With my mods do you guys think I sould go with a 52 or 58 mm tb?

 

As a stand alone bolt on mod, I would just save the money. Once you start adding heads/cam into the mix, a bigger TB may be of some benefit. In your sig, it say you already have a 58mm TB though.

 

Wondering if too big?

 

With port injection it would be for all practical purposes be impossible to go too large. It is not like a carb where you need some velocity to atomized fuel in the intake.

That said a 58mm isn't going to do a lot for a bolton car.

 

should stick with ur stock...

 

"Exactly"........It's funny how many guys out there don't get that concept...and they treat a larger throttle body just like the situation of moving up to a "oversized" carb (which definitely has negative effects when going too large for a particular engine combo)......a throttlebody is just an airvalve that opens and shuts and flows X amount of air......there is no signal to consider......so if your going to spend the cash, I would always go for the 58mm unit so that your TB will never really be the restriction even after all your future mods........Joe

 

Do you guys think a 58 tb would benefit my mods much?

 

I would say no, at that hp level. Spend the money elsewhere.

 

I think what everyone is saying, is if you already have a 58mm TB, it's not hurting anything!!! But don't go out and buy one, until you do more.

 

Since on the subject. If looking at 52mm rebore the stocker, if looking to buy skip right to 58mm.

Aftermarket TBs are not 100% bolton with TPS and IAC issues to tweak so why spend the coin for a new 52mm with those issues when for a lot less there are a lot of places that will rebore a stocker that will bolton and be ready to go.

I would honestly have a rebored stocker had I not come across the 58mm for less than a rebored stocker would have cost.

 

then i guess that's why there's no issue with "tip in hesitation" with a large or oversized throttle body? i assume that anyone who's had a stall or sputter because too big a tb was installed shpuld look into other problems?

no...too big a tb has THE SAME EFFECTS FOR FI AS CARB'D. you wont have any problems as you slightly go from fully closed to fully open, but try that crap with a 0 to WOT situation and you'll get bogged down. there's simply too much air for the cylinders to mix the fuel properly with. there's too much air and not enough fuel....boggin down.

 

I don't have a problem. I usually don't go from idle to WOT though on the street even from a coast that will result in the rear sliding around, on the track I try to load it up a little for slightly less shock on the drivetrain.

The MAF sees the air flow the pcm adds fuel. If you have tip-in issues first clean the MAF then double check mechanical issues and tuning. What do I know though I actually have a 58mm?

 

Actually, on our local board, a dyno test was done between stock, 54mm and 58mm throttle bodies.
The 58 actually gained i think 10rwhp and 15 tq or something like that over stock.

 

Yea, adding a 58mm throttle body (with NO tuning) "can" give you some of those issues.....but tune for it, and the issue is solved........I can't even count how many guys I know with bone stock LT1 engines that are running 58mm throttle bodys with no bogging down , or drivability issues (but they pretty much all have had tuning done)........Joe

 

maybe it also depends on altitude. everyone i know around here has had problems until they added further mods.

to everyon their own

lata