JamRWS6

That's why there should be a window switch about 100RPM before the limiter.

Dave B

iTrader: (2)

I must say, I agree with him. I've seen more than a few T-5, T-45s, T-56s, and whole slew of Honda trannies that have been powershifted and they all met their end either by:

1) fragmented clutch or shredded clutch lining,
2) blued pressure plate and scored/warped flywheel
2) destroyed sycros (most common)
3) sheared gears
4) bent shift fork (another common one)

People need to know that powershifting is very abusive on a tranny, especially the clutch and flywheel. IMO, it's not worth the 0.05 drop in ET. If Nissan pulls a part a failed 6MT that's been powershifted, it would be very obvious. One look at the flywheel would tell the story. Believe me.

Alberto

iTrader: (14)

Ill post pics of my FW when I swap my clutch/fw, you telling me 53K miles on a stock clutch thats been raced isnt a sign that when done right it can last a fair amount of time? I know the dangers of powershifting, but a very fast speed shifter will also run into the same problems. And where are you getting a .05 drop in e.t. are you serious? You cant sit there and type that and believe it. To some powershifting would hurt thier times and def kill their clutch/fw cuz they'd do it slow and jump revs in between shifts. For others it could be tenths of a second faster. For me its just a personal preference. When I speedshift as fast as I can it doesnt feel 1/2 as fast as when I powershift, having to get off and on the throttle seems like it holds me up. Ive dropped tenths of a second off of many friends cars with similar 60ft's powershifting. But again, thats just my personal preference, Im not telling anybody to do it, but I do think its dumb when people make it seem like powershifting will *** up your clutch/fw/tranny MUCH FASTER than a speed shifter would, truth is we dont know how much my powershifting has taken off the life of my clutch/fw, but at 53K miles Ill say I got my mileage out of it considering what its been through

Dave B

iTrader: (2)

Over my years of racing, I've tried powershifting cars like 6MT F-Bodies, 5.0 Stangs, my old Maxima, and etc. The "gains" were hardly noticeable on the slip. I'm talking about hundreths of a second and less than .5mph. If you're seeing tenths of a second improvement from powershifting, then you're simply not shifting fast enough. Even the big dog racers say powershifting is only good for maximum of .1 if you're REALLY good.

I'm a pretty avid drag racer and have been doing it for about 13 years now. My friends with 10-12 second musclecars and imports have been doing it for longer. The general concenous is a fast lift throttle shift is basically as fast as a powershift. By powershifting, you don't give the syncros anytime to so syncronize and you're jamming the shift fork when there's resistance. With a lift throttle shift, the syncros have at least some time to syncronize and the fork has an easier time on the slider.

When I say lift throttle shift, I'm not talking about granny shifting and letting the car nose down between shifts. My shifts and any other experienced driver makes the lift throttle shift appear pretty dang close to a powershift, but we're am letting off the throttle momentarily on the shift. When I sold my 96 Maxima (14.3s@99mph), it had 113K miles and probably close to 200-220 1/4 mile passes with clutch slip launches ranging from 4000-5000rpms with some runs on DRs. The car still had the stock clutch and it never slipped once. The current owner has 135K on the car and the clutch is still perfect. My racer colleagues that have powershifted in the past all had historys of tranny failures. Once they stopped, the trannys started lasting a lot longer.

This is just my experience of powershifting and seeing disassembled trannies that have been powershifted. It's fine and dandy that you powershift. It's your car, but don't you think the "masses", especially the ones that aren't car savvy, should know the downsides to powershifting?

Alberto

iTrader: (14)

You said nothing new to come back at what I responded with concerning tranny/clutch life. It doesnt matter how long you've been dragging Ive seen some $hitty old guys driving(not saying you are $hitty just an example)-this train of thought is stupid, its like saying 80yr old grandpa can drive/knows better cuz hes been doing it longer, I would disagree this is not always the case. I said I prefer to powershift because imo my speed shifting is no where near as good as my powershifts are. I also said I dont tell people to powershift EVER, I only said I prefer to do it. If there was resistance when powershifting you would grind gears and your tranny would def take a $hit much faster, I have no grinding no resistance that you speak of, and my tranny has been, is and will continue to be fine. I also never claim to drop tenths off of MY TIME by powershifting over speedshifting, simply that I have dropped time off of OTHER peoples (lift throttle avg drivers) times-you need to pay more attention when reading

If you can speed shift well, I agree you have no need to powershift. If you can only drop .1 powershifting you are either very very good at speedshifting or you cant powershift fast enough, either way keep doing what your doin you dont powershi,ft again I dont recommend it to anybody.

