AirSpeed VW Community Forums

Technical => Engine Tech Forum => Topic started by: flat4 on May 15, 2006, 08:45:27 AM

Title: Engine Idle Speed
Post by: flat4 on May 15, 2006, 08:45:27 AM

How drastically should idle speed change with/without the fan belt?  I run a CB serpentine belt, broke it at the track this weekend, and my idle speed jumped up to about 3000 rpm.  Is this normal?  If so, seems like it would be a huge HP killer.  Thoughts?  Advice?

Title: Engine Idle Speed
Post by: James Buchan on May 15, 2006, 08:49:52 AM

I wouldn't think you would pick up much rpm (maybe a few hundred at most) with a broken fanbelt, did something take a kit by the broken belt?

Title: Engine Idle Speed
Post by: red snapper on May 15, 2006, 09:37:19 AM

Im no mechanic but anytime I have pulled my fan belt off before racing I havnt noticed a difference at all. You should leave it off anyways for racing. Good luck, Brian

Title: Engine Idle Speed
Post by: flat4 on May 15, 2006, 10:07:04 AM

Take a kit?  Huh?  Well, besides the shards of rubber and a clogged jet from the rubber (I wasn't running cleaners) I don't think so.  The belt was hanging on the alt pulley.  I don't think it went anywhere.   As soon as the new belt was installed, the idle returned to normal (my normal) again.  Very odd indeed.  I was too afraid to run at the track without a belt.

Title: Engine Idle Speed
Post by: James Buchan on May 15, 2006, 01:04:20 PM

I meant to say take a hit :)

 

Title: Engine Idle Speed
Post by: flat4 on May 15, 2006, 02:49:14 PM

My car is not on drugs, creep.

Title: Engine Idle Speed
Post by: Trevor P on May 16, 2006, 05:17:45 PM

Quote

My car is not on drugs, creep.

No,... but maybe you are Fred; if you're saying your idle is gaining that much! :P  

Title: Engine Idle Speed
Post by: dannyboy on May 16, 2006, 07:45:19 PM

Quote

I was too afraid to run at the track without a belt

why??
i would rather run without the belt, rather than explode a fan...

Title: Engine Idle Speed
Post by: flat4 on May 17, 2006, 02:33:07 AM

I guess I have faith in welded fans.  Things at the track here are different, as on Secret Street nights, it's all hot lapping. Perhaps I'll make a few runs sans belt and see what happens. I know it sounds like a crazy issue,but I wouldn't have believed it if I didn't see it for myself.  I'll be checking it tomorrow or Thursday in preparation for Friday.