Pontiac Solstice Forum banner
1 - 20 of 55 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #1 ·
Good Morning All,
I am new to the forum, so my apologies if I am doing this wrong.

I am the proud owner of a 2008 GXP with about 37,000 miles on it. I purchased it stock and in the last few months have done the two upgrades that I had always intended to do. First one is the GM turbo upgrade. It was installed by the only shop in the area with a DYNO.
My graphs before the tune where about 240 whp. and 240 wht. with about 15 psi.boost Quite a bit different than the advertised 260. Nonetheless after the install they where able to push it up to 273 whp. and 310 wht. with 25 psi. boost. Shortly thereafter I got the dreaded check engine light. A few weeks later I dropped it off to the dealer to reset the RKE at the same time I had them read the check engine code. It came back as an old code. Not sure what that really means. Anyway they reset it and in the meantime I ordered the Solo Performance catless downpipe. Sure enough the light came back on and over to the shop I went to have the pipe installed. This is where it gets good.. After the pipe was installed the cars performance shot up like a rocket. It graphs at 301 whp. and torque was at 395. Here is the bad, my guy at the shop couldn't leave it there as it was burning up the clutch. He had to drop the torque down to 314. Of course he reset the engine light yet of course its back on. What I've always been hoping for was to get everything I could get out of this little 2.0 without destroying it. I was hoping for about 310 whp and about 340 wht. and to have that without any orange lights. Any thoughts any suggestions would be appreciated.
Thank you

BTY I live in upstate NY
 

·
Premium Member
Joined
·
17,541 Posts
Welcome to the forum

The before power numbers listed are correct for a stock motor. 260 is at the flywheel. There are losses in the driveline that result in the lower numbers for WHP.

The stock tune is torque managed. It changes engine parameters to achieve 260 ft pounds and the HP is a result. The factory rates the engine at 260 HP but as I say, that is not how the tune functions.

Which tune did you have installed? Westers, HP tuners?

Did you change the sensors?

My car had the solo high flow cat and the GMPP tune. it measured 305 WHP on the DDM dyno with 340 ft pounds.

All dyno's are relative not absolute so while the graph shows 301 if you take it to another dyno it could show 290 or 310. Don't get too excited about any specific number. Its a good indicator but is a better tool to measure the impact of changes. Some give a higher number, some a lower number.

Good luck in your search for more power. Talk with Werks and DDM about a higher capacity clutch.
 

·
Registered
Joined
·
4,886 Posts
Yes, with a GMPP tune, it will come back down, ....IF.... the torque parameter is set lower. The HP and torque are controlled and set by your ECM. So if you have a GMPP tune, I believe (IMSMC) torque is set to 340. SO.....anything over that 340, the ECM will learn-down to 340....

Now MKJ, if you have a "good" tuner, he knows how to limit the torque and let it come in toward higher RPM. You don't want full boost numbers early on in the rpm range!!! My car is set that way. Most tuners will even limit the amount of boost to control the torque in 1st gear! The OE and GMPP tune do this. I believe it's limited to about 10psi in 1st gear IMSMC. My tuner set my car up so that my full torque isn't until around the 3500+rpm range. A good tuner will NEVER give you 100% torque, or allow the car to build torque too quickly. What happens when they do this? Excessive clutch wear and burning the tires off the rear end. So, with that said, I am perfectly happy with my tune bringing the torque in at upper rpms. One other thing I learned is if you are calling for all HP and torque, NEVER turn your TCS off!! These cars are like go karts and unless you have cat like reflexes, they can easily get you in trouble and come around on you quickly because of the short wheel base....
 
  • Like
Reactions: Rosscoe

·
Registered
Joined
·
1,461 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #6 ·
Thank you all for your input..
I have the GMPP tune. New air flow sensors with the actual plug and play kit. I didn't want any splicing. The shop where I take the car has all the GM computer hardware and a dyno. In three months I have never lost the power or the boost. I am thrilled with the performance but truly was looking for that 340 torque that some of you others have gotten.
 

·
Registered
Joined
·
7,668 Posts
Torque doesn't burn up clutches, bad driving does.
There are lots of guys with modded turbos with more torque than that that use stock clutches with no problems.

There is a limit - if you do drag racing starts, you will need a different clutch. If you are tuning to really high torque levels, you can exceed the limit of a clutch and need an upgrade.

But if you drive properly, you aren't going to burn anything up with a tune on a stock car with a CAT delete downpipe.
 

·
Registered
Joined
·
4,886 Posts
Thank kwtoxman....I couldn't remember, thus the IMSMC.... Now MKJ, if you want to see 310bhp, you need an IC and HFC. Those 2 pieces should get you there. I saw 298bhp on 2 pulls and he had to back mine down because I have neither and the car was getting too hot with some engine knock. He said if I had both, I would have easily seen 310-320bhp.... If you have a weak heart, NEVER watch someone dyno tune your car!! And take ear protection....especially if you have aftermarket exhaust!
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #9 ·
I'm pretty content with the 301 whp. That does seem adequate. The torque that I have 314 to the wheels seems off considering it could be as high as 395. I agree not sure how serious torque has much to do with a clutch. I don't want to mash on it and just go spinning like a top but I think 340 torque to the wheels shouldn't be a problem. It is the only shop around. If anyone knows of another in the Binghamton/southern tier area of New York I am open to suggestions. Same thing for the check engine light. Came on after the GMPP tune and before the Solo downpipe. I'll have to bring it back in and see what the codes are. Totally agree on the DYNO tune. Sat there in tears waiting for it to blow up.
Thank you all for your help, it is a appreciated
 

·
Registered
Joined
·
4,886 Posts
Torque has everything to do with clutch failure even if you know how to drive a stick. Your clutch can only hold so much "twist" before it starts to slip. When you start to slip the clutch when it's out 100%, especially at higher pressure, your clutch fails much quicker. The factory clutch is only good to so much torque because the springs can't put enough force on the flywheel to keep continuous grip and not let it slip. So your at 3500rpms when it slips and jumps to 4800rpm. that's 1300rpms of slippage at 100%!!! So 2 scenarios for you:

1) A vehicle that has 400 ft/lbs of toque, with a clutch that's rated for 350 ft/lbs. When you hit that 400, the clutch will "usually" slip, even when it's 100% out.

