Ignition Timing Advance

[RobLav]

I finally broke down and bought a PC3R fuel and ignition modules for the 06 Yamaha R1. I also altered the airbox, added a race filter, removed the secondary throttles, and added some nice velocity stacks. The engine now has a LOT better throttle response.

Anyway, I can pretty much figure out the fuel map thing by starting with a map fairly close to what I have on the engine, but I can't find much information on ignition advance.

First of all, I don't know if the ignition numbers for the maps correspond to actual degrees of timing or some ratio of that. I've read on the R1 forum, for example, that a "10" in a particular cell on the table does NOT mean an additional 10 degrees of ignition timing.

My gut is telling me to add about 4-5 degrees advance at higher RPM's (8500-13,000) at 100% throttle and slope that down to zero additional advance at about 50% throttle. This is with minimum octane for AVGAS.

Any ideas????

[RobLav]

The silence is quite deafening!!!

[RussMcB]

Rob, PM sent.

a couple of thoughts:

As you know, Power Commander site has a bunch of fuel maps for different combinations. I picked one that sounded similar to my set up and it turned out to be way off on the dyno. Hopefully you'll have some way to check AFR to confirm your map is good.

We really don't care too much about part throttle too much, do we? Although, sloping the numbers is probably a good idea.

[RobLav]

Hey Russ, thanks for the PM.

Concerning part throttle - this is the first racecar I've had that I can't mash the throttle so much out of slower corners. Between the added power over FC and the twitchy rear end, I do use part throttle - Big Bend at LRP, a couple spots at NHMS, and the infield at Pocono.

Softer rear springs and wider rims and tires should help this next season.

Sooo - yeah - I am concerned with part throttle too. I found a good fuel map on the R1 forum - a personal one that a guy provided who has about the same alterations. The only difference is that he does not have a tri-Y header and I do. Dynojet provides a fuel map for a tri-Y system for my engine, so I will start with that, then hand alter it to fit in the other map. The Tri-Y seems to be richer than all the 4/1's almost across the map.

[RussMcB]

Here's the part that puzzles me about 'part throttle': Most of the time we're at 100% throttle when we're on the track, and whenever we aren't, that means we do not want as much power as the engine can deliver. Therefore, who cares if the engine makes another 1-2 HP at say 50% throttle - That would only mean you'd have to lift even more to avoid crashing.

Having said that, I can see the value if having crisp and predictable transitional throttle, but that's different.

On the ZX-10R.net forum, several people suggested +4 in all ignition map cells at 60% and greater throttle position, from 4500 RPM and up. Who knows if that might be true for your engine. My hunch is there may be many differences in the characteristics of different engines. Your engine might want something very different. I'm sure fuel type makes a big difference, too.

I really like the idea of logging AFR while you're on track. I have that set up, but for various reasons have not had a chance to take advantage of it yet. My ideal plan was to find out a good AFR for power at the dyno, then log it and monitor it at the track. Ideally you could do HP tuning without going back to the dyno. I also like how you can log/monitor AFR just like other things (OP, OT, WT, FP, voltage, etc.). There have been a few times when my logged data has provided helpful insight. It'd be nice to know if you're running rich are lean. Maybe even set a warning light.

on edit: I have an Innovate LC-1 connected to my AIM Mychron 3. David and Ellen at Veracity have been working with me this winter to get it connected correctly.

[RobLav]

Thanks Russ,

I agree with your part throttle assessment. What difference does it make if the gas pedal is a fraction of an inch more depressed? But we do need good transitional throttle response.

The guy (Mark) who makes the pro-velocity stacks that I bought and George Dean provided a lot of help. I just now started the car after installing a combo map that I made up row by row and column by column. It seems a bit rich cold, but I did not want to run it long in the closed garage. So I started with a dynojet standard map for a Tri-Y header like mine, then altered it based on another personal map provided by another guy who has all my other mods. And I ended up adding +5 at 80% and 100% throttle and sloped it down to 0 at 40% from 8500 rpm up. Mark says +5 does not equal 5 degrees additional advance - more like 1-2 degrees. It's a start, and I'll see where it goes.

The new intake stacks are over 3 inches long, and now with the secondary throttle butterflies removed, the intake tract is overall quite long - almost 6 inches. The engine seems much more alive now.

So next I need to finish up the installation and proper mounting of the boxes and wires.

One more season, hopefully, on this Yamaha, then I get to pick out a new one. Not yet sure which way I'll go.