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Just wondering how everyone "speed shifts" and if it means what i think it does. At what rpm does everyone achieve best results, for example, i usually shift between 6k-6.5k and rev match to at least 4.5k are these rpm optimal, because the powerband seems to suggest they maybe. Anyway let me know what you guys think please.
 

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hey does anyone know if down shifting on a 5spd is bad for the IS300 cuz i bought a PLP short shifter and it says not to down shift

as quoted here :
Notice from Pro Lex Performance: Do not downshift if you are going faster than the maximum allowable speed for the next lower gear. To get on a highway or to pass slower traffic, maximum acceleration may be necessary. Make sure to observe the following maximum allowable speeds in each gear. 1st: 35 mph; 2nd: 60 mph; 3rd: 91 mph.
 

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it means not to downshift until below those listed speed or you will over-rev your car.
 

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Hirun said:
it means not to downshift until below those listed speed or you will over-rev your car.
Exactly what he said. It DOES NOT say "Do not downshift" It in fact says "If you are mentally retarded and shift from 4th gear at 80 MPH to 1st gear odds are you should not have bought a stick, or perhaps should not have bought a car, period.
 

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you'll have a real hard time putting it into too low of a gear. you'd really have to force it.

btw, there is no rev matching with speed shifting. you don't even let off the gas or use the clutch. you just shift.

edit: um, the first post is really old... so maybe nm?
 

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moogs said:
btw, there is no rev matching with speed shifting. you don't even let off the gas or use the clutch. you just shift.
This is absolutely not the case. There are different definitions for speed and powershifting, but what you are talking about in any passenger car is impossible. You will grind the hell out of the gear and destroy the synchos if you try this.
Clutchless shifting is possible with most motocycles and gokarts, although even then I think you have to let off the gas a little bit. You need a small engine (think below a liter) in order for something like this to work on a stock gearbox.

Speed shifting does not involve rev-matching, no, but all it is is shifting fast in general. Let off the gas, dump it into the next gear (using the clutch, of course) and get on the gas again, all in one fluid motion.
Powershifting is basically speed shifting, but getting on the gas at the same time you're releasing the clutch, so it works the clutch to manipulate some of the potential energy from the higher engine speed. This kind of shifting is what will let you chirp second, and even third if you've got a powerful enough engine.

P.S. I think some of the F1 cars also use clutchless shifting. Note the racing gearboxes though, probably straight-cut.

/rant. =)
 

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all F1 transmission use the rotating-barrel system that is 'timed'(no sycro), much like the motorcycle tranny. rev-matching is done entirely by the lectronics and the carbon/carbon clutch is actuated by electro-hydraulic system.
it's basically like a lovechild between motorcycle tranny and bmw's SMGII on ritalin overdose.

as for speed-shifting.. its basically shifting quickly and moving foot quickly enough so the clutch slips a little as the car's accelerates.
 

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blueIS said:
all F1 transmission use the rotating-barrel system that is 'timed'(no sycro), much like the motorcycle tranny. rev-matching is done entirely by the lectronics and the carbon/carbon clutch is actuated by electro-hydraulic system.
it's basically like a lovechild between motorcycle tranny and bmw's SMGII on ritalin overdose.

as for speed-shifting.. its basically shifting quickly and moving foot quickly enough so the clutch slips a little as the car's accelerates.
yeah what he said
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IS300_7o2 said:
hey does anyone know if down shifting on a 5spd is bad for the IS300 cuz i bought a PLP short shifter and it says not to down shift

as quoted here :
Notice from Pro Lex Performance: Do not downshift if you are going faster than the maximum allowable speed for the next lower gear. To get on a highway or to pass slower traffic, maximum acceleration may be necessary. Make sure to observe the following maximum allowable speeds in each gear. 1st: 35 mph; 2nd: 60 mph; 3rd: 91 mph.
reading truly is fundamental

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'03 Intensa Blue Pearl 5 Speed
HKS Carb-Ti Exhaust, OBX Headers/Race Pipe, SRT Intake w/ Race ECU, Teck Grounding Kit(Blue), PLP Gen II Heatshield, PLP Vented Radiator Panel, PLP Short Shifter, JDM Altezza Antenna, JDM Altezza Leather Shift Knob, H&R Lowering Springs (1.5" drop all around),Cross-Drilled/Slotted Rotors (all around), Stand Alone Fog Mod, High Power DRL Mod, 2 10" JL Audio Subs + Alpine V series amp.....more to come

"Friends don't let friends drive stock!"

Turbo.........The Final Frontier!
 

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Morpheus_Zero said:
but what you are talking about in any passenger car is impossible. You will grind the hell out of the gear and destroy the synchos if you try this.
Clutchless shifting is possible with most motocycles and gokarts, although even then I think you have to let off the gas a little bit. You need a small engine (think below a liter) in order for something like this to work on a stock gearbox.

you're absolutely wrong about this too. you can definately shift in and out of gears without using the clutch. (it's not easy, and it's not recommended) but if you're rev matched properly, the gear will slip into neutral with no problem, and then into another gear if the revs are at the appropriate range.
 

