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Speed shifting understanding


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Ok when u UP shifting without using the clutch i understand why it dsnt cause damage. . .when the tranny is underpower, the dogs on the gears are mating on one side. If u leave the throttle and slowdown with the motors back pressure the dogs will just mate on the other side. So as u let go of the throttle the dogs actualy dont mate on eather side alowing u to shift. Now when DOWN shifting its basicaly the same thing. . . If ur going around a bend and ur rpm is to low, u slack the throttle thus swoping the mating sides and as the dogs leave the one side and go towards the other side, the downshift is then alowd. .ive noticed the tranny wont shift if its under power. What i do is while im riding and i wana change up, i apply slight pressure to the gear lever, then as soon as i slack the throtle it goes up. .just as smooth as with the clutch. . .same thing with the downshift. . .but the downshift is very smooth . And so much easier. . . While raceing when uve done like 10laps ur prity screwd and when ur in a bend with low revs its dificult to sortof open ur hand and grip the clutch. Especialy when the turns burs has whoops on. . So its easier just slacking throtle and softly applying down pressure on the lever. . .i would like to hear ur guys take on this?

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Power shifting is where you use the clutch while maintinaing a full throttle. Used alot by AWD cars.

 

Speed shifting is not backing off the throttle. It is shifting when you get to the designated RPM to utilize the maximum power before hitting the redline.

 

http://www.ehow.com/how_2084716_speed-shif...ssion-drag.html

 

You do not need the thing your referring to for changing gears, you can use an override tranny and make full throttle changes without the clutch.

Edited by Bansh-eman
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using the throttle to slack and shift is the way i normally shift 95% of the time. no need to wear on the clutch when i'm not racing or really need a speed shift climbing or in nasty terrain ridding hard. as for truck driving, its a as-per-aplication scenario. slipping the clutch will really save the sync rollers if the geartrain/engine timing/mass isn't going to match how you are wanting to shift. particularly worse with the mack/ford trannies. using the sncros' and rpm shifting on the otherhand, reduces the detremental geartrain impact and clutch wear. i'm partial to the eaton road ranger 18 speed behind a cat. i just love that split shifter (when it's not being slow and making mme miss the gear and have to use the brakesaver to speed things up <_< )

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using the throttle to slack and shift is the way i normally shift 95% of the time. no need to wear on the clutch when i'm not racing or really need a speed shift climbing or in nasty terrain ridding hard. as for truck driving, its a as-per-aplication scenario. slipping the clutch will really save the sync rollers if the geartrain/engine timing/mass isn't going to match how you are wanting to shift. particularly worse with the mack/ford trannies. using the sncros' and rpm shifting on the otherhand, reduces the detremental geartrain impact and clutch wear. i'm partial to the eaton road ranger 18 speed behind a cat. i just love that split shifter (when it's not being slow and making mme miss the gear and have to use the brakesaver to speed things up <_< )

split shifting on the 'brake FTW! also some of the newer trucks simply refuse to shift with the clutch unless the motor is being overrun against the governer down a hill in which case you dont have a choice.

 

 

as far as the banshee, the way i see it a clutch is cheaper than splitting the cases.

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As for truck driving, its a as-per-aplication scenario. slipping the clutch will really save the sync rollers if the geartrain/engine timing/mass isn't going to match how you are wanting to shift. particularly worse with the mack/ford trannies. using the sncros' and rpm shifting on the otherhand, reduces the detremental geartrain impact and clutch wear. i'm partial to the eaton road ranger 18 speed behind a cat. i just love that split shifter (when it's not being slow and making mme miss the gear and have to use the brakesaver to speed things up <_< )

 

Most Heavy Truck transmissions do not have Synchronizers at all, hint why you just can't pop in the clutch anytime and aspect it to slide into gear like a car. If you tear apart an Eaton 6 Speed, then yes there are Synchronizers inside. These transmission are used behind engines that do not put out a lot HP. Once you start getting into 10 speeds and higher, there are no Synchronizers. Non Synchronized transmissions can handle higher HP (Synchronizers are a weak spot). Shifting a heavy truck transmission is all about engine RPM and Gear RPM. As you accelerate the engine RPM becomes greater than the selected gear RPM. When you go to make the next shift, you let of the throttle. Right as you let off the throttle you slide the lever out of gear, as the engine RPM is decreasing there is a point where the engine RPM will match the next Gears RPM. This is when you are able to slide the lever into the next gear without much hassle (when the RPM's are matched). And Mack Transmissions are usually harder to get used to because they are a Main Shaft, Twin Counter Shaft design.

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Most Heavy Truck transmissions do not have Synchronizers at all, hint why you just can't pop in the clutch anytime and aspect it to slide into gear like a car. If you tear apart an Eaton 6 Speed, then yes there are Synchronizers inside. These transmission are used behind engines that do not put out a lot HP. Once you start getting into 10 speeds and higher, there are no Synchronizers. Non Synchronized transmissions can handle higher HP (Synchronizers are a weak spot). Shifting a heavy truck transmission is all about engine RPM and Gear RPM. As you accelerate the engine RPM becomes greater than the selected gear RPM. When you go to make the next shift, you let of the throttle. Right as you let off the throttle you slide the lever out of gear, as the engine RPM is decreasing there is a point where the engine RPM will match the next Gears RPM. This is when you are able to slide the lever into the next gear without much hassle (when the RPM's are matched). And Mack Transmissions are usually harder to get used to because they are a Main Shaft, Twin Counter Shaft design.

-why i said using the syncro's and rpm shift. when i have the radio cranked, and earplugs driving the pos sterling to go fix a truck, i can just press the syncros and it falls in. the 18 speeds i have to pay attention and hear the engine. i just think the ratios really suck in mack trannies. the western star trucks we have also harbor a tremendous amount of geartrain mass in the sisu 6-way diffs that significantly effect timing and backlash effect. also, we have torque fuses in the driveline that prvents abuse that would damage the $45k/ea diffs.

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