Throttle bodies
 

two questions
i've got a 99 cobra with borla catback
-should i get a new throttle body or port the one i got?
-what underdrive pullys should I go with, are they all the same? I looked at steeda and bbk, price...

Neither at this point. The stock twin 57mm is more then enough at this point. Going larger won't make much power and is expensive; you're better off spending the money and time on other stuff.

Go with either Steeda or ASP, which ever you can get a better deal on; They're identical. Two reasons. One, they have a nice crank harmonic damper while BBK and MAC do not (Stock does). Two, another extremely useful modification at this point is the Steeda Timing Adjuster. The TA will fit the stock pulley, Steeda, and ASP crank pulleys with out any other parts. It will fit the MAC pulley with an adapter that costs $30 or so, which negates the price advantage of the MAC pulleys themselves, plus the Steeda/ASP damper advantage. Plus it saves you a bit of a headache for installation. Which BTW to save some time installing both the TA and pulleys at the same time saves some labor, plus the TA and pulleys compliment each other extremely well.

After that the next best step is a H or X pipe. The 4 stock cats are the big restriction in the stock setup. Replacing it with either a offroad pipe(no cats) or a pipe with two high flow cats will yield good results. But that's a whole other topic. http://www.mustangworks.com/msgboard/smile.gif