Helo Boys and Girls.

I need an opinion : What size throttle Bodies should i put on my 12A.

I have access to 2x 58mm (2.28") and 2x 65mm(2.55")


My engine is in my Sig

Thanks!

Karis

 

Even the 58mm will be kinda large. Go with the smaller one. Is this for N/A or forced induction?

 

Your sig says carb, but TB's are a FI thing.

In any case, I think that 2x58mm is too small for a high-reving bridge. In fact the 2x58mm ones have about the same cross-section area as a stock -SE TB. But if carbed, 65s might be too big, I don't know... if your going FI, then the 65s should be just fine

 

Hi!

Sorry for not being precise enough.

Well,it s a well built 12A Bp motor,which will stay NA.

I`am currently running a carb,trying to get some facts of what to use if i would convert to EFI.

So i should use the 58mm throttles ?It weill be used with a programeable(sp?) management system.

 

For FI, the way I understand it is that you want to be sure that the TB is not the restriction in the intake system. Going too big is possible, because as soon as the TB is no longer a significant restriction pushing the gas down further does nothing. I don't know if 2x65mm is too large, but I do know the 2x58mm is abouth the same cross-section as the stock FI TB that the -SE and later NA models used, and that it is known to become a restriction at high rpm.

 

Thanks for the info!
Karis