Tc78 with 1.15 ar vs pt88?
#21
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Just had a good conversation with justin at comp turbos. For $300 they can make me either a 1.15,1.32 or even a 1.52 ar housing. I already don't have much lag so I think I'm going to go with the 1.53ar and call it a day.
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As said above , I have a 383 and TC78, with the .96 housing power would peak at 5000 rpm then fall off fast, would drop 100 hp by 6500 rpm.
I managed to source one of the last 1.32 housings, and what a difference, makes power right to the limiter 6700 rpm, and no noticable difference in spool time.
I have since made a new downpipe that steps straight up to 3.5" after the "V" band and that has made a noticable difference in spool time.
I'm running up to 18 psi boost and there is still a bit more left in it.
would like to upgrade the compressor side to a race cover, but would like some feedback from someone who has done it to know if its worth the hassel of shipping the turbo back and forth to have it done.
I managed to source one of the last 1.32 housings, and what a difference, makes power right to the limiter 6700 rpm, and no noticable difference in spool time.
I have since made a new downpipe that steps straight up to 3.5" after the "V" band and that has made a noticable difference in spool time.
I'm running up to 18 psi boost and there is still a bit more left in it.
would like to upgrade the compressor side to a race cover, but would like some feedback from someone who has done it to know if its worth the hassel of shipping the turbo back and forth to have it done.
#24
Thanks for chiming in Johnv!!
Sprayed 01 I am going to have justin do that to mine too. Let us know what happens, maybe we could send our turbos at the same time and get a little break?
Sprayed 01 I am going to have justin do that to mine too. Let us know what happens, maybe we could send our turbos at the same time and get a little break?
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I'm running up to 18 psi boost and there is still a bit more left in it.
would like to upgrade the compressor side to a race cover, but would like some feedback from someone who has done it to know if its worth the hassel of shipping the turbo back and forth to have it done.
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I should be able to get it off after the holidays and send it out. If anyone else wants to do the same pm me. Il call justin and work out a group buy deal.
What were your hp numbers before and after the housing swap?
What were your hp numbers before and after the housing swap?
#29
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Yea I'm interested in time/numbers as well. I've gone 136 and consistently go 134-135 on my .96 TC76. If he's only going 129 after the 1.32 swap I can't see much merit in it.
While this custom housing interests me, I doubt I'll do it. I put $250 into getting this .96 housing last season (had a .81). I don't really wanna put another $300 into it for a "band aid" type fix. I'd rather just go with the bigger turbo.
While this custom housing interests me, I doubt I'll do it. I put $250 into getting this .96 housing last season (had a .81). I don't really wanna put another $300 into it for a "band aid" type fix. I'd rather just go with the bigger turbo.
#30
I wont knock the Bigger A/R housing at all. I dont understand the issues though. My old shop car trapped 131mph in the 1/4 while running 10.9's with a shitty 60' on 8lbs of boost. It eventualy went a best of 9.6x at a hair over 140 with 15lbs of boost. This was all done a TC76 with a .96 A/R. I am very interested in your all results.
Just for refrence my combo was:
iron 370ci 8.7:1
Speed Inc TU1 cam
Stock 6.0L heads with 918 springs
LS6 Intake/TB
TH400 3000 stall
9"
3.25 gears
325/15/15 DR
Just for refrence my combo was:
iron 370ci 8.7:1
Speed Inc TU1 cam
Stock 6.0L heads with 918 springs
LS6 Intake/TB
TH400 3000 stall
9"
3.25 gears
325/15/15 DR
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I don't understand it either I just know what happened, I mean the car felt like all the timing was pulled out of the tune. On the freeway the car pulled harder in overdrive.
#32
I am damn tempted to put the 370 I have now in my 02 Formula and make back to back comparisons on the TC78 with the various A/R ratios. I dont have time to build the car to run a class, and doing the setups to do get solid info would be a blast.
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All I can say is the car would just fall flat on the top, installed a ST80 w/1.1ar and it doesn't do that anymore. When the TC76 was signing off is about where the ST80 is really hitting it's stride.
#34
Yeah, I really don’t have an issue.... it just seems that if I could let it breathe a little easier it would be a happier engine... I could loose some spool too as it is ridiculous right now
I really want to trap in the 145 area on under 10 psi, so that is my goal
It did 134 with no IC on 8 psi with 30 percent converter slip so we will see
Josh's glide will help
I really want to trap in the 145 area on under 10 psi, so that is my goal
It did 134 with no IC on 8 psi with 30 percent converter slip so we will see
Josh's glide will help
Last edited by rotary1307cc; 12-20-2010 at 07:12 PM.
#35
Yeah, I really don’t have an issue.... it just seems that if I could let it breathe a little easier it would be a happier engine... I could loose some spool too as it is ridiculous right now
I really want to trap in the 145 area on under 10 psi, so that is my goal
It did 134 with no IC on 8 psi with 30 percent converter slip so we will see
Josh's glide will help
I really want to trap in the 145 area on under 10 psi, so that is my goal
It did 134 with no IC on 8 psi with 30 percent converter slip so we will see
Josh's glide will help
#36
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I wont knock the Bigger A/R housing at all. I dont understand the issues though. My old shop car trapped 131mph in the 1/4 while running 10.9's with a shitty 60' on 8lbs of boost. It eventualy went a best of 9.6x at a hair over 140 with 15lbs of boost. This was all done a TC76 with a .96 A/R. I am very interested in your all results.
Just for refrence my combo was:
iron 370ci 8.7:1
Speed Inc TU1 cam
Stock 6.0L heads with 918 springs
LS6 Intake/TB
TH400 3000 stall
9"
3.25 gears
325/15/15 DR
Just for refrence my combo was:
iron 370ci 8.7:1
Speed Inc TU1 cam
Stock 6.0L heads with 918 springs
LS6 Intake/TB
TH400 3000 stall
9"
3.25 gears
325/15/15 DR
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