I was really thinking about selling my car and upgrading to a G8 GXP when it comes out next year, but I could just buy this and it will out perform that car without a problem if my research is right. I just want to know if anyone has put this on their car and what else i will need to do to my car when I put on the Turbocharger.

 

You can run it with just whats in the kit, but you need a good tune.. You may need to upgrade you valve springs. You will probably get into the 11's with drag radials thats a lot faster then a G8 GXP. But the G8 is rear wheel drive and the GP is fwd, so you got to think about too. There is already a supercharged G8 thats probably fast then a turbo GP GXP

 

There is also the issue of how well the GP GXP's trannie will handle the turbo. They aren't exactly the best trannie GM has ever produced.

 

Unless you're going to drive like a granny, you will need to upgrade the tranny. I think gxpjay still has the stock tranny, but I'm not sure that he really beats on the car. I wouldn't trust it personally since these trannys have failed on cars that are stock.

Really, I think it would be a no brainer to go with a G8 GXP(provided you like the way they look, of course). RWD and an M6. That would be a much more fun car to drive. And it's not like you wouldn't be able to easily get a G8 GXP to outperform a turbo Grand Prix GXP. Plenty out there for the LS3. There's even a twin turbo kit available for the G8 GT which would run circles around a turbo LS4.

Besides, it's not really fair to compare a modden car and say it will be faster than a stock G8 GXP(or stock anything). A turbo LS4 running in high 11's is faster than a C6 Vette. Would I take a turbo LS4 over a C6? Hell no.

 

No, GXPJAY's tranny was rebuilt to handle the power. He was looking for $2000 for it when he attempted to sell the turbo earlier this year. Not sure what was done but if you dig up his turbo thread, I'm sure he mentioned what they did.

 

https://ls1tech.com/forums/showthrea...ighlight=turbo

 

Ohh yea I completely forgot that he had it built. Well then, for the OP, there's what you'd need in addition to the turbo.

 

Has anyone around here bought the car tuning kit? I'm just wondering if anyone even bought one?

Looking over the pricing call it 7 grand for a full job (factor in the trans) and I'm a 1/5th of the way to a G8 GXP. Turbo or G8 GXP, hmmm not a tough call.

 

in my opinion its a waste of money. bye bye 100,000 warrenty and hello unreliable car, unless you have a 2nd car to drive

 

I don't think anyone has it besides GXP JAY. I think everyone thought it was going to be a super hit...now it kinda died out.

 

It will happen in a few years just like it did with the 97-2003 body style, people will realize you can buy a W body for cheap, get a turbo kit for cheap and have a car that out powers pretty much everything on the road (in a straight line anyways).

I absolutely LOVE this car, I've thought of selling and I try different cars but you will never get everything in one package like this car has. (Comfort, space and raw acceleration performance)

 

I would be a little nervous about tackling such an upgrade. Plus the dent on the pocket book is rough.

 

As soon as i find a good shop to build my transmission and do tuning for me, i'ill be boosted too, sucks living in a small town.. I

 

I am planning on it. Just need to save up for both the tranny and turbo at the same time.

 

It's just too expensive. Turbo kit + Tranny is going to run you 8-10k with labor. Couple that with warranty issues...yeah. It's gonna be a bit before we see people do it imo.

 

Dude just buy the G8 or hell if you have to have a 4Dr car I'd seriously look at the Charger SRT8. Go check out their forum, those things are putting out 425hp stock, and with a few simple bolt on mods it jumps way up, plus it's RWD!!!

 

The chargers tranny is sloppy my father has one i dont like the way they slip in between shifts my imp shifts harder and smoother than it plus that thing is well over 4klbs the G8 looks better imo and will prob run just as good or better than it but hey to each his own just my .2

 

It's all about being different

 

I purchased the kit from cartuning in june it was finally ship end of sept and installed 2 weeks later. everything came with the kit. i have put 2500 miles on it so far. not one issue. still many upgrades to make. running 5 lbs of boost right now. Car is MONSTER. Changing valve springs turning up the boost and dyno tune jan 17th 2022.

everything if still factory on the car except for what comes with the kit. nobody messes with ya on the road....thats for sure. and the ones that try and pull something you just need to step on the gas and there heads explode cause they never though the car has the raw power that it does. This thing is a FWD LS4 MONSTER!!

just wanted to add put michillan AS4 sport on the front end. absolut3e glue on the pavement.

 

I bought the kit this year. Still factory tranny. Its better to drive it in manual mode tap shift. The turbo is a wicked drive. That G8 with the 6.2 L is very nice!! Putting 10 lbs of boost on the LS4 is right were it needs to be. The G8 is left in the dust. The Grand Prix is also 600 or more pounds lighter.