Originally Posted by Hiboost

So it looks like some turbos are having issues, what doesn't make sense is that if the hotside is unbalanced due to size then why isn't it effecting all of the turbos? Are you saying unbalanced due to compressor to turbine wheel ratios (which seem similar to other GT30 setups) or unbalanced due to the relatively large hotside housing compared to the compressor side?

I guess the only way I can see these turbos lose power due to design would be dropping way below the 58% efficiency islands somehow due to some strange pressure dynamic. You would think having a larger than normal turbine side would be similar to having it ported a little big and would expect the top end performance to be better with some more spoolup lag induced, not reduced power and inefficient boost.

Boostd4: I noticed you had no upgraded O2/Downpipe piece but you wouldn't think reduced flow out the exhaust side would cause this much trouble with the turbo's output.

Maybe a casting flaw inside the turbine or compressor side is blocking flow? It's the only other thing I can think of that would destroy efficiency at higher flow levels. That is besides the wheels being out of balance in some way or not flowing correctly with the housing design.

Finally is there any way of telling if your turbo is going to be "good" or "bad" before installing it?

Originally Posted by Boostd4

If it was a limited run, why would they allow units to get to consumers before going into full production? I was able to get one quite easily through one of their normal distributors. Hell, it's the splash screen on their website, anyone can get one if they want to! There are a few vendors that have posts in the for sale section right now with these turbos...

It would have made more sense to let just a beta group test the turbo. Some of the companies "testing" this turbo haven't even tuned it yet, even though those same companies are reporting shining success.

Please post whatever info you have of this car on a dyno...because honestly you are the first person to have mentioned any type of success with this turbo. If you can back it up with any kind of dyno data, my faith will be at least somewhat renewed.

Originally Posted by evo400

Already posted a dyno plot some pages back .I can assure you there is not a single unsold unit out there with any vendor ,get on the phone and go try by one !. The first batch was allocated before it even hit the trucks !!! The turbo is fine and works awesome along with low turbo speeds and low back pressure numbers that all point to one bad *** turbo from Garrett .

I have a turbo speed vs rpm jpeg on the other laptop ,let me go find it !

Originally Posted by heavyD

So the people here that have installed them have problems with the turbos not making power and a few people/vendors saying that there's nothing wrong with them and there are a bunch of cars running around with these turbos making big power with no problems except no dyno charts to back it up nor have any of these people chiming in to note their success. The only conclusion I can draw from reading this thread is that these turbochargers are $2K paperweights.

Originally Posted by evo400

Boostd4 back on page 23 is our dyno plot . Just reading about your problems . In case's like this its sometimes best to go backwards to reset the data you guys have . Replace all the stock stuff you have and baseline the motor. Hopefully this will raise a problem for you and you can move forward once you determin the problem .

Just for your info we used a M800 ECU with 3000 bucks of sensors on the car with exhaust back pressure Garrett turbo speed sensor on the compressor wheel ,intercooler pressures temps etc etc . We installed the sensors on the base car with stock turbo etc etc so we can see exactly what the car has done and why . The turbo speed on the Garrett is actually lower than stock ! the exhaust backpressure is also less than stock . We have the awesome Deatschworks 800cc injectors in there too!

Good luck .

Originally Posted by evo400

If its a turbo fault I would be suprized . No mirrors here as we tested independant of Garrett . This is why we fit so much data equipment so we know what is actually going on ! .If a turbo is Trash we spot it almost first couple of runs !

Good luck with the quest .

Originally Posted by strocse

I call bs, post a vid of it in the car then walk around get in and give us a pull.

Originally Posted by TTP Engineering

In the video there has to be your mother, a police officer, a pastor, a prostitute and a painter all giving the thumbs up. Then he will believe you.

Originally Posted by Boostd4

Unfortunately, it seems like the turbo is the issue. With the exception of basic bolt on's, the car is stock. If anything, the bolt ons should help the turbo make power more than anything else. We've already gone through a battery of tests on the car...last test is looking at the turbo itself.

And before it even comes up...I'm dealing with probably one of the most well known and respected tuners in the US...

More than likely I'll be yanking the Garrett out this week and putting in a Dom2. My prediction...the car will make plenty of power.

And you still didn't answer my questions...where are the success stories and maybe some vids of your car on the dyno? Your responses are just like the distributors I've spoken with...smoke and mirrors.

Originally Posted by SiC

Dom2 = Great choice, I currently have one in my car. Be sure to back off the wastegate accuator spring since the initial preload is set to about 27psi and it holds to redline. I adjusted the preload to have initial 24psi so it gives me more room to play with.

I also have a GT3076 sitting as a big paper weight......