Gear question

[Deish98]

I'm running a shaw modified with a 383 Chevy small block winters quick change and I have a 5.42 gear in it and I'm runnin 7000 rpm do I need to go down to a 530 or go up to 560 to get 7800 rpm

[racin6mod]

the 560 should get you closer to 7800

[oldtrackchamp4x]

Rule of thumb is 100 RPM per .10 on gears. I'm thinking 600 to 633 depending on track and driver. JMO

[Confused?]

To increase RPMs, go higher numericaly. Ex.5.30 to a 5.80 The 5.8 is known as a lower gear even though it has a higher number.

[modified9]

rpm

dividerpm you want to turn by current rpm then multiply that # by current gear 600 what u need 2 turn 7800

[speedbuggy]

dividerpm you want to turn by current rpm then multiply that # by current gear 600 what u need 2 turn 7800

X2 6.00 will get you there...

[let-r-eat]

Also depends on where your engine is making power. If your engine isn't making power above 7000 then going to a 6.00 from the 5.30 may not make it to 7800. Gearing is about where the engine makes power. No use to gear it if the torque multiplication from the gearing + torque of engine isn't greater than you already have. IETorque at 7000 is 400hp at 7800 is 350hp A 10% gear change IE 5.30 to 5.83 would require the engine to make 360hp at 7800 to equal the torque to the wheels of the 7000 rpm peak. Torque x RPM / 5252 = hp. So without the same acceleration capability you may accelerate faster at a certain portion of the track *torque multiplication,hp) and slower at another portion. Like accelerate faster off the corner but slower at the end of the straightaway possibly in this example. You average the numbers in the operating range to determine what gear is required for MAX acceleration.This is a very rudimentary explanation just to give an example of how a gear change may not directly effect the rpm as we think it may.We don't always need max acceleration though

[Deish98]

I think I'm gonna put a 5.60 gear in her and try getting the rpm up cuz I have no power off the turns and I know drivers that use a 5.70 there

[oldtrackchamp4x]

560 is not going to be low enough. JMO