View Single Post
fredmeister fredmeister is offline
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,174
Garage
safe timing limits on 930 turbo

This question is more of a poll to gather information than anything else related to safe timing advance limits for 930 turbos. This is an attempt to gain a feel for safe timing limits on our cars that still run stock compression ratios but may have upgraded turbos and bigger intercoolers. Sort of a follow up post to a discussion going around on recurving a 930 distributor.

===I would like info on the following 2 scenarios of boost for a 79 930 turbo intercooled 3.3 liter engine running premium street octane 91 or 93:
1) stock 0.8 bar --What is maximum timing advance in degrees BTDC?
2) 1.0 bar W/G spring-- What is maximum timing advance in degrees BTDC?

Basically looking for what experience has taught the tuners out there what is the maximum safe timing limit of degrees BTDC that can be run without detonation at those boost levels.
Once you know the maximum alloweable advance it has to be factored into the amount of mechanical advance and boost retard that you are running to determine the initial static timing points.

Thanks guys......this could be very valueable info to us starting down that slippery road, so let us learn by your mistakes.....

Fredmeister
__________________
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 04-14-2008, 02:47 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)