62mm vs 64 m throttle body

[SilverXJ]

Any reason to go to a 64mm throttle body verses a 62 mm?

[Cheromaniac]

No.
I have a modified Mustang 65mm TB and though it improved throttle response (it's a touch oversensitive now) compared to my old 62mm TB, performance was unchanged.

[SilverXJ]

Thanx. I was hoping to hear from you as I knew you had the Mustang TB.

[John]

The runners on the intake manifolds is the flow limiter, not the TB.
John

[SilverXJ]

In that case has anyone obtained a manifold with larger runners?

[John]

Actually, I wonder how many have maxed out the HP potential of the air flow of what we have? There is a couple ways to increase the internal diameter of the manifolds we have, I have not tried any of them, but if interested, Google extrude honing.
John

[SilverXJ]

I've seen that before... teh pics with the abrasive coming out of it is really weird.

Another option is a custom intake manifold.

[John]

That is a valid option, but consider this from Hesco. http://www.hesco.us/forum/forum_posts.a ... ifold+flow

John

[Flash]

That is a valid option, but consider this from Hesco. http://www.hesco.us/forum/forum_posts.a ... ifold+flow

John

The last statement about heat, in that link, is exactly what 1bolt is accomplishing in his project thread!

Flash

[John]

Maximizing what is present, and reducing existing limiting factors, sounds like hot rodding, I am not trying to talk you out of experimenting with various intakes, trying to point out where the benchmarks exist, There is gains to be made in the system and bigger is not always better, inlet temps, velocity, proper design of a exhaust system make huge differences.
John

[tirod]

Manifold porting is usually selective in improving overall velocity, not necessarily mass flow. That means only certain portions of the manifold get modified - which requires a flow bench and considerable experience. Extrude honing just removes material where the solution passes by the most - generally enlarging everything, good or bad. From what I have researched, topflight manifold porters do an extrude hone to finish the work they have done, rather than to create it.

Kinda like header wrap, it only helps the folks looking for the last 2%. The dyno'd difference between a 62 vs 64mm would be worth knowing just to see if it's worth it. I suspect the stroker could take better advantage of it than stock.

[John]

That would depend also if you are only interested in WOT or throttle response. Stock favors the latter, with the Stock TB and newer manifold on a stroker, I have tired a 63mm and stock on it.
John

[xjcrazed]

I'm not sure if these results apply directly to strokers, but these dyno results of 62mm throttle bodies give further credence that the TB is not the limiting factor:
http://www.rockymountainextreme.com/sho ... stcount=44

The whole threadhttp://www.rockymountainextreme.com/sho ... hp?t=30793 is a good read, but the results are in the previously linked post.

Rob

[John]

Thanks for the link, I suspect that the AllJeep.com's bored (60 mm butterfly with a 62 mm gasket match taper) throttle body....reduced turbulence by gasket matching at the throttle body but succeeded in keeping up velocity at the butterfly area. I like my custom 63mm TB but it has it's own problems. I spoke with Oletshot about making me a CNC custom one a little different.
John

[Flash]

That test was done 2 years ago and there was a lot less stroker in this world. O, and thank, as well, xjcrazed, for the links!!!!!

It would be vary cool to see that test done again with a cam'ed Stroker pulling air thru it!

It's to bad that they couldn't test the spacer as thats still a big question mark


Flash