Zeroshift: synchroless T-56, "Fastest shifting transmission"

[jrkermode]

Re: Zeroshift: synchroless T-56,

I'm no gearbox designer, but here is my guess of how this deal works.

The roller clutches allow you to have all the gear teeth meshed all the time. The roller clutches internal to the gears are what you use to select gears, probably via some sort of ramp.

These roller clutches can also free-wheel, like a backwards limited slip. If 2 gear sets are engaged at the same time, the faster spinning gear gets all the torque (think centrifugal clutch).

I'm guessing they use the input shaft roller clutches on the way up the gears and the idler shaft roller clutches on the way down the box.

So, the shifting process changes.

Regular tranny:
Select gear pair 1 (synchronizer rings doing the work to match the speeds of the gears)
Deselect gear pair 1 (shift into neutral)
Select gear pair 2 (synchronizer rings again doing the speed matching)

Zeroshift:
Select gear pair 1 (use the ramp to engage the rollers)
Select gear pair 2 (this engages the ramp, but the faster spinning gear, gear pair 1, continue to receive all the torque)
Deselect gear pair 1 (leaving gear pair 2 already selected)

This would imply that the "flatliner" they speak of is whatever scheme they use to unload gear set 1, likely by removing the ramp.

I imagine they release the first gear pair softly to prevent a sudden jump in torque.

I'd also guess that the releasing is where all the magic lies.

 

[Joel]

Re: Zeroshift: synchroless T-56,

Makes sense, but how to release them softly ? and how does it downshift smoothly, I imagine there is no facility to automatically match rpm to gears, so is it neccessary to use the clutch when downshifting and "blip"

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

Joel: FlatLiner makes precises cuts/blips up and down the gears AND it takes over clutch control from the driver. Its objective is to maintain constant output torque (i.e. smooth shift ergo FLAT longitudinal 'g' LINE).

When you disengage drive you're coasting - the car is no longer heading for 100mph. It's heading back to 0mph. When you re-engage drive you have to re-establish the momentum you had before you disconnected. The gain is marginally more than the shift time because you don't have to re-input kinetic energy lost (the heading back to 0mph bit). It's not just 0-whatever times, it's LAP TIMES where picking up all the coasting period makes a major difference - hence contemporary F1 transmissions are down to 35 - 40ms now. Even that's too long! Count the shifts in a lap...

Kenvw: Man, have you got burned by a T56 H-gate by any chance??? ZeroShift inhibits impossible shifts so an "Oops I hit 2nd when I wanted 4th" can't happen. The gate of a ZeroShift box doesn't have the dreadful float of a stock T56. I-gates do indeed eliminate shifts in the wrong direction but they demand multiple moves for skip shifts and the most irritating issues are (a) accidentally becoming stationary at a junction in 3rd then trying to pull away in 3rd and (b) a separate means of engaging reverse (return to my parking scenario in an earlier post). In a race car, the latter problems don't matter. In a road car they're an everyday pain in the ass. There are better ways of avoiding wrong-shifts than an I-gate IMHO. Our improved H-gates are only ONE of the means we will offer.

Jrkermode: ALL manual gearboxes have all the gears meshed all of the time ("constant mesh gearbox"). See my first post of 8/12 - the roller clutches are a redundant design. FlatLiner has nothing to do with the insides of the gearbox - its function is to manage the clutch and the throttle.
Re: "I'd also guess that the releasing is where all the magic lies". THAT is a GOOD guess.
There's actually as much magic engaging as releasing.

 

[FE 065]

Re: Zeroshift: synchroless T-56,

I assume that Flatliner is a means of introducing a momentary throttle cut as the gears are changing to relieve the load. If this is the case, is it sensed by a strain sensor in the gearknob ? Does it then interface also with the clutch switch.A further puzzle. A manual shift may take 0.5 to 0.75 of a second. But eliminating this time wouldn't cause a corresponding drop in 0-60 time or quarter mile time. Or is my thinking faulty ?

