POLL: New high performance M20 intake manifold

[Mystikal]

If you make 15rwhp, I'll buy one.

[Budget Beater]

Hey guys, Just FYI

The weight of the M20 intake manifold + throttle body is 21.6lbs

[Budget Beater]

well 15 HP gains throughout the powerband won't happen... but max HP gain, 15hp should be easy, with a 262 cam you should be making power welll up to 7000rpm but intake manifold is choking it off, past 5500 the gains will be excelent, im just trying to concentrate on torque (thats the hard part, HP is easy, its not losing torque thats hard). we will just have to wait and see :) .

[Digitalwave]

That sucks, 5,500+ is the least frequented part of the powerband for me.

[Budget Beater]

its the most frequent for me :) . but i will see what i can do. theres no point in speculating now. just gotta get the car up and running well and start the project asap.

[Mot]

im intrested, except my stroker doesnt like 5500+ all that much, so any kind of gain would be sweet.

[Mystikal]

well 15 HP gains throughout the powerband won't happen... but max HP gain, 15hp should be easy, with a 262 cam you should be making power welll up to 7000rpm but intake manifold is choking it off, past 5500 the gains will be excelent, im just trying to concentrate on torque (thats the hard part, HP is easy, its not losing torque thats hard). we will just have to wait and see :) .

Of course, the manifold wouldn't do a damn thing for before 4500 or so. That's fine by me, B25's need a top end surge more than anything (I'm perfectly happy with the midrange of my car). Not losing any midrange would be better though!

[Budget Beater]

i don't think people realize how much air a 262 cam can flow at high rpms. there is huge potential for high end power. honestly low end might not change too much but with a chip M20 with the proper flow should pull hard all the way to 7000rpm. too hard to say now.... car is up and running now but still needs few minor things before i can get started on the project.

[tonytony]

interesting......

[Jon '92 325ic]

This might help you. It's the airflow test data that came with my extrudehone manifold:

Before EH:
Cylinder 1 airflow cfm - 182.5
Cylinder 2 airflow cfm - 200.5
Cylinder 3 airflow cfm - 178.0
Cylinder 4 airflow cfm - 187.6
Cylinder 5 airflow cfm - 181.2
Cylinder 6 airflow cfm - 197.5

AFTER EH:
Cylinder 1 airflow cfm - 216.4
Cylinder 2 airflow cfm - 228.2
Cylinder 3 airflow cfm - 222.8
Cylinder 4 airflow cfm - 215.4
Cylinder 5 airflow cfm - 229.0
Cylinder 6 airflow cfm - 215.8

Again, no noticeable improvement in performance until 4000 rpm. At lower rpms car runs the same as with the stock intake manifold..

[mcgrath]

any updates?

[nando]

i don't think people realize how much air a 262 cam can flow at high rpms. there is huge potential for high end power. honestly low end might not change too much but with a chip M20 with the proper flow should pull hard all the way to 7000rpm. too hard to say now.... car is up and running now but still needs few minor things before i can get started on the project.

do you mean a 272? or are you talking about using a stock cam with a better manifold?

if you actually go through with it I might be interested, the intake on my car is definetly a big bottleneck with the 284 cam.

[mcgrath]

Updates!!!!! :)

[Rob]

will it be $50?

[xLibelle]

An interesting side note. The intake manifold is actually a decent design.

OMG imagine that! this statement reminds me of every thread where someone wanted to replace/modify the airbox ending up finding out that the stock box with horn was what bmw designed for purpose because it works best.

The runners ARE equal length when compared to each other (all 3 are roughly 18.5-19inches long). HOWEVER, what is more important is the distance from the head ports to the actual throttle body opening, that is more important in my opinion.

Did you originally think they werent equal length??? HOWEVER, port distance to throttle body should be the LEAST of your worries with that junction! The air pressure difference from cyl-1 and cyl-3 over that distance span (between ports) AND because of that chamber's shape makes the issue negligible. I will suggest that air moving from a large chamber into a tube under vacuum would best be suited with v-stack which moves the port of the runner into a larger surface area... just a hint ;)

...ok, i wont be a jerk in questioning your abilities, changed my mind; i wouldnt want to discourage you from your search for a better (realistic) manny.