bhcevo,

That's not necessarily true. Look at the thread that razorlab made about the safer tune making more power.

You will make more power because you may only have to take out a degree or two of timing to get a safe tune whereas the knock counts may be pulling more timing than needed.

Plus, you will feel much better about having a 0 knock tune.

Give it a shot and also take the advice of jcsbanks and let us know.


Great test data.


Eric

 

Good points, Eric.

As an aside, if it looks like my ability to make more torque is being completely bottlenecked by my fuel quality, then possibily going to a bigger/cooler intercooler or more efficient turbo will give me the lower charge-air temperatures I need in place of better fuel.

The way I use the car makes it really impractical to run a race gas tune. My power goals have to be met on 91 oct.

-Peter

 

"Could you elaborate on exactly what you're trying to see? If the octane address changes depending on the fuel I use? Something slightly more sophisticated?"

I think over a certain level of knock for a certain time the octane value will decrease. I think it uses this value to interpolate between the low and high maps where 0 would be running low and 255 would be running high - plus a smooth progression between.

"Are the timing value changes you suggest important for the experiment you want or are you just advising me on how to change my tune to eliminate knock with 91 octane?"

I've not experienced US fuel, but based on the amount of timing being pulled and work with Euro fuels and alky/octane boosters I think this sort of timing would be safer for your 91 octane compared to what you're running now - if anything it would be over-conservative, but this is your fall back low octane map... I'm expecting the ECU will then run somewhere in between the two maps you have, with flexibility in there for running well on 100 and safety even with bad 91. I'm hoping it will also run a bit smoother on 91 for you.

 

Might as well add some fuel and reduce the timing. As it stands your ECU is doing it for you...

l8r)