GM Roadster Tune

[Howster]

I am coming in a bit late here, but am wondering if anyone has the 'GM Roadster' tune with any upgrades like intercooler, exhaust, CAI, etc? After a lot of testing, troubleshooting, and frustration, I am still not seeing any positive outcome with my Wester tune, so looking at possibly trying either the GM Roadster' tune or the GM Stage II.

I have spoken with a service manager at one of the local dealerships and he seems very eager to assist with the cars in any way that he can. I can install the 'GM' kit myself and have him flash it, or I can have him do all of the work. Either way he giving me positive feedback. I spoke with him for about an hour yesterday and he is giving me some good info. Even going to replace the spark plugs just to make sure all is well there.

Anyway, if you had your druthers, which tune do you feel would have the best support/service after the sale? I guess I am just a little skiddish since I have been having such a difficult time with my car. Lyndon has been great, but we just can't seem to get the glitches sorted out. Many of you have been great at answering questions and relaying information, which just shows there are a lot of really good people driving these fun little cars. It would be great to meet some of you, but work just doesn't allow me the opportunity to travel out of my area just now.

Any folks in and around San Antonio, Corpus Christi, or Texas in general-it would be fun to meet and have some fun. I'm not from Texas, so meeting some folks sure would make my recent relocation a little easier.

[LatinVenom]

Howster,
I truly believe you need to try another ECM, or just do what it was suggested by another member.
Have the Dealer flash the ECM that has Lydon's tune with the standard GM Factory Flash.
Then take the original ECM and send it to Lyndon for a reflash and see if the problem still persist. This to me is the best way to proceed right now. If that fails then I would go with the GMPP stage II, this way if the car still acts up you now have GM to blame.
At this point then GM and the Dealer can work on a solution to the problem.

[Howster]

I just spoke with the service manager at the dealership about flashing the ECM with the Wester tune. Once that is done I will have it installed to see how the car runs. If it is ok, then I will know the tune was at fault, or the car just didn't like it for some reason. If it still runs crappy, then I know the ECM is faulty and I will have GM replace it. Will let you know how it goes...

Howster

[wjptcs]

What would this tune do for a car that already has the GMPP tune?

[imaj]

Originally Posted by wjptcs What would this tune do for a car that already has the GMPP tune?

If you are referring to the Wester's tune....then nothing can be done, if you have the GMPP tune. It's one or the other.

Sorry if I misread your post.

[cooler2442]

Howster, my car makes the same sound that I believe your talking about. It sort of sounds like a bunch of fast gun shots to me and the code it would throw is something about detonation I think. My dealer ordered a new boost sensor but said its on super backorder so might not arrive untill march. I am going to go there today and talk to them about it since there making me drive the car for 1month+ when it makes that type of noise / misfire almost daily. I will mention to them about the spark plug thing.

[Tom0000]

Driving a car that has detonation isn't good for the engine. What type of fuel are you using? I only ask because lower octane fuels will detonate at lower compression than higher octane fuels. It might help reduce the amount of engine damage before the part can be replaced, if you use premium fuel and try not to use boost.

[cooler2442]

I am using 91 which is basically the best available in California. The misfiring / noise usually happens under hard acceleration. I called my service guy and he said that he believes that it is ok for me to drive but I am going to visit them today about it.

[wjptcs]

Originally Posted by imaj If you are referring to the Wester's tune....then nothing can be done, if you have the GMPP tune. It's one or the other. Sorry if I misread your post.

Thanks for the info. I did not know if there was a tune that could be done on top of the GMPP tune that would pull off the speed limiter and give any other benefits.

[LatinVenom]

If you are missfiring and you have a 2007 GXP you need to get the hotter plugs.

[cooler2442]

I just got back from the dealer and my service guy wasn't there so I went to the parts department and asked for a list of all the parts they ordered. 3 of the parts are already here but the 4th is on backorder and scheduled to come in at the end of February. They said they ordered an Intercooler, Intake Air pressure + Temp Sensor, Front Bumper Bracket and Spark Plugs. I asked what kind of spark plugs and they said the 09 ones. I wasn't able to ask the service guy since he wasn't in today if it really is safe / alright for me to drive it since the misfiring / sound happens daily, but guess I will go back in tomorrow. Btw Deep sorry for thread jacking lol.

[TbeaunTx]

I have the GMR tune, and the dyno (can't remember the type, but is the type that typically shows numbers 10-20% lower and more accurate than the inflated ones), read 200 whp and 200 ft-lbs trq before the tune, and 239whp, 254 wtrq after the tune with ambient temps of 90 degrees (iirc). My car is an automatic so it had more drive-train loss than a manual. I would estimate that to be around 305bhp and 325btrq. I don't have the graph at work...I can look for it at home later.

[LatinVenom]

By the 239RWHP you posted the BHP will be 287.

[TbeaunTx]

LatinVenom,

Your numbers assume a 17% drive-train loss, with the automatic transmission it is more like 22.5 from what I am told.