***1.8T Intake Manifold Test Results***

[VariantStg3]

Quote, originally posted by Don R »

Reason why ABD has made satisfactory results is do to its short, wide and stuby runner design. I'd like to point out that it's overall performance would not be as expected. Trq in the mid-range would suffer and fuel atomization would be less than opitmal as a result from low port velocity and turbulent flow.

So what we need now is for people who have purchased these manifolds to run a few before and after dynos for comparison.

As far as the length goes Don if your willing? I read slappy saying that if all you wanted was great flow you would just bolt a plenum to the head? this would equal great flow with no velocity. Now, for my application I believe I could use some sorter runners to help horsepower from 5K-8K and also change the torque band upward.

What would be an ideal length for the runners based on the powerband goals? My home brewing logic says bust out the saz-all and cut 2 inchs out of the middle welder back up and let'r eat, but i thought I'd ask before I turn a decent success into a complete failure.

[slappynuts]

Quote, originally posted by Don R »

Reason why ABD has made satisfactory results is do to its short, wide and stuby runner design. I'd like to point out that it's overall performance would not be as expected. Trq in the mid-range would suffer and fuel atomization would be less than opitmal as a result from low port velocity and turbulent flow.

I have looked at most of the runners and I think most of the manifolds in this test(except maybe ABD one) have too long of a runner to take advantage of a bigger turbo.I can tell you this about the manifold I am building,that its about an inch and a half shorter than most of the manifolds in the test.

[04VDubGLI]

Don R - I'm confused as to whether the ABD would not perform as expected in a good or bad fashion? I mean, there are obviously some increases in air flow and seem to be pretty consistent at that...

I now am wondering if maybe it would be worth it to get it extruded and honed. I imagine that would not only clean up all of the slop, but probably even make the runners a little more efficient?

[Don R]

Quote, originally posted by VariantStg3 »

So what we need now is for people who have purchased these manifolds to run a few before and after dynos for comparison. As far as the length goes Don if your willing? I read slappy saying that if all you wanted was great flow you would just bolt a plenum to the head? this would equal great flow with no velocity. Now, for my application I believe I could use some sorter runners to help horsepower from 5K-8K and also change the torque band upward. What would be an ideal length for the runners based on the powerband goals? My home brewing logic says bust out the saz-all and cut 2 inchs out of the middle welder back up and let'r eat, but i thought I'd ask before I turn a decent success into a complete failure.

If I had the time I'd have the pleasure in doing so...but I'm swamped with work.

With regards to your manifold...it would have been great if the OEM injector bungs protruded a lot less into the runner. IMHO, I'd suggest you leave your runners as is (Not unless you plan on revving past 8500 rpm.) - runner velocity plays an important role in increasing flow from better air flow lamination. This involves more flow vectors per cross-sectional area. Furthermore, if you were to increase the distance from runner 1 to TB entry this would help improve flow by eliminating the turbulence happening there.


Modified by Don R at 9:16 AM 2-27-2007

[Don R]

Quote, originally posted by 04VDubGLI »

Don R - I'm confused as to whether the ABD would not perform as expected in a good or bad fashion? I mean, there are obviously some increases in air flow and seem to be pretty consistent at that... I now am wondering if maybe it would be worth it to get it extruded and honed. I imagine that would not only clean up all of the slop, but probably even make the runners a little more efficient?

I mentioned this before in the other thread. These flow results are not be considered definitive since an intake under goes dynamic flow, pressure, temps and transient flow. The extrude hone may improve it but would not be worth it.

[04VDubGLI]

Thanks. I'm definitely going to try to get a dyno up w/it. Of course I still have a small turbo... but that's ok. It'll give some idea anyhow I suspect.

[Don R]

Quote, originally posted by 04VDubGLI »

Thanks. I'm definitely going to try to get a dyno up w/it. Of course I still have a small turbo... but that's ok. It'll give some idea anyhow I suspect.

Don't expect much

[04VDubGLI]

What gains would you expect to see? What would you say is the best SP intake mani then? The SP 007? Or are SP intake manifolds in general not going to show much of an increase due to an apparent max increase of about 200cfm? Sorry, hopefully someone else is a little confused or I'll feel dumb. I guess my real question is what would you expect the cfms to translate to in terms of hp/tq - I know it's a little more complicated than that, but just speaking generally.

