[watdog]

So I have read up a little on the speed 3 and I was wondering what this statement means
"Calls to Mazda yielded tips: Pop the clutch at 2900 rpm, upshift at 6000 — redline is 6700 — and flat-shift through second and third (which means don’t lift at all — the mechanical equivalent of dropping a Steinway on the clutch and half-shafts and violating our test procedure)."

I'm really wondering what that flat-shift statement means.

I found it in this car and driver add. http://www.caranddriver.com/roadtests/1172...zdaspeed-3.html

 

[fgraziano]

means keep your foot on the gas while you're operating the clutch. They might as well tell you to plan on getting a new drivetrain ever 9-10k miles.

 

[DennisW]

So I have read up a little on the speed 3 and I was wondering what this statement means
"Calls to Mazda yielded tips: Pop the clutch at 2900 rpm, upshift at 6000 — redline is 6700 — and flat-shift through second and third (which means don't lift at all — the mechanical equivalent of dropping a Steinway on the clutch and half-shafts and violating our test procedure)."

I'm really wondering what that flat-shift statement means.

I found it in this car and driver add. http://www.caranddriver.com/roadtests/1172.mazdaspeed-3.html [/b]

shifting without lifting your foot from the throttle was known to drag racers as "power shifting" it's actually not that huge of a shock to the drivetrain except the clutch, and in days of old before rev limiters were popular, a missed shift (which sometimes happened) usually meant toasting a motor. Exploding discs and pressure plates were also a potential hazard. It *is* hard on the clutch, for sure and not recommeded if you want your clutch to last for a long time.
Easy for Mazda to tell magazine test people to do this, they don't have to live with the car for more than a day or two, and if they tear it up its just the cost of advertising as far as Mazda is concerned.
It also seems like they were having issues with the accuracy of the shifter. Perhaps a better unit would be more accurate and not require such brutality to achieve smoother and quicker shifts.......
I wonder what Mazda's warranty coverage would be if you brought one back with the clutch disintergrated and escape holes in the bellhousing from "flat shifting" as they like to call it?

In short, its not something you want to be practicing on a regular basis..........

 

[fgraziano]

how are you going to say it's not hard on the drivetrain? technically you're doing a rolling launch every time you shift, you mean to tell me the diffs aren't getting cooked with all that torque? OK...

 

[DennisW]

how are you going to say it's not hard on the drivetrain? technically you're doing a rolling launch every time you shift, you mean to tell me the diffs aren't getting cooked with all that torque? OK... [/b]

you're already rolling when you do a powershift. its no harder than a regular full throttle/lift and shift/back to full throttle shift on the drivetrain. and unless you have an unequal traction situation between the two driven wheels its not any harder on the differential either.
standing start launches are a whole different issue, and yes they are hard on the whole drivetrain.

actually a properly executed power shift (excuse me Mazda, I meant "flat shift") is a thing of beauty, and an almost seamless transfer to the next gear. one that doesn't go so well can be the ugliest thing you've ever experienced in an automobile.

 

[fgraziano]

Ok, so you're saying that shifting normally at around 2000rpms is the same wear and tear on the car as shifting at 5500rpms? That makes complete sense to me.

 

[Wheels]

What about lifting when depressing the clutch and then giving gas when engaing the next gear, like a heel to downshift but on an up shift? Basically I am trying to describe rev matching. I have found this the smoothest way to up shift when accelerating hard. But are you saying this would also be hard on the drivetrain? If so then we probably should do any revmatching on the down shift.

 

[fgraziano]

there's a difference between feathering the clutch and gas at shift, or rev matching (correctly) and literally holding your foot on the throttle while you're shifting, try it, if you don't hit the rev limiter I'll be surprised. I'm assuming this is all happening during a WOT run of course. None of these shift styles should be particularly damaging if you're just doing normal cruising.

 

[rdandy5875]

i thought flat shift didn't necessarily mean "don't lift, rather than it means "keep the rpm's at your shift point."

So if you shift @ 6k, modulate your foot (lifting ever so slightly) to keep the rpm's at 6k during the shift.

 

[watdog]

I don't know what it all means. That's why I was asking. I'm thinking they meant keep the rpm's at 6 during the transition but not sure.

 

[Daridari]

It's for people who have no respect or sympatico for cars...it is neither skilful nor smart.