Good point. You wouldn't gain 1.5 seconds of course. I remember reading when the Pro Stockers were switching to Lenco transmissions in place of 4 spds, Ronnie Sox (Sox & Martin) was one of the last, and he lost ET rather than gained-his shifting is that good. BTW that same article mentioned currently the 60+yo Sox was campaigning an 8sec 4spd nostalgia-type car. Practice, practice, practice... Don't the Vipers with ABS already have most of the important stuff you'd need to be able to (in theory) add on traction control?

 

[Torquemonster]

Re: Zeroshift: synchroless T-56,

Zeroshift - would it be fair to say that one advantage of modifying a sequential box over an H-pattern would be to eliminate the dog shift across the gate - e.g. 2nd to 3rd in particular that seems to catch to lot of drivers out when they try to rush?

Let's say Bob the racer has a rush of blood to the head and hurrys his 2nd to 3rd shift and gets tangled, not finding the right slot. The Zeroshift H-gate may shift instantly once the driver actually finds 3rd - but in the meantime he has wasted valuable time over revving in 2nd gear looking for it or having to back off as he hits the limiter.

Now a sequential eliminates that because provided you actually pull or push the lever into the only available slot - you are into the next gear at exactly the time you intended every time.... so you do not have the delay in getting to the gear you would on a dogshift - even though the actual engagement time may be identical between shift patterns.

Also - on a sequential - coming up to the lights in 3rd is a quick as a flash bang bang to correct. In an H-pattern - going from 3rd to 1st takes just as long - and on the Tremec boxes - can actually jam and requrie brute force if the shifting mechanism is not ideal....

ever driven a Mustang 5sp? They commonly have that issue... I'm driving a Volvo right now with a Cobra V8 and Tremec 5sp and that can be a real SOB at the lights if you do not pull up in first and sit on the clutch but instead slip it out of gear then try to engage 1st from nuetral when the light changes. These boxes are dark ages compared to Japanese or European boxes - but are smooth enough once underway.

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

FE065: The gain will depend entirely on how quick you could shift before. A Lenco is planetary (like an auto) so there's slipping going on. A sh*t hot manual shifter (lighter box, no parasitic losses etc. etc.) would do better - Mr Sox is some kind of motorist...

Traction control through ABS etc. responds to traction breaking. ZeroShift doesn't let it break in the first place - assuming you've got traction in 1st, you'll have it through the shift to 2nd and so on. Now, with reference to FromZero launch control, that WILL allow some wheelspin because it looks for optimum acceleration that may require some wheelspin. It won't barbecue the tyres though because if wheelspin becomes excessive you stop accelerating therefore it will back off the throttle to optimise the forward thrust.

ZeroShift ONLY controls traction BETWEEN gears and FromZero ONLY controls traction at launch. It's not 'traction control' per se. For real drivers, this is ideal - these are real driving performance aids, not argumentative nanny systems. If your car has a nanny system on it already, it may conflict with FromZero during launch so nanny needs switching off if you want FromZero to optimise your launch.

Torquemonster: There is no need to rush the shift - you don't gain anything by doing so. Sure, you may get excited and rush but, as a supercar manufacturer pointed out to us, a beauty of our shift on the H-gate is that you can start moving the stick BEFORE you want the next gear. So, I want to shift at 7500? Whilst accelerating I move the stick into the middle of the gate and watch the tacho (I'm still in, say, 2nd) then as the needle hits 7500 I push the stick to 3rd. In engine braking, the same thing applies. I can fly into a bend in 5th anticipating 3rd for the exit. For now, trust me on this - it's AWESOME!

Sequentials on I-gates and paddles, IMHO, ****. We've patented a better way of doing this with an automated shift strategy in the background. It will almost certainly feature in the TVR when we hand it to the media.

The gearbox in the TVR is probably that Mustang 5-speed (Tremec T5). Yep, 1st can baulk but that's a SYNCHRO problem and we don't have synchro! All the criticism the Tremec boxes get about shift force/quality has its roots in the beefy synchros which make the shift slow and baulky so a long-throw stick is attached to give some mechanical advantage. Of course, that's slow so you fit a quick-shift that then burns out the synchros. Tremec (or anyone else) can't win. Big torque needs big - or multiple - synchros which is heavy and slow. This in turn means you're between gears for too high a % of your 0-100 time. Reducing the shift time with quick shifters kills the box. The problem is the synchros.

