Ok, but be advised that a flowbench can no more reveal what will actually happen when the manifold is subjected to the pulsing air pressure fluctuations of a running engine than can one tell what key a trumpet plays by simply blowing air in it as opposed to actually playing it.

FYI

 

I would love to know how you got an AMS race manifold. The last time I looked we sold one that Paul has now and we have one on our drag car. I could be mistaken but I think you have a standard or twin rail unit...not the larger plenum drag version. we have sold so few and I don't think any of them have made it over seas. A picture would tell us for sure.

Eric

 

You have said some pretty insightful things Ted but this is up there as one of the best. Great way to take a complicated theory and put it in practical terms

Eric

 

I love Ted B.

Jerry

 

yeah, too bad he lives out west, i could use another guru at the shop

 

I want to give you guys someone to hate on and holler at, so I'm back......haha

I have also flow tested intake manifolds/exhaust manifolds in the past on a flow bench. While the pulsing I am sure has some effect on ow it actually performs I can tell you that the flow bench will atleast give you an awfully good idea.

I have no idea what EVO400 came up with for results or any other details.

I do know that in particular when we tested headers/manifolds bolted to a head on a flow bench that the results on the bench were the same as on the car. If it worked best on the flow bench it worked best on the car. We had days of testing in doing this.

As for the intake manifolds we did the same test but did not test them on the dyno afterwards. I have a good idea, of the ones we tested, which one ended up working the best though. BTW, these were done years ago on the RWD Pro Import Eclipse.

As for the AMS intake manifold, I give it a thumbs up. As for some of the others, a definite thumbs down, power loosers.

Looking forward to your testing Paul. I just hope you use a turbo that has some mid-range power so you can see the same results I have in the past. Be warned, you are going to **** some companies off with your results........

 

David you drinking tonight My spelling gets worse when ive had a few

Ill have a t3 35r to test so it should make some good midrange power.

 

Ok David, but I've coincidentally witnessed a very similar test just recently in which the best flowing exhaust manifold (according to a flowbench) actually gave the slowest numbers at the track. This is why manifolds aren't traditionally judged by flow bench tests. Manifolds aren't evaluated with flowbenches not because no one thought of doing it, but because flowbench testing doesn't reproduce what a manifold sees when the engine is running. If it did, the biggest manifold would always be the 'best' and things just don't work that way. Of course, if the manifold (intake or exhaust) has a fundamental design flaw that supersedes any hemholtz tuning shortcoming, or seriously compromises head port flow, that's an altogether different problem.


Actually, I live in the southeast (Birmingham and New Orleans), but I do roam around the country and the planet quite frequently. As they say, it's a 'dirty job', but . . .

 

when youre in the pa area call me.

cb..

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paul get to gettin' on this testing will ya LOL!

cb

 

cb, will do.

One more thought I should probably share before I get on with my day of travel . . .

When we test the intake ports of a head on the flowbench, we obviously learn a good deal about how the ports respond to different degrees of valve lift. And the better our port job, the closer all the ports will flow to each other at any given valve lift.

If we're satisfied with our head, we can then bolt an intake manifold to the head while it is on the bench, and flow it again. While this won't really tell us anything about the actual tuning of the manifold (as I indicated previously), what we can do is compare the flow with the manifold attached to the flow of the bare head with clay radii on the ports.

If we compare the two sets of numbers, we can see if there is a physical issue that causes the runners of the intake manifold to flow differently with respect to each other, or, if there is a physical issue in the manifold that reduces the flow in all ports significantly. We can't gauge how effective our plenum and runner tuning are (which is fundamentally important), but we can check for:

(1) Significant reduction in port flow with manifold attached
(2) Flow imbalance between ports with manifold attached

For example, I had a recent discussion with a renowned head porter concerning a certain engine, and he revealed to me that even with a strong head for this engine, a particular intake manifold reduced the flow to the two inner cylinders more so than the outer ones. Obviously this is something to note, as we wouldn't get even airflow in the cylinders, which will cause uneven fueling, and quicker detonation. A better manifold would have had the same tuning (which we can't check on the bench), but would have had better runner flow and more even flow distribution.

So, while this didn't tell us anything about the tuning of the manifold (which performs well in certain applications), it showed that the design of the manifold has shortcomings that will hamper an all-out effort, regardless of what rpm points the manifold runs at peak efficiency.

Just some FYI.

 

I have conducted litterally about 9 months of intake manifold testing on flowbench and engine dynos (both superflow machines). Just because a manifold looks good statically on the flowbench, meaning it has equal measured flow through each runner, does not mean that it performes well dynamically running on the engine. This point really can not be argued.

In order to take full advantage of Hemholtz and inertial effects, manifolds should have equal length runners so that the intake tuning design takes effect at the same RPM point for each cylinder. The problem that is observed with this, especially from side entery plenums, is that if the runners are truely equal length, it is harder to acheive equal flow on the bench, hence why we often see tapered plenum or tapered runner designs or an overly large plenum.

One thing to remember is that poor manifold design can be masked by boost! Once the plenum is pressurized ( I have done some data aquisition on a few boosted applications where manifold pressure was measured from 100 locations in the plenum, the damn manifold looked like Hellraiser with all the pressure ports coming out) it hides an unequal dynamically flowing manifold, because it generally equalizes the flow distribution out. You will find that Naturally Aspirated intake manifold design is much more critical than Force Induction. Slap a restrictor on to a manifold and then your in for some fun!

 

NOt to nit-pick or anything, but actually having 2 different lengths of runners on the motor can help broaden the effect of the helmholtz effect... Suzuki has great luck with this on the GSXR engines, where the center two runner are nearly an inch and a half longer than the outer two... It does lessen the effect at a specific rpm, but it will spread out that range it does effect...
IIRC the gsxr750 's two lengths were tuned for 9700 rpms and 10,300..... ( i think)

 

All of the mentioned reasons from intelligent posters is why I asked HOW is this testing going to be done. Lots of good information from people with lots of knowledge. It would be nice to see the final dyno results and how that compares to 'tested' results.

 

Very soon

If i didn't have a company to run i would be playing around with this stuff all day long everyday

 

My concerns at least have been addressed. A manifold that flows well at 56psi could actually be 'masking' flaws in design for our puny 37 psi. If it doesn't work at 37 psi, then it probably, or at least likely isn't going to work for the stock turbo at 28psi. That's why I think it's significant to note how the stock manifold works at low psi and 40+ psi. Am I missing something, or is the stocker that good with simple modifications?