HELP! turbo setup sucks
How much boost are you running? Figuring a 402 with 17# of boost and a single 3" exhaust, the exhaust is goign to be going around 588fps and your backpressure is going to be high. By changing the exhaust to a 4" unit and a T6 housing, your exhaust velocity will drop to 330fps and you will free up a TON of horsepower. You want Velocity before the turbo, efficienty wastegates, and low backpressure after the turbo.
Just my .02
Headers 1 5/8" or 1 3/4
Crossover 2.5" with 4" long tubes on the turbo
Downpipe: 4" aluminum
T6 housing
60mm Wastegate dumped externally, needs to be on the turbo
If your going to stay around 17-20psi
3" aluminum tubes feeding the intercooler
I've ran the numbers and this combo works. PM me if you have any questions.
Just my .02
Headers 1 5/8" or 1 3/4
Crossover 2.5" with 4" long tubes on the turbo
Downpipe: 4" aluminum
T6 housing
60mm Wastegate dumped externally, needs to be on the turbo
If your going to stay around 17-20psi
3" aluminum tubes feeding the intercooler
I've ran the numbers and this combo works. PM me if you have any questions.
that's an even cappier part, I DO HAVE SNOW! lol.
Im running 11 and change on the dyno, my gauge at the track shows 15 psi but I don't believe it to be accurate.
I run a 1 5/8" header with 2 1/2" crossover and about 6" long tubes up to the T4 flange.. The cold side is all 2 1/2" I have an externally dumped 60MM Tial. 3" DP mounted right up to the 4" outlet! no transition!
I had a backpressure gauge installed but it couldnt take the heat Im guessing and never read. I may try just to get everything settled in, a T6 housing for my PTE88 and see where it takes me.. Remember though Ill always be on the slow side due to Im keeping the 6 speed at all costs. (There is a record I want one day
)
I would like 3 1/2" cold pipes though....
Thanks for all the help folks1
Im running 11 and change on the dyno, my gauge at the track shows 15 psi but I don't believe it to be accurate.
I run a 1 5/8" header with 2 1/2" crossover and about 6" long tubes up to the T4 flange.. The cold side is all 2 1/2" I have an externally dumped 60MM Tial. 3" DP mounted right up to the 4" outlet! no transition!
I had a backpressure gauge installed but it couldnt take the heat Im guessing and never read. I may try just to get everything settled in, a T6 housing for my PTE88 and see where it takes me.. Remember though Ill always be on the slow side due to Im keeping the 6 speed at all costs. (There is a record I want one day
) I would like 3 1/2" cold pipes though....
Thanks for all the help folks1
How much boost are you running? Figuring a 402 with 17# of boost and a single 3" exhaust, the exhaust is goign to be going around 588fps and your backpressure is going to be high. By changing the exhaust to a 4" unit and a T6 housing, your exhaust velocity will drop to 330fps and you will free up a TON of horsepower. You want Velocity before the turbo, efficienty wastegates, and low backpressure after the turbo.
Just my .02
Headers 1 5/8" or 1 3/4
Crossover 2.5" with 4" long tubes on the turbo
Downpipe: 4" aluminum
T6 housing
60mm Wastegate dumped externally, needs to be on the turbo
If your going to stay around 17-20psi
3" aluminum tubes feeding the intercooler
I've ran the numbers and this combo works. PM me if you have any questions.
Just my .02
Headers 1 5/8" or 1 3/4
Crossover 2.5" with 4" long tubes on the turbo
Downpipe: 4" aluminum
T6 housing
60mm Wastegate dumped externally, needs to be on the turbo
If your going to stay around 17-20psi
3" aluminum tubes feeding the intercooler
I've ran the numbers and this combo works. PM me if you have any questions.
All the under sized piping should just me making the car make more boost. I'm not saying that isn't a problem also but it isn't the current problem. Maybe it wont make power, lay over real early in the power band or have detonation issues, but it should make boost.
Im in Iraq right now, 3 months left of my third 12+ month deployment. So at the moment I can't change springs, but Ill call tial and ask them about it.
Also I see what you're saying about the thing should be making boost with small pipes.. but hell Im so lost, and I know 2 1/2" isn't big enough anyway I was just going to redo it all for the PT3000 anyway.
Also I see what you're saying about the thing should be making boost with small pipes.. but hell Im so lost, and I know 2 1/2" isn't big enough anyway I was just going to redo it all for the PT3000 anyway.
