9ball

iTrader: (6)

I bought this "T66" on here:

https://ls1tech.com/forums/showthrea...713&highlight=

It was confirmed that it was a PTE-66. Could this have been a faked turbo? I'm not blaming the seller, he obviously didn't know any better than me, but I just wanted to make 100% sure. The car made 450rwHP, which would be nice, but you need to see the graph to realize how fubar'd this thing is. Also, it's a cammed 05 GTO running 8-9psi :



I know this could be a HOST of problems (918 springs will be replaced with Patriot Duals), but I just wanted to rule out the turbo being the problem.

Mike at NEP was great to deal with and we couldn't figure out where the Hell the car was losing all its power from. Just so many things that it could be. I just want to clear the turbo as being a cause of the problem.

dcvingv6

iTrader: (3)

Hey man, i was that black procharged trans am, that was on the dyno before you... I am not much of a turbo guy, so i can't help you trouleshoot that, but i have patriot dual spings, and my last pull, mike thought i might have had a bit of valve float He had suggested to me to go to the extreme duals. Just as an FYI.

I hope you get it figured out, that was a nice car!

Thanks...
--Mike

9ball

iTrader: (6)

Haha, small world. Yea, seeing your car run only bummed me out more, haha. I was shooting for around the same numbers you were. Regardless congrats on that thing, the thing sounded mean as fawk! Anyways, I'll looking into the Extremes ... just so many potential areas where this could be coming from ... or a little of everything.

Jake@EPP

The 918s should be plenty depending on your cam.

What setup do you have for a inlet to the turbo? What did boost do when the hp dropped like a rock?

There is alot of unanswered questions here that help everyone out.

Timing?
IAT?
AFR?

Did they graph boost vs HP/TQ?

Tiago

iTrader: (27)

918s should suffice as EPP said.

that looks like a small turbo running out of air on the top. The exhaust side 0.81 is way too small for a single turbo. You need 0.96, major backpressure is probably causing that.

9ball

iTrader: (6)

AFR was 10.8-11.2, timing was 14 degrees. This is where I wanted it, real safe but still enough to make power. I don't remember the exact IAT, but it was real good, especially with the meth. Absolutely nothing too hot.

As for the cam it's a 228/228 .590" 114LSA. Even with the added boost the springs will be ok? As for the turbo set-up, it's the stock STS set-up. 2.5" ehxuast, 2" intake.

Being a rear-mounted turbo, the .81A/R is just fine. Any bigger and have fun with spooling that sucker up.

hellbents10

iTrader: (10)

Rear mount or not you could still be seeing a back pressure issue depending on the exhaust wheel in that unit. Also was there a ton of kr up top pulling timing? Bust knock or something of that matter. Anything is a possibility at this point still. Your AFR and total timing should be just fine though.

Juiced

iTrader: (2)

back pressure.... looks really similar to this the problems Zombie was having

https://ls1tech.com/forums/forced-induction/822122-zombie-rear-mount-turbo-saga.html

9ball

iTrader: (6)

It doesn't look like his problem comes anywhere near what I've been experiencing. He got a little more out of it with the larger exhaust housing, but he's also pushing 16+psi while I'm staying in the 8-10psi. My power band isn't falling short at 6000RPM, the power just stops being made after 4500RPM. Seeing as he was able to work pretty well with his set-up on a .81A/R housing makes me think this isn't where the problem lies.

As far as KR, none that I can remember hearing about. Pretty sure if there was, that would be something to look at, but that clearly was not the case.

HydroStream6

iTrader: (16)

I would back that up that you might want to make sure you don't have anything restricting the inlet to the turbo (clogged filter, kinked hose, etc)... also might want to check that the intercooler is flowing properly (I've seen them clogged as well).

As for your turbine housing, I'm pushing 15psi and 650rwhp through a .81AR housing with the stock STS piping without issue.

Jake@EPP

Whats your exhaust setup look like? Cats?

The 2in intake sounds restrictive, this sounds like a lack of airflow issue.

9ball

iTrader: (6)

Like Adam stated, the set-up itself is capable of a lot more power, so I don't think it's in the STS set-up itself. Again, I've seen peopel with the .81AR housing making 600+rwHP, as Adam again stated, so I don't think that's the problem. The 66mm wheel should be more than sufficient for making ~550-575rwHP which was/is my goal, so unless the turbo isn't what it's supposed to be, I don't see a problem with that. My filter is pretty beat up, but it has made 550rwHP on the previous owners set-up. I'll get a new filter on there just to be safe, just need to find the part number on there.

As for my exhaust set-up, it's running on the stock cats. The stock cats are a restriction, but not enough to make it this down in power. Again, there have been others with stock cats that have been able to make a ton of power. One that comes to mind is a TT C5 rear-mount with stock cats that is making over 700rwHP. Other than that, it's just the exhaust set-up that comes with the STS.

Things I'm looking to change:

1. Spark plugs
2. Dual springs
3. Filter

As for the intercooler, is there a way to test if it's clogged or not? The STS intercooler is pretty efficient for what it is and does fabulous. I don't think the unit is the problem, but if there's a clog in there, I could see that hurting it. How would I look into this more?

HydroStream6

iTrader: (16)

I don't exactly how your intercooler is setup. I didn't use the STS one because I didn't want to pay a G for it, so I made my own using a Precision core from eBay. If it comes off easily it would be easier to check. I know for me to take mine off I'd have to pull the front bumper and crash bar.

Like Mike said also about the cam perhaps being a tooth off, that is a possibility, don't know how easily that would be checked though. I would start off with some TR6 plugs gapped at .025" (yes this is small but it would rule out blow out), some dual springs (again you can get them from NEP pretty cheap and then sell your 918s for $100 on here), run some ground wires to each head right from the battery, and then go from there. All of these things will only end up costing you like $200 and even if it doesn't fix the problem they're good to have anyways. I know you have at least $250....

Dbluegoat

stock cats on a rear mount? BIG NO-NO

Frostbite

iTrader: (14)

Hey Brian, sorry to hear you are having problems with the turbo. I never had a chance to run with that turbo, but I did get it from someone local that I know. He had it on a 302 foxbody and I can personally tell you the car ran very strong. He upgraded to a 76mm and a boss block, which is how I got the turbo. Let me know if there is anything I can do to help, hope everything works out.
Chris

HydroStream6

iTrader: (16)

I ran the stock cat's for over a year while making 550rwhp... with no problems. It's not the best for performance but it's not what's killing him.

Actually the stock cats saved my turbo when I blew a ringland way back when... I took them off and dumped out the pieces.

RW99

Was boost constant across the powerband? And is this an auto or stick? What type of BOV?

9ball

iTrader: (6)

At first no, but after we got things set, it spiked at 9 and stayed consistent at 8, nothing out of the norm. That was the run displayed in the dyno.

It's an M6

TiaL BOV that comes with the STS kit.

LASTLS1

iTrader: (7)

I agree.

HydroStream6

iTrader: (16)

I am running an STS setup on a 04 GTO on the same dyno that he ran on and I put down over 550rwhp on a T60 with a .81 and a T70 with a .81 with 918 springs last year... not saying you're wrong but considering we have VERY similiar setups and I didn't expierience these problems I'd vote against the turbine housing and the turbo. I still say springs.