View Full Version : V8 Supercar flat shifting?
Waatz
04-18-2005, 11:15 PM
How do they do it? please add pictures or a link. Every time I see the foot work of a driver it buzzes me out. I have an understanding of a standard gearbox and clutch etc.
2ndclasscitizen
04-19-2005, 12:47 AM
they use shift cut. there is a button on the top of the gear stick, which when pressed cuts engine power momentairily, allowing a clutchless shift. also, they might use straight cut gears, which also allow clutchless shifts, but i'm not sure
fpv_gtho
04-19-2005, 12:55 AM
Yeah they'd have the straight gut gears and have the dog box rather than synchro's. They still dont survive serious abuse though. The Bathurst weekend goes through 2 gearboxes and 2 engines
2ndclasscitizen
04-19-2005, 01:40 AM
i've always wondered about this, what is a dox box and how do straight cut gears differ from normal ones? i know what straight cut gears do, but i don't have clue about dox boxes
fpv_gtho
04-19-2005, 08:02 AM
Straight cuts are just stronger than helical cut i think, as for the dog box conversions replacing the synchros, i dont know the exact specifications of it all but i think it jut makes it easier to slip between the gears without letting off the throttle
RacingManiac
04-19-2005, 10:22 AM
Straight cuts are just stronger than helical cut i think, as for the dog box conversions replacing the synchros, i dont know the exact specifications of it all but i think it jut makes it easier to slip between the gears without letting off the throttle
No straight cut gear are not stronger themselves, Helical gear has more contact surface and is able to transmit more power, but they also produce side forces and needs to be supported that way, while straightcut don't.
Both kinds of gearbox can have synchro....
Matra et Alpine
04-19-2005, 11:19 AM
No straight cut gear are not stronger themselves,
S/C are strogner because they have a larger cross section of the tooth and hence the ability of the tooth to take a given force is greater.
Helival teeth are actually narrower than s/c to accomodate the helix - and hence are actually weaker :(
But the side forces is the biggest issue, seen gearboxes torn because of side thrust :)
fpv_gtho
04-19-2005, 09:23 PM
Ive heard Helical cuts ae used for road cars cause theyre quieter anyway, so i suppose thats where the trade off from them being weaker comes
Waatz
04-20-2005, 12:08 AM
Straight cut boxes sure do sound nice, what about double hellical? no side thrust, lots of contact area, I guess that's why they are soo expensive.