Throttle body spacers
 

I am contemplating these as it is another way to push more air volume into the intake manifold.

Is anyone using them? Where did you get them from? And do you feel any difference?

I haven't tested anything, but people here that have their cars built, even the forced induction turbo and s/c guys don't need a bigger TB. it's already oversized for stock anyway.

He's talking spacers, not larger throttle bodies.

Back to the topic. I'm curious if they're worth it, but unless the cost was low I'd still wait for a after market intake manifold

So you havent tested anything, yet you make a statement on something that you dont hold knowledge of.
Ok, I was talking about spacers on the throttle body.
To answer your question, I have an increased size tb to 68 and it makes a difference. Not huge but noticeable, so I guess the engine could benefit from more air volume in the intake.

Back on topic! ;)

How does it push more air volume into the intake manifold?

big throtle + spacer make more torque. i'm use 70mm + spacer

Fact or placebo? Have you got dyno charts to show the improvements?

Theoreticly a throttle body spacer should have the same effect as the crawford BPB. ie changes the volumetric efficency of the engine to produce more power/torque in a particular rpm range. Can you get enough volume in a throttle body spacer as compared to BPB wotld be the question and also is that volume increase beter closer to the individual intake ports as oposed to the collective volume increase behind the throttlebody.

The BPB seem to do their best on stock cars with stock tune, they produce some power increase and shift the peak power lower in the rpm range.
Once you start tunig the car and doing other things to increase the volumetric effiency such as cam timing changes and catless headers with different length and diameter primary tubes the increase you get from BPB is diminshed.

Yes you would have to dyno before and after to be sure of anything.

I think the point of the BPB is that the RUN directly into the intake valve runner is longer allowing the intake charge to maintain more momentum into the valve.

My guess is that adding more "Run" before the diverter portion of the intake manifold will make little to no difference.

Or just adding an intercooler with no FI would do that too no?

Which throttle body are you using?

What spacer do you use?

LoL that's something I can't wait to see! Please tell me nobody already does this for other platforms?

Would love to see the dyno sheets supporting claims that larger then necessary throttle bodies add hp/tq.


IIRC, when Shiv tested the Crawford manifold spacers all they did was shift the hp/tq peak with no peak gains. After many hours of tuning he managed to regain some of the higher rpm hp/tq lost with the spacers, making for a slightly wider powerband.

I would have to agree with this. The only way I could see it affecting anything is adding to the plenum volume, maybe, theoretically helping out in the upper RPM's. But I would think the small amount the spacer would add would not be noticeable in the real world. Except to those people who swear they can feel that 3 Hp@7000 RPM that a drop in filter gives them..... :)