Sequential Gearboxes.

[Steve Chryssos]

Originally Posted by race-rodz

ix-neh the 5 spd seq box..... wont hold up to the hp/trq.... besides...what i have of the $13k would better suited to the motor cause.

HOWEVER... i did find this... and the idea of running a bulletproof modded M22 has re entered my head. linky

Now yer talkin!! I see Tex Racing in NC is a dealer. And, ironically, Tex Powell himself has purchased one of my paddle shifters for "some street rod project he's working on". I cautioned that our shifter is not designed to work with manual (or any non-electronic) transmissions. He said don't worry about it, but would not elaborate further. I guess I now know the deal:

-Tex Transmission (plenty strong with with a wide choice of gear ratios)
-Renagate shifter conversion
-Bi-directional linear actuator motor
-Shrifter

But paddle shifter or not, the Renagate deal should cut down shift times and reduce driver error. The big questions are 1) clutch apply (should be standard) 2) if it can work on a 4 speed, can a 5 spd or 6 spd model be far behind?
Very cool. Get on that.
/Steevo

[jannes_z-28]

My absolutely top TV-personality, Jeremy Clarkson at Top Gear, tested an Aston Martin with that gearbox and he 100% disliked it. As it was programmed it never shifted when he wanted it to shift. The computer could delay a downshift for several seconds. Not what you want when you drive hard around acorner.

I think that the problem with these is just the programming, you want smooth shifts when driving normally but crisp hard action when really hitting it. And what do you do when going from 5th directly to 2nd? Counting paddle movements. Or you can do as Ferrari, different buttons for different downshifts.

Even though the coolfactor is high on a gearbox like that I myself like the stick as it is.


Jan

[tjs69]

Please excuse my ignorance but, Is this what the F1 guy's are using ?

[Steve Chryssos]

Well, we are co-mingling a few different issues here:

Sequential Transmissions: Good when shifted by a human, but hard to find one that will handle the abuse of direct, clutchless shifting when installed behind big power. They exist, but they are hard to apply to multi-use applications (drag race, road race and street use)

Mechatronic Transmissions: Doesn't matter if it is sequential or not--uses mechanical engineering, electrical engineering and software engineering to perform shifts. A more mainstream term would be robotics. Works great on an F1 car that operates within limited parameters (road race only) and is operated by a professional race driver (limited failsafes). When applied to the Aston Martin transmission shown above, the programming must account for novice drivers (driver error) and mundane tasks like parallel parking and other low speed maneuvering. Aston Marton does NOT want you to make 5th to 2nd downshifts. If you try, it either waits, or denies the innput altogether.
So the delay experienced by Jeremy Clarkson is due to "failsafe" programming that is designed for novice drivers. Warranty concerns supercede performance capability. And those sophisticated computers? They become downright stupid when faced with mundane tasks like parallel parking.
And as I stated above, the stock algorithm for a 2002 Aston Martin Vantage is most likely useless if applied to a twin turbo 69 Camaro (or Targetmaster 350 equipped 69 Camaro) As such, it would be virtually impossible to develop a production mechatronic solution for the hot rod aftermarket, since there is such a wide range of potential applications.

Are there exceptions? YES! And the exceptions are most likely the future of transmission technology.
1) I recently purchased an Audi A3 DSG. During low speed driving in auto mode, you would be hard pressed to tell the difference between the DSG and an old school automatic. In fact the salesguy kept calling it an automatic even though there are traditional gears inside the case. It's that good. Why? because it utilizes two clutches. And in manual mode--during performance driving, it shifts just like Michael Shumachers F1 car--with lightning quick shifts (where applicable) and no rpm drop between shifts. It's said that DSG will obsolete CVT almost immediately and single clutch mechatronic manuals (on street cars) shortly thereafter.
2) Manumatics. The Mercedez 7G has a stout looking lock-up clutch in the torque converter. So, when locked up and in manual mode (even in 1st gear), you'd have a hard time telling it apart from a true "direct drive" manual. And torque converters are more forgiving that true clutch assemblies. I'm dying to try out a new 6L80E.

The line has become very blurry indeed.
/Steevo

[race-rodz]

im still looking... i really like the idea of the seq gearbox/no clutch action.... human controlled deal. i also dont want overdrive... final drive of 1:1 in the trans is what im looking for. i did look at the t-rex site after i posted the link... and it got me thinkin about jerico and some of the other "clutchless" shifting transmissions. i know i have seen the "straight-cut gear/dogring" upgrade for road race M22's someplace.... then throw one of these renegate shifters to it... and im just about there.(sounds simple enough...riiiiiiiiiiiiiiiiiight)

im tryin to figure out to get the cake and eat it too.... my budget was meant for getting the project finished up.... meaning basically motor and trans.... i cant see blowing it all on just the trans.

[Steve Chryssos]

Attached is a diagram of mechatronics fundamentals.

I hear you on the sequential. Be sure to evaluate functionality in terms of downshifting as well as low speed, part throttle shifting. The Renagate shifter is not a true sequential solution, so I'm sure it ain't clutchless. It's more like a Verti-Gate--which has been around for years (i.e. current Pro Stock)
/Steevo

[67Sally]

Originally Posted by streetfytr68

2) if it can work on a 4 speed, can a 5 spd or 6 spd model be far behind?
Very cool. Get on that.
/Steevo

I talked to Renagate and asked them about 5 and 6 speed applications and they did not have anything in the works at that time. I will dig up the emails they sent to me.
W.

[Steve Chryssos]

That's a bummer. Also I downloaded the "installation" pdf which has lots of great pix. I'm not impressed with the "swivel block" shift linkage. And the mount for the shift arm is a single shear design. It should be mounted in a c-channel as they've done with Hurst Competition Plus shifters since--what?--the early 70's?
/Steevo

[andrewb70]

Holinger Engineering

http://www.holinger.com.au/index.html

Andrew

[Steve Chryssos]

Now that's a thing of beauty.
/Steevo