View Single Post
spuggy spuggy is online now
Registered User
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 2,830
Originally posted by RarlyL8
Mine is a '78 w/Euro CIS/dizzy and stock 7.0:1 C/R set at 26 BTDC @ 4000rpm using stock boost. With your C/R I would set it at the factory specs and see if you can make up for the off-boost lag by timing the cams to pick up some torque.
I guess I must have explained it really badly. Probably just too verbosely..

(BTW, 26 BTDC is factory setting for a US 930, according to my info.)

Stock Euro timing (29 BTDC) is too advanced to be safe on-boost (according to the tuner), it runs very, very, nicely off-boost with that setting.

He's pretty clear; he advises 22 BTDC is absolutely as far advanced as he would go (when on-boost) and counsels less - 20 BTDC.

Don't know how much is down to my specific modifications, I get the impression he would set any '78 930 - even a stocker - to those numbers. He says most people/motors don't notice any effect off-boost from being that retarded. Maybe the higher C/R is the significant factor here?

Retarding the ignition to 20 degrees BTDC, it seems to run very well (noticably better) on-boost and makes good dyno numbers, but it makes it horrid off-boost, cold starting suffers etc.

Hey Brian, are you not using the '87 dizzy (presumably with the boost retard can) you bought from SCHNELLE?

If you just wanted a spare, I got a perfectly good '78 euro dizzy on the motor - swap ya? LOL

A post-83 930 distributor really does look like the easiest way to reconcile the two different settings I seem to need for optimal/safe running both on and off boost. I'm starting to think that's probably why the factory did that, huh?
'77 S with '78 930 power and a few other things.
Old 06-22-2007, 03:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)