 

[Torquemonster]

Re: Zeroshift: synchroless T-56,

wow - this sounds awesome... so if you can take your time with the shift, and you obviously do not have the clutch engaged or you'd be revving the brown stuff out of the engine - where is neutral, and is there any need for a clutch pedal at all?

 

[Joel]

Re: Zeroshift: synchroless T-56,

The from zero "traction control" sounds like the traction control available in the AEM management system in that it measures engine acceleration in each gear and compares it with a preset max rpm accel rate. If it exceeds this, it cuts power back.

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

wow - this sounds awesome... so if you can take your time with the shift, and you obviously do not have the clutch engaged or you'd be revving the brown stuff out of the engine - where is neutral, and is there any need for a clutch pedal at all?

Refer back to earlier posts T Monster! Back off the gas for Neutral. Without FromZero you keep the clutch for launch but ignore for shifts. With FromZero, the clutch pedal goes.

Joel: AEM system is 'mapped' with presets. 9 times out of 10 the AEM system would achieve a similar result I guess. FromZero works with the clutch AND the throttle rather than throttle only. It's a closed feedback loop so it is able to handle all variables including environmental ones like road surface, ambient temperature - plus account for clutch/tire condition etc.. FromZero finds the optimum launch whatever the conditions.

 

[jrkermode]

Re: Zeroshift: synchroless T-56,

Zeroshift,

Enough theory. When do you put one in Nadine's car?

 

[JGK95]

Re: Zeroshift: synchroless T-56,

Hahahahaha

Jrkermode, Great idea If anyone can TRULY test a transmissions, it could only be the Queen of Roadcourses, Staged Burnouts and Quartermilers.

Jay K.

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

I spoke to Nadine this week. Looks like she's got the nearest Viper (I often visit her part of the UK) so if you guys concur that she is the maddest/baddest trial of our product then so be it.

We have other priorities on the T56 before this but (a) Nadine (and Joel) have offered to help and (b) the guys here are happy to rise to the challenge. I guess sometime in 2005, early as possible, we'll find out what happens "When ZeroShift met Nadine & Joel".

There is huge demand for us to do the T56 (from drivers and OE) but I like things to be right rather than early if you catch my drift. However patience ain't one of my virtues either.

In my photos is a Cobra I race (been chatting to T Monster about it) and while it only kicks [a puny by your standards] 702bhp/650lb/ft it's a kind of 'Saturday Club' project to make a T56 for this. Experience of driving this makes it all the more extraordinary to me that you guys are claiming nearly double the BHP/torque in your cars. The Cobra has no respect for physics (it weighs about 2400lbs) - what's it like to unleash four figure outputs???

Raising the bar to 1200lb/ft to stand a chance of satisfying you crazy muthas has already been discussed here. Toughening up the box with a few bigger bits and different heat treatments would be enough for the Cobra but to go Viper-mad we would have to eliminate end loads with straight cut gears (noisy - do you care?) or big expensive custom double-helicals which the ZeroShift mechanism allows space for.

 

[CHAD]

Re: Zeroshift: synchroless T-56,

Noise is fine. Breakage *****.

 

[MoparMan]

Re: Zeroshift: synchroless T-56,

ZeroShift - it sounds like you already have a product that will stand up to a stock or near stock Viper V-10. I'm sure there are many of us mere mortals who would be interested in zero shift. Is it possible that a kit will be available for us in the near future? How much (in USD) do you foresee such a kit costing?

 

[Viper Wizard]

Re: Zeroshift: synchroless T-56,

I spoke to Nadine this week. Looks like she's got the nearest Viper (I often visit her part of the UK) so if you guys concur that she is the maddest/baddest trial of our product then so be it.

I concur!
I think you have found your "Test Pilot"!
If there are any limits with your "ZeroShift", Nadine will find them!

 

[JGK95]

Re: Zeroshift: synchroless T-56,

1000bhp. Jeez, you guys take the biscuit (and PLEASE don't tell me 1000rwtq is lb/ft rather than Nm...) Over here my penchant for pedalling 700bhp is regarded as pretty insane. I just had a PM from a guy plotting 2000bhp. ...

