will go on and I'm ready to go, lots more to do after that. But I am definitely glad I am making the switch, I'll gladly deal with belt issues over turbo issues. Long tubes should be here either tomorrow or Saturday...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Yeah i guess where i come from if i bought a 1000 hp blower i'd be looking for 8's not 9's. This is like 88mm on stock bottom end builds. Its just way overkill but if they fit similar then i guess thats ok. I was under impression the physical size of the F1 was much bigger than the D1.

Just feel you both are out in left field underestimating the d1's capability. But your boost control idea will def require a small pulley to get into boost very fast and then bleed off the rest up top to avoid overboosting. Either blower will be pulley'd way down. Thats gonna be a big belt lol but i also dont think you'll want or need alot of boost down low. Car will leave hard with right stall speed

This was directed to joe but being that you havent really posted alot of data on the previous turbo setup, its hard to say how much power and what not you would need to achieve your goal. With no baseline, one can only assume.

I know what cars run with 550-650 whp. 600 whp thru a th400 is the magic number. 60ft has to be there and you'll go 135+ at 3500 lbs or less. Easily.
Unfortunately with a big trans, rear, and cage, that setup can easily go 3650-3700 lbs in a street car so power required goes up.

Just passing on friendly info from many years of drag race and dyno experience

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

The fastest known D1SC car is Brad Schehr's '89 mustang. 8.74 @ 153. 3300lbs race weight, slicks, skinnies up front, nasty 308" SBF, powerglide, etc. Quite a bit different than a stock 305.

http://www.creperformance.com/bradschehr.html


The crank snout snapping stuff was more of a problem with the big 6-71 blowers and stuff we used to put on speed boats years ago.

Building a 1,000hp motor isn't a big deal. The daunting task is building a car that will pass NHRA inspection to go faster than 9.99, and obtaining your competition license.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Not sure if Brad ran that number with a D1SC, and if he did I wouldn't be surprised if he hit it with some nitrous. He relocated the head unit to the front to be driven off the crank, so he more than likely switched to an F series. Also, although cast, my 305 is far from stock...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I wasn't implying your motor was a POS, the point I'm trying to get across is that getting anywhere near 8's with a D1SC requires a max effort engine.

If you've watched video's of Brad's foxbody, the thing idles like a turd. It's a high dollar build, NHRA certified and a legit "race car" that can compete at any track in any national event.

For your build, which is a moderate 305 with a TPI intake, the F1-A will make up for shortfalls in the engine and get you closer to your goal.

The problem with a lot of guys on the forum (not directing this at you) is they don't seem to know the difference between a car that can go 9 seconds, a 9 second street car, and a 9 second race car. 9 second race cars require tons of money in safety and structural parts, must pass stringent standards, etc. A 9 second street car isn't just a race car with license plates on it, it should be capable of driving from the west coast to the east coast at 70mph, in 95 degree heat, idle well, etc.

A car capable of 9 seconds can be any old barnyard car with a skip white engine. Guys make 2-3 passes on the test and tune day and declare victory. Meanwhile real racers in the 10s compete every weekend during points, raking up thousands of passes on combos that are consistent down to a 2nd and they get no respect because they are not "big horsepower builds".

This site has turned into a fast n furious movie.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Joe, it hasn't turned into a Fast n Furious movie, the problem is everyone is trying to share their experiences and knowledge, and it gets out of hand. I shared with everyone above why I started this build, I started it years back almost on a dare. The build was to emulate the way most Grand National enthusiasts build their cars, because that is who I was hanging with at the time. I already know the engine will run the numbers, it just needs to hold without tearing apart. As for this supercharger debate, let me help members who are reading this understand how they work. A supercharger spins and is controlled by at a certain RPM, that is all it does, the size of the supercharger dictates how much flow, and the pulley size dictates impeller speed. The size of the engine it is on is meaningless, because the supercharger is going to release a given amount of air. The only thing that changes regarding engine size is resistance (boost pressure). Turbo's have a huge advantage over them because their impeller speed is dictated by exhaust gases, so they are not held back and must be controlled via an exhaust bleeder not to over boost. There are two ways to get a supercharger to work the same way, one is to get a much larger supercharger creating that over boost scenario on purpose and controlling it via a controlled inlet bleeder, and the other way is to go with a smaller supercharger but changing the pulley system to cause the supercharger to max out over it's range, which of course will stress the unit out. I chose to go with the former, a larger supercharger, and in this case, it shares the same head unit as the latter. There is really no need for anyone to argue about this stuff. I resurrected this thread because I want to finish what I started, not for everyone to start arguing again...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Lol thats your definition of street car

Any many 346-364" lsx motors in the 9's with d1's with simple heads cam. Far from max effort race mills

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

What problems did you have with the turbo that caused you to change direction?

