how would YOU build the fastest 91 oct stock displacement LS1?
07-10-2009, 04:35 PM
#1
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how would YOU build the fastest 91 oct stock displacement LS1? i have a 1996 firebird no engine or trans
and a 1998 TransAm engine
problem is i need a trans,
but dont know which one to get
the limiting factor is 91 octane
im thinking to get it its fastest,
ill have to use that cali-legal STS turbo kit
(which i could not find, not even the price)
MAYBE later when it goes,
stroke when rebuilding.. what would that be, like a 6.5L or something?
so my question is;
which trans do i get if these are my limits?
i can get a "built" th350 or 700r4 with converter at any stall speed for $700
will i benefit from a th350 with a 91 octane turbo?
or a stroked 91 oct turbo?
will i actually need a th400?
or with 91 oct as a limit, even with turbo will the 700r4 be enough?
im leaning toward the th350 because its lighter than 400 (right?)
and ill have a transbrake
but my "advisor" here says get the damn 700r4 so we can have a lockup clutch and overdrive.
suggestions? advice?
and a 1998 TransAm engine
problem is i need a trans,
but dont know which one to get
the limiting factor is 91 octane
im thinking to get it its fastest,
ill have to use that cali-legal STS turbo kit
(which i could not find, not even the price)
MAYBE later when it goes,
stroke when rebuilding.. what would that be, like a 6.5L or something?
so my question is;
which trans do i get if these are my limits?
i can get a "built" th350 or 700r4 with converter at any stall speed for $700
will i benefit from a th350 with a 91 octane turbo?
or a stroked 91 oct turbo?
will i actually need a th400?
or with 91 oct as a limit, even with turbo will the 700r4 be enough?
im leaning toward the th350 because its lighter than 400 (right?)
and ill have a transbrake
but my "advisor" here says get the damn 700r4 so we can have a lockup clutch and overdrive.
suggestions? advice?
07-10-2009, 07:04 PM
#6
If you are looking for a turbo setup go with something like a single 75mm using truck manifolds or something, no STS. Mike at Cunningham knows his **** about turbos, ill be going there when I can afford to build another car.
91 octane is not hard to make good power with, smog legal is. No matter how smog legal you keep it you will always have problems. I had guys refuse to smog my car when all I had done was a lid and SMOG LEGAL edelbrock headers. So I said screw it and built the setup I wanted and now I just pay $150 or so every two years instead of $50.
I am very happy with my setup, n/a and running 91 octane made 468 rwhp and 435 rwtq...and thats with cheap heads on a fresh motor running thick oil on heavy 17x10.5 wheels and 315 DRs.
91 octane is not hard to make good power with, smog legal is. No matter how smog legal you keep it you will always have problems. I had guys refuse to smog my car when all I had done was a lid and SMOG LEGAL edelbrock headers. So I said screw it and built the setup I wanted and now I just pay $150 or so every two years instead of $50.
I am very happy with my setup, n/a and running 91 octane made 468 rwhp and 435 rwtq...and thats with cheap heads on a fresh motor running thick oil on heavy 17x10.5 wheels and 315 DRs.
07-11-2009, 04:08 AM
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Why not just build a mild 347 and turbo it? You can turn down the boost and have a conservative tune, then crank that bitch and swap tunes/turn on the meth. inj. when its time to play?
TH350 should work fine up to 600hp. I would personally do a 4L85E though, tough as a th400 and OD
they bolt right up and can be made into a manual valvebody set-up so you can skip the $1000 computer.
TH350 should work fine up to 600hp. I would personally do a 4L85E though, tough as a th400 and OD
they bolt right up and can be made into a manual valvebody set-up so you can skip the $1000 computer. Last edited by djsanchez2; 07-11-2009 at 04:24 AM.
07-12-2009, 01:58 AM
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Smog lawz check in
- The motor can be from ANY vehicle - of any year - as long as the engine that is put in is both Newer than the car it is going in and has all working emissions equipment to be able to pass as if it was the car it came from - thats it.
- The motor can be from ANY vehicle - of any year - as long as the engine that is put in is both Newer than the car it is going in and has all working emissions equipment to be able to pass as if it was the car it came from - thats it.
