are these cars as good or better then the same year bonneville and is the supercharger able to produce more boost or the same ......and it has a 3800 in it aswell?

Engine wise they are the same except for a few minor differences like mounts. But power wise, the same, transmission wise, the same. The GTP is a few hundred pounds lighter, so that makes it a bit faster, perhaps half a second on the quarter mile.

also grand prixs are to be nowhere near as smooth

If you want to get the very best times: Grand Prix
If you want to go fast and have a very comfortable ride while doing it: Bonneville

Bonnevilles have a better exhaust

bonneville dont have the stupid ubend?

nope and the exhaust dosen't shoot off the the passenger side half way down the car and then shoot back half way back to meet the Y pipe either ours is fairly straight other than a 6" jog in it about 2 feet before the rear sub frame

Of the supercharged cars, here'* what I have found.

Park Ave: The largest and most luxuriest. The softest ride, cushiest interior and toughest to make it handle better. Engine/trans mods are plentiful for 97+.

Bonneville: Little cousin to the PA, it is the true Luxury with Attitude like the commercial said. Powerful, roomy and some handling mods available. No heated seats until 2000. Engine/trans mods are plentiful for 97+.

Regal: Reminds me of a shorter wheel based Bonneville, yet it was redone for the 97 year. A little lower to the ground than a Bonne. The Regal gives a better turning radius and better electronics that the Bonneville didn't have until 2000. Available with dual heated seats and a ton of suspension mods. Basically anything that works on a GP will work on the Regal. Engine/trans mods are plentiful for 97+.

Grand Prix: Like the Regal this is a W body and was redesigned in 97 with the 3800. Being performance based this car is low to the ground and rides like a sports car. Seats are firm and not comfy for long trips. GP owners suffered a bit as GM gave them the option of only one heated seat. Girlfriends and wives around the world were shunned. Tons of suspension and handling mods available as well as engine and trans mods.

Monte Carlo/Lumina: Oddly both are W bodies and got the 3800 NA motor in 98 only, then the 3800 came back into the Monte around 2004, along with the SC 3800 being available. Being a W body, everything is available for suspension and engine like the GP/Regal. Heated seats unknown.

What can I say..heated seats rock.

Some nice things about the gtps and regals it is easier to stiffen the engine because of the dogbone upper mounts. This also gives you the advantage to rock the engine easily when the dogbones are removed makes it easier for tuneups and if you ever plan on upgrading the manifolds to headers it gives you alot more room. The supercharger belt on regals and gtps are very easy to change as well but because of the design its more prone to belt slip so park aves or bonnevilles have a better design for eliminating belt slip but you have to remove the engine mount to change the belt not sure about the newer bonnevilles they may have redesigned that ? But needless to say any of these cars have the the ability to be fast it all depends what you are looking for.

The 2000+ Bonneville has nothing in the way when changing the belt. It'* a 5 min job like it should be.