I just got done replacing the fuel pump in my 91' Firebird and noticed when I dropped the tank that the back end looks darn near identical to my 2000 Camaro. I took a peak at STS site and noticed they have a 91 LT1 Kit....unless I'm missing something it looks like it would bolt right on to a 3rd Gen.

My TTZ06 is a front top mount kit, and the C5 TT STS kit didn't do all that great..but I know a guy that did a C5 single turbo STS kit and he is in the 8's with that car in the 1/4. So they can be made to work.

Here is the theory I am working off of. I am thinking the TPI already makes good low end tq...good enough to be unusable on stock tires at the lower rpms. We all know that the TPI sucks (or is restricted) above 4K rpms. Because of the location (rear mount) of the STS kit, it really doesn't spool (low boost threshold) until the upper rpms..at least from all of the STS dyno's I've seen they tend to spool around 3800-4K rpms to max boost. ....which is right where the TPI become restrictive. What the STS ends up being is like a centrifugal supercharger (which I also had on my Z06)..which means it doesn't really come alive until around 4K rpms. With boost being added by the STS between 4-6K rpms the TPI shouldn't be hungering for air.

I was also considering adding some 1.6 RRs to the stock cam to increase the lift a little bit. FI doesn't rely on long duration cams, alot of overlap, and head porting to make power..not saying it won't make more hp with all the goodies...just saying that it doesn't rely on it like NA setups.

Anyway just wondering if anybody else has observed the similarities between a 3rd and 4th gen to the extent that the LT1 STS kit could be used on a 3rd Gen.

Thanks

 

Considering the exhausts are are virtual bolt-on swap (minor differences in the hangers), I'd say the biggest "hurdle" would be the floor pan itself. But I also suspect there isn't much of a difference, since the exhaust easily swaps, as well as the front & rear seats (100% bolt-in swap), I'd say go for it!

 

The floor pans are exactly the same from 3rd gen to 4th gen. the 4th gens even have the awesome catalytic converter hump in the front passenger floor even though there isn't a cat there from the factory.

Everything from the rear up to the firewall will be bolt in, obviously getting things into the intake from that point will be a custom deal, but shouldn't be that hard at all.

 

Never really loooked at my thirdgen vs my 4th gen, but does seem similar, atleast the back half is. 4th gens seem to have different exhaust routing as it goes down the driveshaft tunnel more, while thirdgens kick off to the side where the cat hump is. But they end up in the same spot for catbacks so go figure


To do the STS kit all you really need is to get a decent header back thirdgen setup exhaust then put on a flange for the turbo, then run the STS stuff the rest of the way. Cold side piping route may be different tho but easily adaptable.

 

This is my observation as well.
Thanks for confirming.

I see you on the Corvette board but I generally live in the C5 FI section. There is a guy named Stealth 99 that has been running a Cartek "one off" single STS kit....it's really a Cartek big single rear turbo..but it is even on STS site. Anyway he has some tricks but he was has been in the low 9's for years and this past year broke into the 8s.

Years ago I asked him and he told me he was running the stock LS1 manifolds (basically like a factory cast shorty).

I just got the Hawk's SS Y pipe...which is pretty nice 2.5" pipes into a 3" single pipe. I slip fitted it to the stock 2.5" single OEM pipe over the axle to the Flowmaster muffler. In fact the Flowmaster was off of my 2000 Camaro.

So I am thinking if I got the Universal kit or the 91 LT1 STS kit, I could then run the charge plumbing up the front under the drivers side to a FMIC, then drill a hole where some do CAI under the OEM air filter and couple it to the ABS snorkel that leads up to the TB.

I am not looking for the power that you or I have in our TT setups. But when I look at the cost of headers (1 3/4 LTs) and a good intake (HSR) it might net 254 rwhp on a stock L98 for about $1600-1800 worth of mods, and then compare it to buying a rear turbo kit...for about the same cost...I am looking at getting around 350 rwhp for the same price and am able to keep the everything stock on the motor.

I am a little worried about valve float though..so I may swap to a double spring and if I'm in there I might as well upgrade to some 1.6 RRs. This would give the stock cam a little more lift and help it in the upper RPM band.

What do you guys think??? If I spend a little more also I could get a BB Turbo to help the spool drop 300 rpms. With a 9.5:1 CR I am thinking that I could easily run 10-12#s boost..which might even be close to 400rwhp.

