TTS VE Problems : V-Twin Forum: Harley Davidson Forums

stacytmurphy · 09-27-2009, 08:36 PM

Why is the VE so much different between the front and rear.
The motor does not run no where nere as good as thought it would.
The following data is included.

VE GENERATED FILE
http://www.easy-share.com/1907931879/VERun6.pdf

117 MAP FILE
http://www.easy-share.com/1907931880/PJ176-002-B1-117 Motor-007.MT7

V-TUNE DATA FILE
http://www.easy-share.com/1907931881/VTuneData-122.DM3

BVBOB · 09-27-2009, 09:50 PM

Very common to see front and rear VE's very different, mostly due to pipe configuration, couldn't get your files to open. What pipe are you running?

bbrowncods · 09-27-2009, 10:34 PM

I posted a similar issue in the TTS Mastertune thread. If you look at the Vtune data Injector PW width they are close to being equal throughout the RPM range and throttle range. I am not sure how the ECU has such diverse VE values to get the same PW for the front and rear. They should be the same.

Other than just wanting to know why, what is important is that the AFR matches between front and rear and that the injectors are flowing the same amount of fuel between them at the same PW.

I still want to know why the math between the front VE and the rear is different.

bbrowncods · 10-23-2009, 12:48 PM

UPDATE: I was unhappy that my VE tables were so different. I replaced my Gerolomy TB with my original TB and it ran worse. It was tuning but the rear cylinder was at half the VE of the front. Bottom line is I checked for intake and exhaust leaks and noticed a tiny little bit of soot along the slits between the rear cylinder pipe joint. Could that be it? I went to Advance and got a tube of exhaust leak "putty" (in a silver tube). I sealed that joint and the muffler joints as well.
Bingo! VE's are now about 1% of each other, and the bike runs strong.

stacytmurphy, you may want to look at your exhaust pipe joints for signs of leaking (soot).

stacytmurphy · 10-23-2009, 07:04 PM

Quote:

Originally Posted by bbrowncods

UPDATE: I was unhappy that my VE tables were so different. I replaced my Gerolomy TB with my original TB and it ran worse. It was tuning but the rear cylinder was at half the VE of the front. Bottom line is I checked for intake and exhaust leaks and noticed a tiny little bit of soot along the slits between the rear cylinder pipe joint. Could that be it? I went to Advance and got a tube of exhaust leak "putty" (in a silver tube). I sealed that joint and the muffler joints as well.
Bingo! VE's are now about 1% of each other, and the bike runs strong.

stacytmurphy, you may want to look at your exhaust pipe joints for signs of leaking (soot).

I have checked the pipes for cracks, and made sure the gaskets are not leaking.

The Student · 11-06-2009, 09:14 AM

The rear cyl. VE's are reflective of an exhaust leak in the rear cyl...where it is...you'll have to find it...You may also want to check that your CID is correct in the tuning constants..