Hi guys,

I've been tinkering with my timing quite a bit to keep detonation at bay. Now that the temperatures start to rise I get a ping every now and then, and I notice the J&S kicking in sometimes. I realize I'm running ridiculous boost, but I'm not looking for top end power right now, I just love the crushing torque from 3k-5k and set the rev limit at 7k. Anyway, for those of you that run big motors and high boost: I'd love to take a peek at your timing maps! Anyone willing to share? (I use Crome Pro latest version btw).

specs: 84mm GSR, Rollerwaves (CR=9.1:1), combustion chamber matched to bore and pistons by Endyn. Stock M62, LHT, 16-17psi. Base timing stock. Running about 16 degrees max at 2.1Bar (low cam), 17 deg max at the high cam.

 

your running 28+psi (2.1bar) on pump gas? if you are on race gas then that timing sounds about right. and why are u running so much boost for a daily driver?

or r u running 2.1bar - atms pressure = 1.1 bar ~ 15psi? i would probably pull more timing than that. what are you logging in for IAT?

 

also make sure you have the crome timing fix or u may run into some serious issues with not being able to pull enough timing

 

like u said weathers getting hot, you have a supercharger that likes to make heat at high pressure ratios, LHT helps, do know know where the motor is detonating?

 

@boosted k20: I did mean absolute pressure, I'm seeing about 16psi of boost.

@SOHC_MShue: Yes, I have the Crome timing fix! I had bad detting without it.

I get two different detonation issues.
One, when I mash the throttle on the low cam at low revs. When the engine is hot that usually gives me a ping or two. However if I gently ease on the throttle it doesn't so I figure the timing map must be ok?? I tried playing with the tip-in, doesn't help. I wonder if timing also undergoes some sort of tip-in thats in the ECU but hasn't been discovered yet?

Two, when I go through the higher revs (6-7k), the J&S sometimes activates. You can feel the engine hesitate a bit when this happens.

I guess I could pull more timing to probably fix both issues. Safe, but I'd throw away torque. I'd really like to take a look at somebody else's Crome timing maps for big motor JRSC's...

 

what about adding h20/alky injection to help with the temps? i think that would help alot with detonation etc also...