| Dirty25RS | 10-05-2006 08:47 PM |
Power Shifting 2006
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I found no thread with recent posts about shifting methods so i started this one. People were asking if it is a good idea to power shift a scooby and people were answering with "no" based on the tranny's available at that time. What does everyone think of power shifting the STI 6MT, or the WRX 5MT or other aftermarket trannies?
| Impreza01 | 10-05-2006 10:29 PM |
Power shifting is nearly useless, why bother even doing it? And if you kept powershifting in a 5MT Subaru, something in the tranny will give.
| Dirty25RS | 10-05-2006 10:42 PM |
Its not useless, especially with turbocharged cars, letting off that gas will make you lose boost pressure and you will have to rebuild it. Its not that big of a deal with a stock car, but with a big aftermarket turbo the turbolag between shifts can REALLY add up
| REX8 | 10-05-2006 10:54 PM |
Mazda RECOMMENDS it to magazine testers on the MS3...
Wish we had a tranny like that! :(
Wish we had a tranny like that! :(
| kkam030 | 10-05-2006 11:02 PM |
i read that article, im pretty sure thats the only way it got rated such a good number. im sure a lot of cars could get a second faster if you abused the tranny.
| REX8 | 10-05-2006 11:07 PM |
[QUOTE=kkam030;15512572]i read that article, im pretty sure thats the only way it got rated such a good number. im sure a lot of cars could get a second faster if you abused the tranny.[/QUOTE]
Ha, I think the 260+ HP and the weight had a little somthing to do with it!
And Motortrend DIDN'T shift that way, and it outran the WRX....
Ha, I think the 260+ HP and the weight had a little somthing to do with it!
And Motortrend DIDN'T shift that way, and it outran the WRX....
| REX8 | 10-05-2006 11:30 PM |
[QUOTE=kkam030;15512572]im sure a lot of cars could get a second faster if you [B]abused the tranny[/B].[/QUOTE]
Did you miss the WHOLE POINT?
Its NOT abuse if its built to take that kind of use....thats the point!!!
Did you miss the WHOLE POINT?
Its NOT abuse if its built to take that kind of use....thats the point!!!
| Dirty25RS | 10-05-2006 11:32 PM |
exactly
| davis10 | 10-06-2006 01:36 AM |
get a dogbox if you want to gain time shifting like that.
| Dirty25RS | 10-06-2006 06:37 AM |
I was drivin a 400awhp DSM w/ a dogbox yesterday, that's what made me think about it and start this thread, lol.
| KC | 10-06-2006 08:23 AM |
1st you ask a question....[QUOTE=Dirty25RS;15511157] What does everyone think of power shifting the STI 6MT, or the WRX 5MT or other aftermarket trannies?[/QUOTE]
Then you give an answer on the 3rd post....[QUOTE=Dirty25RS;15512331]Its not useless, especially with turbocharged cars, letting off that gas will make you lose boost pressure and you will have to rebuild it. Its not that big of a deal with a stock car, but with a big aftermarket turbo the turbolag between shifts can REALLY add up[/QUOTE]
Why did you ask if you were so positive of the answer already?
--kC
Then you give an answer on the 3rd post....[QUOTE=Dirty25RS;15512331]Its not useless, especially with turbocharged cars, letting off that gas will make you lose boost pressure and you will have to rebuild it. Its not that big of a deal with a stock car, but with a big aftermarket turbo the turbolag between shifts can REALLY add up[/QUOTE]
Why did you ask if you were so positive of the answer already?
--kC
| cooleyjb | 10-06-2006 08:34 AM |
When I look at this thread I think it should go wiht a thread titled
Power Lifting 2006
Power Lifting 2006
| bjorn240 | 10-06-2006 08:38 AM |
When I look at this thread I think, "OT."
| Chuck H | 10-06-2006 08:49 AM |
[QUOTE=REX8;15512917]Did you miss the WHOLE POINT?
Its NOT abuse if its built to take that kind of use....thats the point!!![/QUOTE]
Would you buy that car used after the magazine editors got done with it? ;)
Just because Mazda tells them to do something on a car that they just hand back the keys on if it breaks, and that only has to last a few thousand miles, doesn't mean it's a great idea. It's the price Mazda is willing to pay to post some good magazine numbers and sell a lot of cars.