I have a SD (91') car with a MAP. Just need to work on the tuning and upgrade my fuel injectors to some 42-48 psi. I just upgraded to the Racetronixs Walbro 255lph pump. I have the LPE 255lph pump, 60 mototron injectors, Aeromotive AFPR, and a KB BAP on my TTZ06 and it put down 850 rwhp...and was rich at first with that fuel system. So I know the Walbro 255lph pump is a good pump to have in place.

 

Exactly...if you can do some work yourself, there is no reason not to turbo this car like this Plenty of guys doing 10 psi on stock bottom ends in the mid 300whp range or so, so i think its doable.

Single pump with hotwire is more than up to the task. I think the proper turbo on the back will still spool up fairly quick, just need an exhaust system that will not leak. Vband everything and it should be golden.

 

Do you know if my current PCM can be used to tune a power adder like a trube. I see people refering to $59 code and other PCMs?

Also should I get an Adjustable FPR? Can I hookd up a AFPR to my TPI and make it work?

 

You should upgrade to a different software code but your stock 91 ecm is perfect. Can run code $59 which is boost code for speed density, just wire in a 3 bar map for the code to run and possibly a wideband o2 sensor to get the full benefit of the code. Its what i use and so far i like it

 

I will have to hit you up (as usual) a little more about this after I get my parts together. Was on FleeBay looking for a turbo and saw that there is a new (new to me) 82-92 FBody Twin Turbo out. It utilizes shorty headers and the parts looking great even though the Turbos are probably the cheap Chinese ones. I asked the seller if he had any pics so that I could guage what needs to be removed form the engine bay to make it work. LOL


Just curious why I would need a 3bar map sensor to run the code $59? I don't plan on running 27#s boost. I have a 3 bar map sesnor on my Vette and the highest I went to was 18.4#s.....probalby could have used a 2 bar for that. Need to understand this better...but am relieved to hear that I have a good PCM to start with.

That Ebay 3rd Gen TT kit looks pretty sweet but I'm not sure how much room there is going to be if the turbos hand down low off the headers in a traditional manner. I know if they were flipped up there would not be hood clearance (reverse top mount).

Thanks

 

Well the code is written with 3-bar, but they may have put out a 2 bar code. That would be BEST for your situation. Heck for me as well, but since i planned on 18-20 psi i figured 3-bar would work great.

 

I've been thinkin about this RMT stuff for about 2 years now!!!! But...
I've never found any specs on the turbo STS uses for their LT1 Kits.

I would piece together my own custom set-up and have been lookin at the Garrett Ball bearing turbos..... just not sure which turbo would be adequate.

It would be nice to have an idea of what STS uses.....

 

I have to find out from a local shop here they did a twin mount on a big block car that made 1200whp+ and that car ran 8's. They can make power with RMT's so that way i can keep stock hood Very interested in it

 

59 works with a 3 bar only, since they made the ve table so big, rewriting the code to have a 2 bar too doesn't make any sense.

I run it with a 3bar on one of my cars and its n/a and will aways be. runs great. I got sick of trying to make $8D do what I wanted it to do. plus even with a 3bar the 0-100kpa part of the ve table is bigger then the stock 8d is.

 

It almost sounds like you are saying it makes 850 RWHP with a single Walbro 255 lph and 60 #/hr injectors. The single 255 lph pump will only support about 600 FWHP and the injectors will do about 850 FWHP with a .5 BSFC (almost impossible with a turbo engine) and a duty cycle of 90%.
What is the actual fuel setup you are making the 850 RWHP with?

 

the kenny bell boost a pump might have helped, but still sounds like a lot for a walbouro. are there some new ones out or something? I had one years ago on my car with an fmu and it didn't handle the high pressure well at all, had to add a boost pump inline. and I put one on my n/a car and it failed slowly over time only when it was hot. I spent months looking for what was causing it. not wanting to believe the year old pump could be bad.

 

Delete duplicate post.

 

Actually that is exactly what I am saying and my car has been well documented in magazines and in front of 100's of people numerous times. People have tried to over analyze my setup (me especially) but the funny thing about it is that when I set my boost level to 18#s the first run the afr was 10.1....all the tuner did on the load dyno was adjust the afr over the course of 3 tunes (timing and boost pressure stayed the same) using dual widebands until by afr was 11.7 & 11.9 on L & R banks. HP went from 780'ish to 834 with just afr changes. When I ran it on a Dynojet (248H & X) it made 850 rwhp. Three different dyno's have been used in two different parts of the state during two different times of the year...so I'm convinced it wasn't a magic dyno....lol...it would be just too coincidental to get within 20 rwhp of one another on 3 different dynos...the load dyno was less of course.

