I was talking to a friend about the future plans for the GSX... when the subject of picking up a over bored or BBK throttlebody, he mentioned that the throttlebody would help with top end power, but it would drop bottom end torque due to a loss in intake charge velocity... does anyone have experience with this or is there a solution that I could gain in both area's...

what is the reason/benefit of using a throttlebody spacer???

Throttle body spacers don't do much if anything. Mainly, their good use is for carburetors, which we don't have to worry about.

A bigger throttle body will be similar as if you put a short runner intake manifold on your car. You'll loose some of that low end torque but your gains will be up top. Same principle as if I went from my 2.5 dowpipe with 3in catback to a 3.5in turboback exhaust. The smaller intake/exhaust piping is ok if you want the low end grunt but if you're looking for the top end "oh my god my skin is peeling off my face" do it and don't look back.

Not only can you get an overbored stock TB and a BBK, but I've heard that some of the Ford Mustang throttle bodies will work. They are NOT a direct bolt-on and some drilling/thread tapping is needed but they are larger than the overbored stock or BBK throttle bodies. I believe you have to have an aftermarket intake manifold as well. The main reason the Mustang TBs work is because they have the same style throttle cable and it's on the correct side of the TB for our cars.

Do you know what years for the mustang throttle body?

Not sure but I'll try to find out.

www.roadraceengineering.com also sells bored out DSM throttle bodies.

thats all good info guys... keep it up and thanks

FFWDConnection.com offers the boring of TBs also, with some very nice extras available.

Hey Ben I found the throttle body for us.

Accufab 75mm F7546 4.6l Mustang TB!

We run the Accufab for the 4.6L SOHC mustang motor 75mm. The stock TB is very good and way to go for reliability. The mustang style TB are not designed for our forced induction application. We've snapped the shaft on the BBK one a few times. We currently have a back up TB for when the Accufab breaks. The stock TB does limit the size of your IC pipes though. Will it hurt power production? I'm just guessing the difference would be 580hp versus 565hp.

In other words there's better places to spend the money....

Yup there sure is.

thanks for the advise here guys...

Ben