Teching In
Joined: Sep 2009
Posts: 43
Likes: 0
It will only make more boost at the compressor outlet due to pressure loss through the small cool side pipes. Where are you measuring your boost, compressor outlet or intake manifold? I'd put money on the WG cracking open because of high back pressure.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
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
precision has always told me a 408 was too big for that PT88, which is actually quite a small turbo, Im thinking the biggest issues I have is running a 3" DP in a 4" outlet, and the T4 flange.
Veee 8 name a price man might take me a few months to save up but if you still running it and willing to sell, im still willing to buy
Veee 8 name a price man might take me a few months to save up but if you still running it and willing to sell, im still willing to buy
As for your 408 being too big for a PT88, that's a crock of ****, one of my friends and local shop owners put his 408 w/ PT88 into the 9s here in albuquerque, and the car is also a street monster. Just work with your kit dude, don't give up on it, you're already this far in.
That 88mm is PLENTY for a stout 408 if you're looking for an 8 second car. I'm rocking truck manifolds with 2 1/2" pipes to an 80mm with 15psi and down in the 8's. It is a t6 flange with a 5" dp though. Once you get the bugs worked out you'll be happy. It takes time, that's for certain. Mustang Dyno claims I make 588rwhp at 15psi, just an fyi.
I have no doubt in my mind that the PT88 CAN be an adequate turbo, However with the T4 flange and 3" DP It's not going to to the job. Many people hear are seeing me say the 88 is too small and assume Im talking about the T6 model Im guessing which would be an incorrect statement, the T4 model IS too small.
I have no doubt in my mind that the PT88 CAN be an adequate turbo, However with the T4 flange and 3" DP It's not going to to the job. Many people hear are seeing me say the 88 is too small and assume Im talking about the T6 model Im guessing which would be an incorrect statement, the T4 model IS too small.
TECH Addict
Joined: Jul 2005
Posts: 2,153
Likes: 3
Mike
While the 3" DP is not THE problem it is however not optimal and after all I've spent on this car I am not going to keep something on the turbo which will adversely effect turbine flow. The real problem is most likely in the entire cold side, it's all wrong, and the intercooler SUCKS I get consistently over 180 degree intake temps, and then I start losing ign. timing after that and I only run 16 degrees of timing at the moment just for the break-in tune.. Will be pumping that up to 21 or so after I re-work the PTK kit. and Build the new cold side and put in the PT3000
Here's the old turbo kit I had with a pt88: http://juneau.me.vt.edu/~aweil/turbokit/thumbnails.html
348 hydraulic roller ford, 1 5/8" shorty headers, 2.5" crossover, 4" downpipe. T04 PT88.
Went 5.5's @ 128ish in the 1/8th mile and 8.92 @ 159 banging off the limiter the last 150 feet in the 1/4 mile on BFG radials at over 3300#.
348 hydraulic roller ford, 1 5/8" shorty headers, 2.5" crossover, 4" downpipe. T04 PT88.
Went 5.5's @ 128ish in the 1/8th mile and 8.92 @ 159 banging off the limiter the last 150 feet in the 1/4 mile on BFG radials at over 3300#.
Yes, I no longer doubt the Merit of the T4 PT88 and its capability of being an 8 second turbo.. HOWEVER that is only when it is properly utilized! I would say myself being around 3800lbs, having a 408 (more BP than a smaller motor), having tiny 2.5" Charge pipe, a completely innefective intercooler, an early opening waste gate, 16 degrees ign timing etc, as well as the 3" DP and numberous other things just in effect render it innefective on my setup, I need to keep what I got, fix the crap that's messed up, and it should make some power then. If it doesn't.. then Ill complain.
It's not exactly close to my dream setup, and I probably never get that turbo in the 8s in my heavy *** car with a 6 speed. It WILL however be a very valuable tool in educating myself on making the most with what I have, and what it takes to get a manual boosted car down the track in a hurry, Ill save the 101 for a 6 Bolt Motor and go max effort with that stuff. KEEPING THE 6 SPEED!
It's not exactly close to my dream setup, and I probably never get that turbo in the 8s in my heavy *** car with a 6 speed. It WILL however be a very valuable tool in educating myself on making the most with what I have, and what it takes to get a manual boosted car down the track in a hurry, Ill save the 101 for a 6 Bolt Motor and go max effort with that stuff. KEEPING THE 6 SPEED!
