wow, you peeps have me all messed up now. 52mm or 58mm. I don't know where you all have seen the pricing differences but everywhere I look there is only like 10-20 dollars difference between the 52 and the 58. That being the case I figured why not spend the extra 10 bucks and get the bigger TB. Would it help if I said I plan on spraying down the road or does that not matter either? I'm ready to order this thing one size or the other....

 

I wouldn't think that would make a difference. I'm running a 52mm with my blower car and won't be going to a 58mm even after I bump up the boost. Heck...I think there was an impala with over 700rwhp that was running the stock 48mm tb. I believe it was a cmotorsports prepared car.

Joe

 

I have an idea on how you might test if you need a bigger TB or not...

Grab a scanner and measure the difference between the BAR and MAP Readings at WOT on a stock car. Take this number, compare it to the same numbers on your car... if the difference becomes significantly more then its likely hungry for more air..

someone plz correct my crackpot theory if its not correct I think it makes sense, at least in my head!

 

i just e-mailed bryan at pcmforless about this today. he thought the 58 was good for heavily modified stroked engines and the 52 or stock for normal bolt ons. shavings in the engine are you kidding me? i read the same stuff about a few not making any difference but who wants to take that chance? not me!! how many of you change your oil religously with only synthetic and the best filter you can buy? take off the intake manifold and upgrade your lifters while your at it if you go with the 58. seems like a waste of money to me. my 2 cents.

carl

 

Agree 110%

Nice Cam!

 

Who the heck pays $300 for a 52mm throttle body these days ?

-Shannon

 

Have on coment to youre theory.
I dont think You should compare widh a stock one beacuse the restrictiv stock air filter , Its better to compare wot and 95 % tps, if you dont have any diffrence there you dont need a bigger TB.

About the 700hp impala, Wonder how much he would make widh a 58mm .
Just because somthing works good it doesnt mean it could be better.

 

They didn't say "since it worked good we won't try a 58mm". They said it was for a mathematical reason. There is a big thread on it somewhere.

Joe

 

what causes the 58mm to mess up the idle on some cars but not others. Just a chance you take? And with what Brian at PCM for less said, my car is kinda in the middle then because it has alot more than bolt ons but I don't consider a CC306, stage II heads, 4.10 gears, and Hooker LT's to be a heavily modified car.