THROTTLE BODY SIZE

[383STROKER]

HOW MUCH DOES THROTTLE BODY SIZE MATTER ON BOOSTED APPLICATIONS. I HAVE A BBK 75MM NOW RUNNING 15 PSI. I AM GOING TO A PULLEY WHICH SHOULD GIVE ME 18-20PSI AND I WAS GOING TO RUN A 90MM THROTTLE BODY. I WON AN AUCTION ON EBAY FOR A 90MM THROTTLE BODY BUT WHEN I GOT IT IT WAS ONLY A 80MM . SO NOW SHOULD I KEEP THE 80MM AND BE DONE WITH IT OR SHOULD I PERSUE GETTING MY MONEY BACK AND GET A 90MM? WOULD A 90MM BE OVERKILL?

[TheHawk05]

I trust by your sig you're running a fairly large stroker motor. I'd say the 80mm is plenty big.

[stevieturbo]

I read a few reports ages ago, where guys tried different sizes on LS1's. There wasnt any real noticeable difference on a boosted engine comparing stock 75mm ( LS1 ) to even 90mm TB's.
Even when using the likes of a FAST intake, there wasnt any real gains over a stock TB and LS6 style intake..

[383STROKER]

IF IT MAKES ANY DIFFERENCE THIS IS A 383 FORD IN A 91 MUSTANG.

[stevieturbo]

Cant say for sure. A std LS1 uses a 75mm TB.

What size is your plumbing leading up to the TB ?? if its in and around 3" also, then I cant honestly see teh TB making much of a restriction to airflow as its almost the same size as your pipework which will have a series of bends etc that could also restrict flow.

If your pipework is 3" then I cant see much point in having a 4" TB, esp in a blown application.