Originally Posted by
Ian S
When you're using high boost as I was, 24psi, then being able to adjust the ignition timing is very helpful in dialling out the detonation. Mine would slightly clack at about 3500rpm or so. That limited the boost I could use overall. A few psi extra was found by retarding the TDC sensor, and timing, a bit. But mappable would have been a lot better as, with the new engine, and a 275 cam, during the early running at lowish RPM I was whizzing past cars at only 8psi. That didn't translate proportionally with going up to three time the boost as at only 12psi it was det'ing quite a bit and I had to move the timing back by at least 4 degrees, by reverting the two wires, I forget just now which, but they gave a further 4° advance, and sliding the TDC sensor, losing a lot of that satisfying low to mid rpm torque.
IIRC, many of these 1.4's seem to peak torque at nearer 3500rpm.