cams lower VE
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Joined: Jul 2007
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From: Dallas-Ft.Wth
cams lower VE
Are ya'll getting higher or lower Volumetric Efficiency after you replace stock cams with mild-to-moderate cams?
My config is: 2009 Road King FLHR, stock engine, Heavy Breather AC, stock 2:1:2 pipes to Rinehart slip-ons, TTS Mastertune.
I was using their TD205* calibration file and after I adjusted the VE tables they were mostly in mid 80% efficiency, with a handful going around 100% mark.
I bought Woods TW6-6 cams. A reputable Dealer mechanic did the install yesterday. I found the bike pulls better now, and it has a bit deeper and stronger exhaust sound. To my surprise, I got about twice as much pull as I thought I would get, based on the seat of my pants; but only about half as much bark, based on old, Marshall-damaged ears.
See, I used YA205* calibration file after the cam install. I did 4 VE data-gathering runs. But guess what - now my VE is lower! No, really.
Sure, there are a handful of cells that report 110%+. But that's just a handful, and they're in the upper midrange. The great majority of cells report lower efficiency than with the TD205 file without cams (but the TD205 is not shown to be used for cams). It seems the difference is about 8 or so points lower pretty much across the board.
So - I'm just checking the collective wisdom here - is this similar to what ya'll are getting?
PS: it goes without saying I'm happy as a pig in mud with my Woods TW6-6 and TTS Mastertune. I'm just thinking I did not do something that ya'll would have done instinctively
My config is: 2009 Road King FLHR, stock engine, Heavy Breather AC, stock 2:1:2 pipes to Rinehart slip-ons, TTS Mastertune.
I was using their TD205* calibration file and after I adjusted the VE tables they were mostly in mid 80% efficiency, with a handful going around 100% mark.
I bought Woods TW6-6 cams. A reputable Dealer mechanic did the install yesterday. I found the bike pulls better now, and it has a bit deeper and stronger exhaust sound. To my surprise, I got about twice as much pull as I thought I would get, based on the seat of my pants; but only about half as much bark, based on old, Marshall-damaged ears.
See, I used YA205* calibration file after the cam install. I did 4 VE data-gathering runs. But guess what - now my VE is lower! No, really.
Sure, there are a handful of cells that report 110%+. But that's just a handful, and they're in the upper midrange. The great majority of cells report lower efficiency than with the TD205 file without cams (but the TD205 is not shown to be used for cams). It seems the difference is about 8 or so points lower pretty much across the board.
So - I'm just checking the collective wisdom here - is this similar to what ya'll are getting?
PS: it goes without saying I'm happy as a pig in mud with my Woods TW6-6 and TTS Mastertune. I'm just thinking I did not do something that ya'll would have done instinctively
Road Master
Joined: Dec 2006
Posts: 1,058
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From: Omaha Nebraska
Here is a late response. The VE curve mirrors the TQ curve. When changing cams it's a rob Peter to pay Paul compromise, a more aggressive cam decreases VE and TQ in a lower RPM range and adds VE and TQ to a higher RPM range, thus the minuses and pluses for your VE changes.
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From: Dallas-Ft.Wth
yup
gearGrinder,
yup, I think I understand that now, about cams moving the TQ and VE curves around the RPM chart.
In fact, there's this dyno guy in richardson, tx that set my bike up nicely. And he said pretty much the same thing you said. Well, I can't argue with the great results. I get it now.
Thanks for the insight.
yup, I think I understand that now, about cams moving the TQ and VE curves around the RPM chart.
In fact, there's this dyno guy in richardson, tx that set my bike up nicely. And he said pretty much the same thing you said. Well, I can't argue with the great results. I get it now.
Thanks for the insight.
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