[axlekiller]

200cfm is ~133hp. The question becomes when you can move 200 cfm more. There will be gains but after you install a competent intake manifold, the head/stock cams become the next flow restriction. And yes, the SP 007 will show the best gains of the small port intake manifolds testing, but if you're not already on a big turbo setup, then you have other areas to address.

[Don R]

Quote, originally posted by 04VDubGLI »

What gains would you expect to see? What would you say is the best SP intake mani then? The SP 007? Or are SP intake manifolds in general not going to show much of an increase due to an apparent max increase of about 200cfm? Sorry, hopefully someone else is a little confused or I'll feel dumb. I guess my real question is what would you expect the cfms to translate to in terms of hp/tq - I know it's a little more complicated than that, but just speaking generally.

None of these intakes will yield any significant gains on the stock turbo you may get an increase in trq but that's about it.

I beleive the ABD/Del Rio intake mani was designed to use with the delrio kit that uses the 28RS turbo.

[VRT]

I will be doing a before and after dyno test on my RMR as soon as I get it back

[axlekiller]

Quote, originally posted by VRT »

I will be doing a before and after dyno test on my RMR as soon as I get it back

Good stuff Rob, thanks again for letting us test it. The most interesting results will be from comparing before and after dynos to the flowbench results.

[Don R]

Quote, originally posted by VRT »

I will be doing a before and after dyno test on my RMR as soon as I get it back

Right-on Rob

[axlekiller]

Quote, originally posted by slappynuts »

I have looked at most of the runners and I think most of the manifolds in this test(except maybe ABD one) have too long of a runner to take advantage of a bigger turbo.

Are you including the length of your runner and V stack protruding above/off the plenum floor? That's only going to cause turbulent pockets of air, and you don't have the necessary full radius 1-1.5" on the stacks to make a 270* sweep into the runner entry. Would you like to send your intake for flow testing once completed to compare to these others?

[igotaprestent4u]

Quote, originally posted by Wizard-of-OD »

You deducted this from the results?

pretty much,

lets see, the RMR is one of the best flowing manifolds, with the best distribution among cylinders.
The pricing is spot on, and you have the option of different throttle body options plus the location of the throttle body,

tell me why it isn't a good buy?

[Don R]

Quote, originally posted by igotaprestent4u »

pretty much, lets see, the RMR is one of the best flowing manifolds, with the best distribution among cylinders. The pricing is spot on, and you have the option of different throttle body options plus the location of the throttle body, tell me why it isn't a good buy?

So are you taking these results as defenitive?

[axlekiller]

Quote, originally posted by igotaprestent4u »

pretty much, lets see, the RMR is one of the best flowing manifolds, with the best distribution among cylinders. The pricing is spot on, and you have the option of different throttle body options plus the location of the throttle body, tell me why it isn't a good buy?

Distribution can be fixed on the Homebrew, and you'd still have the throttle options with possibly less price. 007 is the same price as the RMR and can be built to spec and flows more. Like we've stated, distribution will be better under pressure, unlike vacuum. So why is RMR the winner?

[badger5]

quick question.
Runners #1 thru #4 are numbered from throttle end to opposite end yea?
throttle end runner being #1 in the results yea?

If so.... 007 small and largeport... lower on #4 runner... why is this? Plenum size in this end effecting flow? (and if so, what effect on balancing flow would there be from rotating throttle plate? )

[axlekiller]

Yes, #1 is closest to the throttle. Lower numbers on 007's in runner #4 are from the taper of the plenum. Once again, under pressure, runner #4 won't suffer from this.

[slappynuts]

Quote, originally posted by axlekiller »

Are you including the length of your runner and V stack protruding above/off the plenum floor? That's only going to cause turbulent pockets of air, and you don't have the necessary full radius 1-1.5" on the stacks to make a 270* sweep into the runner entry. Would you like to send your intake for flow testing once completed to compare to these others?

Yes I am including the length of the runner and the rest of the port to the back of the head.The 4" plenum is there because of the ugly turn to the first runner and to have extra volume to maximize the amount of area around the stacks.

I used the stock intake to decide on where the"sweet spot" is and then I raised the resonant RPM 1000rpm beyond that.

[rogerius]

can somebody elaborate on how is the flow in the runners respectively during opening/closing of the admission valves?It is an interrupted flow,isn't it?If so,isn't there plenty of time for the flow to equalize for each runner (in the pressence of an adequate plenum) unlike the test showed?Please educate me!

