Adding punch to the Solstice GXP ?

Montanez · 10-13-2009, 04:09 PM

Folks,

I've got a 2008 GXP and have had a blast with it this summer... However, seems that every time I pull up to a stop light there is somebody with a big-V8 making noise and generally asking for it... (the Solstice seems to bring that out in almost everyone who pulls up next to me at a stop light)

Problem is -- I always feel like I need to go home and get the 02 Firehawk out from under her blanket in this situation cuz the Solstice 'looks' bad but is just a bit lacking on the 'launch' factor --- you know stop-light to stop-light....

So... I'm researching a bit to add some punch to the Solstice... I'm thinking

1) Pontiac Power Upgrade:

Accessories Details

2) An Air intake upgrade:

Not sure why I'd pay so much for the GM one VS a 3rd party....

Accessories Details

DEJON | Powerhouse

Looks like you can save some cash with the dejon version...

3) Exhaust Upgrade

Accessories Details

I was looking for something like the Loud-Mouths that I added to my Firehawk (from SLP Performance Parts) --- any suggestions?

4) Intercooler and Pipes.... from Dejon

5) Custom Map - thinking I"ll get the Trifecta

So questions...

1) Any benefit from GM intake pipe over the Dejon one?

2) Can one purchase the new sensors and NOT buy the GM tune? Thinking if I'm going to go straight to a custom tune might save a few bucks there somehow...

3) Any recommendations on exhaust upgrades? What are folks doing?

4) Are there alternatives to the Dejon intercooler/pipes? I didn't find any thought I'd ask...

5) If I stop short of the Intercooler and a custom map will I be 'happy' with the intake pipe, exhaust, and GM re-tune/sensors?

What do you guys think???

-MM

turboman808 · 10-19-2009, 11:21 AM

intakes pipes don't do anything. I bought a set because they look cool.

Someone posted a really hot setup that is very inexpensive.

Turbo wheel upgrade-I think bald turbo freak does this
custom tune-I went with trifecta myself
exhaust and hi flo cat from solo
and finally intercooler

Guy had some real impressive numbers. 335hp and 350lb at the wheels I think I remember.

I really don't think a cai does anything except make alot of noise.

I just did the solo exhaust and cat last friday. I am waiting for Vince at trifecta to update the tune for me so I can take advantage of the new exhaust system.

wspohn · 10-19-2009, 12:04 PM

We are told that the basic programming for this engine is torque based and that no mods you do will have any effect as long as that is so.

You can boost the torque limit up to 340 ft-lbs from 260 with the GMPP upgrade and that allows you to keep whatever warranty coverage you still have (another 4 years on power train?) but don't bother with any of the other upgrades until you go after market tuning as you won't get anything out of them - well maybe a bit of top end power, but nothing that exceeds the new torque limit, apparently.

Even then, the lowest bang for the buck are IC and IC pipes and intakes. Removing the stock CAT is the best value and a lower restriction muffler (which only comes with a whole new exhaust system) then becomes worthwhile.

The GMPP retune is a big step forward and you might be happy stopping there. If you aren't, you can go further (several tuners work with the upgraded sensors) but they can also work with the basic sensors as well.

mistergib · 10-19-2009, 12:07 PM

Quote:

Originally Posted by Montanez

Folks,
I've got a 2008 GXP and have had a blast with it this summer... However, seems that every time I pull up to a stop light there is somebody with a big-V8 making noise and generally asking for it... (the Solstice seems to bring that out in almost everyone who pulls up next to me at a stop light)
Problem is -- I always feel like I need to go home and get the 02 Firehawk out from under her blanket in this situation cuz the Solstice 'looks' bad but is just a bit lacking on the 'launch' factor --- you know stop-light to stop-light....
-MM

Careful....better check what the penalty is if the "man" catches you
between stoplights.....here in Denver, my understanding is that if you
are caught street racing, along with a huge fine, THEY TAKE YOUR CAR!
That's been enough impetus for me to refrain from the stoplight drags....
Just wanted to give you a heads up, hate to see you lose your ride....

Morfious · 10-19-2009, 12:10 PM

Tune, exhaust, hi flo cat. Air intake if you want to look. sound cool. This will be all you need to get going in a hurry! If that's not fast enough, then you have to get into turbo upgrades. Intercooler will help with bigger HP possibilities, but will not give you a bunch more HP in and of itself. It will make adding HP bit easier to come by though.

gmhopeful · 10-19-2009, 08:21 PM

Not sure what the issue is. My GXP, with Stage II GMPP Tune, Solo Street Race exhaust, and GMPP CAI, is noticeably quicker than my 2002 FH ever was. See that car here.