07-12-2009, 02:16 AM
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What I don't get is how your emphasis of 91 octane related to your transmission choice?
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
07-12-2009, 03:55 AM
#14
What I don't get is how your emphasis of 91 octane related to your transmission choice?
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
http://arb.ca.gov/msprog/aftermkt/devices/eo/D-593.pdf
This type of stuff should be stickied given the amount of misinformation that is spewed on this site.
07-12-2009, 02:09 PM
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Not true on the LS1 F-body as per CARB EO: D-593
http://arb.ca.gov/msprog/aftermkt/devices/eo/D-593.pdf
This type of stuff should be stickied given the amount of misinformation that is spewed on this site.
http://arb.ca.gov/msprog/aftermkt/devices/eo/D-593.pdf
This type of stuff should be stickied given the amount of misinformation that is spewed on this site.
When they first came out I could have sworn the EO number only applied to GTO's. Looks like they have expanded it since then.
07-12-2009, 05:17 PM
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^^^ You are right, STS only had the F-body/truck #'s as pending for a couple yrs. So it's understandable that most of us would not know that only recently they were approved (earlier this year). 
07-29-2009, 11:12 PM
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What I don't get is how your emphasis of 91 octane related to your transmission choice?
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
The STS kit is not cali legal for fbodies, the CARB number STS has was only granted for the GTO kit they make.
A nice head and cam package will smack that "smog legal" STS setup badly
91 octane = limited hp
so im looking for a trans that will handle whatever power the car would be able to make with a turbo running 91 oct
a smog legal heads and cam on 91 oct will smack that smog legal sts on 91 octane?
i guess i dont mind paying $150 for smogging.. its all ive ever done anyway.
if i didnt care about smog legal,
how much more could i get out of a turbo car?
i dont know if i can go an "all-out" heads and cam car..
maybe i can not get caught using dual cutouts?
maybe i ought to do that truck-manifold thing..
i bet its much cheaper than the sts kit
07-29-2009, 11:25 PM
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If you didnt care about smog at all, you can easily push 550hp+ through a stock bottom end with LS6 heads, LS6 intake and LS6 cam (or custom spec'd). A front mount turbo/FMIC would be the best route to go, much better spool-up and all round performance, plus there are a few kits that let you keep your A/C. The truck manifold kits will be a great option as they are easily bolted up and you can even have someone custom fab a kit. It will look something like this....
If you were willing to throw down the dough to forged the bottom end and beef up the fuel supply the sky is the limit. If you want to keep it auto and don't mind manually shifting it, a 4L80E would be the way to go. They handle good amounts of HP/TQ yet retain Overdrive for decent cruising RPM/Fuel mileage. 700R is too weak IMHO for anything more than 500hp. Also, you will have to address the rear end as they are weak as well, Just food for thought.
If you were willing to throw down the dough to forged the bottom end and beef up the fuel supply the sky is the limit. If you want to keep it auto and don't mind manually shifting it, a 4L80E would be the way to go. They handle good amounts of HP/TQ yet retain Overdrive for decent cruising RPM/Fuel mileage. 700R is too weak IMHO for anything more than 500hp. Also, you will have to address the rear end as they are weak as well, Just food for thought.
Last edited by djsanchez2; 07-29-2009 at 11:31 PM.
07-30-2009, 02:56 AM
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Ok I'll ask the question that counts. How "fast" do you want to go (spend)? Budget is everything (even with the best combo in mind, you still gotta have the dough to make it happen) and FI is not cheap. Do it right the first time and don't skimp out.
If it were me, I'd build a stroker (402, 416, 427, 434 LSX, 454 LSX) depending on budget and either turbo it (ideally 434LSX with great H/C, huge budget there), or build the nicest motor you can with good H/C and spray on top of it (150 to 200+ shot).
That's where my head's at. Don't forget about a rear ($3k+)...
If it were me, I'd build a stroker (402, 416, 427, 434 LSX, 454 LSX) depending on budget and either turbo it (ideally 434LSX with great H/C, huge budget there), or build the nicest motor you can with good H/C and spray on top of it (150 to 200+ shot).
That's where my head's at. Don't forget about a rear ($3k+)...
