Ported Intake Manifold

[WNH]

Anyone install one???
I hear they increase HP by 10-15 HP, for about $300.

Any comments.

 

[c4c5specialist]

At the sacrifice of low rpm torque.
Personally, I dont recommend them.
Allthebest, c4c5

 

[kelp]

You should have the TB walls even out a bit also. But it is more like 10 RWHP. Nice even throttle response. Be sure the manifold is immaculately clean.

 

[Hib Halverson]

If you're talking about "porting" the plastic intake manifolds used on Gen3 and 4 V8s....where is it that you "heard" there's 10-15hp in doing that?

 

[Warp 10]

Just my TB please

I have "cleaned up" the TB's on both my C5 Z and now my C6 Z.

This according to my butt and a couple of acknowledged automotive engineers on GM performance, worth on average 9 to 10 Hp.

The factory TBs have parting lines and other restrictions that disturb both low and high rpm air flow. Take a look at any aftermarket replacement and you will see what the GM part is not.

As far as the intake manifold, I would leave it alone unless you are racing and know what you are doing. It is a very nice piece as is; or take your heads, intake manifold and TB to a professional porter. There is power to be had there, but it aint cheap!

 

[WNH]

I have "cleaned up" the TB's on both my C5 Z and now my C6 Z.

This according to my butt and a couple of acknowledged automotive engineers on GM performance, worth on average 9 to 10 Hp.

Well, I swapped my intake manifold for a ported one, ported by a pro.
I also installed a Callaway Honker.
I do feel a SOTP difference, but the real test will be at the 1/4 mile track.

 

[Warp 10]

WNH Baseline

Well, I swapped my intake manifold for a ported one, ported by a pro.
I also installed a Callaway Honker.
I do feel a SOTP difference, but the real test will be at the 1/4 mile track.

WNH, do you have a baseline track # to evaluate against?

My reason for asking is that my guess is that you will have a very small diff in track performance. Maybe ,04 to .08 seconds.

Anyway, please let us know if there is a measurable gain.

Bill

 

[KANE]

At the sacrifice of low rpm torque.
Personally, I don't recommend them.
Allthebest, c4c5

Paul is right. He's scratched the surface on something bigger than just the part you were looking at.

There are a lot of parts out on the market that just move the numbers around without any real gains. That low-end helps it get up to the high-end.

If you drive regularly in the high-end... you might need the shift in torque to HP. For a street driven Vette I'm not sure how helpful that would be. For example, I've set up my TPI to breath better up to 5500rpm... but maybe once in a month of Sundays I actually use it. Really- I rarely ever push it past 4500rpm.

I'd say exhaust would be a better investment. I would think for $300, you could have a shop make up a set of in-house "loudmouth" style pipes. But, you asked about the intake itself. Sounds like some folks have found it to be useful. Go for it if you think your combination would benefit.

 

[WNH]

WNH, do you have a baseline track # to evaluate against?

My reason for asking is that my guess is that you will have a very small diff in track performance. Maybe ,04 to .08 seconds.

Anyway, please let us know if there is a measurable gain.

Bill

I did test my 1/4 mile time last week.
I did 4 time shots and ran a consistant 12.4s.
My previous high was 12.75 at the same ambient temp.

BTW, I don't consider .04 to .08 a 'very small' difference.
I'm very satisfied with the gain. I think I can get more, my shifting needs a little improvement.

 

[kelp]

I ported my intake manifold. I didn't notice more than a slight difference, and have yet to hear a dyno tuner confirm a measurable increase. Nevertheless, every little bit helps.

 

[TODD L GRIFFITH]

I ported my intake manifold. I didn't notice more than a slight difference, and have yet to hear a dyno tuner confirm a measurable increase. Nevertheless, every little bit helps.

The only manifold porting I've done was for port matching on a FAST 90. If you are running an LS2/7 throttlebody, there is a big improvement that can be made there also.