Ignition timing for cruising?
09-29-2011, 11:20 AM
#1
Ignition timing for cruising? I was reading somewhere online that gasoline likes timing for highway cruising in the 41-44 range for best efficiency (and 37-38 for E85). Can anyone else confirm this? The reason that I am asking is looking over my tune and my Datamaster scans, I saw that I am running 29-30 timing while highway cruising around 43-49kPa and 60-66 mph, and I thought that seemed a little on the low side.
What do you guys think/run for highway cruising?
What do you guys think/run for highway cruising?
09-29-2011, 11:30 AM
#2
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It really depends on cam, combustion chamber efficiency, compression ratio, and a little bit with A/F ratio. Not knowing how your heads were ported makes it hard to guess. Also what A/F are you running at cruise?
If the mixture is leaner than 14.7 it might not require as much timing. If richer it would typically take more.
If the mixture is leaner than 14.7 it might not require as much timing. If richer it would typically take more.
09-29-2011, 08:19 PM
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Are you sure you are at 14.3-15.3??? if you are running E85 it shouldn't be there.
Anyways a good indication of where you should be is to advance the timing and see if you create more vacuum. If you do; keep going until you stop making more vacuum. Then pull about 2-3 degrees out to give a little room. THIS is only for the cells that you are in while cruising!!!!
Anyways a good indication of where you should be is to advance the timing and see if you create more vacuum. If you do; keep going until you stop making more vacuum. Then pull about 2-3 degrees out to give a little room. THIS is only for the cells that you are in while cruising!!!!
09-30-2011, 07:46 AM
#5
Are you sure you are at 14.3-15.3??? if you are running E85 it shouldn't be there.
Anyways a good indication of where you should be is to advance the timing and see if you create more vacuum. If you do; keep going until you stop making more vacuum. Then pull about 2-3 degrees out to give a little room. THIS is only for the cells that you are in while cruising!!!!
Anyways a good indication of where you should be is to advance the timing and see if you create more vacuum. If you do; keep going until you stop making more vacuum. Then pull about 2-3 degrees out to give a little room. THIS is only for the cells that you are in while cruising!!!!
