E85 Timing Maps
#139
Evolving Member
I want to run lower boost and need to know if I will require a complete retune.
My car was dyno tuned at 30psi and made 450whp. It holds that psi till 5500 rpm before it starts to drop down. It doesn't drop below 25psi until 6500 rpm.
I no longer feel safe spiking that kind of boost and would like to drop it down to 25psi across the board. Below is screen shot of my timing map. Do you think the car will remain safe once the boost is lowered which will normally result in a lower load but higher timing?
My car was dyno tuned at 30psi and made 450whp. It holds that psi till 5500 rpm before it starts to drop down. It doesn't drop below 25psi until 6500 rpm.
I no longer feel safe spiking that kind of boost and would like to drop it down to 25psi across the board. Below is screen shot of my timing map. Do you think the car will remain safe once the boost is lowered which will normally result in a lower load but higher timing?
#141
Evolved Member
iTrader: (5)
Stock turbo or other? What is your load curve?
I want to run lower boost and need to know if I will require a complete retune.
My car was dyno tuned at 30psi and made 450whp. It holds that psi till 5500 rpm before it starts to drop down. It doesn't drop below 25psi until 6500 rpm.
I no longer feel safe spiking that kind of boost and would like to drop it down to 25psi across the board. Below is screen shot of my timing map. Do you think the car will remain safe once the boost is lowered which will normally result in a lower load but higher timing?
My car was dyno tuned at 30psi and made 450whp. It holds that psi till 5500 rpm before it starts to drop down. It doesn't drop below 25psi until 6500 rpm.
I no longer feel safe spiking that kind of boost and would like to drop it down to 25psi across the board. Below is screen shot of my timing map. Do you think the car will remain safe once the boost is lowered which will normally result in a lower load but higher timing?
#144
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Join Date: Nov 2011
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I do have a wideband. Should stop being lazy and wire it to the ECU to log instead of eyeball.
One question for you guys. Why is the load curve significant? I know it's the cells being hit during a pull but why do you guys ask for it when giving advice? Thanks!
#145
Evolved Member
iTrader: (5)
Thanks ReaperX.
I do have a wideband. Should stop being lazy and wire it to the ECU to log instead of eyeball.
One question for you guys. Why is the load curve significant? I know it's the cells being hit during a pull but why do you guys ask for it when giving advice? Thanks!
I do have a wideband. Should stop being lazy and wire it to the ECU to log instead of eyeball.
One question for you guys. Why is the load curve significant? I know it's the cells being hit during a pull but why do you guys ask for it when giving advice? Thanks!
The reason we ask is that for us to give advice we need to know what cells the car is hitting. You can have a smooth map that looks pretty, but may have too much timing for a given load/rpm. The more info you can give us, the better we can help you.
#146
Evolving Member
How's this look for HTA73 Green with S3 cams running 11.8 AFR steady to redline. I seem to be getting random knock now doing pulls. I just did a log and picked up 2 counts of knock just a touch past 5k RPM that became 1 count at at 5600 and went away at 6250. I tried to lower timing earlier and what was 2 counts of knock went to 3. I had never seen 3 counts before that either. Always picked up 1 or 2 maybe. Is it possible that I need to throw more timing at it??? Feels weird to add timing to get rid of knock so I wanted to get a second opinion. I never pick up knock past 7k where I'm running high timing.
I'm 350 load from 4k down.
I'm 350 load from 4k down.
#147
EvoM Guru
iTrader: (1)
how much boost are you running? Does adding the degree of timing back give you power increase? With E85, the big thing is make sure you're not past MBT. E85 doesn't really knock, it typically goes straight to full on detonation..
#148
Evolving Member
When people say they start adding a good bit of timing after peak torque what do they consider peak torque? My torque curve stays flat and I am holding boost so is it just where it first hits near peak?
Right now I'm only running around 25 psi. Hit 24.6 psi at 4k, 26 psi at 4500, and back down to 24.6 psi at 6875. That log had 1 count of knock from around 5600 to 6300. I'm waiting for my double pumper to turn up boost much more. Didn't want to bump it up any until I figure out something about the knock either.
#149
EvoM Guru
iTrader: (1)
You can always add timing as rpm's go up, even if the torque curve is holding flat. You could probably add 1-2 degrees all the way out the top, but with a little less timing around 4k with a little faster ramp from 4500-6, going up one degree every 250rpm instead of every 500, and ending up at 17 or 18 out the top. I can't divulge my timing curve because its not mine, but I'm running 32psi at 4500 tapering to 28 out the top, and my timing is more aggressive then yours. Granted, cams play a role in how much advance the car will take, as well as intake air temps, so take that with a grain of salt.
I would try 1* from 4 - 4500, then ramp it smoothly to 10 at 6k, then ramp it smoothly to 17 or 18 by 8k. See how that does.
I would try 1* from 4 - 4500, then ramp it smoothly to 10 at 6k, then ramp it smoothly to 17 or 18 by 8k. See how that does.
Last edited by letsgetthisdone; Aug 18, 2015 at 03:57 PM.
#150
Evolving Member
You can always add timing as rpm's go up, even if the torque curve is holding flat. You could probably add 1-2 degrees all the way out the top, with a little faster ramp, going up one degree every 250rpm instead of every 500, and ending up at 18 or 19 out the top. I can't divulge my timing curve because its not mine, but I'm running 32psi at 4500 tapering to 28 out the top, and my timing is more aggressive then yours. Granted, cams play a role in how much advance the car will take, as well as intake air temps, so take that with a grain of salt.