2) A vehicle that has 300 ft/lbs of torque, with drag radials that won't allow the tires to slip....your clutch will give out!!

There are many factors that go into clutch failure, but you get the jist...
 

·
Premium Member
Joined
·
17,541 Posts
Actually the GMPP tune does learn down. But for most situations you just don't experience it. The software is not changed by the GMPP tune, the data tables are changed. The GMPP tune data tables start at a higher level and they have increased tolerance before it limits power increases but it does.
 

·
Registered
Joined
·
1,461 Posts
Actually the GMPP tune does learn down. But for most situations you just don't experience it. The software is not changed by the GMPP tune, the data tables are changed. The GMPP tune data tables start at a higher level and they have increased tolerance before it limits power increases but it does.
What a ridiculous point to make. Since the GMPP limits are set so high as to not have any learn down on the stock turbo with any mods, to play devils advocate in a description that does not physically exist is just idiotic. Let's call a spade a spade.
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #13 ·
That makes perfect sense Ghost, I appreciate the explanation. Still the question persists, if others are getting 340 torque with a standard clutch, I would like to as well. I will run it back down to the shop and try to get the bugs worked out. Hopefully Tom my technician can zero it in. He did smooth out the power band after the downpipe was installed. Bottom line I'd like get the 300 hp and the 340 torque without the check engine light coming on, or having to do major upgrades. I think everyone agrees that is reasonable and doable. Right?
 

·
Registered
Joined
·
7,668 Posts
The factory clutch is only good to so much torque because the springs can't put enough force on the flywheel to keep continuous grip and not let it slip. So your at 3500rpms when it slips and jumps to 4800rpm. that's 1300rpms of slippage at 100%!!!
The point is that it won't do that on a stock clutch even with a turbo mod, if you avoid slipping the clutch on starts. Stick 500 bhp in front of it and even tippy-toeing may well result in slippage, but anything under 400 shouldn't unless you have

a) bad driving habits
or
b) clutch linings already glazed from previous use (see a above)

We can agree to differ, but I have seen so many clutches toasted by people that either don't know or don't care about driving so as to avoid problems.

I raced for 30 years and never, ever had to change a clutch due to slippage, despite running twice stock torque. It was road racing and didn't require standing starts. Obviously the drag racers better have a spare clutch in the tool box, but that sort of abuse is avoidable/optional in street driving.

BTW, I use a stock clutch on a 375 bhp/375 Tq Solstice and expect not to have any slippage issues - the slippage is in the tires when I boot it!
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #15 ·
It is very possible there is glazing from the original owner. At 50 years old and driving a tractor trailer since 1988, Id like to believe it's not me. At least I can say I have never had transmission issues in any other vehicle.
 

·
Registered
Joined
·
7,668 Posts
It is very possible there is glazing from the original owner. At 50 years old and driving a tractor trailer since 1988, Id like to believe it's not me. At least I can say I have never had transmission issues in any other vehicle.
You are probably a better gearjammer than 98% here.
I bet you do have some glazing - what a pain!

If you end up changing the clutch anyway, then there is no reason not to go to one with some added margin. Talk to Dave at DDM.
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #17 ·
Thank You wspohn
I will let you know how I make out. I do wish there was an alternative to the current technician. Good guy seems to really know what he's doing, but this is like my child and it never hurts to get a second opinion.
 

·
Registered
Joined
·
7,668 Posts
Thank You wspohn
I will let you know how I make out. I do wish there was an alternative to the current technician. Good guy seems to really know what he's doing, but this is like my child and it never hurts to get a second opinion.
I know what you mean. I always did all my own work building race cars and enjoyed it, but with bad knees and the lack of a garage monkey to bring me the wrench I left on the bench when I got under the car, the inclination to do all of my own work on the Solstice was less, so I found a very thoughtful and careful tech that did a bunch of work for me on the car.

Then the bugger retired and I am still looking for someone that I trust! :frown2: For some reason my wife declines to act as garage monkey.....
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #19 ·
Just a little update.. I've taken the car back to the shop and had it slightly adjusted. It is hovering around 325 torque and 301 hp. It only hits 21 psi and the check engine light has come on and off and is, back on. The feel and the performance of the car is outstanding especially around the curves, which is one of the main reasons I bought it. I eventually have to figure out the check engine light which they tell me has something to do with evap system. For now though, I just enjoy it. I love this machine for what it is. Fast, agile, and beautiful. Ill never understand the person who buys this and is interested in 1/4 mile runs. I am not judging just saying there are better choices out there for that purpose. Nor will I ever understand the owner who constantly criticizes it. I knew when I bought it, it was a Pontiac it has it's issues!! Never mind the fact that they where phasing them out.
Thank you all for your input, it was greatly appreciated.
 
1 - 20 of 55 Posts
Top