Its NOT abuse if its built to take that kind of use....thats the point!!![/QUOTE]
Would you buy that car used after the magazine editors got done with it? ;)
Just because Mazda tells them to do something on a car that they just hand back the keys on if it breaks, and that only has to last a few thousand miles, doesn't mean it's a great idea. It's the price Mazda is willing to pay to post some good magazine numbers and sell a lot of cars.
| danmezz | 10-06-2006 08:49 AM |
Idonno about power shifting an 06, but generally it's not a good idea unless you have the money for replacement transmissions. It's not uncommon to grind up a transmission learning to get the shifts right... at least this is my experience on NA vehicles.
All you have to do is miss a few times and the gear box turns to confetti...
All you have to do is miss a few times and the gear box turns to confetti...
| akuhner | 10-06-2006 09:04 AM |
[QUOTE=KC;15515429]1st you ask a question....
Then you give an answer on the 3rd post....
Why did you ask if you were so positive of the answer already?
--kC[/QUOTE]
Because he wants validation before going out and blowing up his tranny, that way rather than just being his own bad idea it was a collective bad idea. :p
I do belive that Otis still uses the clutch and lets off the gas for a split second when shifting in the Group N. rally car with dogbox.
So Dirty, are you going to do it, or is this a hypothetical question?
Then you give an answer on the 3rd post....
Why did you ask if you were so positive of the answer already?
--kC[/QUOTE]
Because he wants validation before going out and blowing up his tranny, that way rather than just being his own bad idea it was a collective bad idea. :p
I do belive that Otis still uses the clutch and lets off the gas for a split second when shifting in the Group N. rally car with dogbox.
So Dirty, are you going to do it, or is this a hypothetical question?
| Dirty25RS | 10-06-2006 09:21 AM |
I just wanted to start a discussion on the subject. I power shift now out of habit. And I did just want some more input.
| Chuck H | 10-06-2006 10:24 AM |
[QUOTE=Dirty25RS;15515886]I just wanted to start a discussion on the subject. I power shift now out of habit. And I did just want some more input.[/QUOTE]
Change your habit. It ain't worth it on a street car. If you're that worried about acceleration time, increase your hp instead but still take the time to lift throttle during shifts.
Change your habit. It ain't worth it on a street car. If you're that worried about acceleration time, increase your hp instead but still take the time to lift throttle during shifts.
| REX8 | 10-06-2006 11:10 AM |
[QUOTE=Chuck H;15515617]Would you buy that car used after the magazine editors got done with it? ;)
Just because Mazda tells them to do something on a car that they just hand back the keys on if it breaks, and that only has to last a few thousand miles, doesn't mean it's a great idea. It's the price Mazda is willing to pay to post some good magazine numbers and sell a lot of cars.[/QUOTE]
Of course not...
but...
My point in only this...
Think you'll find a Subaru engineer saying, "Drop the clutch at 5k, flat shift the shifts after 2nd gear, go ahead, IT WON'T BREAK"
^^^Never in a million years. Not saying I'd treat my car like that, but it goes 100% toward the strength of the box.
And apparently it doesn't need to be shifted like that to run good numbers (see all the other tests done on the thing).
Just because Mazda tells them to do something on a car that they just hand back the keys on if it breaks, and that only has to last a few thousand miles, doesn't mean it's a great idea. It's the price Mazda is willing to pay to post some good magazine numbers and sell a lot of cars.[/QUOTE]
Of course not...
but...
My point in only this...
Think you'll find a Subaru engineer saying, "Drop the clutch at 5k, flat shift the shifts after 2nd gear, go ahead, IT WON'T BREAK"
^^^Never in a million years. Not saying I'd treat my car like that, but it goes 100% toward the strength of the box.
And apparently it doesn't need to be shifted like that to run good numbers (see all the other tests done on the thing).
| akuhner | 10-06-2006 04:27 PM |
[QUOTE=Dirty25RS;15515886]I just wanted to start a discussion on the subject. I power shift now out of habit. And I did just want some more input.[/QUOTE]
Can you please explicitly define what you mean by "power shifting," step by step? Just to be sure we are all on the same page here...