My point was I dont like how people claim powershfiting will kill your tranny, clutch, etc, and dont believe a person that can speed shift just as fast as a great powershifter will not run into any of the tranny problems a powershifter would. At the end of the day a very fast speedshifter/powershifter will at some point experience a clutch/tranny failure, nobody really knows how much longer if any the lift throttle drivers tranny will out live the powershifter's tranny. See my point? There are downsides to all types of racing especially drag racing a MT if your fast. I dont see you posting to the "masses" about how regular speed shifting can also prematurely kill synchros, how slamming lift throttle gears can also bend shift forks, or how just being a $hitty driver who burns their clutch to get going could have premature clutch wear. At the end of the day its up to each individual to decide how they drive their car, Ill stick to how I like to shift and what works for me, you stick with yours, but dont get down on powershifitng like its a 100% guaranteed f'd up tranny-THAT IS ALL.

Dave B

iTrader: (2)

Well I disagree and your Grandpa example isn't relevant. It takes a lot of practice at the track to get a solid launch down, shift points, etc. NO ONE is a natural at first. It does take numerous passes to get it down and even then, only a handful are really good at it.

When you're violently slamming a gear, you're not really going to notice any resistance. I'm not talking heavy resistance. A lack of grinding doesn't always mean there isn't a syncro failure looming in the near future either. You know what a syncro looks like right? Assuming you do, it's clear why one can totally fail without warning.

Yes, I did misread and I appologize. Now that I understand you more clearly, wouldn't you think your overall driving is what helped and not the powershifting? It's kind of misleading. From what I've read on this site and G35driver.com, most guys can't launch these cars and most get 2.2+ 60 foots which is pretty sad. If you put someone in the seat that can launch effectively, you're going to see a huge improvement. Wouldn't you agree?

I agree, speed shifting as you call it, will wear out and break components too, but it's been my experience and the experience of many others that powershifting is FAR worse and when you see a major MT failure related to racing, it's almost always related to one of the following three things:

1) Powershifting
2) A hard, traction-full launch usually on slicks
3) Misshift

This is just my experience and I'm not trying to get into some sort of pissing contest. I just think some people need to know what can happen if you powershift because no one seems to ever bring it up.

Alberto

iTrader: (14)

Good post Dave, I dont mean to get into a pissing contest either, I think we can disagree without turning it into one.

Ehh I see some guys at the track every time Im there and some just dont improve unfortunatey, there are always exceptions both ways. My first pass ever stock in the Z, was a 13.80 (2.1 60ft), followed by a 13.77 (2.0 60ft) and then a 13.86. Then I went home happy, 3 runs all 13's all within .1 of each other Now if I could just pull this damn 1.7 60ft on slicks and go 12's


Yes and no. For example I know of a modded base Z, the guy can pull 1.9 60ft's on stock tires, yet he shifts like grandpa and runs a best of 14.2 @ 99 with bolt-ons. These cars are very easy to launch on stock suspension, anybody that cant at least cut a 2.1 after a few passes should just give it up. I do agree maybe my overall driving helps but then again I dont pull stellar 60ft's imo. For example I pulled a $hitty 1.9 60ft and ran 13.1 @ 107, there have been a few NA Z's running 13.0-13.2 and they were all cutting 1.7- low 1.8 60ft's with similar mods, in this case Id say the shifting made up for the average launch.

Fair enough Dave, I Cannot sit here and tell you what you are telling me from experience is wrong. But I can tell you that Ive had several friends destroy transmissions and they dont all powershift, but they do all race. I guess I have been lucky with this latest revised tranny, and my stock clutch. I just read some post where some guys clutch is slipping at only 28K miles-he seems pretty new to the MT. Now imagine that guy racing, powershifting or not I guarantee you his tranny wouldnt live as long as mine because he would prolly be grinding, missing gears, whereas I am not....

