Stang4Point6GT98

I am thinking about buying a BBK upper intake plenum for my 1998 GT. I was wondering if I should buy a throttle body with the intake and if i should get the 70 or 75 mm. Will the new upper intake plenum and/or the new throttle body affect my car's driveability at all or create any unwanted problems on my (so far) problem-free car? Also will the performance gains be noticeable?

mdvaldosta

You wont have any problems but you wont be gaining much power, maybe 5-6 rwhp at the most if you do both plenum and tb at the same time. TB & plenum isnt as much a bottleneck on pre 99 cars as it is on the PI motors. It'll probably feel like more though since throttle response will be better. Stick to a 70mm throttle body unless you get a C&L plenum then get a 75mm. C&L wouldnt be a wise choice for a near stock non-PI car though.

andy98gt

I have a far from stock 98 GT and i have a BBk 70 mm TB w/ a C&L plenum. I could feel the differance when i put them on together, the throttle response is great. Id go w/ 70mm, i hear you only need 75 for s/c or high n/a horsepower cars.

Deannostang

I have a 70mm Ford Racing TB with Accufab plenum on my '98 GT vert and like the combination. Took all of 30 minutes to make the swop. Car runs much smoother overall now. Check out the TB/Plenum combos halfway down the page on this link: http://www.accufabracing.com/Flow%20Data.htm Accufab blows the other plenums away for highest total HP and torque gain.

Good luck!

Stang4Point6GT98

Thanks alot for the advice guys. I appreciate it. My 1998 GT also has really bad throttle hang. When I rev it up it takes such a long time to come back down - the RPMs hang really bad. Has anybody experienced this with their 96-98 GTs? Do u think a new upper intake and/or throttle body will solve this problem? Help!

andy98gt

Yeah it seems mine got a lil bad after my long tubes got put on and i didnt have the rear o2's plugged in. Other then that never had the problem.

zerosgt

I have a 98 GT that is as stock as the day it was driven off the lot and it has the same deal. It's not a lot of fun, but it's work able. Will the throttle body\plenium effect this?