The Lotus Cars Community banner

1 - 20 of 30 Posts

·
Registered
Joined
·
446 Posts
Discussion Starter #1 (Edited)
The most recent generation of the Toyota MR2 with the 1.8 litre 1ZZ-FE engine has been available with Toyota's "clutchless" sequential manual transmission (SMT). I understand that with this unit, shifting is accomplished by using an up/down shift located in the standard position or up/down buttons located on the front and back of the steering wheel. This option carries an MSRP of $1,000 on the MR2; but that SMT, unlike BMW's SMG, has no automatic mode.

http://www.toyota.com/vehicles/2004/mr2spyder/key_features/smt_shifter.html

Granted that Toyota never offered the SMT with the 2ZZ-GE engine in the Celica GTS, but why on earth would it not be possible? It's not like the 1ZZ has a lot less torque than the 2ZZ (which is what typically kills transmissions AFAIK).

If the SMT was offered in a later version of the Elise or Exige (if it comes here), who here would get it? I would definitely trade in my Elise at that point... assuming I have it by then :rolleyes:
 

·
Registered
Joined
·
3,577 Posts
Does it rev match? What does it weigh? Personally in this car I think that I prefer the good old fashioned three pedals and an oar.

~Paul
 

·
Registered
Joined
·
446 Posts
Discussion Starter #4
Rev match? I would certainly expect so. That's what I love about these sequential gearboxes... 100% perfect downshifts into corners.

Weight? Dunno. The MR2 was a pretty light car so I would bet it is a relatively light unit.

The only concern would be the speed of the upshifts. Motor Trend (although I discount everything they say) seems to think that while the SMT downshifts perfectly, the upshifts are slow compared to other sequential options on the market. http://www.motortrend.com/features/112_0208_trans06/index.html
 

·
Registered
Joined
·
4,985 Posts
I've never driven it, but I recall that none of the magazines particularly liked it compared to the other manufacturer's SMTs at the time.
 

·
Registered
Joined
·
446 Posts
Discussion Starter #7
master said:
... It's still an auto! ...
You may not like them, but these sequential boxes are not automatics. They have a clutch (or two in Audi's case), not a torque converter, but it's hydraulic operation is controlled electronically instead of with your left foot.
 

·
Registered
Joined
·
1,834 Posts
apparently there is only one shift "program", meaning all shifts occur at the same speed. Shifting under heavy acceleration was described as ponderous.

BMW's SMGII seems to be the best system out there, though the Auto mode is horrible.
 

·
Registered
Joined
·
1,198 Posts
I would pass on the option. I like the "old" manual, there is an element of skill that goes missing on any other systems even though the driver may be selecting when to shift, he doesn't do it himself the computer does it for him, not the same in my opinion!:no:
 

·
Registered
Joined
·
446 Posts
Discussion Starter #10
I agree that Toyota's SMT is not the best...

...but something makes me believe that Toyota has the technological capability to make it upshift faster:


Heck, maybe even Lotus could have tinkered with the transmission's ECU - like they did with the motor's ECU - to improve performance. Pure speculation on my part.

BTW, the double clutch systems are better than BMW's SMGII for street use, that's why BMW is developing one of their own for release in 2006.
 

·
Registered
Joined
·
5,160 Posts
One thing to remember is that all of these "sequential" transmissions are only so through interface. They usually use the same mechnical transmission as their standard counterparts. A true sequential box is fairly expensive, but you'd get a race feel with straight cut gears and quick shifts.

Wouldn't check that box on the option chart, but seems intriguing.
 

·
Registered
Joined
·
12,374 Posts
Vantage said:
a race feel with straight cut gears and quick shifts.
Straight cut gears have nothing to do with quick shifts in racing transmissions. They are simply stronger. They are also very noisy, that's he reason most "street" transmissions have helical cut gears. The gears (except for reverse) on modern transmissions don't actually move - they are constantly engaged (the old term "constant mesh") - the synchronizers are what actually slide on the shafts in the transmission and engage the sides of the gears.

However if the transmission is using "dogs" (like a lot of motorcycles), then the gears might actually move and straight gears would be appropriate. But, not many street transmissions use dogs, which are non-synchronized.
 

·
Registered
Joined
·
116 Posts
Re: I agree that Toyota's SMT is not the best...

coulthard fan said:
...
BTW, the double clutch systems are better than BMW's SMGII for street use,...
Yeah, until the repair bill comes in. I expect those trannies cost big bucks ;)
 

·
Registered
Joined
·
2,195 Posts
Is the Toyota MR2 SMT using a real clutch, or a slushbox?

