Flatfoot or powershifting

[blackshine007]

That's good to know!
I was referring to clutch dumps which can cause bad wheelhop and hop is what typically breaks halfshafts. I didn't mean to imply shifting would hurt them

Decent struts and good motor mounts will quell most of the wheel hop

 

[Betelgeuse]

it is dude. I have seen toothless STi trannies because of it, and as we all know STi tranny > MS3 tranny. So you can only imagine. You can reduce the damage but not avoid it.

Just curious. What makes you think an STI tranny is stronger?

 

[Kosh]

I leave the throttle open a bit when shifting for a smoother shift. As long as you get in gear before you dump the clutch I don't see it doing much harm in the long run.

 

[Jays07MS3]

Mazda says that if you're gonna flat shift, do it from 2nd to 3rd, 3rd to 4th and so forth. I do it all the time. It's not bad on the car as long as you have good mounts and not grinding gears

When racing thats what I do. Even lifting during 1-2 and dumping the clutch is pretty hard on the drivetrain. You can definitely feel how hard the shock is. But from 2-3 & 3-4 isn't too bad on the drivetrain but I wouldn't recommend doing that for normal driving.

Here's a log of a run (from DashHawk) I did the other day with normal 1-2 shift and powershifting 2-3 & 3-4. You can see that the RPMs only shoot up <500 more during the shift and that the 2-3 shoots up a tad more than the 3-4 due to the slightly increased shift time. But you can definitely see how much the shift time is reduced compared to the 1-2 shift.

 

[ForceFed]

Hm, I have to disagree, i still think that no matter how smoothly it is done, it will still do some damage, because you are not forcing the clutch to adjust to the rpms you are just slamming it into an immediate force/rpm.

Youre not forcing it at all.
Like I said...Pedal to the Floor...CLutch in shift...and clutch out.
If done quickly and smoothly, you will only raise a few hundred RPM's ,minimal Clutch slip and almost no shock to the Drivetrain. This will also net the Fastest ET's Vs. LTS.

I have been Dragging for about 13 years in many different vehicles..and I have only EVER lost one tranny...And it was my fault for totally missing a gear and shearing off teeth from the gear. It was also done using LTS method.
I bet I have made 2000 Passes on the 1/4 with never a broken ride from a tranny but once.

Its really not hard on the tranny at all...unless you are not good at it,Grind gears or let the RPM's raise too much by being a slow shifter. I see it all too Often people who think they are "Quick" shifters...But in reality,they are killing their ET's.

I would in no way do this on a regular basis during normal driving..Only during races...Whether it be at the track or on the street. Also..Only from Second Gear on..2-3/3-4..we never make it to five....Unless its a highway run...so that doesn't count.

I gaurantee I would impress you with my shifting abilities. I would be glad to hop in anyones ride and net them a better time than they have ever gotten themselves. I have done that numerous times and people dont understand how I can best their times using ther own car...Its all in the technique.

 

[Haltech]

so when you are doing 50mph or more, where does that tension go, because you sure as hell arent burning rubber. the tranny absorbs it just like the STi's, regardless of the drivetrain. Yes, from a dig it would be different. But not from a roll. How would you minimize the damage of powershifting [to none] from a roll? please educate me.

How can you break teeth off your gears when youre using the clutch and not grinding? ive been powershifting my cars for 21 yrs my friend and never had broken teeth in my tranny because of it. If you dont use the clutch, than i can see the toothless point being brought up.

Youre tranny isnt absorbing it! the AXLES are! The load is carried to the axles because thats where the power is being transmitted.. Put your manual car on jackstands... start it up.. Leave it in neutral and see what your front wheels do.

 

[BLKOUT MSP]

No lift shifting is no harder on a tranny then any other method if done right. I ran my Evo that way for a couple years and never had any problems. The only problem you will run into is if you shift to slow and end on the rev limiter all the time. In my Evo I ran a clutch engaged rev cut to make the car cut back to 5k when shifting to make sure that didnt happen and it worked great.

 

[LENNY127]

you can powershift but the risk is higher, as for the loss of time, I run a gtech and for the 1-2 shift and the 2-3 shift you lose about .35 to.4 of a second in speed say I shift 2-3 and at the point of begining to shift i am exactly at 50mph and 4.0 seconds into the 1/4 mile, by the time you see an increase in speed from 50mph in 3rd gear its 4.35 seconds into the 1/4 mile, I have tried shifting as fast as possible while half engaging the clutch and thats how long it takes at best. if you look at the acceleration chart of a car with a dsg tranny you will see it steadily goes up with no bumps in between.

 

[LENNY127]

the 3-4 shift is about .25 of a second just because it seems to be easier to do.

 

[clos561]

When racing thats what I do. Even lifting during 1-2 and dumping the clutch is pretty hard on the drivetrain. You can definitely feel how hard the shock is. But from 2-3 & 3-4 isn't too bad on the drivetrain but I wouldn't recommend doing that for normal driving.

