<VV> Early Turbo EFI

kevin nash wrokit at hotmail.com
Mon Apr 6 10:39:51 EDT 2020

 With the recent discussion on Turbo's and powerglides and timing strategies in mind, I thought I would post a
little bit on my car, and its wild timing. It has taken me a long time, experimenting with every concievable timing
strategy, and what I have going now is by far the best I've ever done, and is likely as far as I can go with a simple
2 dimensional timing, which is to have the same manifold pressure timing curve for all rpms. It has vacuum advance and boost retard, laid on top of base timing. The base timing is best described as 140 timing up to
2750 rpm... 18 degrees at 1000 rpm, 30 degrees at 2750, and a 110 timing added on top of that, 31 degrees at 3000, and tops out at 34 degrees at 4000 rpm. It has 10 degrees of vacuum advance that is all in at 11 inches
of mercury, and is done adding timing at around 3 inches. The "boost retard" part starts retarding the timing a little at a time while the engine is in vacuum, at a rate of 1 degree per psi and stops at 15psi and 16 degrees, and ends up with a maximum total timing of 18 degrees at 15 psi of boost and beyond. Driving this car with timing like this is freaking hilarious!! it runs and takes off like a NA car does out of boost. Hammering it in first gear though will give up to 15psi of boost and is accelerating every bit as hard as 15psi of boost is supposed to give, and second and third gear will get over 20psi if I let it. Lordy, does that thing scream at 20psi!!! no water injection, no intercooler, no waste gate and pump gas. But it does have a Safegard!!
The other thing that is super cool with this timing strategy is that I can stand on it in a tall gear and relatively low rpm and it takes off like a NA car would do under the same load, without a lot of gawd awful pinging, something that has been a seriously long fought battle! the slight, occasional random pinging if I load it like that for long is likely because of running plugs that are too hot.
Kevin Nash
63 Turbo, EFI Daily driver,
baddest cooling fan on the planet!!

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