Now here is the only point I can offer to people (myself included) because I played with all of the brake fuel pressure and boost fuel pressure calculators and software (injector sizing smokemup.com). But all I can tell you after seeing the result is that if my fuel system was not up to task I would have had a lean condition and not a rich condition and we would not have been able to add fuel to the point that we did...the fact that it was rich showed that the fuel system worked flawlessly. My friend had a 427cid SC car with the same fuel system except he had the 70lb fuel injectors and he made the same hp but started to lean out...so he was at the limit but it's pretty well documented (in the LSx community) that the Centri SCs actually need more fuel as they take power to make power unlike a Turbo...and I have had both setups. Plus he had a 427cid and I have a 347cid...we were damn near the same hp level..but I had fuel to spare...only difference in the fuel system are the 70lb injectors.

Once again my fuel system on my TT Z has had the following for close to 7 years now...in fact the first TT system went on March of 2003...replaced the SC that I had on.

LPE 255 Walbro (one in tank pump)
KB BAP
60lb mototrons
Aeromotive AFPR with 3/8" (-6 an) return line

Fuel pressure was rock solid over all dyno runs at 72 psi throughout...idle is 62 psi (not in boost before KB BAP kicks in)

The vid is below that was shot by somebody unknown to me but posted on the Corvette Forum, and the magazines you can find the write ups about my car are Nov 06 Vette Magazine "Horsepower Party" and in an Issue of Street Scenes..yes an import mag.

Click on the link below for the vid. BTW this is the Dynojet 248x which is only rated at 1100bhp (IIRC) and nobody had heard anything wind that dyno that hard...listen to spool down...I thought something was going wrong with my car when I heard the dyno spool down...the shop belongs to a friend of mine and I have seen 100s of cars dyno'd on it and never heard that sound before. lol.

website for all the cool mods I have done :yesnod:
http://temp.corvetteforum.net/member...es/shinobis97/
347cid PTK TT 01 Z06 835/804 rear hp/tq..on really low boost Here is the vid link http://s128.photobucket.com/albums/p...BBQ6-30-07.flv

 

Whats that beast trap at the track? Thats insane for a single pump. I was told by many pump "experts" a single with boost a pump would not support more than 600whp. I went with 2 pumps

 

Haven't ran this car (with the TT setup) in the 1/4...and don't really plan on taking this one back to the strip (last time was with my D1 Procharger in 2003..ditched it because of belt slip..I ran faster with my H&C setup)....but I also don't have the $$ for a constant C5 drivetrain replacement plan. I do plan on taking it back to the track though...roadcourse you can see pics of that on my homepage in the link above. If I go back to the strip it will be in one of my F Bodies...not my Z. The 1k hp run was just for ***** and giggles and the magazine article. I drive the car on the low boost setting 9#s which was tuned with HP tuner SD 3 Bar software for 18#s...oh yeah my car is on HP's website too....so I drive the car detuned on purpose. I run 335/30 18" Toyo Proxes (DOT road course tires) as they are the only tires that I have found that will hold a full 4th gear WOT run. So I feel like between 575-600 rwhp is great street power setting with the current tires I am running.

But just for comparisons. Since you are on the Corvetteforum do a search for Nick Yoskin. He had a C5 Auto/Vert with the identical TT setup and fuel system as me (except he used a 97/98 fuel rail like LPE uses). My fuel system copied the MDMC setup (Optic Z06's car) who had the first ATI Centi SC in the 9's w/manual tranny. Anyway Nick used C5 front wagon wheels with Nitto DRs...so 17" DRs....and his first day to the track with our setup he ran a 9.89 @ 145mph (stock suspension). When he decided to move up to a 427cid from his 347cid, he ended up needing dual walbro pumps. Speed Inc now sells the dual pump and hanger system that he used hin his car..except they use the Bosch 420 pump...I tried the Bosch 420 pump (single...the dual wasn't out yet) boost referenced and it didn't work as good as the LPE 255lph pump non boost referenced.

 

Just curious to see what trap speed you'd hit with 800+ whp. i was thinking it be well over 155mph

 

Click on the High Pressure 255 lph here:http://www.autoperformanceengineerin...l/fpspecs.html

at 72 psi and 13.5 volts that pump will RELIABLY flow 55 gph.

one gallon = 5.8 pounds (normal gas)
55*5.8 = 319 #/hr

assuming .55 (turbo engine) BSFC,
319 / .55 = 580 FWHP
at .50 BSFC,
319 / .50 = 638 FWHP

If that pump was run at 20+ volts for the one time 850 RWHP then it could be possible or it could be an odd ball pump way exceeding spec. He normally runs it at a HP that is closer the spec.

