LM-2 Logs for Turbo Busa

[65Cobra]

I think I finally have the BEGI working the way it should (will post that issue separately). Up until today I've only used the LM-2 while the bike was in the garage, taking readings at various rpm levels between idle and 4,000 rpm, so nothing in gear or under boost.

Today, I created two test logs riding to and from my house to a local store... a little over a mile... just to see what the logs looked like under those conditions. I intentionally shifted at 4,000 rpm on the only straight section so nothing exciting... sorry.

Looked at the logs and now I have questions...

There were three periods when the A/F was 14.7:1 or leaner. They lasted 1.5 to 3.5 seconds each with the A/F becoming as lean as 18.5:1. In each case it looks like I let off (closed) the throttle so I assume these were during periods of deceleration. Is it normal for the A/F to go that lean when letting off the throttle? If so, why doesn't this burn holes in the piston or otherwise destroy the motor?

I noticed the LogWorks3 trace lines for A/F, TPS and RPM go all over the place at times. I'm assuming that's normal considering I was riding to a local store... three stop signs to get out of my plan, a couple bends, and one straight section. Does that mean I should only create logs while riding on a highway... i.e. cruising at different speeds or under acceleration... and logs like the ones I made today are useless?

Thanks

 

[dadofthree]

 

[202mphbusa]

I think I finally have the BEGI working the way it should (will post that issue separately). Up until today I've only used the LM-2 while the bike was in the garage, taking readings at various rpm levels between idle and 4,000 rpm, so nothing in gear or under boost.

Today, I created two test logs riding to and from my house to a local store... a little over a mile... just to see what the logs looked like under those conditions. I intentionally shifted at 4,000 rpm on the only straight section so nothing exciting... sorry.

Looked at the logs and now I have questions...

There were three periods when the A/F was 14.7:1 or leaner. They lasted 1.5 to 3.5 seconds each with the A/F becoming as lean as 18.5:1. In each case it looks like I let off (closed) the throttle so I assume these were during periods of deceleration. Is it normal for the A/F to go that lean when letting off the throttle? If so, why doesn't this burn holes in the piston or otherwise destroy the motor?

I noticed the LogWorks3 trace lines for A/F, TPS and RPM go all over the place at times. I'm assuming that's normal considering I was riding to a local store... three stop signs to get out of my plan, a couple bends, and one straight section. Does that mean I should only create logs while riding on a highway... i.e. cruising at different speeds or under acceleration... and logs like the ones I made today are useless?

Thanks

Normal for it to go lean under decel
if you could post a picture of your log or send me a copy of the log I can tell you if the "jumping around" is normal or not

 

[GPW]

Normal for the AFR to go as lean at 18:1 when throttle is closed...some add a tad of fuel in the 0% percent throttle range to reduce popping, overheating and start-up issues.

 

[GSX1300R-T]

Are you logging throttle percentage and RPM along with the A/F? A must to make quick changes to the Power Commander map. Just my 2 cents!

 

[65Cobra]

GSX1300R-T, I'm logging TPS and RPM as well.

GPW, I'll keep the 0% suggestion in mind... sounds like a good idea.

202mphBusa, I'll send you the log and also try to post a picture.

Thanks all.

 

[GPW]

please post the log...turbo's like load/need for tuning if your not getting on a dyno find some hills...whats your base fuel pressure?

 

[65Cobra]

Base fuel pressure is 42 psi... that's with vacuum. The '99-'00 Busa's are vacuum referenced so I use the BEGI MR2035 which combines a 1:1 fpr and R/R in one unit. Will attempt to post the log now.

 

[65Cobra]

Attachment...

"2009-08-30 Hayabusa File 002 Session 1a.zip"

 

[65Cobra]

Took Busa out and created a new log but didn't want to to too far from home for the first run. Used full throttle in 3rd but had to shut down at 7,000 rpm. Pictures of that portion of log follow. Also posting full LM-2 Log file. If I should be posting differently please let me know. Thanks.