TC78 vs T76?
Thread Starter
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
TC78 vs T76? Im thinking about upgrading to a TC78 with a S wheel. Looking to pick up 50~75HP and a couple hundred RPM over my current T76 p wheel. If anyone has any info I would like to hear. Thanks J
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
Drturbo is your man,
Not sure if you will gain much, maybe quicker spool up.
make sure you go with a 1.15 AR houseing or larger with your 370.
I have a TC78 on a 383 and it is chokeing with a .96 AR housing, power peaks at 4800 rpm then takes a dive, trying to source a 1.32 Ar housing without much luck.
Not sure if you will gain much, maybe quicker spool up.
make sure you go with a 1.15 AR houseing or larger with your 370.
I have a TC78 on a 383 and it is chokeing with a .96 AR housing, power peaks at 4800 rpm then takes a dive, trying to source a 1.32 Ar housing without much luck.
Your best bet would be to go to a t78 with a F1 turbine wheel and a 1.15 a/r. A tc78 vs. a t76 would be pretty close. The TC's smaller cover does not flow as well as you bigger cover. If you have room the GTM cover with a 78mm wheel would give you another 100+ hp.
Thread Starter
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
Drturbo is your man,
Not sure if you will gain much, maybe quicker spool up.
make sure you go with a 1.15 AR houseing or larger with your 370.
I have a TC78 on a 383 and it is chokeing with a .96 AR housing, power peaks at 4800 rpm then takes a dive, trying to source a 1.32 Ar housing without much luck.
Not sure if you will gain much, maybe quicker spool up.
make sure you go with a 1.15 AR houseing or larger with your 370.
I have a TC78 on a 383 and it is chokeing with a .96 AR housing, power peaks at 4800 rpm then takes a dive, trying to source a 1.32 Ar housing without much luck.
Trending Topics
Dam, Please dont say that, I am building a 383 with a Turbonetics T-76 with a .96 AR. Back then I did a search, called a couple of turbo companies and all told me this turbo would suffice for the 750-850 RWHP I am looking for. They said it was good for app 1000 FWHP. I made 648 RWHP on pump with a supercharger and was hoping to make at least a 100 more with the turbo...
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever
Verdad Gallardo Yes you can get a 1.15 now, I do not think they offer anything larger at this time. They listed a 1.32 and a 1.5 but I was un able to get one through FI.
We are running a 1.15 on a 370 @850whp, its a TC78 though. BP is high still but better then the .96. I would not run it on anything in the 400ci range but 383 is acceptable for the most part.
moehorsepower, You could achieve those numbers through a 6sp but a unlocked 400 there will be no way. The turbo would make 1000+fwhp no problem on a 238ci v6, on a 383 I would imagine 925fwhp would be pushing it.
We are running a 1.15 on a 370 @850whp, its a TC78 though. BP is high still but better then the .96. I would not run it on anything in the 400ci range but 383 is acceptable for the most part.
moehorsepower, You could achieve those numbers through a 6sp but a unlocked 400 there will be no way. The turbo would make 1000+fwhp no problem on a 238ci v6, on a 383 I would imagine 925fwhp would be pushing it.
I am 6 speed now, well if even 900fwhp is achievable then I should make my goal of at least 750 RWHP but I was sure looking for a little more...
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
My 383 with the .96ar is making boost from 1600 rpm and on the wastegate at 3200 - 15 psi boost, but hits peak torque at 3900 rpm and peak power at 48-5000rpm then drops off fast, looses 130 rwhp by the limiter at 6700rpm.
The engine will not take much timing due to the high back pressure at the top end. Have just added meth which is helping alot but not the ideal solution.
I have been told the 1.32 and 1.52 housings although listed are not available at present
and was also told that a devided T4 housing flows 10% less then the same size undevided T4 housing, so the 1.15 will flow more but not as much as you might think !
The engine will not take much timing due to the high back pressure at the top end. Have just added meth which is helping alot but not the ideal solution.
I have been told the 1.32 and 1.52 housings although listed are not available at present
and was also told that a devided T4 housing flows 10% less then the same size undevided T4 housing, so the 1.15 will flow more but not as much as you might think !
Thread Starter
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
I haven't dynoed my new 370/T76 combo but in bad air it went 10.3@129MPH @4950lbs, in 4wd through a unlocked 4L80E. The calculators are showing ~820 RWHP running down the 1/4 mile.
[QUOTE=Johnv;12024664]My 383 with the .96ar is making boost from 1600 rpm and on the wastegate at 3200 - 15 psi boost, but hits peak torque at 3900 rpm and peak power at 48-5000rpm then drops off fast, looses 130 rwhp by the limiter at 6700rpm.
The engine will not take much timing due to the high back pressure at the top end. Have just added meth which is helping alot but not the ideal solution.
Well My set up has headders instead of a log setup, hopefully this will reduce the backpressure..
Thats encouraging, I went 138 mph with the supercharger setup...
The engine will not take much timing due to the high back pressure at the top end. Have just added meth which is helping alot but not the ideal solution.
Well My set up has headders instead of a log setup, hopefully this will reduce the backpressure..
Thats encouraging, I went 138 mph with the supercharger setup...
The pipes feeding the turbo aren't making the back pressure though, it's trying to cram all of that exhaust volume through that small exhaust housing on the turbo that makes BP.
Gotcha, Frost do you think I will hit my mark of 750-800 Rwhp with my set up? as follows: Remember that it made 648 RWHP on Pump with 12 lbs and 722 RWHP with the fast gas at 14lbs
Engine: 383 LT4
Heads: LT4 Ported
Intake: LT4
T/B: 58mm
Compression:9:5:1
Cam: 23X-23X/ 588-588 on a 114 LSA.
Tranny: M63
T-76 with a T4 flange and a .96 AR
Last edited by moehorsepower; Aug 6, 2009 at 12:53 PM. Reason: forgot to add an item