My somewhat coherent thread on the topic of street/strip turbo LS combinations.
08-22-2012, 09:04 PM
#61
I have a PT76GTS (.96) on my 370ci, TU1 cam..
What cubes is too big for a 76GTS? It spools instantly and w/ slicks and off a transbrake I dont see why it wouldnt break into the 8's. I think it works great for a low-mid 9sec street car. I think a bigger turbo would suck...unless you wanted to go faster.
What cubes is too big for a 76GTS? It spools instantly and w/ slicks and off a transbrake I dont see why it wouldnt break into the 8's. I think it works great for a low-mid 9sec street car. I think a bigger turbo would suck...unless you wanted to go faster.
What would be a better turbo for me that I could use for my application and not have to worry about changing the hotside too much?
08-22-2012, 09:18 PM
#62
TECH Apprentice
compressor:
66mm inducer
91.4mm exducer
turbine:
80mm inducer
73mm exducer
BUT the very popular S480 is rated a 80/96 and has the wheel size spec configuration you mentioned. Was just trying to say that not all of their turbos are configured that way. I totally agree that some research needs to be done to make sure you are looking at comparable units.
08-22-2012, 09:21 PM
#63
FormerVendor
Thread Starter
7675 on an LS is pretty much ideal on 5.3-5.7 IMO. 6.0 is the most displacement I would like to see it on.
I've tuned a few on 402-408ci and they max out at around 775rwhp with severe power drop off after 5500rpm (whereas they will do a bit over 900 and 6500rpm on a 346).
I've tuned a few on 402-408ci and they max out at around 775rwhp with severe power drop off after 5500rpm (whereas they will do a bit over 900 and 6500rpm on a 346).
08-23-2012, 09:35 AM
#65
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08-23-2012, 10:59 AM
#66
7675 on an LS is pretty much ideal on 5.3-5.7 IMO. 6.0 is the most displacement I would like to see it on.
I've tuned a few on 402-408ci and they max out at around 775rwhp with severe power drop off after 5500rpm (whereas they will do a bit over 900 and 6500rpm on a 346).
I've tuned a few on 402-408ci and they max out at around 775rwhp with severe power drop off after 5500rpm (whereas they will do a bit over 900 and 6500rpm on a 346).
If my current turbo doesn't work out, I think a 7675 would be more than I will ever need.
Thanks for taking the time to share all this information. It has been great.
08-23-2012, 11:07 AM
#67
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Good info in here. Hopefully next week I can give some insight on how my ls3 headed 370 with a 76gts turbo works out with a t56. I am going for a killer street car that sees occasional track duty.
08-23-2012, 11:52 AM
#68
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Any thoughts on E-85 or E-98 use for a street/strip car?
08-24-2012, 08:06 AM
#69
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I have a GT 42-94R on my Z06 cammed lq4. Blow thru car. Trapped 131mph on 12#.
It has a t6 housing on it which I'm not too fond of, but it still spools very fast once there is sufficient heat in the pipes and housing. I am very happy with this turbo for my combination.
Oh, that's also with 4" charge pipes after the giant 5.5" core intercooler. I'm sure that isn't helping spool time any.
It has a t6 housing on it which I'm not too fond of, but it still spools very fast once there is sufficient heat in the pipes and housing. I am very happy with this turbo for my combination.
Oh, that's also with 4" charge pipes after the giant 5.5" core intercooler. I'm sure that isn't helping spool time any.
08-24-2012, 09:55 AM
#70
The 7675ceas are what we must be running on Steve's car but with 80 A/R housings. That's a 422 and twins spool very very quickly. IMO, a single one of those is undersized for any v8 (even a 4.8). I'm not saying it wont work, I'm just saying that something with a bigger exhaust wheel would work better.
08-24-2012, 12:39 PM
#71
FormerVendor
Thread Starter
Well again, it depends on your goals. To say it's designed to be run as a twin or on a 4 banger is not correct when one of them will make 900rwhp and turn 6500+rpm on a 346.
I think we have a different definition of spooling "very very quickly". You're talking about a pair of turbos that can make over 2000hp so it's not going to be super responsive down low.
I did mention that with more displacement than a 6.0 I agree that I would not run this as a single turbo.
I think we have a different definition of spooling "very very quickly". You're talking about a pair of turbos that can make over 2000hp so it's not going to be super responsive down low.
I did mention that with more displacement than a 6.0 I agree that I would not run this as a single turbo.
08-24-2012, 02:06 PM
#72
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Well again, it depends on your goals. To say it's designed to be run as a twin or on a 4 banger is not correct when one of them will make 900rwhp and turn 6500+rpm on a 346.
I think we have a different definition of spooling "very very quickly". You're talking about a pair of turbos that can make over 2000hp so it's not going to be super responsive down low.