Either way, it doesn't make much sense to try and get that much HP out of a single 255 lph. Running two is both cheap and reliable for over 1000+ FWHP.

 

You are doing a real good job with your internet research and playing with calculators...stuff I did years ago. Sorry this is difficult for you but it is what it is and I'm sorry it is troubling you. I have done the best I can to offer you information if you choose not to believe me it is really no sweat off of my back but I wish you the best in finding peace with it. Those that know me in the C5 Corvette community all know my car...never any secrets. Been that way for almost 7 years in FI C5s. If you want to buy the car I will give you a good deal on it. Merry Christmas.

PS You should make a user account on the Corvetteforum like Orz, Anethes, and myself. Go into the C5 FI section and start doing some reading that way it will not seem so strange to you. A lot of those guys running low 10's and high 9's. In fact you can go on LPE's website they had one of the longest standing 1/4 mile manual tranny times and they were using one LPE 255lph Fuel Pump, BAP, 97/98 Fuel Rails, and I think back then only 48 psi injectors....on there 427s too!

BTW I don't disagree with running two pumps, but that option was not available to me at the time of R&D for the C5. SpeedInc ended up coming out with a dual pump and bucket assembly shortly after because the larger cubes were really begging for more fuel. I just copied what was working for the highest powered SC and TT charged C5s at the time...which came from LPE and Modern Day Muscle Cars. Both had FI high boosted 700+ rwhp cars at the time and were in the 9s.

The thing that was unique to my car was that MDMC sold me their return system out right to help me out...it cured my need for a good return system.

Prior to my current fuel system I was using an Aermotive A1000, FMU, and FMS Green Top Injectors (48-50 lbs). It barely powered my D1 Procharger at 10#s boost (630 rwhp). That's why I ditched it. I have been really happy with my fuel setup as the Z runs perfect. I think I mentioned the fuel pressure at idle is 62 psi...gotta remember C5s and LSx's run at 4 bar (58-60) psi from the factory...Fuel Injectors are rated at 3 bar (42.5 psi). So the 60lb mototrons I am running are rated at 60lbs at 42.5 psi. At the stock C5 pressure they are more like 75lb injectors. Now add a better fuel pump and bap and I am running at 72 (could have been 74..been a while) psi. That is quite a bit more then the 42.5 psi the 60lb injectors are rated at...you could have taken a ruler across the afr line on my dyno tune...that's how good the fuel delivery is.

Here is LPE's install instructions supports some of what you are describing (theory) but you are off on the voltage, gph, and reliabiltiy. You also have to remember what fuel pressure the injectors are rated at...which is at 42.5 psi.
http://www.autosmanual.com/726/c5-fu...tructions.html

 

I have no problem with your HP figures and that pump. I design & build stuff and have a good understanding what goes on with production. Like I said, either that pump is an odd ball or it was run at high voltage. In manufacturing, not all pieces will be the same. Yes, it sounds like you got lucky with that pump. I would not recommend others hope they get lucky and try it. Some may find that the lose an engine trying to save a few 100 on a pump.

BTW, that link supports the exact info. I posted. The only difference is that the link I posted has more/better info. with the actual chart. The +10 PSI is for the boost differential across the injector. We both know two pumps is the smart reliable way to go. There is no R&D in putting in two pumps. You just modify the sending unit and and more lines. It is rather simple. When I hear the "R&D" it is usually people trying to give designing a fancy word to sell stuff.

 

Yeah it would been cool if they had the two pump bucket assembly at the time. I switched to the Bosch pump because it was supposed to flow better..and I went boost refereced with it...my fuel pressure would spike to 78 (which was good) but then it would wander until got down to 72...the lack of 1:1 boost reference and wandering fuel pressure made it difficult to tune around. I then pulled the bosch pump out and stuck the LPE 255 lph pump back in and took the boost reference out. It's been awhile but my fuel pressure not boost referenced (as is) might go from 62 psi to 74 psi (with BAP) not 72...which ever it was though I know that the fuel pressure didn't drop (once the BAP kicked in) because I put a mechanical fuel gauge on the rail and measured it during the tune under boost from 2000-6700 rpms.

