SMIM Showdown! Lets figure this out once and for all! - Page 7

95talonracer · 12-22-2008

This will cause uneven power and would that be hard on anything like bearings, pistons or just the total output of power and the equal power numbers made per cylinder.

C3L1CA · 12-22-2008

Cool to see some results. I have a stock 2g mani that you could use if you wanted a base line, could take as long as you wanted with it too.

**Halon** · 12-22-2008

Are you posting this on other forums? I'd like to hear what others have to say about this since, again, I'm far from an expert on any of this. I'd assume there's a lot more to IM performance other then what was tested here also.

Someone had mentioned something about this test being done with the manifold under vacuum, while it's usually under boost in our application, so are these results valid for our application. I have no idea, just like to see it put up elsewhere besides on here so we can get more input.

iroc_g · 12-22-2008

I'm honestly not an expert either, so I just have to trust what I have been taught by my boss, who is deffinatly an expert. Flow is flow, no matter if under pressure or vacuum. Intact, I remember reading a few things saying that a pressure situation would actually agravate the issue.

I want to hold off a day or two on spreading the link. I'm working with scheides on having it hosted here instead of my served (borrowed web space from ProKART!) once we get that worked out, then I deffinatly want to get this out!

And yes, baselines are hopefully coming very soon. If I can get some stuff done around the house, I'll pull my stock 1g tonight. And iceminion has offered his cyclone. Doing a 2g would be good to, so long as I don't have to modify my test fixture too much.

**JET** · 12-22-2008

Alright, I was holding off on saying anything about this until I saw how the test was going to be performed. I think there are a lot of people that are going to misinterpret this data. The test is NOT representative of the numbers that will be seen inside the engine.

One of the first things many people will notice is that there is no Heimholtz resonance taken in to effect because that can only be seen with the valves opening and closing. In a manifold with a straight back wall, this will not create a difference in flow balance between cylinders, but may change the flow numbers either plus or minus.

Another thing that is a larger issue is that there are no restrictions farther down line in this test (both sets of valves and turbo). This restriction downline from the IM will help to even out the flow of the intake manifold, so you will not see the imbalances to the degree that this test shows. Think of it this way, you have a 5" exhaust with a 1" outlet, will a 6" pipe with a 1" outlet flow any more? No, they will both be limited by the 1" restriction, the restriction is the valves and turbo. The degree of this can't be known unless a running engine is tested at a high flow rate.

I am not saying this test is not useful at all, but people need to be informed to really see what these results mean and I bet the vast majority of the people that will look at these results will not meet that criteria.

Kevin 1G Drummer · 12-22-2008

So one thing I was curious about. Did you number the runners like they would be numbered on the car? I.E. runner #1 being farthest from the TB?

iroc_g · 12-22-2008

Yes, runners are numbered as your sparkplugs would be.

Scheides got me setup to have this hosted on this board. Thanks alot! I'll get the change made tomarrow and we can start spreading the info.

wheelhop · 12-22-2008

Quote:

Originally Posted by JET

Alright, I was holding off on saying anything about this until I saw how the test was going to be performed. I think there are a lot of people that are going to misinterpret this data. The test is NOT representative of the numbers that will be seen inside the engine.

One of the first things many people will notice is that there is no Heimholtz resonance taken in to effect because that can only be seen with the valves opening and closing. In a manifold with a straight back wall, this will not create a difference in flow balance between cylinders, but may change the flow numbers either plus or minus.

Another thing that is a larger issue is that there are no restrictions farther down line in this test (both sets of valves and turbo). This restriction downline from the IM will help to even out the flow of the intake manifold, so you will not see the imbalances to the degree that this test shows. Think of it this way, you have a 5" exhaust with a 1" outlet, will a 6" pipe with a 1" outlet flow any more? No, they will both be limited by the 1" restriction, the restriction is the valves and turbo. The degree of this can't be known unless a running engine is tested at a high flow rate.

I am not saying this test is not useful at all, but people need to be informed to really see what these results mean and I bet the vast majority of the people that will look at these results will not meet that criteria.

AMEN!!! I'm glad most havn't chosen an intake manifold based on constant volume flow. Resonance or not, the intermitant flow demand placed on the intake manifold will make a compressable fluid like intake aircharge act VERY different than a flow bench. The only way to tell which manifold flows the best is th put it on a motor with a known reliable maf like a 2g maf. If you want results for each cylinder, put a wideband on each cylinder and see how lean each is. . . Otherwise look at the whole picture like the real world has to

**Kracka** · 12-22-2008

I'd imagine this testing is at least a good starting point in the research/decision process, correct?

iroc_g · 12-22-2008

I agree that these tests aren't the whole picture. But, one has to ask the question, "why don't any of these manufactures flow test, or anything other than dyno test their parts."

I plan on showing the constructive critisisim comments to my boss, who will be able to much better answer these questions. One thing I can tell you though, at 30+ pounds of boost, we are forcing much more air through the intake than the flow bench is capable of. Makes you wonder how the incocsistency translates at those levels. I don't think that anybody can argue the importance of having each cylinder having balanced output, which will require balanced input.

wheelhop · 12-22-2008

Yes balanced flow has it's place and is important in that place. Where did the stock 1g manifold rate?

Please don't stop testing!!!! Good stuff. This is why I registered to this forum. I think you should go to the next level since you have the manifolds (if you get permmission). Do better than what the vendors do. Log the volume flow difference on a common setup like 272s and a stock exhaust manifold varying from 20-30psi and typical intercooler piping diameter and typical intercooler. There's lots of variables there, but so many choose close to the same thing WRT sizing and cams, that you will find good data for many.