Can you please explicitly define what you mean by "power shifting," step by step? Just to be sure we are all on the same page here...
| bjorn240 | 10-06-2006 04:39 PM |
Alex,
Why do you insist on continuing this thread o' magical asshattery? Can't we just let it fade off the front page never to return?
- Christian
Why do you insist on continuing this thread o' magical asshattery? Can't we just let it fade off the front page never to return?
- Christian
| Yotsuya | 10-06-2006 05:43 PM |
Does powershifting look as silly as powerwalking? It sounds as silly.
OT-bound?
OT-bound?
| Evil STI | 10-06-2006 05:57 PM |
If you do not care about clutch/synchro wear, I say go right ahead.
| hotrod | 10-06-2006 07:03 PM |
[quote]Can you please explicitly define what you mean by "power shifting," step by step? Just to be sure we are all on the same page here...[/quote]
It's also called flat shifting, you shift without ever lifting the throttle. It keeps the engine on boost, and is worth a signifant reduction it acceleration times.
It's not something I would do on a daily basis but I do it at the drag strip.
Your window for error becomes very small, but if done correctly, it no more "abusive" on the transmission than a throttle lift shift. It just changes the type of wear and tear on the tranny.
If you throttle lift on the shift you completely unload the drive train and suspension, and then reload it with the clutch is released. That also puts stress on the transmission and all the suspension links as they have to re-load to take the acceleration in the new gear.
Under a power shift the shift is so quick that many of the suspension parts never have time to "unwind".
It does put extra wear on the syncro's as you tend to "blow by" the balk rings and that is a bit hard on them.
Pay your money and take your choice. You can replace several sets of syncros for what a dog box setup costs and the dog box has its own "drivablitiy issues" so its not a complete win win trade off.
I wouldn't recommend it for someone who is "timid" about shifting hard and worried about breaking the tranny. It is no different than the "abuse" heaped on the suspension system by the rally-x guys, the brake systems/tires of the track cars. It comes with the territory, if your not willing to go 100% for the performance you want, and not willing to expose the car any "stress of competition" you shouldn't be entering the car in any competitive event.
Larry
It's also called flat shifting, you shift without ever lifting the throttle. It keeps the engine on boost, and is worth a signifant reduction it acceleration times.
It's not something I would do on a daily basis but I do it at the drag strip.
Your window for error becomes very small, but if done correctly, it no more "abusive" on the transmission than a throttle lift shift. It just changes the type of wear and tear on the tranny.
If you throttle lift on the shift you completely unload the drive train and suspension, and then reload it with the clutch is released. That also puts stress on the transmission and all the suspension links as they have to re-load to take the acceleration in the new gear.
Under a power shift the shift is so quick that many of the suspension parts never have time to "unwind".
It does put extra wear on the syncro's as you tend to "blow by" the balk rings and that is a bit hard on them.
Pay your money and take your choice. You can replace several sets of syncros for what a dog box setup costs and the dog box has its own "drivablitiy issues" so its not a complete win win trade off.
I wouldn't recommend it for someone who is "timid" about shifting hard and worried about breaking the tranny. It is no different than the "abuse" heaped on the suspension system by the rally-x guys, the brake systems/tires of the track cars. It comes with the territory, if your not willing to go 100% for the performance you want, and not willing to expose the car any "stress of competition" you shouldn't be entering the car in any competitive event.
Larry
| afpdl | 10-06-2006 07:58 PM |
Ill flat shift into 3rd during autoxs occasionally. It seems to go into gear easier and doesnt upset the car as much. Been doing it for 3 years and havent noticed 3rd acting any different than the other gears.
| O5UUREKS | 10-08-2006 01:19 AM |
So flat shifting (power shifting) is relying on fuel cut or the rev limiter ?
