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Discussion Starter · #1 ·
does anyone have a bored throttle body on their 2nd gen? is there a big difference with it? i noticed corksport selling them and was wondering if it was a good upgrade our cars.
 
G

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Discussion Starter · #2 ·
Bored TB

I have no personal experience, but anything that helps the engine breath better is worth it. I've heard that a bored TB is good for 4-6hp. A worth while upgrade in my opinion. Just my 2 cents.
 

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Thumbsup on this mod...

I've got a 65mm TB, bored at a local machinist, on my 94PGT. I've loved it from the get-go.

As to actual results, check out my web page, under "Dyno Plots". A friend & me dynoed his 94PGT then, while the car was still on the rollers, swapped in a 65mm TB and then dynoed again. The results are pretty dramatic for a comparatively cheap mod.

BTW, see if you can get a TB from a wrecking yard and shop around local, competent machine shops. Chances are pretty good they'll do it cheaper than Cork will sell one for. Just tell the shop to allow no more than about 0.002" or so between the new plate and bore (otherwise the car will not idle right.)
 

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oops...

JPMX6GT said:
So you're saying that with a 0.002" bore on the TB, you'll get 4-6HP??? Is this right?
No, sorry for the confusion. The bore itself is done to 65mm (the stock diameter is 60mm). A new throttle plate is then fabricated from brass (usually) stock, maybe 0.035" thick.

The 0.002" I refer to is how tightly this new throttle plate should fit the new bore when the plate is in the closed position (closed throttle).

On mine, the shop did it a bit looser the first time around and the engine idle was all over the place; oscillating from 400 to 1500 rythmically back and forth. Turns out that the throttle plate wasn't fitting tightly enough and was, so the theory goes, sending the PCM outside its idle closed loop control: alot of metered air getting in, but the idle switch indicates closed throttle = scrambled PCM idle-control logic brains.

I had them re-fab a new throttle plate that fit much better, re-installed it and all was fine.
 
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