65? 70? 75?

[Guffinator]

Talking about thottle bodies. I know that most manifolds have 70mm openings, but the difference between 65mm and 70mm seems so minute, I can't see how going with a smaller TB (65mm) could really be a hinderance. Does anybody have a reason that I should look for a larger size?

[Saleen91]

I say get whatever fits and whatever you find a deal on...and if you can swing it, go with an Accufab.

[89LX306]

I would say the only "real" difference made would be velocity. The old saying, "bigger is not always better."

I agree with Ben though. I went with a stock TB bore to 63 mm for a sum of $10.

[Chad82GT]

With the blower the difference is even less significant since all the air is being physically cramed in there. It's always "cool" to go fast with smaller parts which is a vote for the 65... but if a sweet deal on a 70 comes up then go that route. I think realistically you'll have a better chance of finding a cheap 65 over a 70 tho.

Final answer: get what's cheap :)

[White90GT]

Pretty much same answer, get whats cheap and what fits. Joe Warwas 347 powered cobra. Not sure if you remember, last year at one of the KOTS events at Sealy, the throttle blade broke on his BBK 70 mm. He had his wife bring the stock 65 up there, installed it and ran the exact same number as he ran with the 70 previously.
I'm running a 75mm on my car. I started originally with an explorer 65mm t/b converted to work on my car, then bought a 70 for like $120, then traded it for a 75. My intake is open to a 75. I don't see it hurting my car any, but I didn't really see much gain out of it either. Only ran the 70 for one track trip I believe.

[Chuck98GT]

I picked up about a 10th going from a BBK 65 to an accufab 70. But if you look at the two TB's side by side, you can tell the accufab flows better than a BBK even if they are the same size.

[kbrew8991]

the air does seem to slow down alot anyway once it hits the plenum

the only place i could see it helping would be if you had a handiling car where you would need precise throttle modulation (ie youve got the car at the limit and you're balancing it with the throttle) bigger is harder to modulate....