Hmm apparently tubulance had no effect on flow numbers as some manifolds flowed less and had less turbulance than others and some runners of the same manifold had more turbulance but flowed in the same area or more than others.

iroc_g · 12-23-2008

Actually, the turbulance had a large impact on the flow. One of the manifolds we spent a little time wessing around with, we were able to eliminate the turbulance, which brought the flow numbers within 1%. None of that is noted because that would be a design change, which I have no wish to get into.

I have been approached by a company wanting to take this to a dyno test in the spring. I honestly don't know if that will materialize or not, as people are not going to want to lend out their manifolds then, but well see what we can come up with when the time comes.

And as far as the 1g intake, I JUST got mine off. I have 3 bloody knuckles to show for it as well. I guess I'll start that wire tuck since there's nothing I the way now.

I'll update with the 1g findings, and hopefully the beyond redline numbers tomarrow, if ups can manage to deliver somthing on time for once!

Pushit2.0 · 12-23-2008

First off is thanks for getting this together, and second is just wow at the numbers. I can not take credit for the runner design or die I am using, and the rest is to close to the AMS VSR that I do not want to get into it. I do know why that number 1 runner did a little less, its good to see the little things are what makes the difference.

I have a finished "race" manifold here I am going to get in your hands before the holidays. This unit has a bigger plenum and a bigger radius on the runner inlets. I am also going to make a "drag" version which will have a lot bigger plenum and a little different runner setup. I would like to see the manifold tested that was on my car, that was a little different then either one I have made also (talk to GREASEMONKEY he has it now). And I do plan on making these by order: the customer would specify runner length, runner tapper, radius size into runners, vac port locations and plenum volume and TB flange. I will also be warranting these manifolds to as much boost as you can get in there from a turbo, and anything besides a major nitrous back fire (I inside/outside weld the hole manifold, minus the end cap and TB flange, but I can weld the inside of the end cap with request, and with a Q45 TB flange I might be able to weld the inside of that also).

Which I can/could add nitrous and additional injectors at an added fee. And I plan to do this at mostly the same price. I hope the rest of the flow bench test go well and it would be nice to see these on a car to see the numbers backed up. JET get one done so we can see what it will do.

~John

Swifty1638 · 12-23-2008

Wow, thanks to all who repsonded ,and participated. It was a pleasant suprise the response I got from a few of you whom i texted that night a few weeks ago. Now we have a solid base from all manifolds tested to present to everyone. Thanks to Greg for actually doing all the testing.

I'm sorta suprised that my new mani didn't do better then it did. But, i do see that i should run the q45 and not the 1g with the plate..lol

-A. Swift

niterydr · 12-23-2008

Hmm....

**scheides** · 12-23-2008

MattD has my stock evo manifold and TB....you should test it once he gets it back to me.

We may have a ported manifold and 65mm TB for you to test soon thereafter. These are hot mods for the evo guys.

Andrew7dg · 12-23-2008

Quote:

Originally Posted by JET

Alright, I was holding off on saying anything about this until I saw how the test was going to be performed. I think there are a lot of people that are going to misinterpret this data. The test is NOT representative of the numbers that will be seen inside the engine.

One of the first things many people will notice is that there is no Heimholtz resonance taken in to effect because that can only be seen with the valves opening and closing. In a manifold with a straight back wall, this will not create a difference in flow balance between cylinders, but may change the flow numbers either plus or minus.

Another thing that is a larger issue is that there are no restrictions farther down line in this test (both sets of valves and turbo). This restriction downline from the IM will help to even out the flow of the intake manifold, so you will not see the imbalances to the degree that this test shows. Think of it this way, you have a 5" exhaust with a 1" outlet, will a 6" pipe with a 1" outlet flow any more? No, they will both be limited by the 1" restriction, the restriction is the valves and turbo. The degree of this can't be known unless a running engine is tested at a high flow rate.

I am not saying this test is not useful at all, but people need to be informed to really see what these results mean and I bet the vast majority of the people that will look at these results will not meet that criteria.

Well put...

I am kind of interested in the LSE manifold design. It is interesting to look and compare the pictures of the designs and then try to figure out why they flowed like they did.

I am curious, why isn't the LSE manifold taper at the end like the rest of them? or is it and I am just at a bad angle?

Or is the design Top Secret?

I have been reading up on intake manifold designs (in actual BOOKS!) and just curious why it is designed that way compared to other aftermarket intake manifolds.

Shotgun! · 12-23-2008

Really cool to see results!

Pushit2.0 · 12-23-2008

I am the guy to ask about the LSE manifold, PM me with specific questions. When I finalize a base design that will be "mass" produced I will write up all the details and why the manifold ended up the way it did.

~John

**JET** · 12-23-2008

Quote:

Originally Posted by iroc_g

I agree that these tests aren't the whole picture. But, one has to ask the question, "why don't any of these manufactures flow test, or anything other than dyno test their parts."

It may be because these results do not translate to real life at all, but I am not sure if they do or not. I know when the other SMIM test was done they decided not to do a flow bench because it was not realistic. Instead they put each one on the dyno.

I wish I had more information to help put this together, but I don't. One thing is for sure though, a balanced manifold on the flow bench can't be a bad thing on a real car.

And yes, the air going through a flow bench is not even close to the air going through it at high RPM, the air is at over 200mph in a real car.