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forwheeler forwheeler is offline
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Join Date: Oct 2007
Location: Idaho
Posts: 193
Originally Posted by JFairman View Post
I left both vacuum lines on the '87 USA distributor and turned it clockwise advancing it as far as the adjustment slot allows without pulling the distributor out and reindexing it one more gear tooth.

I'm scared to remove the vacuum retard line so far because I don't know where the timing would go under boost then. Just too risky.

I need to get some kind of degree wheel or tape that can be attached to the crank pulley and has the degree marks on the edge so it will be visable when pointing a timing light down at it before I experiment with timing safely.

At the moment I have the MSD 8762 set to retard timing 2 degrees for each psi of boost starting at 5psi but I will probably change that a little with more experimenting. I run maximum boost 1 - 1.1 bar or around 15 psi with street gas, usually chevron high test.

The motor has stock 7:1 pistons and cylinders, 964 cams, Garretson long neck half bay intercooler, and B&B headers.
It has fuel enrichment with a modified IA fuel head and Brian Leask adjustable WUR to control it.
I agree with the degree tape. I can't tell for sure where my advance but it is about 1mm to the left of the timing mark on my 79 ROW car. This should be -29 which is specified for this car in the manual.

I too run at 1 bar and use Shell 93.
My car does move out pretty before boost onset (maybe due to sc cams and the -20 advance) but I don't have a car to compare it to. I would like to advance the timing a couple of degrees to see the difference but I am afraid to without boost retard like you have or a SafeGuard with knock sensor.

I would think that the guys with US cars could run the -29 advance as long as your octane was 93 or better before adding an any aftermarket boost retard. But that is just my opinion.
Old 11-16-2009, 10:41 AM
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