sequential shift tranny

[CraigMorrison]

So we got our new issue of RacecarEngineering magazine and found a really, really cool product http://www.proshift.co.uk/ . It's an aftermarket paddle-shift setup for manual transmissions. The only drawback is that it requires a sequential shift transmission. So the question of the day: is there a sequential shift transmission out there that will bolt up to a small / big block Chevy? Yes, there is the clutchless Liberty for $7500+, but are there any others? Thanks!

[ProdigyCustoms]

We are putting together a project now that will use one, trans is $20k.

[CraigMorrison]

that's kind of what I was afraid of. Do I need to plan on selling a few organs to pull this thing off or are other options?

[jeff s]

Quaife make's em $5200-6300.
Saenz, others too, can't think of em right now.

[BB69]

Xtrac makes them out of the UK.

http://www.xtrac.com/mainindex.htm

Big dollars as well though. Kennedy Engineering may be able to help with an adaptor to mate a V8 to any number of transmissions.

http://www.kennedyeng.com/

They specialize in VW and Porsche stuff, but since the dune buggy scene has moved to LS1 and Northstar V8 engines, they now make adaptors for those engines as well.

Mendeola in California also makes sequential boxes, but they actually transaxles, meant for mid/rear engine vehicles. They also specialize in off road, so the power levels they can handle on the street are a lot lower.

Good luck.
Ken

[ProdigyCustoms]

A Quaife that will handle ant real horsepower and torque is WAY more then $5000

[USAZR1]

A Quaife that will handle any real horsepower and torque is WAY more then $5000

Yeah,,around $15K.

[CraigMorrison]

I just checked out the Quaife America site and their 6-speed Viper trans (sequential) goes for around 16k less bellhousing. For the budget minded, their H pattern 5-speed is a mere 10K.

[Mean 69]

Before you get too deep into this idea, I'd sincerely suggest calling the folks that make these and tell them what you intend to use the trans for. No question, they are cool, but keep in mind these are RACE transmissions, and contrary to what many people sometimes think, RACE means NO GOOD FOR STREET.

I spoke to the guys from Quaife at SEMA, having the same idea (although no paddle shift for me), and one of the big concerns was the ability to keep the trans in a particular gear. They use straight cut (you HAVE to, no such thing as a helical sequential), and if you are not on the power, or brakes (i.e. loading the trans), some funny thing can occur, per them.

And yes, they aren't cheap, and the unit you pointed out for the Viper cars is the minimum you'd need for a high torque motor. I won't be using one for the street car, but the race car we plan on building after the three projects we have underway will without question get one.

Mark

[trackrat79]

I was not looking at a sequential box but I was considering strait cut gears in a standard H pattern. DO you still have to worry about problems on the street. When you say you need to keep the tranny under heavy load I am guessing that a sequential tranny has a tendancy to change gears un expectedly if you float the rpms. Is this right or is it something else.

[ProdigyCustoms]

As I said, it's $20k, actually a tick north, i just rounded numbers, been to school, got a tee shirt, LOL! If things go as planed, we may be doing this soon, very soon, so we may very well be the test dummy.

[THX 138]

so the point of this is to find a sequential mechanical shift tranny verses the hydraulic automatic tranny style?

[andrewb70]

Holinger from Australia is another option, but it too is very expensive. Somewhere around 18K as I recall. Craig keep in mind that even sequential gear boxes need a way to take a slight load off the input shaft in order get it out of one gear and into another.

If you look at this picture:



you will see that the shift knob has wires. These wires are hooked to the engine management system. The shifter handle actually has an adjustable strain gauge built into it. So when the driver pulls or pushes on the handle, there is a signal sent to the ECU that cuts the ignition for a very short time (milliseconds). This stutters the engine just long enough to make the shift. This will work in a similar fashion with the pro-shift system.
The Liberty 5 speed while being clutchless is not really a sequential gear box. It has a vertical gate shifter and it can only be shifted up, not down. So it is made specifically for drag racing.

Andrew

[Steve Chryssos]

Paddle shifted sequential manual transmission for hot rods? Yeah sure. Piece of cake. No Problema.

[Elusive R]

Paddle shifted sequential manual transmission for hot rods? Yeah sure. Piece of cake. No Problema.

I was starting to think the same thing, but then I had visions of my controls classes and some very large dollar signs that just said "forget about it....."

Maybe someday???

Ryan

[andrewb70]

Paddle shifted sequential manual transmission for hot rods? Yeah sure. Piece of cake. No Problema.

Its only that complicated if you have to use the clutch.

Andrew

[Steve Chryssos]

Not Quite. Clutch and paddle shifter require mechatronic control of engine load, wheel speed and brakes. But you are correct in that the equation gets way easier if you retain a clutch operated by a human.

[andrewb70]

With a racing sequential gear box like the one from Holinger the clutch is only used for taking off and when the car needs to stop. The clutch is not used at all during the upshifts or the downshifts.

The diagram that you posted applies to applications like the Aston Martin (and many others). Where a synchonized T56 is used in conjunction with a host of hydraulics to activate the clutch while shifting.

Then there is ZeroShift...


Andrew

[Steve Chryssos]

The diagram that you posted applies to applications like the Austin Martin (and many others). Where a synchonized T56 is used in conjunction with a host of hydraulics to activate the clutch while shifting.

...Uhh you mean like a hot rod driven on the street?

[Hidro]

Its not a sequential trans but has anyone seen one of these sequential shifters? http://www.renagate.com/


-Ed