'01 Ultra - Delphi w/T-max efi tuning

[mayor]

good question.  We have reduced a good bit of timing from the original base map we used for the build though. 

here's what we started with:


and here's was from one of our recent attempts:


the butterfly is opening around the 8.5 degree range, so that would place the timing around 30-31 degrees where it's surging a virtually no load.  I just can't see that being too much at 2.3k.     We've been pulling the timing back, and we've even tried increasing the timing to see what that did.  for what it's worth, he was running about 31 degrees in that rpm range at 16 inHG (54 kPa and less) on his DTT ignition when it was a carb with none of these issues. Our next attempt was going to be a little more timing (34 degrees), do you think that we should try 28 degrees of timing there instead?   

As you can see in the above charts, the base map that we're working with had too aggressive of slopes for Sonny's bike.  He's running about 190 ccp with grooved heads, so it's not very advance friendly.  He keeps getting vibration from too much timing, so we've been playing with trying to get the slopes right. 

He's also getting a good bit of tink from his exhaust after he parks the bike, which also has me curious about whether the o2 sensor readings are accurate.  He's running a supermeg 2 into 1, any known issues with cross talk with that pipe?     he said the bungs are shallow depth nuts, and the o2 sensor appears to be well in the stream. 

[PanHeadRed]

still experiencing bad light throttle surging.
Any idea's folks ? 


Cold only?.......Leak?

All the time?........ To much cold air from the Stage I? .....Try the stock air filter?

Just guessing.

[mayor]

still experiencing bad light throttle surging.
Any idea's folks ? 
Cold only?.......Leak?

Sonny tested for intake leaks, and that was fine.  I can say for sure, but my guess is he tested the exhaust for leaks as well. 

according to Sonny, it seems to be there only when the bike is up to operating temp, which could likely mean it's an afr issue since the warm up stages is intenially set richer in the programing.   We've tried running the surging areas richer and that didn't seem to help, but we didn't go overly agressive in the settings yet though.  Our next test is to reduce the timing in the surging areas to see if that helps.  We're going to try 28 degrees at light throttle at 2304 to see what that does.  We also retarded the surrounding maps around that one as well.

[Ajayrk]

still experiencing bad light throttle surging.
Any idea's folks ? 
Cold only?.......Leak?

according to Sonny, it seems to be there only when the bike is up to operating temp,

Check the HTS for intermittent problems.  You probably already know the TMax uses that sensor more than the stock ecm.

[Sonny S.]

Haven't noticed any problems with HTS during data logging. Rise in head temp always looks gradual and steady.

[Sonny S.]

with the head temp at 45* and the engine off, is a throttle position reading of 13.11 correct ?

[mayor]

I have a data recording on my bike where the TPS is 12.67 without the bike running, at a 170°f head temp.   

[Sonny S.]

Mayor that doesn't sound right. You should check yours tonight while it's nice and cold 

[mayor]

I might have, if you would have posted early enough for me to have thought about bringing my laptop at home hith me ..   

[Sonny S.]

No problem tomorrow will be fine 

[Sonny S.]

Anyone know why IAC looks so erratic ?
It starts out fine when loading a new map, but then in time the chart looks like this.
Mayor thanks for the screen shot 

[Sonny S.]

Oh...it's supposed to be that way. :-)