Know Ign Advance For Best Peak Hp On Xu9ja

[snillet 1]

What sort of ignition advance is common on the XU9JA engine with high compression (around 11:1) and standard camshaft ( i have the JA camshaft in my JAZ engine, see my signature for the rest)?

 

I´ve ended up with 28-29 BTDC which seem to give me the best performance, if any more andvanced the engine seems to start working against itself instead, which should indicate that max power is actually achived somewhat below those numbers.

 

I just want some input on what numbers is common to end up with around 5500-6500 rpm om these engines.

 

Now... i run on ethanol but at max power/high rpm the ignition timing is not really differing much between those fules, at part load and low low it differs TONS though.

[petert 586]

Best is 31-32 degrees total (not including vacuum advance), but you'll need mapped ignition or a modified dizzy to control the pinging down low and to enable it to start easily. I like to give the cranking map just 5 degrees so it spins over quickly, then 12 degrees at 1000 rpm.

[snillet 1]

Ah, this means i´m in the "close" ballpark then.

I run on the ethanolblend E85 to so the figures goes up slightly in my setup.

 

I run 34max at high rpm, 24 max at low (1000) rpm, 15 at idle under vacuum and 6 degrees as crankadvance.