Does any know much about the 3.8 TPI v6's?

 

do you mean the 3.8 in the 95+ v6 fbody's? if so they are NOT tpi, SFI i beleive.

i use to have a '98 v6 3.8....

Jon

 

2.8 & 3.1 were MPFI

 

No I mean the 3.8's that were in the bonnivilles and I think they may have been in buicks or caddies. I have seen Tuned Port Injection on bonniville engines and on the backs of some other cars. Does anyone know what I am talking about?

 

No we don't. There is no such thing as a Tuned port Bonneville. I have a Bonneville and it sure as hell isn't Tuned Port. I also have a Camaro, that is tuned port injected. I believe you are mistaken. Its either an EFI, SFI, MPFI but not TPI. No way to do it... the TPI is for a V8 and a 3.8 is a V6...

 

In Chilton's 1982-1990 Firebird manual all the fuel injected engines are referred to as TPI, the 2.8, 3.1, 5.0, and 5.7

Later,

Dave

 

We used to own a '93 Transport that had a 3.8 in it. On the side of the van it said"Tuned Port Injection". One day I noticed it and took a double take. It was just wierd seeing that on the side of a mini van.
Later Barrett

 

Wow, i know what your talking about. It was in a front wheel drive car but i can't remember what it was. My sister's ex-boyfriend had one. I also did i double take when i saw "Tuned Port Injection" stamped on top. I keep think it was a pontiac...just can't remember....Reminded me of the Buick Le Sabre in styling cue's...grrr...now i am itching to know what it was....

 

Red Iroc just because you don't know it and haven't ever seen it doesn't mean it isn't true. I know I have seen them but I guess they didn't make them to many years. I also heard rumor that the 89 fiero GTP was supposed to have a TPI V6 a 4.3 but the car got canceled. Oh well thanks for you replies I will go digging on my own from here.

 

I test drove a '93 buick a while back that had a 3.8 liter TPI in it. A little sluggish. The car was in great condition though, only like 30,000 miles on it.

 

Starting in 91, the GM front wheel drive's with the plastic upper
intake manifolds are tuned port engines.

 

Also they never put a 3.8 in a Caddie, though it is a better engine.

 

yes, they do exist. its not a long runner design like the V8 TPI though, its more an LS1 style composite intake manifold. heres the specs:

205HP@5200
230FT/LBS@4000

not bad for a 3.8, heavy car though

 

I just measured one here and the runners are about 7 1/2" long.
5 1/4 in the upper and 2 1/4 in the lower.

 

As a purely technical matter (despite the NAME put on an induction system) all intakes are tuned at SOME RPM range, so they are all "tuned" systems. If they have port injection, you do the math...

 

Well, yes and no. The early V6 Buick, 91 and backwards had an intake that consited of basicly a large plemun with short 3" runners which are too short to be considered tuned. But yes you are correct, 95% of intakes are tuned to do a specific job: performance, towing, economy etc. But I feel if the runner is less than 4 or 5 inches long there is no tuning effect to it and will probably suck for anything other than mid to high rpm use.