How much timing?
#1
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How much timing?
I have an 01 ws6 with an HKE 408, 243's, MS4, FAST 90/90 (no nitrous) and full bolt on's. My question is how much timing can I safely run in my car. It has been tuned by a professional but I would like to get the most power for the track. I will be running 92 octane. I don't really have access to non-leaded race fuel so staying pump gas is going to have to be a must for me. Do the Octane boosters help at all?
Thanks Brandon
Thanks Brandon
#2
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Brandon, do you have a way to datalog it? If so, you could try slowly adding more timing until ya start to get knock retard, but adding timing won't necassarily get you more power. Also, you would need to datalog it at the track or dyno to varify if you're gaining/losing power.
Maybe some of the other MS3 users out there will chime in with their timing tables. ?
Mike
Maybe some of the other MS3 users out there will chime in with their timing tables. ?
Mike
#3
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I would start by finding out the comression ratio. Next thing is the 243s have a very efficient chamber, and usually don't tolerate alot of timing. I've tuned 243 headed motors, on race gas, that didn't like any more timing than a lower compression pump gas motor. I would start low (low 20s) and creep up a degree at a time. Do multiple runs in between making changes. Don't make a change, make a pass, and make another change. No consistency there.
#7
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I'm gonna go against the grain of the thread and tell you that even if he was conservative, it's unlikely that you are going to find much of any gain. If the car is knocking you will, otherwise, I would doubt it. That last degree or two the car will want may only make a couple (literally) of ft/lbs. You be better focusing your time and effort in other places unless you KNOW that tune is whack timing-wise.
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#8
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So am I wrong to think of this as an old sbc where you can crank the ditributor until it pings then back it off a little until you get no ping while under a load?
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What you don't know, is how MBT point relates to
ping-point across the (RPM, CYlAir) surface. While
"find the KR and pull out 2" has worked OK for me,
if you have the time and the consistency the right
thing to do is push timing up from the low side until
it simply stops giving you anything. That should be
well short of ping. But it requires you be able to see
some quantitative, fine grained, PCM-independent
measure of output (not a 1/4-mile MPH, too coarse;
not Delivered Torque PID, too bogus).
I've seen papers that showed -2 from ping being the
MBT but that would vary with the motor a lot, I
reckon. All I can say is that when mostly-stock, it
was an OK target for me when done. Although there
was some hot-weather sensitivity I had to tweak out
in the adder tables after.
ping-point across the (RPM, CYlAir) surface. While
"find the KR and pull out 2" has worked OK for me,
if you have the time and the consistency the right
thing to do is push timing up from the low side until
it simply stops giving you anything. That should be
well short of ping. But it requires you be able to see
some quantitative, fine grained, PCM-independent
measure of output (not a 1/4-mile MPH, too coarse;
not Delivered Torque PID, too bogus).
I've seen papers that showed -2 from ping being the
MBT but that would vary with the motor a lot, I
reckon. All I can say is that when mostly-stock, it
was an OK target for me when done. Although there
was some hot-weather sensitivity I had to tweak out
in the adder tables after.