Dave B

iTrader: (2)

Agreed on all accounts

fowlman01

iTrader: (1)

I have a 5AT, but I can tell you that Corsair on this board has been using Alberto's techniques and has gone from consistant 13.7's to consistant 13.4's. Must be something to it. I would love to pick up 3/10's just by shifting differently.

Dave B

iTrader: (2)

Well it's all dependant on a handful of things. Were the conditions better, was his 60 foot better, did he change tires, did he add additional modifications.

I can tell you that conditions alone make a big difference. In 70 degree humid weather, my auto G35 sedan went 14.49 with a handful of 14.5s. In dry mid 40-degree weather and with absolutely no changes to the car, it went 14.32 with a handful of 14.3s and low 14.4s. The weather alone was worth nearly .2 and 1+mph.

fowlman01

iTrader: (1)

Same bolt ons. same tires (DR's) and same temp/humidity. Infineon is almost always the same during drag season.

Alberto

iTrader: (14)

Thats nice to hear. Did your buddy PM me or talk to me online? I have sent prolly 200 PM's to people regarding how to shift faster, then if they feel they want and/or can do it, how to powershift correctly. I know for sure Ive helped 3 or 4 guys get faster e.t.s with simialr 60ft's as before. Like I said a few shifting tips + practice = better e.t.'s....

fowlman01

iTrader: (1)

yes, Corsair (Sean) did contact you. He went through 2 trannys before he started power shifting and is on the same clutch tranny etc since. He runs once a week during the season out here, so that is a lot of times down the track. He once had 35 runs on a Saturday at Sacto Raceway. He has had NO problems.

Alberto

iTrader: (14)

Awesome, cool to hear that, send him my compliments on gettign better, I may have already(dont remember) but like I said Ive given out so much advice via PM and IM I cant keep track of the good ones If he continues to powershift well he wont have any isues in the near future.

max2000jp

Alberto, do you have any runs with throttle lift shifts? I always lift during shifts and so do all my friends. The instant torque placed on the drivetrain during powershifts isn't good for transmission longevity. OEM transmissions aren't designed for the load placed on them instantly. Eventually, something will break. Maybe you are lucky???

ZON

iTrader: (2)

^ He probably has his timing down. If done near perfectly then maybe he has something there. Besides, if your going to race around all the time your torturing everything related anyway. Might as well race like a man and git 'er done!!!

max2000jp

If you powershift often, better have a savings account dedicated to replacing transmisions. Shifting fast only wears out your clutch quicker from my experience.

Alberto

iTrader: (14)

No I dont have any lift throttle shift times, next time I go to the track, if I remmeber Ill take a regular run and see. And yes Id say I do have my timing down, like Zon said. Z tranny's/stock clutches are stout man, a measly 262whp powershifting wont destroy it, at least not in 24K it wont. Wait till Im at 370+whp with the Turbonetics kit and I do it, then we will see....btw 53K on stock clutch here

max2000jp

I don't know how strong the Z's transmission is, but I know that the 5 speed manual in my Maxima was known to be fairly weak. The problem with powershifting is that instant torque is placed on the drivetrain and basically shocks it. Transmissions are tested/rated with constant torque placed on them. Either way, if you speed shift or power shift, you are wearing down your clutch and transmission internals faster. Powershifting is something I personally don't do because I personally don't think it's worth it. I can shift quickly enough with lift throttle shifts, I really don't think that keeping my foot in the throttle will do much. All you are removing out of the equation is moving your right foot. I have fairly good reflexes, so keeping it down might shave .025 seconds off a single shift.

southern_info

iTrader: (3)

Dude are you serious! 25 hundredths of a second. I can tell you from my experience with powershifting. It is a little bit more faster than lifting to shift. It'll be more like .1-.3. To me it seems like the transmission allows it to flow a little bit quicker and smoother into the next gear. When I first talk to Alberto about this and he told me the concept. I was practicing it and to be honest I was in the next gear faster than I would thought. Seriously it was like a hot knife cutting thur butter. The gear came so much faster unlike when your lifting to shift, you would have to wait a little bit for it to set itself into gear before coming off the clutch or you would grind or miss the gear.