cldnails

I have been reading about the new plenum's and 75 MM TB's and how they are increasin the HP by about 10 ponies. Has anyone installed these and know if they knock down your low end torque? I may be looking at purchasing these.

Currently I have:

3.73
Tri-Ax
King Cobra Clutch
Steeda UD's
Fender Well Cold Air

Any info would be well appreciated.

04mustang

if you dont have FI id go with a 70 MM TB. the 75 might breathe better but you loose velosity. kinda like putting 3in exhaust pipes on a 200 hp car it will have negative torque affects.

cldnails

No FI but that is what BBK was suggesting. They only listed the HP ratings but not torque.

Jakes

What 04mustang said....

Good breathing depends, not just on free flow, but also velocity (creates momentum) of the intake and exhaust gases. High velocity intake helps force more air in, and high velocity exhaust actually helps suck the spent gases out. Top end HP relys on high rpm's to create the needed velocity, so the bigger the better. TQ at lower rpm's requires balancing free flow without losing velocity. If you go to big on either end you'll get free flow but you'll lose velocity. It all depends on what you're setting out to accomplish. High end HP race engine or a torque'y, light to light, street car.

Generaly, a 70mm TB is considered adequate for an NA 4.6L street car. If you plan on SC'ing go with a 75mm. The SC will give you all the charge velocity you'll need.

I just added an Accufab 70mm TB and Plenum to my '02 GT. I didn't notice any SOTP change until it hits 3000-3500 rpm, then the added flow kicks in and it pulls alot harder to redline.

RollinThunder

I've felt that I"ve lost a little bit of low end tq...but after 3000rpm she sure makes up for it..