The I4 & V6 throttle bodys are both different, simialiar, but different. Local machine shops are incompetent. I still need someone who can do this for me.
Steve at www.throttlebodys.com doesn't think this can be done and he actually has my spare TB right now. I have found www.maxbore.com & www.o2induction.com, we are talking about either of them doing this. So for anyone else interested, you might contact them. In the meantime, when I get mine finished I'll let everybody know how it turned out & who to do yours.
I joined the board to show to post this pic showing why these TBs aren't good candidates for boring. At least not if you're paying someone $100 or so for the work.
Here's a pic of the TB wall where the shaft passes through. (taken when I had redstar_gearheads' TB here)
I believe the hole for the shaft measures 10mm and you can see the wall thickness there isn't much over 1 mm. Thanks Steve
« Last Edit: November 06, 2006, 01:47:09 AM by steve monroe »
I joined the board to show to post this pic showing why these TBs aren't good candidates for boring. At least not if you're paying someone $100 or so for the work.
Here's a pic of the TB wall where the shaft passes through. (taken when I had redstar_gearheads' TB here)
I believe the hole for the shaft measures 10mm and you can see the wall thickness there isn't much over 1 mm. Thanks Steve
steve, you'll have to go to photobucket (or email me the pic and i'll upload it. shiano13@yahoo.com) to get the pic to show up.
Not knowing what kind of gap there's be if the wall broke through, I didn't think the gain was worth the risk on redstar_gearheads TB especially since it looked like he put some hours into polishing the outside of it. Very likely if the gap by the bearings was large, the TB would cause a high idle condition.
The idle would only be higher. Air bypassing the plate will raise the RPMs. Lean / rich won't happen b/c the MAF is going to be reading the grams per second and supply the correct amount of fuel for the motor to match the airflow.
the computer uses the tps vs MAP(there is no MAF Steve Monroe)
without a TPS.. the computer wouldnt know how much you were pressing the throttle. It would have a very hard time calculating load. Which also determines timing and shift points.
You cant bore a TB without making a new plate. Its like having a vacumm leak. The IAC can only adjust so much for the extra air getting by
OK thanks Burn504. I didn't know it was MAP. Most GM are MAF & I'm familiar with those. Main reason for posting was maybe to save someone the time & $ of shpg their TB to assorted machining companys by posting a pic of how thin the walls are on this model TB. Not a candidate for boring IMO. If you can't get around 10% gain, I doubt you'd pick up any HP. If you can DIY then it could help. Thanks Steve
I believe he maybe right, but I can tell you can go bigger w/o hitting the bearings. I think you could go from 54mm to maybe 57mm (this is pushing your luck). The wall between next to the berrings would be super thin. Steve, I still may have you try to do this, but definitely not 58mm. More like 55mm or 56mm. I think some more air would be better than none, and it's a risk on a spare TB I'm willing to take. The only other problem I can see, is if you get any kind of carbon build-up in there.