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-   -   Dogbox gearing? (https://www.rx7club.com/race-car-tech-103/dogbox-gearing-718227/)

Xeonith 01-04-08 10:31 AM

Dogbox gearing?
 
I'm curious about how differently dogboxes actually feel when they shift as opposed to helical gears. Does it feel harder, or does it take more effort the push the lever into gear?

Kim 01-04-08 12:09 PM

I've drove a Hewland dogbox in a Van Diemen F2000.
It had a firm feel to it, but never hard to get in gear, sure it's noisy but the openwheeled chassis and loud exhaust solved that for me :D
Felt like a tight streetbox.

kwerks 01-04-08 12:14 PM

very easy, my friend uses a 5sp dog box in his 93vw drag car. Its louder than my fd's stock tranny.

ccanepa50 01-04-08 10:41 PM

raced a custom Dog gear box for years in a vintage road race car, shifting very precise, think more like a motorcycle than a car shift........ shifts just snick right in, the travel (throw) way short............timing and speed of shift critical, clutching/hesitation works against it, shifts are so quick you could flick a downshift to 1st at an apex and just shoot out of a turn toward trackout (ie: Sears Point T7 & T11)........ (1st was geared higher than stock 2nd so all 4 gears were used at speed) the whine was probably as loud as the exhaust...just plain awesome to drive.....
chuck

speedturn 01-08-08 07:32 AM

For over 4 years I have been road racing a dog ring G-Force GF-5R road race tranny. The faster you upshift, the smoother and easier it is. If you try and upshift slow like a street car, it will grind metal.

Down shifts are hard to get used to. If the revs are not close, it will crunch loudly.

PS: It is not a matter of straight cut gears versus helical gears
It is a matter of dogs engaging versus synchronizers engaging. Synchros have a cone faced clutch surface to try and get the synchro teeth at near close speeds before engagement. With the dogs, there is nothing to try and get the teeth to match speeds; when they engage it is hard steel on hard steel.


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