Many wanna-be 'sporty' cars have gone to an automatic (torque converter) with a "manual" mode that lets you shift by telling the automatic when to shift.

I thought Toyota's was like this. Is it really using a mechanical friction clutch? Anyone driven one? Impressions? The MR2 Spyder is still on my list of alternates if Lotus can't deliver.

Audi's is something different altogether with dual clutches.
The Lambo 'e' transmission sounds like the real deal -- mechanical clutch controlled be computer with rev-matching and the works. Makes everyone sound like a pro going into corners. :)
 

·
Registered
Joined
·
4,985 Posts
It's a real manual transmission with a manual clutch. I believe it does the whole rev-matchine routine as well. The knock on it that I've read is that it reacts wayyy to slowly and has no auto-mode either.

I don't like hearing that you're starting to look around out of worry. You're nine cars ahead of me!
 

·
Registered
Joined
·
770 Posts
Yes, it does rev-matching. I've test driven one at Toyota dealer last summer. It also has limited automatic function (only from first gear to neutral).
The shifts are slow and it's hard to spin tires on standing start. 0-60 time is a second slower because ot it. I remeber seeing a good review online (edmunds.com I think).

I don't think the person who wished to have it on Elise would be happy.


andykeck said:
It's a real manual transmission with a manual clutch. I believe it does the whole rev-matchine routine as well. The knock on it that I've read is that it reacts wayyy to slowly and has no auto-mode either.

I don't like hearing that you're starting to look around out of worry. You're nine cars ahead of me!
 

·
Registered
Joined
·
5,160 Posts
TimMullen said:
Straight cut gears have nothing to do with quick shifts in racing transmissions.
Hi Tim,
Didn't mean to imply that they did, but rather than the true sequential box would give a race feel with quick shifts and have straight cut gears.
 

·
Registered
Joined
·
79 Posts
The computer was programmed to be very easy on the clutch unfortunately so you will compromise performance for the ease of shifting.

A Spyder owner made a custom wheel with paddle shifters for his SMT. That would be a very cool combination if the computer could be reprogrammed.
 

·
Registered
Joined
·
729 Posts
Hi Chris, good to see you here too!!:)



The SMT tranny on the MR2 Spyder is exactly the same with its Manual, three peddal counterpart. In additional, the SMT have a hydraulic unit mounted on top of the tranny that weighs ~20 lbs that controls the gear and clutch engagement.


Most reviews out there for the SMT Spyder are on 2002 model year. But since 2003, Toyota updated the SMT computer to do faster upshifts.
More info and video here:
http://spyderchat.com/phpBB/viewtopic.php?t=14586

03+ SMT is not much slower than the manual counterpart. If the video is still available here:
http://spyderchat.com/phpBB/viewtopic.php?t=1222

You can see from a rolling start on a test circuit, the SMT is only a split second slower than the manual transmission.

Also, It is not much slower off the line if you dare to drop the clutch on the SMT at 5k rpm. I really don't see how this will cause more damage on the SMT, as some might say here, compare to the manual gearbox if you were the do the same on it. Both are virtually the same in design where it takes the most stress.

If you want a Paddle Shift assembly, I got one here fro sale:
http://spyderchat.com/phpBB/viewtopic.php?t=11666
 

·
Registered
Joined
·
1,122 Posts
My other car is a 2002 MR2 with the SMT. For 2002, only about 500 were produced. It's a 5-speed. In 2003, Toyota went with a 6-speed version.

I absolutely love it. It's a blast to drive. I love anything unique, and this certainly is.

apkom said:
It also has limited automatic function (only from first gear to neutral).
Well, not exactly. It automatically downshifts from ANY gear. No matter what gear you're in (1-5), when you brake, the SMT automatically downshift to 1 when the car reaches about 2-3 mph. It stays in 1 as you sit at the light, so to accelerate, you just need to step on the gas. So, to come to a stop (from any speed/gear) and then start up again, you never need to touch the gearshift. Very cool.

Other than that, tho, the rest is fully manual.

Showing it off to people is a hoot, cause most have never seen anything like it. But the beauty is, if you can drive a stick, you can pick this up in 60 seconds. And my partner, who really never drove a stick, picked this up in about 5 minutes.

Obviously, others will have differening prioirities. If you're looking for straight-out acceleration, this probably isn't the way to go. But I don't drive a car at 10/10, so any loss in acceleration just isn't that important to me.

Having said that, there were service issues with the SMT, particularly the 2002. And I never took the car to a track because I wasn't sure just how it would be to shift under race conditions, and if the transmission would handle the stress well.
 
1 - 20 of 30 Posts
Top