Re: M5 help (a little long, but please read!) (archive)

You are talking of the variable intake plenum. When you start the car, the plenum flap will close (open at stop) and open twice. You can see this by observing the linkage on the plenum cycle. If that is working, the system is likely fine.

Neil Deshpande
http://www.neilwerke.com

***

I recently bought a 91 M5 with around 95,000 miles. I had a compression test and everything. It came out to 195psi in two cylinders, and 190 in the rest. I thought that was pretty good but any feedback would be greatly appreciated. When I test drove the car, I felt that it had great low end power, really pulling from 2500 rpm up. Before I bought it, but after my test drive, the dealer did a full service, including valve job and putting in a new intake gasket. The car still runs well, but it seems to have much more lag when below 4000 rpm.

I read that this car has a neat vacuum operated system which apparently forces more air into the cylinders than they would draw normally. The artice I read said that if this system was not working a lot of power would be lost, especially between 3 and 4000 rpm. If this is true, can anyone tell me how I can test to see whether this device is working? ie, where it is located, how it should be connected, etc. Any feedback would be greatly appreciated. I'm so excited about my car that it's hard for me to complain, but of course I want it to be perfect!

Thanks,

Murphy

Follow Ups:

what the flap gives you (m) ///M5AD 20:57 10/04/2001 (5)
- Anthony, is your car totally stock (no chip)? KJK 12:03 10/05/2001 (2)
  - As far as I could tell the ECU had not been (m) ///M5AD 13:19 10/05/2001 (1)
    - Would love to see post chip dyno (more) KJK 13:38 10/05/2001 (0)
- Re: what the flap gives you (m) Murphy Clarke 22:41 10/04/2001 (1)
  - resonance flap in the intake plenum (nt) danny 09:14 10/05/2001 (0)

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