[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: distributor cap manipulation

> From: Gary G. Erickson <erickson@teleport.com>
> Bruce Bell wrote:
> > 
> > NO!  Works on the VW because of Knock sensor. THe 85 Coupe has no knock
> > sensor. Advance timing on the coupe that much and you WILL lose power.
> > try it, but do some 3rd gear Runs between 2 & 4 k rpm then 4-5krpm and
> > for your self!! NJT
> Bruce,
> I have to disagree here.  I'm running an '85 GT with the timing advanced
> to 12 degrees, and it DOES make a perceptible (and measureable)
> difference.  You are correct that the '85 has no knock sensor however. 
> I will only run 92 or higher octane when I have the engine tuned like
> this.
> The effect is more noticable when you have other modfications done as
> well.  I have a 2 1/4" free-flow exhaust and am running additional fuel
> enrichment at high RPM's, but I have done this to otherwise stock cars,
> and it will help them as well.

More enrichment changes the rules!

and Mike Tipton said:

On my 86 Coupe I run an adjustable cam sprocket at 2 degrees advance!
It works,(ask NED) and it brings the torque peak down in the rpm range. 
Setting it the otherway puts the torque peak higher into the rpm range.
Anything above 2.5 degrees either way, and it doesn't run quite well.
With the sprocket you must reset the distributor back to the factory 
setting, for 93 octane pump gas! Racing 106 octane is a different story!

Yes Mike; but, you are running a highly modified motor with a 10.5:1 CR  
No fair :-)

Then Gary Erickson Said:
WRT to the optimal adjustment, according to Ned Ritchie, the best
setting is supposed to be 12 degrees of advance.  I've played with and
run anywhere from 6-16 degrees.  You can feel the difference between the
6 and the 12, I've yet to find much between 12 and 16.  I may not have
had the right fuel in to take advantage of this.

Gary, I talked to Ned about this at length when in Steamboat for the winter
driving school last year. Ned, I'm sure is running 12 deg advance; however,
he has made other mods to the electronics (not specified) that change the
advance curve.  

With regard to Darryl Vittone at tectonics advancing the timing on early
pre knock sensor cars, It is true. However, when they were doing the tests
in EC during the mid 80' on exhaust, timing and Cams he said while the
advance worked on the Knock sensor cars it would not help the 8.5:1 CR
motors nor the 16 valve. Remember, when doing the early VWs the hot ticket
was re-curving the distributor which was considered mandatory  in order to
run a large initial advance. If I remember correctly, they also shot for a
36 degree total advance. If you are running 16-18 deg, you are well beyond

I just tried this myself 10 days ago. Used a stopwatch to measure the
difference and it WAS measurable. I lost power at 12 deg initial advance.
lost about 0.1 second on average from 3k-4k and 4k-5k rpm.

Bottom line, I don't want to see a person on this list burn a valve or a
piston because he/she tried to emulate what someone else has done with a
modified motor.

Be careful if you go there - more isn't always better.