HP/TQ with GMPP Tune...

Howster · 09-01-2009, 02:58 AM

Hi all,

I assume the range will be varied due to mods and gearboxes, etc, but just wondering what numbers people are seeing with the GMPP tune. Not so worried about mods as I have a number of them myself. Has anyone seen over 300 rwhp with the tune yet? Thanks for the info.

Howster

nester · 09-03-2009, 11:32 AM

I was under the impression that the K04 just wasn't going to hit 300whp without spinning the thrust bearing out of it..

kwtoxman · 09-03-2009, 12:03 PM

There lots of people on the cobalt forum well above 300whp on the stock turbo. FWD will dyno higher, but it seems that the trifecta tune may be able to get the solstice 2.0's above 300whp. The turbo appears to be pushing awefully hard for that so I wouldn't expect a ton of life out if it.

AFAIK NO ONE with the GM tune on the solstice is pushing above 300whp. In fact, NO ONE WITHOUT an upgraded turbo is pushing above 300whp regardless of tune. But the trifecta may change that.

nester · 09-03-2009, 12:25 PM

Yeah, I can't imagine that turbo will put up with that abuse for long at all.. The turbo that I bought on ebay was already showing major signs of wear. This was from an 08 with 30k miles..

Assuming it was running at stock boost levels, these turbos are not very robust..

I'll know more when I get my upgrade turbo on, and can pull my stock unit apart and inspect the journals.

kwtoxman · 09-03-2009, 01:35 PM

Interestingly I just spoke with Vince at Trifecta and he says the turbo isn't overspinning, he adjusts the duty cycle of the waste gate, etc.. The load is higher, but he thinks it should be pretty reliable compared to stock.

nester · 09-03-2009, 02:12 PM

At what boost level?

What I'm most concerned with is thrust load.. The turbine wheel trying to eat it's way through the thrust bearing. The thrust bearing on the K04 is tiny.

kwtoxman · 09-03-2009, 02:17 PM

He is boosting 27 psi +. He is the expert. Certainly not me.

. Call him at trifecta and have a talk. It wouldn't hurt....

LatinVenom · 09-03-2009, 05:02 PM

I have the upgrade K04 with the larger wheel from BTF racing.
I thought something was done to it, but can not remember.

kwtoxman · 09-03-2009, 06:12 PM

Sorry Latinvenom, but ??? I don't understand

nester · 09-04-2009, 07:31 AM

Here's some comparison pics of the internal components, and why I'm skeptical of the longevity at that high of boost..

First pic is a TD05 bearing housing and thrust washer, compared to what's in our cars..

Second is a side by side of the SRT4, Solstice, and TD05H turbine wheels and their thrust washers.. The numbers are the inducer/exducer measurements of each wheel.

Third pic is a **UPGRADED** SRT4 (TD04LR) thrust washer, after someone put 357whp to it, at ~21-22psi.

Howster · 09-04-2009, 11:13 AM

I definitely understand the inherent problems that can occur when parts are submitted to longtime abuse, especially when those parts aren't built to tolerate that abuse. That is the very reason I have purchased the GMPP tune. I like the idea of this kit not voiding the warranties, so I feel a little safer. I don't submit my car to much abuse at all, but sometimes when out on the back roads I like to play a little. I don't even have the tune on the car yet, but like the idea of a sports car being, well, a sports car. I am used to having much more powerful vehicles, and the GXP, even with 260 hp, isn't really what I expected it to be. So with the upgrades I have I feel I do have a vehicle that just might be a bit more worthy of being called a "Sportscar". Many may not agree, but with the experience I have from building hotrods and European sports cars for many years, this car, although it can be fun to drive, is not a thoroughbred. We all know that, and that is fine. I may oneday drop in a V8 and then we may get somewhere, but until then, I will tweek and play and just have a little fun while I can. I do think the Solstice is up for that. Thanks to all for your input.

P.S. I think if I go with a larger turbo or upgrade the stock one, that does void the warranty, so I will leave that alone for now as well. Have a great Labor Day weekend everyone.

Cheers,

Howster

LatinVenom · 09-05-2009, 12:14 PM

I do not know if BaldTurboFreak still reads this forum post, but I believe the upgrade wheel size is about 2.0...
I thought the place he send the compressor to have all the balancing done etc also did something to the thrust bearing but I can not recall.
He also answer my question about the flow and he said it 38lbs/mn vs the 34lbs for the stock K04. I thought it was 41lbs/mn and not 38lbs/mn unless I have it backwards.
All his posts were erased when he was no longer a supporting vendor, there was a lot of good information in those threads.