Sold the Hawk on Dec. 26, bought the GXP on Dec. 31. GXP doesn't have the V-8 rumble, of course, but in every other way, it's much more fun, and quick and nimble.

SCCA HP Racer · 10-19-2009, 08:48 PM

Quote:

You can boost the torque limit up to 340 ft-lbs from 260 with the GMPP upgrade and that allows you to keep whatever warranty coverage you still have (another 4 years on power train?) but don't bother with any of the other upgrades until you go after market tuning as you won't get anything out of them - well maybe a bit of top end power, but nothing that exceeds the new torque limit, apparently.

I don't think this is true. The torque curve of the GMPP tune is no longer a plateau at a certain level, it now has a peak. I also read that any upgrade you do after the GMPP tune results in more power. It removes that torque limit, not raises it.

Anyway, a tune is where to start.

wspohn · 10-19-2009, 09:01 PM

Quote:

Originally Posted by SCCA HP Racer

I don't think this is true. The torque curve of the GMPP tune is no longer a plateau at a certain level, it now has a peak. I also read that any upgrade you do after the GMPP tune results in more power. It removes that torque limit, not raises it.

I had thought the same way you do, until two tuners told me otherwise. Apparenty torque limiting is fundamental to the GM program and the only way you can program around it is to raise the torque limit values in the program up above any reasonably expected real figures.

Perhaps a tuner may see this and comment.

MF656174 · 10-20-2009, 10:39 AM

Quote:

Originally Posted by wspohn

I had thought the same way you do, until two tuners told me otherwise. Apparenty torque limiting is fundamental to the GM program and the only way you can program around it is to raise the torque limit values in the program up above any reasonably expected real figures.

Perhaps a tuner may see this and comment.

I'm not sure if im understanding this correctly...So the gmpp tune doesn't have a learning feature?

wspohn · 10-20-2009, 11:29 AM

Quote:

Originally Posted by MF656174

I'm not sure if im understanding this correctly...So the gmpp tune doesn't have a learning feature?

Apparently (and disappointingly) I was told that the GMPP tune simply raised the 'allowable' torque figure - by a large amount, mind you, from 260 to 340 ft-lbs, and that it still limited you to that, thus mods won't have any further effect. But the learn down appears to be intact, it is just the point to which it goes down to that has changed, if I am understanding the program geeks correctly.

I'd love to see some independent confirmation of that. For instance, we know that with the basic tuning, no mods give you any increase in torque, so adding that exhaust system changes sound but not power. I chose exhaust because that is one area where solid improvements are possible, unlike CAI etc.

So if anyone has a GMPP tune car and has added a free flow exhaust system and has a dyno curve that shows more than the 340 ft-lbs., I'd be happy to go back to the tuners and ask how that can be!

And despite any limitations of the GMPP tune, I still love it compared to the stock 260 BHP tune!!!

SCCA HP Racer · 10-20-2009, 11:55 AM

Then I would expect to see a plateau on the torque curve unless they conveniently made the learn down start where the natural peak of the curve is, which I suppose would be possible...

Many folks have adjusted the wastegate rod and not experienced a learn down with the GMPP tune.

Yes, we need confirmation! Someone prove it!

Lithium Lotus · 10-20-2009, 11:55 AM

Swap an LS7 into your Solstice, problem solved

wspohn · 10-20-2009, 12:00 PM

The other thing that I have wondered is how the ECM reads torque. Are there torque sensors in these things? What do they look like?

Smokescreen · 10-20-2009, 08:12 PM

Swap whatever you want. Change out everything, but think twice at that next red lite next time when that "Loser" revs his engine. Keep the racing to the track. If you screw up and kill someone, you'll never recover from the guilt. Street racing is for "Losers"

Montanez · 10-20-2009, 08:58 PM

Quote:

Originally Posted by gmhopeful

Not sure what the issue is. My GXP, with Stage II GMPP Tune, Solo Street Race exhaust, and GMPP CAI, is noticeably quicker than my 2002 FH ever was. See that car here.

Sold the Hawk on Dec. 26, bought the GXP on Dec. 31. GXP doesn't have the V-8 rumble, of course, but in every other way, it's much more fun, and quick and nimble.

I guess I need some upgrades in the Solstice then cuz right now cuz my 02 Firehawk 'feel's much faster/stronger on the launch....