76 gts spool time
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Teching In
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76 gts spool time I've got a front mount turbo kit for my gto ready to install with a pt 76 gts
.96 turbine A/R and .70 compressor A/R. This will be put on a completly stock ls2. I've been told this is the best match for a stock cube engine, but will it be overkill for a non-forged motor? If i do decide to forge the motor it'll be about 2 years down the road. Since i will not be forging the motor boost response and not peak hp will be my primary focus. At what rpm will a pt76gts spool at with a stock ls2 motor? Would there be a better suited turbo that will spool significantly faster and still make 550-600 rwhp on a stock ls2? I will be pushing 8-10 psi max. Those are my goals for now because at the moment i don't feel like doing a crazy transmission/tire/fuel system upgrade but would like more power on occasion. Will a tc76mps fit my needs better or should i down grade to a 66mm turbo? Thanks in advanced for any help. Please throw some other options out as well if you think a different turbo will fit my needs better.
.96 turbine A/R and .70 compressor A/R. This will be put on a completly stock ls2. I've been told this is the best match for a stock cube engine, but will it be overkill for a non-forged motor? If i do decide to forge the motor it'll be about 2 years down the road. Since i will not be forging the motor boost response and not peak hp will be my primary focus. At what rpm will a pt76gts spool at with a stock ls2 motor? Would there be a better suited turbo that will spool significantly faster and still make 550-600 rwhp on a stock ls2? I will be pushing 8-10 psi max. Those are my goals for now because at the moment i don't feel like doing a crazy transmission/tire/fuel system upgrade but would like more power on occasion. Will a tc76mps fit my needs better or should i down grade to a 66mm turbo? Thanks in advanced for any help. Please throw some other options out as well if you think a different turbo will fit my needs better.
seriously the info is all here and any question you could possibly think of can be found with patience. IMO a 76mm would be the smallest turbo I would run on a 364. Thats about the limit for a t4 turbo as far as backpressure goes from what I've read. A st76 would be great for that ls2 from forced inductions(t4), but a 76mps and a 76gts would work fine also. The 76gts will supposedly support another 40-50whp. And don't worry about spool time. Those are all fairly all small turbos and with a fm setup you will start seeing boost around 3000rpm in most conditions. Thread Starter
Teching In
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well reading compressor maps doesn't look that hard, can someone show me where i can access a database of compressor maps so i can pick one for myself? Specificly I'd like to compare the st76, 76mps, and 76gts, but would also like to look at a few 66-70 maps as well. From what i saw just initially looking at forced inductions.com if i don't plan on pushing more than 12-13 psi (which i don't) a 66mm turbo would still be operating very efficiently, plus i'd have near insta-boost.
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Teching In
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i recall reading a post that suggested the 76mps will spool 4-500 rpms quicker than a 76 gts. Can anyone verify this from real world experience? If this is the case i will probably be looking into trading out my gts before the install/tune. From looking at compressor maps i see no reason why a 66-70mm turbo wouldn't do what i want on a non forged engine and still have room left over. Those saying a 66 is too small for a 364 i would like to hear some justification to this arguement.
with 6.0 liters you do not need to worry about spool time with a turbo as small as a t76. My rear mounted 76R with a ..96 a/r housing spools fast enough to loose traction on drag radials anywhere under 100 mph.
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hey zombie i appreciate the feedback but that isn't really the answer i was looking for. I've seen many people talking about not worrying about spool time but they are concerned about turbo spooling at full throttle and on the drag strip. I have no intrest in racing at the strip, this will be a 100% street car. I'm concerned about part throttle response and quick spooling ability. A turbo that doesn't spool until 3500-4000 isn't acceptable for me as a street car, I'd like my power to come in quite a bit sooner.
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Verdad Gallardo hey zombie i appreciate the feedback but that isn't really the answer i was looking for. I've seen many people talking about not worrying about spool time but they are concerned about turbo spooling at full throttle and on the drag strip. I have no intrest in racing at the strip, this will be a 100% street car. I'm concerned about part throttle response and quick spooling ability. A turbo that doesn't spool until 3500-4000 isn't acceptable for me as a street car, I'd like my power to come in quite a bit sooner.
My repsonse still stands, a t76 is small and spools fast on a 6.0. I hope you are planning on using an auto trans since you're concerned about lag. manuals spool really slow compared to an auto. I can stab the throttle in any gear and be at full boost before someone with a manual trans can finish their downshift (I can do it in 3rd then downshift to second while WOT for even faster spool). It takes me from 60-67 mph to go from 18" vac at light cruise to 20psi in 3rd gear (1:1), about 1 second (if I get traction and I usually don't). Spools faster if I'm in gear and under some load. I'm actually considering moving to a 1.15 a/r housing to soften the hit due to traction issues. Anything over 1/3 throttle results in boost building.
My best track time is in my sig. The car sees way more street time than track time, hence the choice in gears.
I am curious b/c I think that the th400 is the best way to go for many reason's except for the obvious one of no o/d if you do some highway driving. Now most that ahve serious cars like these trailer to track and don't take on long hauls but some do and go with the 4l80e. I am torn b/w the two and if money was no object I think I'd go with the 80. Just curious, with those gears, what are you revving at when cruizing on the highway say at 60-70 or so. Thanks 
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Ok guys i spoke with the boys at ForcedInductions and I'm going to swap out my pt76gts for a tc76. I'm needing to sell my 76gts but i can't post in the for sale section yet. Anyone looking for a 76gts? It has a .96 turbine .70 compressor. This turbo is brand new and has never been used. It came with my turbo kit which is why i'm swapping it out without using it. I'm wanting $1200 shipped OBO. Pics available upon request.
