Tame my 4-speed Stroker....
Here's something I wrote a few minutes ago in response to a guy with a 3950lb Chevelle with a 454/T56/RXT dual disc that's trying to improve his [email protected] with a 1.97 60'...
One key to a good 60' is making HP in the first 15'-20' of the run. I took a flying guess on tire size, but attached is a rpm/mph chart of your gearing...
To travel 60' in 1.7sec, here's the average time/distance/mph/rpm intervals for the gearing chart...
.3sec 1.65' 7.5mph 982rpm
.4sec 2.93' 10mph 1309rpm
.5sec 4.58' 12.5mph 1636rpm
.6sec 6.6' 15mph 1963rpm
.7sec 8.99' 17.5mph 2290rpm
.8sec 11.74' 20mph 2618rpm
.9sec 14.85' 22.5mph 3599rpm
1.0sec 18.34' 25mph 3272rpm
1.1sec 22.19' 27.5mph 3599rpm
1.2sec 26.41' 30mph 3927rpm
1.3sec 31' 32.5mph 4254rpm
The time interval above is basically the slip time you need to maintain that minimum rpm. Basically if overall slip time is only .3sec, engine rpm will drop to 982 1.65' after launch. Obviously you are not going to get a 1.7 60' if rpm drops to 982, as even if your engine made 600ftlbs @ 982rpm, still that's only 112hp thru the low point of the bog. Bump that slip time up to 1.3sec, now that 600ftlb is producing 486hp thru the low point of the bog. Far better chance of getting that 1.7 60'.
What a clutch hit controller does is give you a consistent way to adjust how long the clutch slips after launch. The longer clutch slip time is stretched out, the softer the hit will be. That softer hit allows raising launch rpm, which also makes more stored energy available for the launch.
If your car had an automatic, mid 12's would be possible just by choosing the right converter. With a stick, you get there by controlling the hit of the clutch. The downside to a converter is that a proper converter for your current combo may not work well at future power levels. Put a hit controller on your RXT, the clutch you already have will work for both your current combo and most future upgrades.
Grant
Here's something I wrote a few minutes ago in response to a guy with a 3950lb Chevelle with a 454/T56/RXT dual disc that's trying to improve his [email protected] with a 1.97 60'...
One key to a good 60' is making HP in the first 15'-20' of the run. I took a flying guess on tire size, but attached is a rpm/mph chart of your gearing...
To travel 60' in 1.7sec, here's the average time/distance/mph/rpm intervals for the gearing chart...
.3sec 1.65' 7.5mph 982rpm
.4sec 2.93' 10mph 1309rpm
.5sec 4.58' 12.5mph 1636rpm
.6sec 6.6' 15mph 1963rpm
.7sec 8.99' 17.5mph 2290rpm
.8sec 11.74' 20mph 2618rpm
.9sec 14.85' 22.5mph 3599rpm
1.0sec 18.34' 25mph 3272rpm
1.1sec 22.19' 27.5mph 3599rpm
1.2sec 26.41' 30mph 3927rpm
1.3sec 31' 32.5mph 4254rpm
The time interval above is basically the slip time you need to maintain that minimum rpm. Basically if overall slip time is only .3sec, engine rpm will drop to 982 1.65' after launch. Obviously you are not going to get a 1.7 60' if rpm drops to 982, as even if your engine made 600ftlbs @ 982rpm, still that's only 112hp thru the low point of the bog. Bump that slip time up to 1.3sec, now that 600ftlb is producing 486hp thru the low point of the bog. Far better chance of getting that 1.7 60'.
What a clutch hit controller does is give you a consistent way to adjust how long the clutch slips after launch. The longer clutch slip time is stretched out, the softer the hit will be. That softer hit allows raising launch rpm, which also makes more stored energy available for the launch.
If your car had an automatic, mid 12's would be possible just by choosing the right converter. With a stick, you get there by controlling the hit of the clutch. The downside to a converter is that a proper converter for your current combo may not work well at future power levels. Put a hit controller on your RXT, the clutch you already have will work for both your current combo and most future upgrades.
Grant
