Difference between MSD 8572/8571 ?
Thread Starter
Racer
Joined: Oct 2004
Posts: 285
Likes: 0
From: Stockholm
Difference between MSD 8572/8571 ?
I must buy a new distrubutor since my old stock have goon bezerk.
Timing differs between 5-25 degrees at idle.
It must have someting to do with the vacum advance, if I remove the vacum inlet to distrubutor it runs fine (but I don't have enough timing at 2500 rpm).
Any way, I have looked on MSD for a long time.
If I select the MSD without any vacum advance (8571), is it ok to use it in a street driven car?
Or is it only for pure racing?
Timing differs between 5-25 degrees at idle.
It must have someting to do with the vacum advance, if I remove the vacum inlet to distrubutor it runs fine (but I don't have enough timing at 2500 rpm).
Any way, I have looked on MSD for a long time.
If I select the MSD without any vacum advance (8571), is it ok to use it in a street driven car?
Or is it only for pure racing?
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Vac adv is not absolutely necessary for street but it does provide better gas mileage, you can always not use it if you do not want it, I have the 8572 and is like a peice of art, well at least when it was brand new. 
BTW it sounds like you have the vac adv hooked up to an unported source, sees vac all the time so you are getting vac adv at idle.
Check this out if you need help with timing:
https://www.corvetteforum.com/techti...=109&TopicID=3
BTW it sounds like you have the vac adv hooked up to an unported source, sees vac all the time so you are getting vac adv at idle.
Check this out if you need help with timing:
https://www.corvetteforum.com/techti...=109&TopicID=3
Last edited by Fevre; Aug 29, 2005 at 02:48 PM.
Thread Starter
Racer
Joined: Oct 2004
Posts: 285
Likes: 0
From: Stockholm
It worked perfect for 2 day's ago.
12 degree at 800 rpm and 34 at 2400 rpm.
Now it just works from 1500 rpm and up.
As soon I goes under 1500 rpm the engine stops.
Have checked all vacum leads, no leakage.
12 degree at 800 rpm and 34 at 2400 rpm.
Now it just works from 1500 rpm and up.
As soon I goes under 1500 rpm the engine stops.
Have checked all vacum leads, no leakage.
Instructor
Joined: Feb 2005
Posts: 153
Likes: 1
From: Monroe MI
I replaced my mech advance with an MSD vac advance. This way I can go mech or vac by taking the vacuum module off. If your distributor is working which it sounds like it is and your happy with it just go buy a new advance module and save yourself the 350-400$!