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

Building the 1000 hp motor and driveline properly is much more daunting than the safety stuff. The licensing and safety stuff is easy. Just have to find a cage guy that knows the specs. 100$ a point and its done. Fire jacket and window net perhaps. Little odds n ends. All easily purchased and added.
Licensing passes just require a few runs from 60' to 1/8 then full pass. Do that and they sign you into the club

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

It is a daily driven car that I take to the track, not a track car that I drive on the street. Went through three thrust bearings on the first turbo, then finally the shaft gave way. This will happen on a daily driver that gets driven hard. Then of course the oil feed and return, which, had its' share of leaks, but I am tired of looking for them. Loading the turbo, lag was never too big of a concern, but it's nice to have the pressure from the supercharger to be there immediately, remmeber this is a street car that see's track time. Finally, the AC, I plan on reinstalling the AC system. I also work in NYC and I am tired of getting oil on my hands. Now, others will say that they have no problems with their home built daily driven turbo cars that are driven hard, but sadly I do not believe them. The turbo setup that I fabricated, although nice and compact, was just too much maintenance for a daily driver, but that is my experience with it, others may like dealing with those issues...

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

What brand turbo did you have again? Thats weird to have that many issues on them. Borg warners are doing great in reliability but i had success with turbonetics and master power surprisingly

With ac the blowers make sense tho

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

safety stuff is mostly just extra expense, not difficult. the cage is nearly as important to the chassis as it is to your safety once you are running 9s. the difficult thing is knowing what the car wants you to change each time you make a pass. tire air pressure, rear shock adjustment, front shock adjustment, converter stall/slip, front/rear springs, front/rear weight, swaybar preload, instant center, anti squat, launch rpm, boost at launch, timing at launch, boost/timing ramp after launch..... etc. etc. etc. etc. etc. nearly endless variables.


turbo longevity- a good turbo should be good for 100k+ miles. some strictly performance turbos may not last as long. ebay units for sure may not last very long. garrett turbos on duramax and powerstroke trucks routinely go 300k miles.

quick search on a d1sc i found a guy selling one off of a 306 sbf. went 121-125 every time out at 3600lb. (tim miliken)

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I hear precision turbos go out often on race cars but do make some of the best power. But a couple of race car turbo guys i know use various brands and send them off to look at every season or two. Most of the time nothing is really needed as long as oil is clean and you arent runningthem to the limits. Aka maxing them out

And right on about the pass to pass changes. It took me a whole season of time tuning and messing with the combo of suspension parts and tune to finally find what worked best. Basically 20+ passes to get from breaking 8.90's to finally 8.2's. If that combo would have lived it may have gone 7.99

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I can tell you have not done this before. It's been over 10 years since I've run points myself, but the safety is even harder now than it was back then.

Licensing isn't just "Running a few passes", in fact the hardest part is the cockpit orientation test. Unbuckling your stuff, crawling out the window, etc while blindfolded isn't exactly easy in the time allowed.

But anyway, current rulebook says:

Class 4 NHRA License minimum
Snell 2005 full face helmet
Driveshaft loop
Flywheel shield meeting SFI specification (if manual)
Jacket and pants, gloves, SFI
Neck restraint, SFI
Full cage
NHRA Chassis certification
Restraints, SFI, within 2 years of exp
Flexplate must be SFI
Flexplate shield mandatory, SFI
SFI 4.1 transmission blanket in addition to flexplate shield
Metal screw in valve stems
Engine diaper or other full engine oil retention device
Window net
Harmonic balancer, SFI certified
Aftermarket axles
Axle retention devices (must be bearing type, not disc brakes)

Just a wee bit more than a cage and a jacket..

So yeah, this is why I lost interest in building competitive cars. I don't live near any unsanctioned hillbilly tracks.

-- Joe

Re: Chronicles of a 9 Second Trans Am... Final Chapter
 

I used to trap 120mph with my S-trim (1200cfm) in a 3640 lb car, so that's not too far off. The D1 should flow a bit more.

I'd be psyched if my T-trim would trap 125-130mph, as long as I don't breakout ET.

I agree with you that all the other stuff is just money, but it's also just an epic PITA.

Some of this new strictly-stock stuff is interesting me. You can buy a brand new 800hp car and run it w/out a cage or anything as long as it's unmodified.

-- Joe