200whp with stock N/A rotating assy?

[LJ851]

Interesting that the stock manifold (basically) meets back up with the ITB's @ .5 inch lift.

What kind of valve lift are the various m20 cams generating?

[ForcedFirebird]

It's because the ITB's are maxing flow. I haven't flowed one individually, but it's right where Dynomation says a 40mm throttle potentially flows. .500" is 12.7mm, doubt many people are running that kind of lift, specially on a stock head. Would have to cut a stock manifold to measure diameter, but remember, manifold runner would be also lacking a butterfly (throttle plate).

[LJ851]

^ Right, and it also doesn't include the resonation effects of the stock plenum either...

[ForcedFirebird]

This is static flow testing resonance and reversion would be in a running engine.

To add, we should be looking at mid lift numbers as that's where the valve spends most of it's time, the valve sees mid lift twice per cycle.

[digger]

It is expected that head flow goes down a bit when you add the intake.

Pretty sure e21 JPS said the 40mm ITB flows well over 200CFM but I have no idea if it is with the manifold and trumpet or just the ITB with clay entry.

Then there is the length the RHD kit is ~12” and stock is ~17” from memory.
12” tunes at an rpm much better suited for making hp as it is an rpm when most M20 are starting to choke. 17" makes good midrange but not topend.

It reinforces the notion that there is more to the induction design than pure flow numbers.

[digger]

is the head going to be ported and with cam on this build?

[ForcedFirebird]

272 IE cam, and +1 valves. with very little porting.

[ForcedFirebird]

Pretty sure e21 JPS said the 40mm ITB flows well over 200CFM but I have no idea if it is with the manifold and trumpet or just the ITB with clay entry. .

I stand corrected. The dynomation figures are in 1.5" Hg, not 28" h2o. Doing a conversion with math, that should equal almost 200cfm.

[digger]

I stand corrected. The dynomation figures are in 1.5" Hg, not 28" h2o. Doing a conversion with math, that should equal almost 200cfm.

its probably enough not to cause any real loss on the majority of m20's.

did you flow the rowlands and extrudeabody?

[ForcedFirebird]

I wish it could have happened now. Wanted to get that (green) Extrudabody car together first to do the tuning sessions to have a base for this (white) car since they will both be running Motronic. More on a timeline budget for the white car than the green one. The green car is getting a plenum built and turbo in a few months, so it will be apart again and can test then. There is a spare set of Rowland here that could be messed with, but no extra TB's.

They both have 272 cams, the green car is an automatic transmission (cough, cough), but they will both hit the dyno.

As afr as the peak TB flow, I looked at dynomation's flow and saw what happened with the flattening of the curve on the chart. the numbers matched max in 1.5"Hg and instantly thought it was peak flow for the throttles at 28"H2o, but now it has me curious.

Did a lot of flow testing today, made it to the stock head with over sized valves (standard valve job to fit valves, no porting). Surprisingly the average flow dropped a lot, very little gain below mid lift, and a loss everywhere else.

[digger]

i have the dbilas manifold job lying around doing SFA and it would accept the same 45TB as the extrudabody to compare the manifold section. if you ever get around to testing the rowlands give me a heads up a few weeks before and i can ship it over.
its not an original piece as i did port it a little but the fundamental alignment issues and poor shape are still present.

[ForcedFirebird]

Wonder how close they will be the the Jenvy stuff. Do you have pics or dimensions? Just would need one throttle/pair for real world testing. Now that we have benches in two states, we have been pondering the pass around plates to calibrate the benches to the network.

[digger]

Wonder how close they will be the the Jenvy stuff. Do you have pics or dimensions? Just would need one throttle/pair for real world testing. Now that we have benches in two states, we have been pondering the pass around plates to calibrate the benches to the network.

the dbilas manifold adapter has the same DCOE bolt pattern. jenvey, RHD, extrudabody, efi hardware or any other DCOE throttles should bolt up perfectly.

its in two pieces 1-3 and 3-6 .

i used it with 42 throttles but the entry is enlarged to 45mm (it comes like that). its only short about 70mm long IIRC so the transition from 45mm to the equivalent 885 size of about 37mm is relatively abrupt.

[ForcedFirebird]

It's nice to have the equipment needed to test things.

Newest comparison of data.

You already saw the first three tests. .500 lift was removed to avoid confusion, and the fact that we will not see lift that high. Pay attention to the mid lift areas (under .300") as well as the average flow. Many people get confused and just want to see high numbers, but in fact it's more important WHERE the gains are. The valve sees mid lift twice per valve reciprocation, so peak numbers aren't as important as area under the curve (much like dyno numbers).


Test #1 is a stock bare head with test jig.

Test # 2 is a stock head with the stock intake and TB attached.

Test #3 is a stock head with the ITB's

Test #4 is a stock port, no induction (bare head with test jig) and a 1mm over sized valve. Take note of the mid-lift numbers.

Test #5 is a stock port, again no induction, custom valve job to suit the over sized valves.

Test #6 is same as test #5 with the ITB's added.

Test #7 is also the same as #5 and #6 with some port testing and doing some simple touching of the ports where needed. Almost NO material removed. Not even enough to make a pile.




I have a feeling by doing a little to the manifolds without removing much material, we could see a little more, even, but this is good enough in my opinion. The gains were moved into all the correct lifts. Boundary layer is a good friend of mine. Creating flow and velocity and not increasing port volume by much is a wonderful thing. Do what needs to be done, where it needs to be done can have great effects. "Hogging out" and removing large amounts of material isn't always best for any given situation.

Also, take note of the over sized valve flow. Sure one would think adding bigger valves is better (bigger is better, right?), but, the bench doesn't lie.

Now to finish the head up, get it on the car and let's see what the dyno says.

[guibo09]

So would you argue keeping stock sized valves and slapping on ITB is possibly the easiest way to get gains without screwing things up?

Can you describe the touch up you did for test #7?