ok lets say (estimate) in first gear at 30 mph the engine is reving at 7500 you push the clutch in with foot still on gas fuel cut happens and revs stay at 7500 now you shift and let out the clutch and the revs drop 2 maybe 3 k I'm thinking that this couldn't be near as bad for any of the drivetrain as most of our launches are. (this is more of a question than a statement)
ok lets say (estimate) in first gear at 30 mph the engine is reving at 7500 you push the clutch in with foot still on gas fuel cut happens and revs stay at 7500 now you shift and let out the clutch and the revs drop 2 maybe 3 k I'm thinking that this couldn't be near as bad for any of the drivetrain as most of our launches are. (this is more of a question than a statement)
| Impreza01 | 10-12-2006 05:58 PM |
[QUOTE=hotrod;15523422]I wouldn't recommend it for someone who is "timid" about shifting hard and worried about breaking the tranny. It is no different than the "abuse" heaped on the suspension system by the rally-x guys, the brake systems/tires of the track cars. It comes with the territory, if your not willing to go 100% for the performance you want, and not willing to expose the car any "stress of competition" you shouldn't be entering the car in any competitive event.
Larry[/QUOTE]
Funny, Gary Sheehan rarely did it. You can even go watch his footbox video on his website. I guess since he didn't flat shift, maybe he shouldn't have entered the car in the USTCC. :rolleyes:
OP: Your points are valid. However, for road racing, I don't see too many STI and WRX drivers needing to flatshift. I don't think Gary Sheehan flat shifts in the ESX STI that runs in the World Challenge series, and I believe that STI uses a moderately large turbo to get the 600hp needed. For a daily driven car, I would not recommend flat shifting unless you have the money to replace parts if it breaks.
Larry[/QUOTE]
Funny, Gary Sheehan rarely did it. You can even go watch his footbox video on his website. I guess since he didn't flat shift, maybe he shouldn't have entered the car in the USTCC. :rolleyes:
OP: Your points are valid. However, for road racing, I don't see too many STI and WRX drivers needing to flatshift. I don't think Gary Sheehan flat shifts in the ESX STI that runs in the World Challenge series, and I believe that STI uses a moderately large turbo to get the 600hp needed. For a daily driven car, I would not recommend flat shifting unless you have the money to replace parts if it breaks.
| silver arrow | 10-12-2006 06:16 PM |
[QUOTE=REX8;15517120]Of course not...
but...
My point in only this...
Think you'll find a Subaru engineer saying, "Drop the clutch at 5k, flat shift the shifts after 2nd gear, go ahead, IT WON'T BREAK"
^^^Never in a million years. Not saying I'd treat my car like that, but it goes 100% toward the strength of the box.
And apparently it doesn't need to be shifted like that to run good numbers (see all the other tests done on the thing).[/QUOTE]
Actually, they said that right after the STi launch. When I test drove my car the salesman made a point to let me know you can drop the clutch on an STi without it breaking. Subaru had the magazines doing it too.
I wouldn't do it on the street, but have no problem beating the car on the strip or autocross course. It's why I bought the car in the first place, to drive hard in competition.
but...
My point in only this...
Think you'll find a Subaru engineer saying, "Drop the clutch at 5k, flat shift the shifts after 2nd gear, go ahead, IT WON'T BREAK"
^^^Never in a million years. Not saying I'd treat my car like that, but it goes 100% toward the strength of the box.
And apparently it doesn't need to be shifted like that to run good numbers (see all the other tests done on the thing).[/QUOTE]
Actually, they said that right after the STi launch. When I test drove my car the salesman made a point to let me know you can drop the clutch on an STi without it breaking. Subaru had the magazines doing it too.
I wouldn't do it on the street, but have no problem beating the car on the strip or autocross course. It's why I bought the car in the first place, to drive hard in competition.
| ChrisDP | 10-12-2006 07:00 PM |
[QUOTE=silver arrow;15590993]the salesman made a point to let me know you can drop the clutch on an STi without it breaking. Subaru had the magazines doing it too.[/QUOTE]
Since when has a dealership salesperson job required an engineering degree? Good luck explaining "but the salesman said I could!" to a service advisor. And for that matter, secondhand info about what "magazines are told to do."
At least the FWD Mazda has a nice driveline shock damper also known as wheelspin. Either way you're chances of long-term success in reliability are decreased, moreso on a Subaru for aforementioned reasons. But it's not my transmission, the salesman's, or the magazine's... It's yours. Good luck with that!
Since when has a dealership salesperson job required an engineering degree? Good luck explaining "but the salesman said I could!" to a service advisor. And for that matter, secondhand info about what "magazines are told to do."
