Just wondering if anyone out there bores the stock throttle bodies for the 2.8?
I know the Fierstore sells them but they're too much. (in my opinion)
And yes, I know Darrel Morse used to do them. (wish he still did!)

Would prefer to send mine out for machining to avoid the swapping & core charge stuff.
Also, I do have a concern about throttle plate mismatching since I have read a thread or two
about the Fierstore's Big Bore throttle bodies having the wrong size or misadjusted throttle
plates which had caused some to have high idle issues.

Thanks, Kit

Member "Dawg" on here does them.

See this thread. I think he bores them for $120.00
https://www.fiero.nl/forum/Forum4/HTML/051596.html

katatak has one for sale at the moment ready to go.

Probably belongs over in the Mall but I have a bored TB - my cheap digital caliper says it's 55.93mm. It is off a running/driving 88 2.8. Comes complete with the TPS and IAC. No high idle issues, motor ran great! - painted black. Make me an offer!




Pat

I have a FS throttlebody and like it was mentioned above, the throttle plate was the wrong size. The car idled at 2500 until I replaced the throttle plate with one that I cut down from a larger blank. Several folks in our club recently purchased bored throttle bodies from:

http://www.throttlebodys.com/FieroTBs.htm

These are bored more than the FS version and appear to be well done.
Jim

Kit, PM 2 u

If you're using a stock intake, even ported one, you won't see much if any gains in power over a stock TB.

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[IMG]




trueleo.com
RSpiderII@aol.com

quote Originally posted by Francis T: If you're using a stock intake, even ported one, you won't see much if any gains in power over a stock TB.

Yep, Darrel Morse used to port the upper intake too at a much more reasonable price. Why did he quit doing these?

quote Originally posted by Francis T: If you're using a stock intake, even ported one, you won't see much if any gains in power over a stock TB.

If you were doing a 3.1 stroker or 3.4 conversion, this would make sense though?

quote Originally posted by USFiero: If you were doing a 3.1 stroker or 3.4 conversion, this would make sense though?

Not if you have the stock intake. The bigger displacement, the worse the stock intake becomes. It's just barely acceptable for a 2.8 IMHO.

quote Originally posted by USFiero: If you were doing a 3.1 stroker or 3.4 conversion, this would make sense though?

You still have the bottle neck known as the fiero manifold. If you matched the upper, middle and lower along with the TB, ported the exhaust manifold and cut up the Y pipe and did some port work there you will yield about *6-10HP on a good day.
*Results may vary.

quote Originally posted by Francis T: If you're using a stock intake, even ported one, you won't see much if any gains in power over a stock TB.

I know a guy who built a 3.4L with the ported intake and the oversized Morse TB and he claimed that it worked well. If he switched over to your Truleo manifold would the difference be that noticable?

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, ZZP Intercooler, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Wasn't the throttle body bore on the 3.4 F-body the same size as the stock Fiero 2.8?

quote Originally posted by Dennis LaGrua: I know a guy who built a 3.4L with the ported intake and the oversized Morse TB and he claimed that it worked well. If he switched over to your Truleo manifold would the difference be that noticable?

I believe it would. With the bottleneck in the stock (even modified) upper intake, the engine will run out of steam at ~5000.
Doesn't matter what else you do. Cam, porting headers, etc. It's all limited by the upper manifold.

The Trueleo made the rest of the mods on my 3.4 worthwhile. Before I did that, I was looking for another engine to swap in.
A larger TB, in addition to the Trueleo, will help even more. Someone (don't recall who) was doing 63mm throttle bodies.

[This message has been edited by Raydar (edited 10-09-2011).]