Advance Curves

[Kevin Hall]

For all you guys running the advance hungry N/A F4's, what does your advance curve look like? Right now for VE tuning, we are sticking to 40deg max. We are basically running 25deg at 3000RPM and running a linear gradient up to 12000RPM where we run 40deg. I know we are running it on the retarded side, but I'm not sure how soon we can pile 'er in.

How early can you run full advance? How prolific is knock in these engines? Will it be obvious enough that we'll have 10 seconds to back it off before we have shattered pistons?

So far, we are seeing really nice power curves, a little soft in the bottom end, but from 7000RPM on, we've got 45Nm of torque, which starts to fall off at about 11500RPM.

Kevin Hall
University of Saskatchewan
Engine Guy Extraordinaire

[Kevin Hall]

For all you guys running the advance hungry N/A F4's, what does your advance curve look like? Right now for VE tuning, we are sticking to 40deg max. We are basically running 25deg at 3000RPM and running a linear gradient up to 12000RPM where we run 40deg. I know we are running it on the retarded side, but I'm not sure how soon we can pile 'er in.

How early can you run full advance? How prolific is knock in these engines? Will it be obvious enough that we'll have 10 seconds to back it off before we have shattered pistons?

So far, we are seeing really nice power curves, a little soft in the bottom end, but from 7000RPM on, we've got 45Nm of torque, which starts to fall off at about 11500RPM.

Kevin Hall
University of Saskatchewan
Engine Guy Extraordinaire

[Kevin Hall]

Does anyone know where I can find the stock advance curve of an F4?

[B Lewis @ PE Engine Management]

We have never seen much improvement by using over 45 degrees of total advance.


Brian Lewis
www.pe-ltd.com (http://www.pe-ltd.com)
"Compelete Engine Managenent Systems"

[mason]

Anybody want to share advance values for a yamaha R6? We're maxing out a 55 degrees advance right now

-john mason
chief engineer engine team
Cal State Northridge
www.ecs.csun.edu/sae (http://www.ecs.csun.edu/sae)

[Angry Joe]

55 degrees is the maximum factory timing. We're not seeing much benefit to advancing past 45 degrees but frankly I don't have the nerve to push it too much

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[wes k]

I have no experience with the f4, but I know on our f2 we saw no gain in running more advance than the factory called for (29 degrees). I advanced it way past that and never saw knock. I would personally not deviate much from the factory max value, and maybe experiment with bringing the timing in faster to enhance response down low. I found on the f2 the factory curve seamed pretty good. I am assuming the newer engines like that advance because of the larger bore/smaller stroke? I think in these bike engines torque starts to drop off from too much advance before knock sets in. At least it does on the f2.

[Brigadier General]

We just try and keep our car off the retarded side.