At least the FWD Mazda has a nice driveline shock damper also known as wheelspin. Either way you're chances of long-term success in reliability are decreased, moreso on a Subaru for aforementioned reasons. But it's not my transmission, the salesman's, or the magazine's... It's yours. Good luck with that!
| MRF582 | 10-12-2006 08:47 PM |
[QUOTE=silver arrow;15590993]Actually, they said that right after the STi launch. [/QUOTE]
Any magazine articles that reported that? How did you come to learn of this?
Any can someone post a link or quote from the magazine article where the MS3 engineers told the magazine to 'abuse' the gearbox?
Any magazine articles that reported that? How did you come to learn of this?
Any can someone post a link or quote from the magazine article where the MS3 engineers told the magazine to 'abuse' the gearbox?
| solo-x | 10-12-2006 11:34 PM |
a properly designed gearbox/engine/clutch combo will be able to absorb even the most retarded clutch drop. typically, the manufacturer designs the clutch to slip at a point well below the failure point of the gearbox. usually, with a properly executed flat shift the only part that sees abuse is the clutch. a poorly executed flat shift is tough on syncro's. of course, it seems subaru designed a gearbox for the wrx's that was barely rated for the stock motors output and it would appear it's weaker then even the clutch is. the STi seems to have a much more robust gearbox, but all bets are off if you upgrade to a clutch that is grippier.
should you do it? depends. is your reward for getting it right worth more then a new clutch or gearbox?
should you do it? depends. is your reward for getting it right worth more then a new clutch or gearbox?
| Mr.C | 10-13-2006 05:22 PM |
[quote=ChrisDP;15591515]
At least the FWD Mazda has a nice driveline shock damper also known as wheelspin. Either way you're chances of long-term success in reliability are decreased, moreso on a Subaru for aforementioned reasons. But it's not my transmission, the salesman's, or the magazine's... It's yours. Good luck with that![/quote]
I was waiting for someone to say that. When Mazda does that with an AWD car, they can talk. And let them brag about acceleration times. When they can do it in the rain/dirt/snow as well as dry pavement, I'll be impressed.
At least the FWD Mazda has a nice driveline shock damper also known as wheelspin. Either way you're chances of long-term success in reliability are decreased, moreso on a Subaru for aforementioned reasons. But it's not my transmission, the salesman's, or the magazine's... It's yours. Good luck with that![/quote]
I was waiting for someone to say that. When Mazda does that with an AWD car, they can talk. And let them brag about acceleration times. When they can do it in the rain/dirt/snow as well as dry pavement, I'll be impressed.
| akuhner | 10-13-2006 11:19 PM |
[QUOTE=Mr.C;15604589] When they can do it in the rain/dirt/snow as well as dry pavement, I'll be impressed.[/QUOTE]
[url]http://www.burmeisterrallysport.com/[/url]
[url]http://www.burmeisterrallysport.com/[/url]
| silver arrow | 10-13-2006 11:29 PM |
Listen, if you abuse anything it can break. If you race a vehicle it can break and you are responsable to fix it. I abuse mine in competition, not out of malice but if you push a car 100% then it is being abused. I don't abuse it on the street. If it breaks I will fix it.
Anyone who says they compete in motorsports is abusing the car. If you are pushing the car 100% why compete?
For everyone else that DD, I wouldn't drop your clutch or powershift, it will increase shock loads and wear on your car.
Anyone who says they compete in motorsports is abusing the car. If you are pushing the car 100% why compete?
For everyone else that DD, I wouldn't drop your clutch or powershift, it will increase shock loads and wear on your car.
| silver arrow | 10-13-2006 11:32 PM |
[QUOTE=Car #187;15607938][url]http://www.burmeisterrallysport.com/[/url][/QUOTE]
lies, SRT4 is fastar :lol:
lies, SRT4 is fastar :lol:
| Dirty25RS | 10-16-2006 09:27 AM |
in the millisecond between when the damaging load is applied and the clutch releases to protect the tranny, the load is transfered. So it will damage the transmission some. A clutch cannot predict transmission damaging loads and take evasive action. If you understand/believe in the big bang theory you understand a lot can happen in a ms
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