[petesell]

can anyone speculate at what power levels the stocker runs out of breath in order for these manis to have a reasonable cost/benefit ratio? has there even been a back to back dyno with just a manifold swap on a BT setup?

good thread

[slappynuts]

Quote, originally posted by petesell »

can anyone speculate at what power levels the stocker runs out of breath in order for these manis to have a reasonable cost/benefit ratio? has there even been a back to back dyno with just a manifold swap on a BT setup? good thread

No they cant.

[TyrolSport]

Quote, originally posted by petesell »

can anyone speculate at what power levels the stocker runs out of breath in order for these manis to have a reasonable cost/benefit ratio? has there even been a back to back dyno with just a manifold swap on a BT setup? good thread

Based on the 386CFM of the stock small port, I wouldn't consider an intake manifold until I was over 300whp, or my turbo was maxed in it's current sub 300whp configuration.

[Aeneis]

I rarely post on this forum anymore, but I happen to see this. BIG PROPS to everyone involved who made this possible, great objective data to override butt dynos.

[enginerd]

Most "choking" on these cars is the turbo running out of steam, or back pressure in the exhaust causing the boost to fall off. I wouldn't attribute this fall off to the manifold runner length.

The fall in power matches the original one, if it was the slightly longer runners causing the problem you would see it lose power in the upper range.

I saw some decent gains on my car with the small port 007 till it leaned out on the dyno. Most gains were in the midrange, which is what I was looking for. I am not sure what the max gains would be up top because I leaned out, however I feel that the upgrade from stock was definitely worthwhile. Even with a measly 265 whp. The fact that I was leaning out and went up to 100% duty cycle showed a big flow increase.

[enginerd]

Quote, originally posted by VariantStg3 »

As far as the length goes Don if your willing? I read slappy saying that if all you wanted was great flow you would just bolt a plenum to the head? this would equal great flow with no velocity. Now, for my application I believe I could use some sorter runners to help horsepower from 5K-8K and also change the torque band upward.

This is my problem with the ABD manifold, the taper they have and the stumpy runners make the runners part of the plenum. Good for flow, but bad for any kind of resonance tuning.

The OEM manifold is actually kind of short for an engine designed to run 6750 max RPM. Looks more like a honda manifold than a vw.

[Don R]

Gents, I'm going to have appologize on Stu's behalf for deleting my posts. Apparently, I have been braking the rules so I am going to refrain from any further participation.

Thanks.

[enginerd]

Don,

enough with the fearmongering, there is no conspiracy

[SAGTI]

I for one would have really enjoyed Don R's continued input here.

[enginerd]

There are other places that this can be discussed without outside influence, or restraint.

[VariantStg3]

Quote, originally posted by Don R »

If I had the time I'd have the pleasure in doing so...but I'm swamped with work. With regards to your manifold...it would have been great if the OEM injector bungs protruded a lot less into the runner. IMHO, I'd suggest you leave your runners as is (Not unless you plan on revving past 8500 rpm.) - runner velocity plays an important role in increasing flow from better air flow lamination. This involves more flow vectors per cross-sectional area. Furthermore, if you were to increase the distance from runner 1 to TB entry this would help improve flow by eliminating the turbulence happening there. Modified by Don R at 9:16 AM 2-27-2007

Well now that your not gonna participate here anymore hopefully you can get some other work done. Thanks conspiracy creators wherever you may be.

Thanks for the input on the runner lengths I have put the saw-zall down and am backing away from the manifold. I am going to use the material I haveleft from RMR to lengthen the plenum. I only have 1.75" to play with though. I am gonna make drawings and post them on the other forum for you to gander at. Cheers!

[slappynuts]

Quote, originally posted by VariantStg3 »

Well now that your not gonna participate here anymore hopefully you can get some other work done. Thanks conspiracy creators wherever you may be. Thanks for the input on the runner lengths I have put the saw-zall down and am backing away from the manifold. I am going to use the material I haveleft from RMR to lengthen the plenum. I only have 1.75" to play with though. I am gonna make drawings and post them on the other forum for you to gander at. Cheers!

Not longer,shorter.

[SAGTI]

Quote, originally posted by enginerd »

There are other places that this can be discussed without outside influence, or restraint.

Yes I have joined up there, thanks

[enginerd]

Quote, originally posted by slappynuts »

Not longer,shorter.

I think he is talking about lengthening his plenum, not his runners.

Giving more entrance length to his plenum should help with distribution.