Launch RPM

[CJME]

This is a strip only car. Current clutch is a non adjustable Ram powergrip (Sintered iron/Organic). The trans has a 2.20 first gear. Engine is a 12.5:1 iron headed 327 running on VP 110. Is there a way i can get the clutch to slip more on the launch? I will try raising air pressure.

[btrc]

Just curious about the Coyote Stock guys. What transmission are the fast ones using? 4 speed, 5 speed?

[weedburner]

Originally Posted by btrc

Just curious about the Coyote Stock guys. What transmission are the fast ones using? 4 speed, 5 speed?

They are allowed to select from a menu of approved 5 and 6spd transmissions and ratios. 4th is always 1:1, so they only use 1-4 and generally remove the overdrive gears. I might add that they are required to shift using the clutch, no clutchless shifts allowed. Here's a link to their '16 rules... http://www.nmradigital.com/dl/rules/cs.pdf

Permitted Manual Transmissions:
1. Tremec T5
2. Tremec T45
3. Tremec T56
4. Tremec TR3550
5. Tremec TR3650
6. Tremec TKO
7. Tremec TKO-II
8. Tremec TKO500
9. Tremec TKO600
10. Ford Getrag

[Stephen & Horace Johnson]

Originally Posted by weedburner

They are allowed to select from a menu of approved 5 and 6spd transmissions and ratios. 4th is always 1:1, so they only use 1-4 and generally remove the overdrive gears. I might add that they are required to shift using the clutch, no clutchless shifts allowed. Here's a link to their '16 rules... http://www.nmradigital.com/dl/rules/cs.pdf

Permitted Manual Transmissions:
1. Tremec T5
2. Tremec T45
3. Tremec T56
4. Tremec TR3550
5. Tremec TR3650
6. Tremec TKO
7. Tremec TKO-II
8. Tremec TKO500
9. Tremec TKO600
10. Ford Getrag

They are using the gforce 101A trans. All those listed above were breaking like toothpicks!!

[weedburner]

Originally Posted by Stephen & Horace Johnson

They are using the gforce 101A trans. All those listed above were breaking like toothpicks!!

Sorry, i copy/pasted from the original '16 rules instead of the mid-season update, didn't notice that the additions were not on there...

• G-Force –G101A, GF4A – 2.933, 1.867, 1.333, 1.000
3.000, 1.870, 1.340, 1.000
3.173, 1.960, 1.346, 1.000
3.252, 2.009, 1.380, 1.000
3.300, 2.100, 1.406, 1.000
• Jerico –DR4 -
• Liberty -LCS 5000 4-Speed**
• Andrews Transmission –A431 H-Pattern 4-speed**
**Contact NMRA Tech Department for permitted gear ratios

[weedburner]

Originally Posted by CJME

This is a strip only car. Current clutch is a non adjustable Ram powergrip (Sintered iron/Organic). The trans has a 2.20 first gear. Engine is a 12.5:1 iron headed 327 running on VP 110. Is there a way i can get the clutch to slip more on the launch? I will try raising air pressure.

Here's a few options...

1- less aggressive disc
2- smaller diameter disc or reduce the effective diameter of the disc you have
3- reduce clamp pressure by either swapping to a weaker PP/spring or shimming your existing PP away from the flywheel
4- temporarily hold back some clamp pressure with your foot, basically ride the clutch out for 5-10 feet. Adding an adjustable spring loaded pedal stop can make it easier to consistently find the sweet spot in the pedal travel
5- temporarily hold back some clamp pressure with a timed mechanical device