I am going to be doing my heads/cam swap in the next few weeks, and I have been trying to decide on what throttlebody to get. I will be going with fully ported heads that flow 265/192 @ .600, Comp XE 236/242 on a 112, fully ported intake, long tubes, 30 lbs SVO's, and tons of bolt ons that will be installed at the same time. It is going on a stock shortblock for now, and I have plans for a stroker motor in the future. Right now I am trying to decide if I need the 58mm, or stay with the 52mm. I know the 58mm is good for blower motors and all out race setups. Anyone have any opnions on which one I need??

Brian

 

I'd say a 52mm is plenty.

 

I hear that if you put a 58mm TB, it doesnt do any good unless you port your intake to match it.....its all up to you...since your going to have the intake off, why dont get it ported out and get the 58mm?

 

I see too many people buy the 52mm, only to buy the 58mm later on. Personally I'm getting the 58mm right off the bat instead.

- Brent

 

Thanks for the opinions so far, but is there anyone out there that has used both sizes to compare with. I was thinking about just getting the car running with the 48mm, and then going from there. I have just heard that the 58mm is over kill for anything less than a stroker or blower/nitrous car. Any more help would be appreciated.

Brian

 

i'm running the stock 48mm w/ P.P. heads and the XE230/236

afaik, rskrause is/was running the stocker w/ his 700+ rwhp 383...

i've yet to see definitive dyno results stating the limitations of the stock tb...

 

question on your wheels....are they 18x9.5's all around?

 

You should start of with the 48mm stocker & then go bigger & tell us if there is any gain to be had. This would be a good learning expirience for all of us on your account...

 

Yes my wheels are 18x9.5 all the way around. If you want to ask me some more about them, just send me an email and we can talk.


I probably will start out with the 48mm, but I havent decided if I will really need anything bigger. If rskrause is still running the stocker on 700 rwhp, then there isnt any need for me to go any bigger. If someone wanted to loan me a 52 or 58mm throttlebody , I would do back to back tests on the dyno to see if you actually gain any power. Well enough for now, its off to work.

Brian

 

rskrause is FI though, isn't he? Might be a case of apples and oranges there. There still doesn't seem to be a definitive comparison of a 48 and a 52 back to back on the same car..

 

I will soon have this same setup. For now at least, I will keep the stock 48. In the research I have done, no one has been able to quantify a difference bewteen all 3 sizes.

BTW WJH.... How does your car run with this setup?

 

I have a 383 with a 52mm.

What do the heads flow at .550 lift?

 

This is definitely an interesting debate. One that I'm curious of also. I still have my stock throttlebody in the attic, and a 58mm is on the way which I bought used(hopefully ), the 52mm is on the car now. When the weather clears up around here(probably may or june w/all this snow) I'll take my car to the dyno again and find out and I'll post the results .

 

Hopefully in the next few weeks we will decide this debate.
I have both a 48mm and 52mm.
The car is going to get dyno tuned on my new setup.
XE 230/236 on 111LSA & PnP Combination Motorsport Heads.

Me and Ed Wright were talking about this very same thing and we are going to start off with the 48mm and than put a 52mm on it to see if its going to make a differance or not. I also have 30lbs injectors on the car as well.

 

this summer i plan to test tons of stuff

before and after
CAI
heads
LCA
Shocks
3.73--->3.90 gears
skinnies
48--->58mm tb


I'll be posting results