mattysmith440
New member
I have 8dn20's, 4.5 tip, 4.5 heel, with a ywy. 60 twist with green in secondary, with a hauck 49/41.I have 8 tooth drivers, 23/39 gears. I have a 1.75 back country track. Engagement is 3900-4000
Out of the hole, I hit about 8100 rpms, but top end im at 7800-7900 and only 95-100mph.
What would I do to get my engagement, WOT rpms, and speed up?
Out of the hole, I hit about 8100 rpms, but top end im at 7800-7900 and only 95-100mph.
What would I do to get my engagement, WOT rpms, and speed up?
well first off, its not going to go much faster then a 100mph with a 1.75 lug track and your 23/39 with 8 tooth drivers is geared at 1.91 ratio.
second the low topend rpm is due to overshifting, the clutchs are getting ahead of the engine because the gearing is deep and allows the engine to shift the front clutch faster because there is less load on the engine, your secondary clutch is torq sensing and your lack of topend torq is making the secondary want to backshift while the front clutch is trying to upshift,,but you dont have enough spring pressure in the secondary likely. In other words the helix is shifted out but the engine really needs to have a slower secondary shift to control the rpm.
likely cure, twist the sec. spring up another 10 degrees to 70, if better... go to 80 and report back rpm.
second the low topend rpm is due to overshifting, the clutchs are getting ahead of the engine because the gearing is deep and allows the engine to shift the front clutch faster because there is less load on the engine, your secondary clutch is torq sensing and your lack of topend torq is making the secondary want to backshift while the front clutch is trying to upshift,,but you dont have enough spring pressure in the secondary likely. In other words the helix is shifted out but the engine really needs to have a slower secondary shift to control the rpm.
likely cure, twist the sec. spring up another 10 degrees to 70, if better... go to 80 and report back rpm.
Last edited:
mattysmith440
New member
thanks alot mrviper! Ill try the 70 and 80 twist today. Also I have a 24 tooth top gear, I may throw that in tomorrow when I put her inside to install my transfer rods.
Would a couple engagement shims help as well?
Would a couple engagement shims help as well?
mopar1rules
Active member
engagement shims will help raise rpms, but you do know that by changing your 23t gear for a 24t gear, is going to gear your sled taller (more top end) and probably require you to alter clutching again. i would try 80deg wrap w/green sec spring like mrviper suggested.