Sequential Flatshift

[Bob_n_Cincy]

Can someone explain how Sequential Flatshift works for me. I want it.
See video
Bob



http://vimeo.com/80361400

[Xusia]

Bob, that just looks like a sequential (rachet style) transmission coupled with some kind (there are many) electronic shift aid. Motorcycles have used sequential transmissions for years, and electronic shift aids are fairly commonplace in both motorcycling and cars these days. I'm glad someone has finally put both into the same car! It's literally about time. I just wonder how much that custom goodness cost!

[DodgyTim]

I'd like one too, but at 9,500 euro ? :eek:
https://www.facebook.com/permalink.php?story_fbid=648483298507089&id=358064300882325

[C.Plavan]

Crazy expensive- And crazy expensive upkeep.

[The Race Line]

Yep that is a sequential gearbox. There are many out there for the Subaru. You see them more in the Rally Cars, then you do the street cars.

They are expensive, and they require quite a bit of upkeep and maintaining. If you want to play, you got to pay. If you really want one, let me know and I will run some pricing for you.

Happy to help,

Erik Johnson
The Race Line
(970) 344-7761 phone

[Bob_n_Cincy]

Yep that is a sequential gearbox. There are many out there for the Subaru. You see them more in the Rally Cars, then you do the street cars.

They are expensive, and they require quite a bit of upkeep and maintaining. If you want to play, you got to pay. If you really want one, let me know and I will run some pricing for you.

Happy to help,

Erik Johnson
The Race Line
(970) 344-7761 phone

Is it a 2 clutch system. one clutch is on 1st,3rd,5th and other clutch is on 2nd,4th,6th.
When in 1st, 2nd is engaged waiting for the clutch to switch.
when in 2nd, 3rd is engaged waiting on the clutch switch. and so on
Is this the way it works?
Bob

[The Race Line]

Hey there Bob,

What you are describing is the Porsche PDK gearbox layout. There are a couple of others as well, by other manufactures. No this is not what is being used in this gearbox. A sequential is different from a PDK gearbox.

A sequential is a flatshift no clutch gearbox on upshift, so long as your foot is flat on the floor, but you have to use the clutch on a downshift. The gearing is dog - engagement rather than synchronized. The shifts are more of a bang as the gear dogs engage the op sleeves far more aggressively. While there is no synchronizers to wear out, the dogs take a lot of abuse as do the gears, as they are shock loaded on a consistent basis.

Happy to answer any other questions you might have.

Erik

[CHOTIS BILL]

According to Hewland the faster you shift a dog ring gearbox the easier it on the dogs. On the flat shifting the most common way of doing that is to put some pressure on the gear lever and cut the ignition as you shift. Cutting the ignition releases the pressure on the dog ring and it pops into the next gear. After the shift the ignition is enabled and if done properly you can barely feel the shift. Some system cut the ignition for a given time but the one I made used proximity sensors to start and end the ignition cut.

Bill Lomenick

[longislandwrx]

With an accessport and a 2.5L you can do flat foot.

Not quite as cool but $400 vs $14000

http://www.accessecu.com/support/docs/tutorials/Subaru_LC-FFS_FAQ.pdf

[DodgyTim]

the racelogic traction control that was part of the group buy also enables flat foot shifting, but not clutchless shifts as it uses a clutch position switch to set a lower rev limit
It probably gets you most of the gain for $700 pain, plus a good traction control to boot:cool:

Add one of these for about $1600 and you'd have sequential flat foot shifting!
http://www.rhdjapan.com/ikeya-formula-sequential-shifter-gdb.html

Then all you'd need would be and endless supply of gearboxes:rolleyes:

[Xusia]

Bob, what you were describing is commonly called a dual-clutch transmission. It is another way to increase the speed of shifts. Most can operated manually or by electronics.

[Bob_n_Cincy]

I found a good video of how it works.

https://www.youtube.com/watch?v=Meb5NIXeU2A

It is really just a different kind of shifter on a dog box transmission.
For that not to break anything I suspect the clutch slips a little bit right after engagement on the new gear.
Why do you have to hold in the clutch during downshifting?

[Xusia]

Typically that's because the upshift is made clutchless by cutting ignition. The same tactic does not work when downshifting; you would need a throttle "blip" which is much harder to do (i.e. How much blip? For how long? Etc.).

[Bob_n_Cincy]

Typically that's because the upshift is made clutchless by cutting ignition. The same tactic does not work when downshifting; you would need a throttle "blip" which is much harder to do (i.e. How much blip? For how long? Etc.).

Back in the day, BGSU was using a UNDER/OVERDRIVE transmission between the electric motor and the transmission. In my motor controller I had two encoder inputs (elect motor and diff speed). I would speed match before engaging the gears. Took about a full second. (slow compared to what I see in the video above)

http://www.roadtripamerica.com/wheels/flc.htm

[FlatironsTuning]

The one point that I would make, just because I have not seen it mentioned so far, is that all of the Subaru sequential transmissions currently on the market are for the 6MT, not the 5MT. The biggest reason for this is the design of the cases. The 5MT is split down the middle, where the 6MT housing comes over the input and output shafts, and the bell housing bolts to them separately. This allows the design of a custom center section that can house the cam for the sequential shifting. As was stated before, all of these use a standard clutch. I am not aware of a Subaru Dual Clutch

The sequential 6MT systems that I know of to date are:

Hewland
Modena
Kaps
I think Quaife had a sequential gear box in development a while a go, but I don't know what ever came of it...

For the 5MT, if you have a set of dog gears installed, you would need some mechanism that would work the shift rods in their OEM location to allow you to shift sequentially. Kaps did this with the 6MT a while ago, but that is completely different from the 5MT. It could be done, but I am sure that it would not be cheap. It sure would be fun though :-)

[Jaime]

BTW, the shifter in the video is the same setup as pretty much every motorcycle transmission. It's very easy to convert that style to push-button upshifting or autoshifting with an air cylinder and some electronics.