 

[mazda_dude]

shifting without lifting your foot from the throttle was known to drag racers as "power shifting" it's actually not that huge of a shock to the drivetrain except the clutch, ...
[/b]

Funny, I've caused transmission damage doing this (not a Mazda).

 

[jvicary243]

Two points:
One, Flat Shifting, as Mazda refers to it, is done by maintaining the engine revs (and boost) at a "high" level during shifting. It's really all about the boost, this is the proper way of accelerating any turbo charged car. I have accelerated my car multiple times by actually planting my foot on the gas pedal and not letting up. If you can't shift and re-engage the clutch before the car hits the rev-limiter, then you can't shift, go get an automatic. Oh, by the way, if you're shifting at red-line, you've already given up the ghost, this cars runs out of power well before that. Otherwise, this style of driving yields the greatest acceleration performance bar none. As far as damage is concerned, get off your rockers people. The car only sheds about 1000-1200 revs from gear to gear anyway, it's really not shocking the system much at all. The gear-set, clutch, wheels, tires, drive-shafts, and the whole car already have a lot of momentum, so the relative stress is not significant. In fact, it's the smoothest way to maintain your acceleration rate and when done correctly, it's very, very smooth. If you don't know how to do it or can't do it, stay in the truck. Once you learn how to do it correctly, you'll find I ( and Mazda, remember them?) know what I'm talking about. You can't be hesitant though.

Two: Power Shifting is when you shift without lifting the throttle and without using the clutch at all. Good luck trying that with a cable actuated shift mechanism.

 

[sbspeed]

Yep - the rev limiter on this vehicle is butter smooth.

Like he said: "If you can't shift and re-engage the clutch before the car hits the rev-limiter, then you can't shift, go get an automatic."

WOT shifts are much smoother on the drivetrain than WOT/SHIFT/WOT.

 

[White MS6]

Yep - the rev limiter on this vehicle is butter smooth.

Like he said: "If you can't shift and re-engage the clutch before the car hits the rev-limiter, then you can't shift, go get an automatic."

WOT shifts are much smoother on the drivetrain than WOT/SHIFT/WOT.
[/b]

I totally agree. However, remember that you have a rubber clutch line that doesn't transfer fluid as well as a solid or braided one. You may have some lag in the clutch engagement and do a little damage to the synchros. I suggest a steel braided clutch line if you plan to speed shift a lot.
I did it all the time in my 2002 Trans Am and had no problems when I got rid of the car with 75,000 miles on it. (And about 200 passes at the track)

 

[DennisW]

Funny, I've caused transmission damage doing this (not a Mazda).
[/b]

true........i guess i was sorta overlooking that :hoho:

we used to take the syncro rings out of the Muncie 4 speeds and file every other tooth off of them, made them work better with power shifting.

The worst example of what can happen when it all goes wrong was a guy I saw many years ago at the dragstrip with a Boss 302 Mustang. I thought those things came with rev limiters but either I was wrong or he had disconnected it.
He tried a full-throttle 2-3 powershift, missed it completely and blew part of the clutch right thru the hood. It destroyed the bellhousing, took a chunk out of the back of the block (fortunately a small one, and not in a critical place, put a hole in the passenger side floor, and broke the input shaft off of the tranny. There was also nothing left of any of the clutch assembly. The man was extremely lucky that it went out the passenger side, or he would have been missing parts of his right leg. Scattershields were your friend, and he did have one after that, along with a new hood, clutch, and trans and other assorted parts.

 

[rfawcett]

I totally agree. However, remember that you have a rubber clutch line that doesn't transfer fluid as well as a solid or braided one. You may have some lag in the clutch engagement and do a little damage to the synchros. I suggest a steel braided clutch line if you plan to speed shift a lot.
I did it all the time in my 2002 Trans Am and had no problems when I got rid of the car with 75,000 miles on it. (And about 200 passes at the track)
[/b]

Is the rubber clutch line the reason our cars are hard to engage smoothly sometimes?

 

[sbspeed]

More importantly, is a solid or braided line available anywhere?

 

[DennisW]

More importantly, is a solid or braided line available anywhere? [/b]

and if it isn't you could probably get a good hydraulics shop to make you one up, or possibly even a company like Earl's. The important part is obviously the end fittings.

 

[eagle 5]

More importantly, is a solid or braided line available anywhere?
[/b]

Yes, I forget which site but whoever sells the braided brake lines also has a braided clutch line.