I did mention that with more displacement than a 6.0 I agree that I would not run this as a single turbo.
I think we have a different definition of spooling "very very quickly". You're talking about a pair of turbos that can make over 2000hp so it's not going to be super responsive down low.
I did mention that with more displacement than a 6.0 I agree that I would not run this as a single turbo.
08-24-2012, 02:11 PM
#73
FormerVendor
Thread Starter
08-24-2012, 04:38 PM
#74
I had a 76GTS on a 346 with a reverse grind 227/224 114lsa camshaft.
While I think this turbo is a little too small and agree with los, that with a reverse grind cam with less exhaust bias and a late EVO event it can work.
That said I am still a huge believer in big turbine wheels, tight ar housings and the correct camshaft to spool it with and run hard up top like a turbo should.
While I think this turbo is a little too small and agree with los, that with a reverse grind cam with less exhaust bias and a late EVO event it can work.
That said I am still a huge believer in big turbine wheels, tight ar housings and the correct camshaft to spool it with and run hard up top like a turbo should.
08-24-2012, 05:58 PM
#75
FormerVendor
Thread Starter
I had a 76GTS on a 346 with a reverse grind 227/224 114lsa camshaft.
While I think this turbo is a little too small and agree with los, that with a reverse grind cam with less exhaust bias and a late EVO event it can work.
That said I am still a huge believer in big turbine wheels, tight ar housings and the correct camshaft to spool it with and run hard up top like a turbo should.
While I think this turbo is a little too small and agree with los, that with a reverse grind cam with less exhaust bias and a late EVO event it can work.
That said I am still a huge believer in big turbine wheels, tight ar housings and the correct camshaft to spool it with and run hard up top like a turbo should.
I don't think reverse split cams are ever necessary. Every one I've tried has lost power and response so I stopped using them. Of course a 3 deg split isn't too far off from a single pattern cam anyway.
And don't get me wrong, if you couldn't tell by most of my posts I'm a believer in freeing up the exhaust side as well but the fact remains that a 7675 will make good power if you don't try and put it on too large of an engine.
08-24-2012, 08:29 PM
#76
What power did it make?
I don't think reverse split cams are ever necessary. Every one I've tried has lost power and response so I stopped using them. Of course a 3 deg split isn't too far off from a single pattern cam anyway.
And don't get me wrong, if you couldn't tell by most of my posts I'm a believer in freeing up the exhaust side as well but the fact remains that a 7675 will make good power if you don't try and put it on too large of an engine.
I don't think reverse split cams are ever necessary. Every one I've tried has lost power and response so I stopped using them. Of course a 3 deg split isn't too far off from a single pattern cam anyway.
And don't get me wrong, if you couldn't tell by most of my posts I'm a believer in freeing up the exhaust side as well but the fact remains that a 7675 will make good power if you don't try and put it on too large of an engine.
I also don't like reverse grind splits and I go back and forth with a good friend of mine(you know who you are
) about this all the time that they aren't needed and with a properly sized turbine a normal small traditional split with a tighter than what most off the shelf boost cams offer lsa and icl will make more power and spool better every time IMO. I also like single pattern stuff for smaller sized turbines and turbo's and some larger stuff to a degree, but agree 100% about the reverse splits. I guess sometimes space is so limited or you have a guy that just has to run a turbo that is on the small side and in that case a small reverse split can work, but nothing I ever spec intentionally are reverse split.
Video of said car on 11psi:http://youtu.be/yS-3C-fC2iw
Dyno:
Last edited by Sales@Tick; 08-24-2012 at 08:34 PM.
08-24-2012, 10:07 PM
#77
I'm a firm believer in my reverse split cam. Sold it at one point. Installed a smaller, 228ish even pattern cam. Car was noticeably slower, and spooled slower too. After a year or two with it in the car.... I tracked down the reverse split cam I sold and the owner still had it sitting in the box I shipped it in 
Bought it back, reinstalled it, and the car then hauled *** on the top end again.
A couple local tuners thought I was an idiot for thinking going to a smaller cam would be faster.... And they laughed when I reinstalled the reverse big stick and picked up hp. "Duh" they said.
Bought it back, reinstalled it, and the car then hauled *** on the top end again. A couple local tuners thought I was an idiot for thinking going to a smaller cam would be faster.... And they laughed when I reinstalled the reverse big stick and picked up hp. "Duh" they said.
08-25-2012, 07:23 AM
#80
on my 6.0l cam only lq9 i had a tc78 at 12 psi would run 142mph swapped to the 7675 with no other changes car went 152 and ran that number consistently. the lq9 ate a piston swapped in a 5.3l with the same cam and with the 7675 best the car ran was 142.