Gains from 75mm TB and new upper intake plenum on 99 GT?

[ThrowedOff]

I am considering purchasing a 75mm TB and an upper intake plenum for my 99 GT, and was wondering what kind of hp/tq gains I could expect if I were to do so... The car is stock except for CAI and flowmaster mufflers for now.

Also, what kind of additional gains would I see from adding a TB spacer + intake spacer to the above combo?

Right now I'm looking to spend $300 or so on something, and it looks like I can get all 4 of these for under $300. It seems that this would give me pretty good bang for my buck so to speak, considering it's price, but perhaps you guys have some better suggestions?

 

[TrueBlue03]

i dont know the exact hp, but you definitely feel the TB & Plenum above 3500 rpms

thats a good deal. Take it!

 

[myponyrocks]

I'd pass on the intake spacer, just my opinion.

you can expect any where from 6-12 hp gains in the band and at the wheels assuming. What brand?


*EDIT* Oh and the most important part... improved throttle response

 

[bluextc]

I added the tb/plenum and xcal 2 all at the same time so I can't single out the tb/plenum, but I can tell you there was a significant difference when I did it.

 

[sgarlic]

I noticed a nice gain when I put the 70mm Accufab combo on in the higher RPM range. I'll get it redyno'd one of these days.

 

[Jsun3701]

Just like they said, you will notice it around 3-4k, I have that set up right now. But dont get the spacer, it doesn't fit with the BBK plenum I have. I would think it may be the same for you.

 

[twogts4us]

I noticed a nice gain when I put the 70mm Accufab combo on in the higher RPM range. I'll get it redyno'd one of these days.

Same here - at 3K + RPMs, it just seems to find new life and pulls noticably better.

 

[HoustonGT]

Hmmm, interesting. This makes we want to dig into the S/C fund and get a plenum and TB...After all, it's a supporting mod for the supercharger anyways

 

[bluextc]

Hmmm, interesting. This makes we want to dig into the S/C fund and get a plenum and TB...After all, it's a supporting mod for the supercharger anyways

Do it! Add a little fun while you wait for the s/c!

 

[HoustonGT]

Do it! Add a little fun while you wait for the s/c!

Well, if i run a 13.4 hopefully tomorrow, then MAYBE with Drag Radials on 15" wheels and with the Plenum/75mm TB Combo, i'll POSSIBLY have a freak chance of 13.0 or 12.9....That would be