2 quick transmission questions

  • Thread starter Thread starter KSaiyu
  • 10 comments
  • 951 views
KSaiyu

KSaiyu

(Banned)
Messages
2,822
Sorry if I've been asking a lot of questions lately, but I get great info and advice here than other forums :D

I was reading an article on downshifting from high gears to low gears (like 4th to 2nd etc) and how they explained double clutching to use when you want to downshift like that. Somewhere in that article it mentioned about shifting without using a clutch, which reminded me what my dad told me about matching revs to something so u can shift without a clutch.

Does anyone know what's involved to do this, as I've found some sites that mention it, but not fully explain it.

Also, I tried finding out what a twin or triple plate clutch does different to a standard clutch, but all I could find out was that it accelerates better, but no where explained WHY.

Thanks :)
 
Try this thread.

Multiple-plate clutches simply increase the bearing capacity of the clutch, by distributing the torque load across more surface area within the clutch. This lets the clutch take more power without slipping.
 
when up shifting on a car that is geared real low you can shift with out the clutch because the gears are soo close together. they do it race cars NASCAR, Trans-Am, etc. and down shifting from 4th to 2nd would only be possiable if you where going real slow in 4th because you can only go so fast in each gear. like on my car 2nd gear tops at like 55mph and 4th tops at 100mph. so theres know way to go form redlining 4th to 2nd with out going to 3td and when your down shifting in a car with synchronized gears you can just rev match while your changing gears. you don't have to double clutch unless your driving a car with bad synchro's or an unsynchronized car like an 18 wheeler or a real old car. like 40's or 50's. but once you master downshifting you can move on to learning how to heel-toe shift. thats down shifting while holding the brake down. i learned by watching racecar drivers do it on t.v.

with 2+ disk clutches they just grab alot quicker and hold more hp and tq. the NHRA drag cars have like 6-8 dick clutches. but racecar clutches are very hard to slip. this means its very hard to take off normal and smooth.
 
Thanks for the answers.

So for example, if I wanted to downshift from 4th to 3rd without a clutch, I would just have to let go of the accelerator, shift down, then go back on the accelerator? Wouldn't I have to rev up the engine to match something when I downshift without a clutch?

BTW, what exactly do they match the revs to, the shaft connected to the drive wheels in the gearbox??
 
I've tried shifting without the clutch a few times, in my experience you have to match the road speed to the engine speed, to within a few hundred rpms. So, for example, if your car is running 4000rpm in 2nd gear at 40mph, if you want to put the car into 2nd gear without the clutch at 40mph you have to rev the engine to roughly 4000rpm. At least that's how I got my car to shift smoothly without a clutch. I don't know how you would learn what engine speed to rev to though, maybe just a lot of experimenting or something. Or maybe it's easier to do than I think.
 
My mate baris can do this in his Integra type R, 2002 model, From take off.Eg friction of course, but after 1st he can go all the way to 6th.. Its a nice party trick.. :) Alot of practice.. Don't do it unless you no what your doing ;)
 
hmmmm look at this:

http://www.aj-racing.com/spoon-sports/integra-drivetrain.html

and go down to cross gear set.

Is it just me or does this make no sense: "Each gear is also longer than stock, allowing the engine to reach a higher maximum speed in each gear. This improves the driving feel, power delivery, allows higher speeds to be carried through corners without shifting to higher gear, and increases the power available while exiting corners."

Then it gives the ratio numbers compared to stock and most of the gears are shorter than stock? Unless they meant longer as in bigger number? :confused:
 
you wont believe how many times ive explained this.

its not hard instead of asking just hop in a car and try it (if you can) :)
 
Originally posted by neon_duke
Try this thread.

Multiple-plate clutches simply increase the bearing capacity of the clutch, by distributing the torque load across more surface area within the clutch. This lets the clutch take more power without slipping.
Click to expand...

Another quick note about twin plate + clutches. they require a very heavy clamp rated pressure plate. This is due to multiple friction and fibre disks. Once you go beyond a twin plate the ease of use decrease dramaticly.
Tripple plates can be a virtual nightmare to use in heavy traffic. They are almost an on/off type of clutch. Hill starts and smooth take offs become an art form.

Also mulitple plated clutches do not last as long as say a factory or even uprated full single disk type. The more plates the shorter the life and more towards racing.

they also come in different configurations such as a three puck to 5 puck with the 3 puck being the worst of the lot to use smoothly and lasts the shortest in milage and use. They also can not stand being slipped unless you want to spend huge money on a Kevlar/carbon fibre.
 
I wanna try it but I can't find any place where it's explained how it works :confused:

So far I found a few sites that say you have to match the input shaft speed to the new gears RPM wheen you do shift. For example, one of the forums: http://www.automotiveforums.com/t89618.html

I still dont understand that Spoon site and how they explain the ratios :banghead:
 
Originally posted by KSaiyu
Is it just me or does this make no sense: "Each gear is also longer than stock, allowing the engine to reach a higher maximum speed in each gear. This improves the driving feel, power delivery, allows higher speeds to be carried through corners without shifting to higher gear, and increases the power available while exiting corners."

Then it gives the ratio numbers compared to stock and most of the gears are shorter than stock? Unless they meant longer as in bigger number?
Click to expand...
KSaiyu: The bigger the number, the more biased the gear is towards accleration, and against top speed; the higher the revs the engine will be turning. This is referred to as "shorter" gears. Taller or longer refers to gearing with smaller numerical ratios, like you said.

Perhaps the final drive ratio is a lot taller, meaning that the actual output in each gear ends up being longer than the stock transmission?
 

Latest Posts

Back