Here's a log of a run (from DashHawk) I did the other day with normal 1-2 shift and powershifting 2-3 & 3-4. You can see that the RPMs only shoot up <500 more during the shift and that the 2-3 shoots up a tad more than the 3-4 due to the slightly increased shift time. But you can definitely see how much the shift time is reduced compared to the 1-2 shift.

is the dashhawk good or what? that is my next purchase plan.

 

[blackshine007]

Megasquirt does the same thing too

 

[LENNY127]

i cant speak for the dashhawk , but the gtech is a nice way no to have to go to the drags to see improvements , all u need to do is set up a mirror run while at the track to ensure it's as accurate as possible and the ss is 199 bucks, the dash hawk can do more s*** but pulls infor from the cars obd2 port , I have added a couple of things to my speed3 and the 1/4 mile times dropped by 3 to 4 10ths on the g tech which was verified through the actual 1/4 mile strip

 

[SSMS3]

i cant speak for the dashhawk , but the gtech is a nice way no to have to go to the drags to see improvements , all u need to do is set up a mirror run while at the track to ensure it's as accurate as possible and the ss is 199 bucks, the dash hawk can do more s*** but pulls infor from the cars obd2 port , I have added a couple of things to my speed3 and the 1/4 mile times dropped by 3 to 4 10ths on the g tech which was verified through the actual 1/4 mile strip

It would be nice to have one for testing purposes.
How accurate is your Gtech compared to actual track times, ET and MPH?

 

[LENNY127]

et within .15 once you set up the correct weight and pitch angle(the car lifts the front so it takes away from the readings of the accelerometer inside the g tech) mph within 1 to 1.5 mph, but again all you need to do is do a couple of passes and adjust the weight of your car to slow oe speed the run to match the 1/4 exactly , once u do that they re practically identical. but if you just put the weight of the car + yourself and get the pitch angle close to what it should be you will be within the parameters I told you. I dont have access to a dragstrip often enough for me to see the results of my mods but the gtech once baselined is like a taking the dragstrip with me, measures 60 ft, 330 ft , 1/8 mile, 1000' 1/4 mile plus a detailed graph of the 14 seconds that elapsed showing you mph every step of the way. Only catch is that when u use it you are risking a fat ticket cuz taking this car 100mph on a secluded street is pretty risky......from what I hear..hehe

 

[SSMS3]

thanks Lenny, going to investigate further

 

[dkswim]

from what i have gathereds on the subie tranny is it is normaly the first gear in the regular wrx that gets stripped and it is from droping the clutch at 5 grand and letting the awd sort out the traction thats why 1st geer in wrx wasnt warented. the sti transmission is quiet a bit stronger then wrx one there are 700 hp sti ouththere and also the sti transmission stands up to rally abuse but thats enough about subbies i lift in first and and power the rest sometimes my 2-3 shift is C#@^ it will just need more work

 

[fourthmeal]

Rally cars have dirt under their tires. This is big for saving teeth on a trans.

 

[dkswim]

Rally is not just dirt there is tarmac there is snow/ice there is gravel there is also sand. I am committing on the fact that the STi tranny is stronger then the WRX tranny and the fact that most incidents on stripped teeth was from the WRX tranny.

 

[Jays07MS3]

i cant speak for the dashhawk , but the gtech is a nice way no to have to go to the drags to see improvements , all u need to do is set up a mirror run while at the track to ensure it's as accurate as possible and the ss is 199 bucks, the dash hawk can do more s*** but pulls infor from the cars obd2 port , I have added a couple of things to my speed3 and the 1/4 mile times dropped by 3 to 4 10ths on the g tech which was verified through the actual 1/4 mile strip

I have both a G-tech and a DashHawk. I like the G-tech but as I don't take it to the track anymore I don't use it a whole lot. As far as 0-60 times, 1/4 mile times etc, the G-tech is probably slightly more accurate because it actually measures acceleration instead of vehicle speed. The speed measurement can be upset by wheel spin but the acceleration measurement can be upset by hard shifts. And as your tires wear, the vehicle speed becomes less accurate.

When I used the G-tech on my Eclipse at the track, the E.T's were off about .1 sec and the mph was off about 3-4mph but thats because the traps speeds at the track are averaged over the last 60' while the G-tech is instantaneous and actually more accurate.

But the DashHawk is great for data logging and as a scan tool. And I'm amazed at how many different parameters it can log (over 100). And since it reads boost, I no longer need a boost gauge. The parameters I usually monitor are boost, timing, Intake air temp, engine coolant temp, and throttle position, just not all at the same time. But you can display up to 6 parameters at once if you want. I usually display 3 but you can set up to 11 different displays and cycle through them with a push of a button. The PC software is extremely nice as well. My only gripe is that on our cars, the highest sampling rate (data logging) I can get is about 5 samples/sec. But thats good enough for me.

 

[elderlycoffee]

According to mazda "flat shift through 2nd/3rd for max speed" "you won't break it"