10-66 weights...8300 should I go to 68?

[the_dougdangerak]

Hey 440! Run yours at 8400, with good porting run 84-8600. You will see 8700-8800 on your tach memory, but thats from your track unloading.

 

[440dart]

its been awhile doug i played with rpms last year i coulda swore it ran better at 8700 but i cant remember i havnt got out on the snow this year

 

[allblowdup]

Pulling timing out a small amount 1 or 2 deg max will actually extend the power peak above what the pipe wants to run by a 100 rpm's or so. After that it will drop real fast.

 

[RMK-King]

So tonight I switched from 10-66 and put 10-58s in for the MTNs. Took the sled for a quick rip and still couldnt pull over 8100 RPMs,I figured it would be 8600 dropping that much weight. I have 19/41 gearing,140/330 primary and team black secondary. "stock" Why am I not getting higher RPMs? I was getting around 8000 with the 10-66. at 2000ft