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p1nk50ck said:
you're absolutely wrong about this too. you can definately shift in and out of gears without using the clutch. (it's not easy, and it's not recommended) but if you're rev matched properly, the gear will slip into neutral with no problem, and then into another gear if the revs are at the appropriate range.
he wasnt absolutly wrong, as he was referring to full throttle no clutch shifting, that would grind the hell outta the gears. your correct you can shift without the clutch, but not with the gas pedal on the floor. (in a stock trans)
 

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moogs said:
you'll have a real hard time putting it into too low of a gear. you'd really have to force it.

btw, there is no rev matching with speed shifting. you don't even let off the gas or use the clutch. you just shift.

edit: um, the first post is really old... so maybe nm?
LOL, MUST HAVE TRIED IT ON THE FREEWAY :p
 

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Morpheus_Zero said:
This is absolutely not the case. There are different definitions for speed and powershifting, but what you are talking about in any passenger car is impossible. You will grind the hell out of the gear and destroy the synchos if you try this.
Clutchless shifting is possible with most motocycles and gokarts, although even then I think you have to let off the gas a little bit. You need a small engine (think below a liter) in order for something like this to work on a stock gearbox.

Speed shifting does not involve rev-matching, no, but all it is is shifting fast in general. Let off the gas, dump it into the next gear (using the clutch, of course) and get on the gas again, all in one fluid motion.
Powershifting is basically speed shifting, but getting on the gas at the same time you're releasing the clutch, so it works the clutch to manipulate some of the potential energy from the higher engine speed. This kind of shifting is what will let you chirp second, and even third if you've got a powerful enough engine.

P.S. I think some of the F1 cars also use clutchless shifting. Note the racing gearboxes though, probably straight-cut.

/rant. =)
hmmmm,... i believe that power shifting requires you to have the car at full throttle between shifts... correct me if i'm wrong but leaving a car at full throttle(rev limiter) while shifting cuts down on the amount of time between shifts. this is only for n/a cars.... i don't do it anymore...

mikey
 

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Pretty much most of you are right to a point....

Speed shifting (it has had a few definitions over the years,but here is the most widely accepted one):Shifting as fast as you can using the clutch and slaming into the next gear as fast as you can. If you are good enough, your foot will NOT come completely off the gas by the time you are done with clutching and shifting to the next gear. Thus you will just be ideally halfway off the gas before you have to floor it again

Powershifting is even more stressful on your tranny: Your foot never leaves the gas, it stays floored. But you clutch and shift as fast as you can while still on WOT. If you are good at it, you can complete a shift withen 300-400rpm. I know of more than a few guys who do it in less than 300rpm increase, 200 to be exact on high powered cars.
 

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kponti said:
Powershifting is even more stressful: Your foot never leaves the gas, it stays floored. But you clutch and shift as fast as you can while still on WOT. If you are good at it, you can complete a shift withen 300-400rpm. I know of more than a few guys who do it in less than 300rpm increase, 200 to be exact on high powered cars.
If you were WOT, why would the revs drop at all? Wouldnt you keep bouncing off the limiter untill the clutch fully engages?
 

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IS-300-Rulez said:
If you were WOT, why would the revs drop at all? Wouldnt you keep bouncing off the limiter untill the clutch fully engages?
No I was implying a 200-300rpm increase with a great powershift. IE if you were to begin the shift process at 6200rpm, then the car should free rev to about 6400-6500 and the shift should be completed with clutch reengaged by then. A good shift regardless of type should not hit the rev limiter.

Also get rid of the CDD if you want to shift faster, no question. Just take it out and replace with a 10mm female to female brake line union/coupler. I got mine for 0.99 cents from Autozone, and get a good dot 4 fluid (Used a synthetic one). Took maybe 10-15mins to replace and about an hour to two hours to jack up car, take off panels, bleed system and a put panels back.
 

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The only situation when you need to do that type of shifting is "Drag Racing"

There is really no need to Speed or Powershift even when you are doing a track day.

Believe me, it isn't that fun drag racing the IS unless you have some F I mods. Car is too slow for most of the equal priced competition out there..
 

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kponti said:
No I was implying a 200-300rpm increase with a great powershift. IE if you were to begin the shift process at 6200rpm, then the car should free rev to about 6400-6500 and the shift should be completed with clutch reengaged by then. A good shift regardless of type should not hit the rev limiter.

Also get rid of the CDD if you want to shift faster, no question. Just take it out and replace with a 10mm female to female brake line union/coupler. I got mine for 0.99 cents from Autozone, and get a good dot 4 fluid (Used a synthetic one). Took maybe 10-15mins to replace and about an hour to two hours to jack up car, take off panels, bleed system and a put panels back.
Oh okay I was not sure. I still dont think I would ever do that to my car :jawDrop: .
 
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