You did account for the 60lb Mototrons being rated 60lbs @ 42.5 psi? It took me a bit to figure that out a few years back when I was playing with all of the calculators trying to figure out injector sizing and fuel pressure. Once I figured out that my starting pressure was 62 psi and that it equated to like having larger fuel injectors, it allowed me to start with a 75lb injector size. When you account for the rise in fuel pressure with the BAP (which I didn't have at the time..came after the dyno tune)...it was easier to understand how I could end up being rich and having enough fuel to support my power numbers. But as I mentioned above some guys copied my setup and used it on their 427cids and started out lean not rich.

I do think a lot of it has to do with having a good return system. The stock 97/98 return that LPE used had small tubing. The -6 an to the Aeromotive AFPR and then back to my tank really made a huge difference in my fuel system...when I didn't have it my fuel pressure would spike and then go down to the low 60s...which is quite the opposite with it. Also my return plugs into my crossover tube between the fuel rails and not at either side or the end...so I think it get's balanced pretty well.

Thanks for the questions but lets get back on topic and maybe I can lean on you for some info if you don't mind when it comes time for me to put a turbo on my 91' Bird.

I know for the moral majority of turbo nuts that we balk at the thought of having the turbine at the end of the exhaust system and not where it belongs. LOL. BUTTTTTTTT I do know some guys who have turned some really fast times with large single turbos out back where they don't belong...they will even tell you that it helps with the weight transfer...because the turbo is hanging on the ***. ..can't argue with their times though.

Being that the TPI is 9.5:1 CR, it seems like a perfect candidate for a Centri SC or a Turbo in the 10-12 psi range. I am assuming a later spool with a rear mount...above 3800 rpms...but that is exactly where a TPI car needs the power. Do you think adding 1.6 roller rockers would help the stock cam by giving it a little more lift and allowing the car to pull into the higher rpms some? Do you think my stock stall converter can handle 10-12# boost....at least for a little while.

I am pretty confident that I can fab up a GT 35 (T4), 60-1, or 76 GTS in place of my muffler, and run the charge plumbing to a FMIC and plug right into where the current air intake sits on the passenger side of the vehicle (cut a hole on the bottom like the CAI I've seen). With my the Racetronix 255lph pump....will I need a BAP to run 10-12#s boost? Probably need at least 42-48# injectors too...wished I wouldn't have sold all of the injectors I have tried. LOL.

I was hoping the banks style log manifolds would allow me to keep all of my accessories but it doesn't look like they will.

 

I dont know how different sizing a turbo for rear mount is compared to a front mount in a typical single turbo arrangement, but I think a single T64-T70 would be a nice choice for most 400-500whp setups. 60-62mm for up to 400whp which will perfect for a L98 on stock internals. Probably want to keep the rear turbo a touch smaller than what you would run on front, since the heat/exhaust energy is less at the rear. T4 60-62mm setup should be good to go.

Single racetronix kit with hot wire will handle that easily. I ran 400whp in my 383 no problems with single pump. My friend Tom (87TA) has done much more power than that on a single pump with his 406 motor.

 

Good recommendation(s) and that is about the power level I am shooting for.

 

Much clearer now. I didn't catch the fact you were running a boost pump (BAP) earlier. Between the Walbro and booster it makes sense now.
Yes, most (not all) injectors are rated at 3 bar. Your injectors at 60 PSI will look like sqrt(60/42.5) * 60 #/hr. Then with a 1:1 normal FPR it would have fuel_pressure+boost_pressure at the top and fuel_pressure at the bottom of the injector. With boost_pressure in the intake, the injector sees just fuel pressure.


A rear mount can work just as well as a front mount. It all depends on how much one wants to spend in terms of time and money. If good insulation (stainless, inconel, heat wrap) is used then all the energy goes into spinning the turbine. Most people just use mild steel and lose a lot of energy and get a late spool. Some cheap 409 stainless and heat wrap would make a world of difference. Losing heat means a smaller turbine is necessary to spool, but chokes quicker up top.
The previously posted recommendations for the compressor side seem fine.

A Walbro 255 lph as is and 42 #/hr injectors at stock fuel pressure are good for 550 FWHP or a little more if you want to operate with less margin. It has been done plenty of times, but the safety margin is reduced. You can up the fuel pressure to make the injectors flow more, but this makes the fuel pump flow less volume (see charts I posted a link to) and then requires two pumps or a boost pump.

I would put the 1.6 rockers on it. At the stock compression I would put a FMIC and water/alky injection. With a proper turbine it will spool before peak torque and between the compression ratio, cam, and boost it will want to knock around peak torque without the FMIC and water/alky spray.
Just a recommendation.

 

I saw a decent gain with 1.6 rockers on a n/a L98 so a boosted one should show good gains

 

shinobi ,, love that dyno vid ,, Timmy