[bahambart]

Quote: Originally Posted by obehave

With the exception that you are not locked into having to modify of buy an intake.
My Alta for instance becomes useless with the AGS unless I change something.

Not saying yes or no to the AGS.
Don't want the M7 posse coming to get me

I see your point, very interesting. Was only comparing the pipe piece only in the sense of shape and diameter. Ridiculous question if there is room for the tube to be more oval / round - any idea why BMW would flatten it out? Is there any argument for the stock shape?

I think you got something here - I went and posted it on NAM - just to get more people thinking & opining about this.

Kudos to you.

[obehave]

Quote: Originally Posted by bahambart

I see your point, very interesting. Was only comparing the pipe piece only in the sense of shape and diameter. Ridiculous question if there is room for the tube to be more oval / round - any idea why BMW would flatten it out? Is there any argument for the stock shape?

I think you got something here - I went and posted it on NAM - just to get more people thinking & opining about this.

Kudos to you.

One thing they do well there is voice opinions
Pretty darn good here too.

Just a thought but as much as the engine moves forward under hard acceleration, it may have been a safety/part longevity issue.

Isn't there an "a" missing from your name?

[minimc]

Quote: Originally Posted by obehave

One thing they do well there is voice opinions ...

Quote: Originally Posted by obehave

Just a thought but as much as the engine moves forward under hard acceleration, it may have been a safety/part longevity issue.

Didn't it have something to do with eliminating some unwanted resonance?

[obehave]

Quote: Originally Posted by minimc

Didn't it have something to do with eliminating some unwanted resonance?

You're probably right. Now that you've said it there's an old dusty bell ringing.

I would like to see if any of the AGS tubes are being pinched. Particularly in cars wth stock motor mounts.

[roland2003]

Ho obe, 273bhp,+track tyres+ porsche brakes+ driven hard + stock mounts = nothing touching (so far )
Regards Roland GTT

[shazam]

Thirty quid!

That is one cheap mod considering the work Roland has put into it.

Keep up the good work fella.

[petecrosby]

Quote: Originally Posted by minimc

Didn't it have something to do with eliminating some unwanted resonance?

I believe you are confusing this pipe with the pipe between the grill and the airbox.
There is a little cylindrical piece molded into the side of it for, I think, the reason
you mentioned.

[obehave]

Quote: Originally Posted by petecrosby

I believe you are confusing this pipe with the pipe between the grill and the airbox.
There is a little cylindrical piece molded into the side of it for, I think, the reason
you mentioned.

No he wasn't talking about that.
I remember the discussion now. I think it was something about the part if it were round acting somewhat like a trumpet like horn that could amplify induction noise.
OK for some of us but not for the quiet crowd.

The resonance horn on the intake tube is a different thing, as you've noted. It also serves to trap small amounts of moisture and has a drain hole at the bottom.

[norm03s]

Any more news on this developement?

[obehave]

Quote: Originally Posted by norm03s

Any more news on this developement?

LIke I posted on that other site I need to find/design a giant catheter.
Make it out of a bike inner tube or something.
Shove it in the tube and only heat the area I want to expand.


Obe Inlet Plenum Expansion Catheter is U.S. Pat. Pending

[St00ge]

remember obehave that there are two places to massage out. Apparently you can just heat the thing and push out the creases with a broom handle. I would really like to see the differences in pressure drops between a stock and modified piece. As the general rule of thumb is an extra 1 psi on the downstream side of the supercharger is an extra 10 hp. The "sucking-custard-through-a-straw" effect that the supercharger has to carry out will be greatly reduced, and this can only be good. The supercharger doesn't have to work hard to make the same boost...

This is one thing i will definately be doing, but i might send for a new pipe from roland, and give him mine in return. From memory he'll charge about 30 gbp for a new pipe, plus shipping.

[norm03s]

Etalj, didn’t Roland show those results from his early testing?
I think 10 Hp is a worthwhile endeavor for a bit of work and little $. Modifying the duct
isn’t all of it or the big part, it’s taking the car apart to get to the darn thing that’s time consuming.

Obehave, I like your concept of Plenum Expansion Catheter, but (BIG BUT) the duct would have to be heated very uniformly. Then due to the internal intrusion variances expansion would be irregular. Another concern would be distortion of alignment at component interfaces on the ends. The broom stick and heat gun is the KISS solution IMHO.
I have a some background work experience from where we used a soft neoprene balloon type device that was inflated in ridged plenums to seal it off at variable locations for pressure testing.

[St00ge]

Quote: Originally Posted by norm03s

Etalj, didn’t Roland show those results from his early testing?
I think 10 Hp is a worthwhile endeavor for a bit of work and little $. Modifying the duct
isn’t all of it or the big part, it’s taking the car apart to get to the darn thing that’s time consuming.

oh yeh i know, but i don't wanna do either

i think roland's testing was taken at the throttle body, with different intakes. AFAIK, he didn't compare vacuum at the SC inlet using stock and modded plenums. Please show me where he did, cos i missed it.

BTW, lots of people tend to agree on 10hp for every psi before the SC....

[norm03s]

Quote: Originally Posted by etalj

oh yeh i know, but i don't wanna do either

i think roland's testing was taken at the throttle body, with different intakes. AFAIK, he didn't compare vacuum at the SC inlet using stock and modded plenums. Please show me where he did, cos i missed it.

BTW, lots of people tend to agree on 10hp for every psi before the SC....

Your right went back and read it again. He took vacuum readings from the PVC hose connection point.
So I ignored my own favorite quote by jumping in before thinking this through.
Roland posted some numbers from his testing that’s great but his components and mine are different. Is there potential here, possibly. There needs to be some base line testing done.

[roland2003]

Hi Guys, yes there are 3 places you can measure 'overall' restriction of the air filter +Throttle Body . Two of these are on the 'plastic plenum' itself. One goes to the upstream map sensor the other the brake servo. The third connection is on the inlet side of the S/C itself and goes to the PCV valve. This is the place I connected the vacuum guage, and is the only place that will measure the 'overall' restiction of the airfilter,throttle body AND the plastic plenum, as it is downstream of all three components. I would have liked to perform an 'identical condition before & after test' but as I say earlier is alot of work to swop it back to stock to do the test. In summary I think its a very worthwhile but but ONLY if you are removing this part or removing the front end of the car anyway..... happy tweaking Tweakettes
Regards Roland Gt Tuning

[St00ge]

Probably the best thing to do is this: the next person who does this mod, hook it up to a manometer when it's in it's stock shape, and then retest after modding it

[norm03s]

Quote: Originally Posted by etalj

Probably the best thing to do is this: the next person who does this mod, hook it up to a manometer when it's in it's stock shape, and then retest after modding it

Or a vacuum gauge, that is exactly the base line testing I was refering to.

[St00ge]

Quote: Originally Posted by norm03s

Or a vacuum gauge, that is exactly the base line testing I was refering to.

Do you mean while it's on the car? Cos surely this would measure the vacuum caused by the throttle body and intake as well as the SID ?