Zeroshift,

How do you plan to approach 2000bhp? Most realistically, is it possible for any transmission vendor to support/design such a solution for a performance car that doesn't have the name Caterpillar on it?


Jay K.

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

Jay:

2000bhp ... +1200lb/ft ... are just numbers. Granted, they're pretty wild numbers but if you stir them in with truck outputs, Top Fuel outputs, Formula 1 outputs (inc 19,000rpm) they're not physics-defying numbers.

The highest torque production car is currently the CL65 AMG Mercedes-Benz (738 lb/ft, limited (!) to protect the gearbox). It's likely the Koenigsegg CCR supercar (www.koenigsegg.com) may exceed this figure. At the top of the market there is a small but growing demand for uber-transmissions but the trick will be for them NOT to look (and weigh) like they came out of a bulldozer.

There are some fundamentals about how ZeroShift works that help with this - hence the degree of confidence that a T56-based transmission may well survive into the realms of four-figure-foot-pounds. The engineering team here has, before jumping ship to ZeroShift, designed and built a wide variety of winning race transmissions and transmissions for some of the world's most famous 'poster cars' including hugely uprated one-off transmissions for middle-east clients.

I participate in the odd Web forum (a) because I love cars and like to shoot the breeze with fellow enthusiasts and (b) because [I hope] some of you guys are future customers.

Our 'stock' T56 will have useful headroom over and above a standard box. I think an outcome, for me, of this thread is to radically raise the torque rating of a super duty version and without doubt the car to prove it in will be a Viper. Nadine's Viper by the sound of it since it has a 'super duty nut behind the wheel' as well!

I came close to buying a Viper RT/10 back in 1995. This thread and clicking through the excellent Slideshow feature has whetted my appetite all over again!

 

[Chuck 98 RT/10]

Re: Zeroshift: synchroless T-56,

No clutch pedal? No rev matching? How about building it so it "automatically" shifts at the correct rpm too?

Wow, what fun that would be.

 

[ZeroShift]

Re: Zeroshift: synchroless T-56,

Chuck:

Don't go teasing out all my secrets.

P.

 

[JRod]

Re: Zeroshift: synchroless T-56,

TTT

Any more word on this?

 

[GTS Dean]

Re: Zeroshift: synchroless T-56,

Jay:

2000bhp ... +1200lb/ft ... are just numbers. Granted, they're pretty wild numbers but if you stir them in with truck outputs, Top Fuel outputs, Formula 1 outputs (inc 19,000rpm) they're not physics-defying numbers.

At the top of the market there is a small but growing demand for uber-transmissions but the trick will be for them NOT to look (and weigh) like they came out of a bulldozer.

You say that like there's something bad about bulldozer transmissions...

 

[Bill B]

Re: Zeroshift: synchroless T-56,

Any machine that has wheels (or tracks) taller than you is COOL!
I'm fortunate to work in a field that puts me in position to drive odd stuff like the above dozer .

 

[Nadine UK GTS]

Re: Zeroshift: synchroless T-56,

I phoned them end of last year...the guy Phil that was posting here from Zeroshift and had talked to me, has since left, but the company were still wanting to trial one in my car...someday. It could however be another year until a tranny is ready for a Viper test! They said they were having to do a lot more design to safeguard it, such as against driver error, the tranny was needing to be hooked up and controlled by the vehicle ECU/PCM and this had put development back by at least 9 months.

 

[Torquemonster]

Re: Zeroshift: synchroless T-56,

Thanks for the update Nadine.... sorry to hear Phil left - he was a great guy, we too had chatted back and forth quite a bit. They were keen to do a special box for 2000hp (which would make similar torque not just a paltry 1200..lol) - and he was testing a Zeroshift in his road race Cobra last I heard. Phil had very strong ties in big places - its a pity he left.

I wish Zeroshift the best - it's a revolutionary concept and can be fully manual or fully auto - at customers request. Hey - it is a Kiwi engineer that invented this - it has to be good