After installing my new runners/intake a few weeks back, I noticed that the throttle would sometimes remain "open" after letting off the gas. Other times it would close, but close REALLY slowly. I took it off and gave it a thorough cleaning and sprayed some WD-40 in some key areas hoping it would clear up the sticking problem but it never really went away.
The final straw which lead me to buy a new one, was when I was driving home after work and had to slow down for upcoming traffic on the free-way. The throttle once again stuck open and the engine was spinning at nearly 4000pm. Unfortunately, my brakes just weren't strong enough to bring the car to a complete stop with the engine spinning that high and I was approaching the stopped cars up ahead real fast. I shifted the tranny to neutral, and slammed the breaks.
I could see I wasn't going to make it in time so I veered onto the shoulder and finally was able to bring the car to a complete stop right beside the car that would have been directly in front of me. It was one of those tiny little "smart cars" and the old bag driving it looked over at me and gave me this real dirty look and shook her head at me. WTF? :confused:
She must not have had any idea just how close she came to getting run over, had I not pulled off onto the shoulder as soon as I did....
Anyways, I popped the hood and manually pushed the throttle closed and carefully drove home as slow as I possibly could.
I wasn't going to take the chance of having the same thing happen again and wind up in a serious accident so as soon as I got home, I placed an order for a new throttle body. Since I was about to spend the money anyway, I figured I'd get something nice to go along with my new intake and runners so I ended up going with Holley's billet aluminum throttle body.
When I ported out my plenum originally for my bigger runners, I increased the size of the entry ports behind the throttle body to roughly 52mm thinking that if I ever decided to go with a larger throttle body in the future, the plenum would support the extra flow. It's a good thing I did as it ended up coming in handy after all.
I just finished installing this a few minutes ago. I still have to hook up a scanner to adjust the TPS sensor but so far, the car runs fine. It's obvious that the intake is sucking in a lot more air then before 'cause you can literally hear the air going into the plenum through the larger throttle body. A quick spin around the block revealed that throttle response (thankfully) remained crisp and instantaneous. I was originally a bit concerned that the larger throttle body would have a negative effect on throttle response since that's a very common "side effect" of using larger than stock throttle bodies but I guess porting out the plenum to match the the new TB payed off after all.
The final results?
The car pulls noticeably harder from 3500 and up which was a nice surprise. Not like it gave me an extra 50hp or anything
but enough to feel a definite improvement over the factory 48mm. The Holley is a really nice piece for sure. It really cleaned up the engine compartment nicely and it's silver finish matches my AS&M runners perfectly. Very sharp looking if I do say so myself.All in all, I'm happy with the purchase.
Here are a few pic's I snapped off of the throttle body on its own and once I installed it on the motor. I give Holley's TB two thumbs up as far as build quality and over-all "eye-candy" is concerned. The red throttle blades look so nice it's a shame they can't be seen once the air intake is installed. If only the intake tubing was made of clear plastic, you could see everything. (Hmmm....I think I just came up with my next project idea....)
Finally, although I did get an improvement in performance, it's only because I have an intake set-up that takes advantage of a larger throttle body's increased air flow. I wouldn't recommend one for a stock intake car 'cause there'd be no need for one but if you (like me) have an intake designed/modified to take advantage of the increased air flow, go for it.
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