Throttle Body

[Scut95]

I was looking at some throttle bodies and was wondering if i could ask you guys for some help. Edlebrock says that 65mm is whats recomended for a stock 5.0 manifold but 70mm is good for a Performer 5.0/Performer RPM 5.0 EFI intake and Total Power Package, it also gained 10 hp over stock. I was wondering if anyone was running a 70mm with a stock intake manifold and if so did you need to modify anything to get it to work. I would like to go with the 70 mm if possible so i can get more flow and horsepower. Also, why do you need an EGR plate for a new throttle body, what does it do? and why do you need it? And i know this may be a dumb question but does a new throttle body come with a new TPS? and would you recomend paying a little more to get one with a new IAC valve? By the way, im driving a 1995 GT.


Thanks

~Scott

[Zim]

On my cobra I have a BBK 70mm TB with the stock upper intake manifold and it bolts up just fine. Im not sure about the EGR stuff, but you'll more than likely re-use the TPS from the stock TB to the new one.

[Tbird232ci]

but you also have to remember, the 94-95 Cobra's have the Cobra intake manifold that people buy aftermarket

i believe for a 70mm, youll have to do some minor porting

[bbunt302]

I'm not sure what your mods are, but as long as you are running the stock upper intake the 70mm TB will be a waste of time. A 65mm will be more than enough, the intake is more of a restriction than the throttle body. Even if you are planning more upgrades down the road, the 65mm TB may still be enough. It takes a fairly serious HCI 5.0 to actually need a 70mm TB. I'm not sure if the 70mm will actually hurt performance or not when using a stock intake. But, it may however if the opening on the intake is not as large as the one on the TB.

As far as the TPS, yes you'll have to re-use your stock TPS. The IAC may or may not be necessary depending on what kind of condition yours is in. If there is nothing wrong with the current one, there is no need to replace it. If you are having any type of idle problems currently however, you may as well go ahead and replace it.

The EGR plate is necessary for the same reason the TB is necessary, more flow. The aftermarket EGR plate will have a larger "bore" than the stock one to match the TB.

[wytstang]

A TB on a stock or slightly modded car (bolt on + exhaust) is a waste of $$. Spend your $$ else were, you will gain next to nothing with a tb as of now. I have the usual bolt ons plus exhaust running the stock tb and see no need for a bigger tb on an engine that's not asking for it.