My latest experience with my PowerCommander calibration

A while back I was telling everyone about the struggles I was having with vibration in my EVO. I’ve done a lot of work to it over the last few months trying to get a grip on what this is. After changing several parts such as fuel injectors, intake gaskets, fuel filter, engine temp sensor, intake air sensor, routing the oil breather to the ground, checking engine alignment and mounts, I wasn’t able to change a thing in the way it ran. I guess I chalk this up to process of elimination.

I finally came up with another experiment. Since I was also struggling with spark knock in the 70% throttle range I decided to attack the calibration in a different way. Instead of increasing fuel in those areas I decided to do some drastic spark reduction. I read somewhere that when you increase compression in an EVO you end up having to reduce the spark advance. I just didn’t know how much. Long story short, this is what I ended up with and it not only got rid of my spark knock but also smoothed out a lot of the vibration I was feeling in the engine. It is much more drivable now.


RPM 60% 80%
1500 -3 -4
1750 -4 -5
2000 -4 -5
2250 -4 -5
2500 -4 -5
2750 -4 -5
3000 -4 -5
3250 -4 -5
3500 -4 -5
3750 -4 -5
4000 -4 -5

I would like the old timer EVO experts to tell me if this makes sense or if I am possibly hurting the engine by reducing that much spark.

I am also very upset with PowerCommander that they don’t have a 70% throttle column in the software. 70% was where all my spark knock problems are. And why in the world does it have a 2% column

I hope someone can learn something from this. All comments are appreciated.

Hey Chuck,
I'm more than happy to try and answer any questions that you have. We'll keep this thread going if you want.

I have been very reluctant to take it to a certified PowerCommander dyno place. Although I understand that they have a semi-automated dyno tuning system now to fill in the MAP in all the speed/load points. I understand how they can do this with torgue and A/F feedback. But, if enough changes are done to an engine (any engine) the proper spark conditions will change and I just don't see how they can spend the time to do this. Nobody can but the owner and his (her) ears and a lot of guessing. So you spend 300 bucks to get a tune and you only have half the work done

Aside from the spark timing, I think one of the best ideas is a system that uses 2 wide band O2 for 100% closed loop control like Terry components Terminal Velocity. But it should also have a learn feature so that it doesn't always have to make corrections every time you run the bike. The ECM should be able to fill a table like in PowerCommander and use that table first then make corrections due to wear and tear of the engine. I don't know enough about Terry Components to know if they already do this or not. I think they do.

If I had to do it all over again I would like to try the Terminal Velocity. But, I'm broke now and the bike is running good enough.

What do you mean by reading the charts? Do you have the software loaded on a Laptop? Can you open the software to the main window that has the grid or MAP with the engine speed on the left and the throttle position across the top?

If so then you want to start by finding a map online for the type of performance parts that you put on your bike, such as, V&H pipes with HD Stage II kit. Sometimes you can get a real close map online to get started with. Take the file and copy it to the powercommander directory on your computer.

I tried to do a print screen of the powercommander software but I can't seem to do it with this laptop. I can do it with my other laptop if you want to see what it looks like. Let me know.

Cowboy,

I'm no expert, but, I've been able to handle the PCIII USB pretty good.
I should install a O2 sensor to watch while I ride. I've just not gotten around to it.

I'll help you out if I can, no problem. Although I'll be riding for all of next week and don't plan to bring my laptop with me. I'll catch up with you after that.

My boss is giving me a hard time about taking next week off. I'm going to threaten him today and tell him I'll take the work laptop with me.... drag it behind the bike on a string