I was just sitting back watching the back and forth, I was actually learning some things. Its interesting to me because my brother has a bonneville GXP and we have this argument all the time. Im gonna takes some pics of both of them together this weekend and put them up.
But one fact is true, and thats these are completely different cars and comparing them is not the easiest, except the fact they both wear the GXP stamp! ]
I promise i'm gonna put a vid up in the morning. i have been compliments daily since I got the car. If anyone has ever heard a GP GXP with a modded exhaust they know it sounds amazing. My girlfriend says she can hear me from almost two blocks away however its not obnoxious either. I hope the video does it justice!!

Can't wait.

And for the record, I never compared both cars. They are very different and both have somewhat different purposes. I was simply clarifying things about the northstar and explaining why some of them are known to be unreliable since that'* one thing that drew the OP away from them. I'm not trying to say his purchase was stupid, because I love those cars as well and given the right opportunity I would buy one myself as well. The only fault in the GP GXP is the transmission.

The shortstar mentioned earlier for example has the same head stud problems that other earlier northstars do. Since it seems people are up for some learning, I'll outline the problem.

These are aluminum blocks with aluminum heads, so for structural purposes, cylinder head studs stick out of the block, and the heads are tightened down with nuts. On older model engines, the bolts were short and fine threaded. Fine threads will eventually start to rip out of the aluminum block, causing head gasket failure. GM tried the same with longer studs, and that improved things but ultimately did not solve the problem. The solution to every person who gets a head gasket job done on a Northstar (and they are rather few), is to use longer coarse thread studs, which do not budge. To my knowledge, the LD8 in the Bonneville GXP'* uses long coarse thread studs, so that'* one big improvement.

As for their ability to take boost, well, that'* a discussion for the brainstorming section as I could go on all day about that.

In my mind, they're comparable. They are a Pontiac Bonneville and a Pontiac Grand Prix with GXP badges. In theory, they're more alike than the 92-99 Bonnevilles and the 00-05 Bonnevilles.

Just because they have GXP badges doesn't mean they are on the same level, now you wanna tell me that the pontiac solictice is also something to be compared to the bonne gxp just because they have a GXP badge on the doors and trunk
One is luxury sedan and one is sport sedan, that'* like comparing water to fire because both have an oxygen badge with them

I'm not going to tell you the Solstice is on the same level. It'* not the GXP badge - it'* the GXP badge on two four-door sedans with V8s, front wheel drive, and other similar features including the layout. The Solstice GXP is a 2-door sporty thing with an L4, RWD, and not too many similar features including the layout.

The GP GXP is more raw. Its more of a muscle car than the Bonneville GXP. It has a better front to rear weight distribution for traction, and also has wider tires up front in order to reduce understeer. It has a stiffer suspension, more power at low RPMs, more performance-oriented seats, and is based on the w-body platform. Its not as large as the Bonneville GXP, and not as refined. It is targeted toward a younger audience than the Bonneville GXP is.

The Bonneville GXP is more refined. It has less bottom end power, yet it revs easily, and has a proven reliable 4T80E transmission. It'* a larger car, has a higher quality interior, is built better than a w-body all around, has self leveling suspension, projector foglights, softer seats more geared toward casual or cruise driving, and has better safety ratings than the GP GXP. It requires 8 quarts of premium synthetic, runs on premium fuel, and sports a stabilitrak stability control system taken directly from the cadillacs. Even if you turn off traction control, you still can't spin the tires from a dead stop. Its not a raw muscle car.

The two are very different, and while their performance in the 1/4 mile is pretty close, that'* one of the few similarities they share.

something is wrong with your car

They are both kewl, I can adapt paddle shifters to my 2500 HD LB7 So I am pretty sure someone can make then work on the Bonneville...

And remember the Bonne GXP was lets say it was the V8 test mule fir the GP

this shouldn't be a comparison, yet a friendly discussion

A comparison can be a friendly discussion!

Well I can lose traction, but only for a certain amount of time, lol. I can't light them up I guess is what I was trying to say.

And yeah, it is a friendly discussion. I just figured it was relevant, and at the least interesting. We have to do *something* while we wait for those videos, lol.

And i still say the SSEI out performs.. Hehehe.. and no one can argue with its reliability and aftermarket support from manufactures.