S/C a 91 Grand Prix

[lancerswimmer89]

okay, so i'm supposed to b buying my uncles 91 Grand Prix, and i was wondering if it'd b possible to supercharge it. It has 150K miles on the engine and body, but the Trans has only 30K on it. Would the S/C put too much stress on the engine??

also, i need a list of the parts i'd need to do a complete s/c install.

[RedZMonte]

it would all be custom. I would look at a vortec kit like RSM/PFYC sell for the 3100/3400's and modifying it to fit your car. Or do what Myself and a few others have done and turbo rather then S/C. If you have the means to build custom parts the turbo is pretty simple.

as for the motor holding up..... Impossible to say.

S

[lancerswimmer89]

well, if its a 3.8, can't i just take parts off a early to mid 90's GTP??

[DEI37]

Yeah, having the turbo 3.1 to get ideas off of puts you at an advantage, seeing as how GM did it from the factory with that car. I'd turbo it, and get it tuned right (also somewhat easier, as GM had it done factory, so there IS a base out there), and enjoy yourself a 200+ HP 3.1 GP!

[DEI37]

well, if its a 3.8, can't i just take parts off a early to mid 90's GTP??

In 1991, it's almost certainly a 3.1 MPFI V6. The 3.4 DOHC V6 debuted that year, but the odds that THAT car has it are mighty slim.

[RedZMonte]

well, if its a 3.8, can't i just take parts off a early to mid 90's GTP??

how did you conclude a 1991 GP has a 3.8?

[lancerswimmer89]

Hey, i'm new to these cars. so bite me. I thought they all came w/ the 3.8

[RedZMonte]

Hey, i'm new to these cars. so bite me. I thought they all came w/ the 3.8

Lol. Just givn u a hard time. If its a MPFI and you can find a "89-90" Turbo Grand prix to rape parts off of or a member here that has the parts it should be easy to boost it. My old TGP had 160K and going strong. if its a 3.4L DOHC then i would 1st make sure its mechanicaly sound before you even think about boosting it. The DOHC is a strong engine as long as it has been properly maintained. T-belt, Intake gaskets, tune up....Ect.. But it is also a very finiky motor if not given allot of attention.

FYI i have a stock X-Over for a 1989/90 Turbo Grand prix... (3.1L MPFI) if that helps

S

[lancerswimmer89]

ok, i did a lil research, all the coupes in 91 came w/ the 3.4 V6 in em.

also, how would i go about checkin if the engine was sound enough to handle boost??

[RedZMonte]

compression test is a good start. if the compression is low then the rings are wearing out. I know the honda guys like blow by cause it allows them to run more boost but in the long run blow buy indicates a very tired motor. all cyl will very a little but should all be close to one another. Someone here should know what the compression should be. also if it is a DOHC you need to check the T-belt. if it goes your in for a lot of work. should be done every 60K miles. you can check it by pulling the front t-belt cover and it will be obvious that it is warn.

[RedZMonte]

"kbb.com"
SE Coupe
4-Cyl. 2.3L Quad 4
V6 3.1 Liter
V6 3.4 Liter

GT Coupe
V6 3.1 Liter
V6 3.4 Liter

[lancerswimmer89]

should i upgrade my ecu...to an obd2 or something i think its called?