ECUflash/ Tactrix cable newb thread
#211
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Given your fairly low boost level (~5psi), 11.5:1 should be fine to run. I have run 11.8:1 on the Evo at 25 psi before in the summer (for some reason it likes leaner fuel and more timing in the summer) with no issues. But, I don't think that fuel change really made a difference other than make the engine sound a lot better.
Since you're learning, I'd suggest playing with different values to see what you end up with. Start with 11.2:1 or so and get a solid tune built. Get some power numbers from one of the dyno calculators available in the ECUFlash forum. Then, pull a little timing and run it up to 11.6:1 or so and see where you end up. See which the car likes better.
Peak power from fuel occurs between 12.2:1 and 13:1 on a turbo car. That shifts a little leaner on an NA car I believe. Within that range, there is little change in power ... but if you are below that range, you can see gains. But, as Horn said, power generally comes from timing.
If you are tuning for the absolute 100% most you can get from the car, you can sometimes squeeze out another HP or 2 by finding the maximum timing you can run and then fine tuning the peak cylinder pressure with the fuel mix, assuming the temps are acceptable. I don't recommend that though as it's not worth the time and doesn't leave much safety margin in the tune.
Since you're learning, I'd suggest playing with different values to see what you end up with. Start with 11.2:1 or so and get a solid tune built. Get some power numbers from one of the dyno calculators available in the ECUFlash forum. Then, pull a little timing and run it up to 11.6:1 or so and see where you end up. See which the car likes better.
Peak power from fuel occurs between 12.2:1 and 13:1 on a turbo car. That shifts a little leaner on an NA car I believe. Within that range, there is little change in power ... but if you are below that range, you can see gains. But, as Horn said, power generally comes from timing.
If you are tuning for the absolute 100% most you can get from the car, you can sometimes squeeze out another HP or 2 by finding the maximum timing you can run and then fine tuning the peak cylinder pressure with the fuel mix, assuming the temps are acceptable. I don't recommend that though as it's not worth the time and doesn't leave much safety margin in the tune.
Oh ok haha i need to add alot more fuel then, im at 12.3 AFR but im not getting any knock, only after 4,300k because i never pulled timing up top yet. So ill set it so its about 11.3 to start and ill do the steps you mentioned above
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#212
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I was reading through a post that steven made about the low and high octane timing maps, On the Evo ECU ROM that im using do i use the high octane map for power and edit the low octane map to control knock? Say im getting 4 counts of knock at 3,500 RPM at 120 load. My timing on the high octane map it 7 and on the low octane map its 2. Do i pull timing on the low octane map and change it to 1 degree (pull timing one degree every 3 knock) right?
#213
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I was reading through a post that steven made about the low and high octane timing maps, On the Evo ECU ROM that im using do i use the high octane map for power and edit the low octane map to control knock? Say im getting 4 counts of knock at 3,500 RPM at 120 load. My timing on the high octane map it 7 and on the low octane map its 2. Do i pull timing on the low octane map and change it to 1 degree (pull timing one degree every 3 knock) right?
Do this to sort of learn, compare the value in the high octane map, the low octane map, and the actual timing you had at that specific spot in your log. I'm betting with no knock, you're at the high octane value, with some knock, you're between the 2 values (of hi and low), and then when you knock like 10...probably the low value. Let me know if that is the case, I'm curious.
#214
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The high octane map should be "knock-free" throughout the entire WOT pass, and then the low-octane map should be just a few degrees lower all over the map. When you get knock, I think it merges the 2 values together (more knock, and it goes closer to the low octane number), so that low octane map is used when the engine has "problems". You want it running as smooth and knock free under optimal conditions, and then under less than optimal conditions that low octane map will help correct . Those sorts of conditions are like, bad gas or water in the gas, problems with injectors, hot day, like, everything that could possibly go wrong, those values allow for a margin of error.
Do this to sort of learn, compare the value in the high octane map, the low octane map, and the actual timing you had at that specific spot in your log. I'm betting with no knock, you're at the high octane value, with some knock, you're between the 2 values (of hi and low), and then when you knock like 10...probably the low value. Let me know if that is the case, I'm curious.
Do this to sort of learn, compare the value in the high octane map, the low octane map, and the actual timing you had at that specific spot in your log. I'm betting with no knock, you're at the high octane value, with some knock, you're between the 2 values (of hi and low), and then when you knock like 10...probably the low value. Let me know if that is the case, I'm curious.
![](http://img294.imageshack.us/img294/7223/printscrn1.jpg)
As you can see, in the screen print, starting at 100 load (where boost starts to occur) at 2750 (near where turbo starts spooling) The difference between the high & low octane maps is that there 5 values apart, all the way through. Now say at 3500 i experience 8 counts of knock at 125 load, High octane value is, 7, low octane value is 2, still 5 values apart. Now what i dont fully understand is, do i change the value in the low octane map to say "0" and keep the high octane map to "7" and since the margine between the high and low octane values are now further apart, the calculation value should also drop timing more when knock occurs, know what i mean? Or do i change both the high and low octane values, for example change the high octane value "7" to "6" and change the low octane value "2" to "1"? See what im saying?
Last edited by Mitsu.kid.02; Oct 28, 2010 at 08:26 AM.
#215
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Ok, so im going through this thread now. Learning what I can and Im coming on my first issues. A few light pulls around town im coming into some knock. At least thats what the ecu is trying to tell me. I dont think it is because of the light load and low rpms.
Somebody mind looking at these and let me know if this is what phantom knock looks like? If its real knock the knock voltage should be near the amount of knock if graphed right?
Also im trying to log my wide band through evoscan but the values look off for the column WBO2. Is there a formula that I have to change to get the values correct or should they already be applied?
Thanks for looking
Somebody mind looking at these and let me know if this is what phantom knock looks like? If its real knock the knock voltage should be near the amount of knock if graphed right?
Also im trying to log my wide band through evoscan but the values look off for the column WBO2. Is there a formula that I have to change to get the values correct or should they already be applied?
Thanks for looking
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Last edited by Green_Bandit; Jun 7, 2011 at 10:58 AM.
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