HST vs. Gear Drive
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plastikosmd
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"I doubt many hardcore sports car drivers would agree with that. "
Well you are wrong in in my case. Maybe you meant "nostalgic sports car drivers" or missunderstood the way the car works. Think of it as an automatic and a manual car without a clutch, you pick the mode. It still can be a "manual" car, that shifts in less than 0.1 seconds, the "clutch" is just no longer a pedal on the floor...but in the sequential shift transmission.
But you are correct...there are fewer and fewer clutchs that ya gotta push with your foot...and the only thing worse than a clutch is a brake...there is no power going to the ground with a depressed clutch. Your statement regarding RPM has nothing to do with the "curve," you should be picking the right gear. If you are talking about trying to match your engine RPM to the drivetrain (for example reving it on a downshift) that is necessary if you are limited by your gears, or maybe you are driving an 18 wheeler! Flick your finger and you are in the right gear, RPM in the right range for your power and you will blow by someone having to clutch, with 8 to choose from I'm not over/under reved. Anyway..I dont want to detract from the OP topic....maybe this will help....
"Ferrari first introducted "clutchless manuals" with the F1 gearbox. It is, as the name indicates, a Formula 1 derived gearbox. Maserati and Aston Martin also use the technology, and Audi just developed a similar gearbox with dual clutches called the DSG.
SMG uses an electro-hydraulic clutch paired with a standard manual gearbox (Getrag six speed for the M3, I believe a 7-speed for the M5). Shifts are accomplished using paddles behind the steering wheel. Different shift speeds can be set (S1 to S6), with the fastest speeds being somewhere around 80 milliseconds. The upside is there's no clutch pedal, and shifts are far faster than a human can shift."
Well you are wrong in in my case. Maybe you meant "nostalgic sports car drivers" or missunderstood the way the car works. Think of it as an automatic and a manual car without a clutch, you pick the mode. It still can be a "manual" car, that shifts in less than 0.1 seconds, the "clutch" is just no longer a pedal on the floor...but in the sequential shift transmission.
But you are correct...there are fewer and fewer clutchs that ya gotta push with your foot...and the only thing worse than a clutch is a brake...there is no power going to the ground with a depressed clutch. Your statement regarding RPM has nothing to do with the "curve," you should be picking the right gear. If you are talking about trying to match your engine RPM to the drivetrain (for example reving it on a downshift) that is necessary if you are limited by your gears, or maybe you are driving an 18 wheeler! Flick your finger and you are in the right gear, RPM in the right range for your power and you will blow by someone having to clutch, with 8 to choose from I'm not over/under reved. Anyway..I dont want to detract from the OP topic....maybe this will help....
"Ferrari first introducted "clutchless manuals" with the F1 gearbox. It is, as the name indicates, a Formula 1 derived gearbox. Maserati and Aston Martin also use the technology, and Audi just developed a similar gearbox with dual clutches called the DSG.
SMG uses an electro-hydraulic clutch paired with a standard manual gearbox (Getrag six speed for the M3, I believe a 7-speed for the M5). Shifts are accomplished using paddles behind the steering wheel. Different shift speeds can be set (S1 to S6), with the fastest speeds being somewhere around 80 milliseconds. The upside is there's no clutch pedal, and shifts are far faster than a human can shift."
OP
jas67
Platinum Member
Minotbob said:
LOL!!!!
I did this already, when I bought my G1800-S. Problem is that I have probably used that card up for a while; then a nice G1900-S with PTO and three point (my G1800-S doesn't have those options) turned up for only a few hundred $ more, and I had to pass it up. In fact, I did it again, I just picked up a three-point post hole digger on Friday.
jas67
Egon
Epic Contributor
Lets not get carried away by the HST! You know its not a proven product.
N80
Super Member
plastikosmd said:
You're probably right, but maybe I should have said 'nostalgic sports car racers'.
And if I'm not mistaken, the heel-and-toe technique is used to maintain engine rpm while shifting and braking in a turn. I guess if these new systems shift fast enough the engine loses no RPM in the turn, and I'm sure that's true for a Formula 1 car. Not so sure if it would be true for a Mitsubishi tuner.
And with such high tech systems the line is blurred a bit if you have control over which gear the car goes in and when. I suppose some might say that the clutch is what makes the car a manual, others might say its the ability to select exactly what gear you want it in and when. Other's might say it is the mechanical integrity of the drive line. One of my biggest complaints with typical viscous coupled automatics (including CVTs, one of which I own) is the torque converter lag. I hate it. I'd assume that high end 'automatic' sports cars have this ironed out? I rode in an automatic RX-7 that a friend of mine bought for his wife and it was a fine car with plenty of power,but the lag between the time you punched the accelerator and when the torque converter locked up was maddening. But that was 10 years ago. I'm assuming things are better now.
Egon
Epic Contributor
You just gotta check out some of the new Tractor transmissions.
Paddle shift seems to do okay on on the Indy circuit!
Paddle shift seems to do okay on on the Indy circuit!
N80
Super Member
Egon said:You just gotta check out some of the new Tractor transmissions.
Paddle shift seems to do okay on on the Indy circuit!
I think my L4400 could tear up the Indy circuit. Literally.
It is interesting to me to see how things have changed even in the sports car world, which I assumed would be the holdout for manual transmissions. The new Nissan GT-R....which by all accounts appears to be a world beater has one of these incredible and incredibly complex hybrid gear boxes, as do BMW M5 sedans.
Oddly, Porsche seems to be the holdout. The top of the line 911 ($190,000) retains a 6 speed manual. But it seems like Porsche has always be a bit anachronistic.
In any case Egon, don't give 'them' any ideas. I have no doubt that if Kubota hears there's interest in a paddle shift B series....they'll make one and someone will just have to have it to mow their lawn.
Soundguy said:
Chris, you did contradict yourself on this one. You listed the gear as more durable, yet you personally have seen clutches burned up in 30 minutes! And the exact word used was "reliable", not durable.
Durability or reliability is a function of mean time to failure. Economical is a function of cost to repair. You should recognize that! You do realize that the guts of an HST are just a couple pumps, right? Much less complex that a gear transmission with fewer parts. (Not counting the new e-hydro or whatever it's called. I don't know what's under there!)
You also should know that there are no "rubber" parts in the HST to wear out. The variable displacement pump is hardened metal pistons in hardened metal bores. Very little to fail. And they are protected by a relief valve. You got any relief valve equivalent in a gear transmission to save it when you snag a root or buried cement block? I've busted teeth off plowing into a chunk of snit buried under the earth, that wouldn't have happened with an HST. The clutch is EXPECTED to wear out in a gear tractor every 2000-4000 hours with the minimums down to 30 minutes as you noted. The clutch in an HST is expected to last the life of the tractor. What's more durable? As far as cost, last time I checked it was about the same to cheaper to replace the guts on a hst than gear transmission. That's a VERY variable situation, so who knows what the cost is today, but it's probably still about the same.
I ferget who posted that hst are only on small tractors, but what about the 5yd articulating 30,000 pound payloaders? Does the hst in them not count or what?
Still, when you step back from the minutia, 95+% of "gentlemen ranchers" will never have to perform repairs on either. So, does it really matter?
jb
jas67 said:
That's the real advantage of HST - let's you concentrate on the work at hand vice the tractor. For what you are doing - reliability is likely not an issue. Besides - with regular fluid and filter maintainance - the HST will last a good long time (and probably longer than a clutch in the hands of an infrequent/weekend user).
Joe