PDA

View Full Version : A/C torque change below 3500?


bobthebuilder
9th November 2005, 14:41
Hi all,

I am currently running an 04 1200R with SE II exhaust and stock air cleaner. Dealer says they rejetted at pre-delivery (1 up from stock) and I note the air screw plug has been drilled out.

Bike runs fine, needs enrichener to start and then behaves normally with NO carb farts etc. What I would like, if possible, is a bit more low down (takeoff) and cruise (approx 2900 RPM in 5th) torque, especially as I have the tall 30 tooth front pulley.

Looking at the HD accessories book, it shows stock VS stage 2 dyno runs with majorly increased HP and torque above 4-5k RPM, but almost no change at all below 3500 RPM.

Given that I am perfectly happy with acceleration etc in the higher rev ranges, and am only looking for increased torque down low (which from the info I have, I won't get), am I wasting my time going for free-flowing A/C ($$$) and rejet again?

Cheers,
Bob

CBAS5
9th November 2005, 15:53
and am only looking for increased torque down low (which from the info I have, I won't get), am I wasting my time going for free-flowing A/C ($$$) and rejet again

Be warned that I have no experience in this area, but I don't think you are wasting your time. Look at the dyno section where someone is running cycleshacks and the arlen ness big sucker. The bike produces over 50lbs of torque at 1.5K rpm, 60lbs at 2Krpm, and 70+lbs from 2.5K-5.5K with a peak of 78lbs. I'm not sure what stock runs, but that setup has some nice torque. I think the bike will inevitably open up a lot more at higher rpm's because that's where the exhaust and intake start to really choke the bike.

http://xlforum.net/vbportal/forums/showthread.php?t=12737

BobboJama
9th November 2005, 21:06
Sporties really don't turn on till 3000 to 3200 rpm thats where the torque band starts to kick in. The AC will not gain much of anything as low end flow is not the issue. If you want more botton end, a SuperTrap 2:1 Exhaust can help, but the cost will far out weigh the torque gain. High lift short duration cams will build torque, but sacafice housepower and usable rpm.