ignition timing w/36-1 toothed wheel from goingsuperfast.com

trond · trond's Garage

I had my car on the dyno yesterday (Dynapack 6042 chassis dyno). We found 12 HP more, mostly caused by too much ignition timing. Very pleased !

It was very confusing with the ignition timing. Not only were all the markings on the goingsuperfast.com toothed wheel off significantly as seen with a timing light, but also the indicated timing on the laptop must have been off by at least 15 degrees (actual numbers to be confirmed). I was pleased with how the car drove but felt it was a bit lacking above 4000 rpm.

I had made a ignition map with WOT advance curve in the megaJolt software based on postings and what I thought was sensible. WOT advance in the map was 29 degrees at WOT/6500 rpm. On the dyno there was detonation (as can be seen on the before curve from the dyno) and we ended up backing off on the timing by some 15 degrees to get max power.

Here are the curves, before and after

MBruns · 01-26-2011, 07:12 AM

Most managment systems have the ability to set the "crypt" to compensate for what or wherever the missing tooth is on the flywheel or trigger wheel and that has to be verified with a timing light, never assume any of that.
Mike Bruns JBRacing.com

sjf911 · sjf911's Garage

I had a GSF 36-1 wheel on my pulley originally and it was 10 degrees off so I had to re-drill and tap the pulley (Clewett pulley) to get the correct offset for EDIS. The difference in quality between the GSF and Clewett trigger wheels is quite pronounced. I was never able to use the GSF pulley because while advertised as compatible with an SC, it turned out to only work on a turbo or 3.2 Carrera as the AC pulley is larger. Never did get a resolution with them. I am also running GSF headers which had the #5 sealing ring welded wrong. I sent it back to them and it came back worse. I cannot recommend them for anything.
I don't know Megajolt but MS2 allowed you to adjust your trigger offset to match your crank angle within certain limits.

brads911sc · brads911sc's Garage

Megasquirt 2 V3.57 actually uses Jumpers and is plug and play. No need to solder anything for ignition control. Just swap out your old MS board for the newer MS2 V3.57 or MS3 board and you wont need to rig it... get a clewett trigger wheel ($96) and it will all line up. Several guys here have done it...

http://www.clewett.com/index.php?main_page=index&cPath=3_25

Quote:

Originally Posted by sjf911

I had a GSF 36-1 wheel on my pulley originally and it was 10 degrees off so I had to re-drill and tap the pulley (Clewett pulley) to get the correct offset for EDIS. The difference in quality between the GSF and Clewett trigger wheels is quite pronounced. I was never able to use the GSF pulley because while advertised as compatible with an SC, it turned out to only work on a turbo or 3.2 Carrera as the AC pulley is larger. Never did get a resolution with them. I am also running GSF headers which had the #5 sealing ring welded wrong. I sent it back to them and it came back worse. I cannot recommend them for anything.
I don't know Megajolt but MS2 allowed you to adjust your trigger offset to match your crank angle within certain limits.