Guest tom sixbey Posted October 16, 2000 Share Posted October 16, 2000 ok - i know you can upshift a manual tranny at the right rpm without using the clutch, but what are these clutchless shifting/ straight cut gear transmissions claiming - that you can downshift without a clutch also? - my mind is blown to pieces - can somebody explain this to me? ------------------ Tom 6B (73NIC) "why slam on the brakes when you can slam on the gas?" Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted October 16, 2000 Share Posted October 16, 2000 this is terrible... i'm not going to be able to sleep tonight. - i must be really dumn. - i just now heard about the jt5 the can shift clutchlessly up or down. - WTF!? how can it downshift without a clutch? - surely it cant downshift good enough to roadrace without the clutch! - whats going on here guys - i've really never heard of this before and my world is upside down! ------------------ Tom 6B (73NIC) "why slam on the brakes when you can slam on the gas?" Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 16, 2000 Share Posted October 16, 2000 I think this has something to do wit hthe dog clutches used instead of friction type synchros. Is that right? Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 16, 2000 Share Posted October 16, 2000 clutchless shifting...... non synchro boxes ie... dog rings style box. jerico-saenz- any gearbox with strait cut gears..you can even buy all the gears for a nissan tranny to make it this style-- $4500 USD though! a saenz will run $5k+ with the bellhousing. there is no "synchro" to affect rpm so all you do is lift of the pedal slightly to remove the torque and pull that shifter. faster and no wear on the clutch. my next race car will likely have either a saenz or a jerico in it... ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 16, 2000 Share Posted October 16, 2000 Pete, you hit it pretty close. The Tremec's I've seen setup for this had what I think was the dog gear (?) with every other tooth missing. A bunch of welding done in there as well to reinforce things. Not for the street as even part throttle shifts will snap your neck.... Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 16, 2000 Share Posted October 16, 2000 a dog gear works on a slider mechanism , i dont know how removing a tooth on a helical cut gear would work that well... it needs to be a straight cut gear to engage smoothly and last a long time. also a straight cut gear doenst rob HP like a normal style gear thus all real race cars use straight cut gears-- i beleivbe ALL jericos are straight cut check out their website it used to show what a dog ring engagement looked like. ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 16, 2000 Share Posted October 16, 2000 you need to be able to heel toe very well to make a smooth transition so as to not upset the car. i know someone who bought a saenz new and never got to the point where they could shift it. ended up selling it to someone else... but those that can click off the shifts end up being very fast and smooth. it shouldnt be jerky at all....... was what i was trying to get at in a longwinded way! ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted October 17, 2000 Share Posted October 17, 2000 so basicly, all the non-clutched shifts are for acceleration purposes, and are jerky? - its not like they've eliminated the art of the heel-toe downshift have they? ------------------ Tom 6B (73NIC) "why slam on the brakes when you can slam on the gas?" Quote Link to comment Share on other sites More sharing options...
Guest Jason Posted October 18, 2000 Share Posted October 18, 2000 I think straight cut gears wear out faster (with all things equal) because each tooth always sees the same point of contact. I doubt this is a concern for racers who can afford to replace tranny gears often. Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted October 18, 2000 Share Posted October 18, 2000 whew... - i was way off base there.. - thanks for all the answers guys! ------------------ Tom 6B (73NIC) "why slam on the brakes when you can slam on the gas?" Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 18, 2000 Share Posted October 18, 2000 Didn't mean that you remove anything from the helical gears but from the more rough looking things that are on th efaces of those gears. I can see it in my mind's eye but I'll be damned if I can explain it better! some of the Mustang mag's have detailed how it works but digging through MY collection for that one article could take weeks! Quote Link to comment Share on other sites More sharing options...
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