John_D.

iTrader: (2)

I bumped up my timing advance a bit, and I made my knock sensors less sensitive at the same time. I was still expecting to see a little kr, to see if I had gone too aggressive with the timing. But I got zero KR.

My stock "speed bump" in the timing map was
4000 25
4400 24
4800 23
5200 26
and 28 from there on up.

I flattened it quite a bit
4000 28
4400 29
4800 30
5200 30
and 30 from there on up.

Is it reasonable to have no KR with those settings?

Or do I need to "re-sensitize" my knock sensors just a bit?

This is on a '98, using hptuners.

SmokingWS6

iTrader: (1)

That sounds good to me. I have a similar setup. Last time I checked I was getting a degree of retard but it was fairly hot out.
4400+ 30

jimmyblue

iTrader: (11)

The max timing depends on the CylAir you have. I can't
go above 28 at 0.80 g/cyl. I used to be able to run more
spark when I had a pig-rich factory PE table.

samz28

some people run leaner and less timing, some run richer and more timing. Both accomplishes a similar goal. Finding the perfect balance to avoid excessive EGT's might be a good idea if you haul *** around. I can run 31 with no KR, i doubt it gains any more power but it works. I think A4's unlocked have a little more tolerance given the dampening effect of the torque converter

Third Gear

iTrader: (3)

I've been running 29 max, and I get no KR on WOT with crappy California 91 octane.

John_D.

iTrader: (2)

Cool... I feel better now.

Off to Beech Bend (Bowling Green KY) later today to shoot for an 11.9x time or better.

Grant B

Do our engines actually need that much timing?

My FRC trapped 109.5 with only around 24 degrees of timing and nothing but Z06 mulffers and intake manifold. I was pretty impressed it went that fast with so little timing. The problem was it was Florida in July, and I didn't have a cold air intake, just a stupid K&N filter. The intake temps after sitting in the staging lane lines were 150F. They dropped to 130F by the end of the quater mile. Naturally I tried reducing the timing pulled due to AITs, but then it just knocked for real and pull the timing anyways.

I would think with a higher CR even less timing would be needed.

John_D.

iTrader: (2)

My stock map was at 28 after it got past the "4K speed bump".

So 30 isn't too much more than stock... I mainly got rid of most of the speed bump.

2 degrees is supposed to be around 10hp if I remember right.

So going from 23 degrees to 30 degrees at 4800 rpms could bump my hp, at that point in the curve, by about 35 at the crank or about 29 at the wheels.

The pcm will still pull timing if the iat or the ect starts climbing. That 30 is just a best case scenario. Cool weather, etc.

In my case, even though I have ported heads, I didn't opt for higher compression because I was planning for some form of forced induction later.

Oh yeah, I didn't get to run it today because I got stuck at the house with 6 hours of on-call problems from work...

Grant B

Well, the point of timing is to start the combustion at the right point, so the combustion energy can peak at the right point in the power stroke (which is dependant on CR, rod ratio, and probably some other stuff I don't know about). So you can have too much timing just as easily as you can have too little. Some cars will knock before they get to the point that more timing makes less power, but some won't. I don't know if the LS1 will or not - thats why I'm asking.

John_D.

iTrader: (2)

Very true... I was going to take it 2 degrees in either direction (4 degree range) and see which one gave me better times at the strip today. 28, 30, 32. But didn't get to make it out there today. Maybe next weekend or the following...

Mainly I just wanted to make sure I hadn't gone too far, as far as possibly detonating and not knowing it, with the knock sensors desensitized and the timing bumped up at the same time.