Dolomite CVT Gearbox?

[Galileo]

To add to the debate about which is better between single and 3 rail gearbox's, I was just reading that a CVT gearbox was fitted as a test!

Tests by BL Technology showed that a CVT equipped Dolomite returned 56mpg at 30mph compared with the 49mpg of it’s manual counterpart.

[sprint95m]

The test car still exists. It is Tony's daily transport (Tony is Mig Welder on this forum),
now converted to manual overdrive.
Running CVT it achieved some 50 mpg, a marked improvement over overdrive and
that was running on SU carbs too



Ian.

[Carledo]

The test car still exists. It is Tony's daily transport (Tony is Mig Welder on this forum),
now converted to manual overdrive.
Running CVT it achieved some 50 mpg, a marked improvement over overdrive and
that was running on SU carbs too



Ian.

Of course it performed like a snail on Mogodon with the CVT fitted and the only surviving photo of it from those days shows it at the side of the road with the bonnet up, which is hardly encouraging! But it was good on gas! Though one wonders whether they included the trailer ride home in the MPG figures

[SprintMWU773V]

CVT seems to be making a comeback these days. It's a bit weird to start with but actually you get used to it and they are actually alright. Toyota use them in their hybrids and I also once drove a Nissan in Australia with one. I know they work well in the hybrids because they are very compact and help the car to run at its most efficient.

I suspect BL would have made a better use of their time/money is actually developing the basics of their cars rather than messing around with the CVT gearbox. Back in the day it was only really Daf who developed the CVT system, albeit one with rubber bands. Actually very crude in comparison to the modern electronically controlled systems. The modern boxes can't replicate the Daf party piece though of going full speed in both forward and reverse gears!

[Jon Tilson]

Tony's car was tested by Autocar when fitted with a Perbury CVT.

They quite liked it IIRC. Be interesting to see if anyone still has the article.

Jonners

[Carledo]

Small Fords have CVT as well as Nissan Micras and even some Rover 25/45 models.

Personally, despite my love of auto transmission in general, I wouldn't have a CVT car as a gift. They STILL haven't ironed all the bugs out!

Steve

[tony g]

I've worked and stripped a few modern cvt's and theyre very cplex now. torque converter plus valve body controlling the ratios via the steel "belt". They even go to the trouble of making the shift points a feel like an auto shifting to give the driver a.feel for what's going on. Very efficient now but not.very swap friendly unless you can hack The TCU

Tony

[James467]

Probably the most common yet relatively unknown 'CVT' was the Audi multitronic.

[Jod Clark]

....and the Fiat Speedgear

[harvey]

and even some Rover 25/45 models.

MrsH had a CVT Rover 25, hateful little piece of crap, and when the box started howling like a banshee at about 40K miles it got made into fridges. Best thing to happen to it.....

[James467]

Best thing about the Audi, sit at the lights with it in sport mode, when they go green floor it. The revs go up to the red line and just stay there as you watch the speed going up and up and up!!

There were never any gear changes that you could feel when you did that, it was a bit odd the rev needle just sat stationery on the red line!

[MIG Wielder]

Well, well ! Fame ! Yes I still have the car complete with its history folder and technical details but as has been noted it is now an 1850 standard 4 speed + overdrive.

Yes, those figures for fuel consumption appear in my data ... but who drives at a constant 30mph ? Its a bit academic that measurement.

If anyone does have the Autocar data or knows of a source I'd be quite interested to obtain a copy. Was it really that slow ?

Yes, I do have that original photo of it with the bonnet open ... maybe they just stopped for a cigarette break ???
It was interesting to talk with the Museum staff at TDCIR who have a restored version of the Alec Issigonis CVT fitted to a Mini. It looks like Triumph and Austin/ Morris were both working on CVT but with different technical solutions.

TBH the Perbury CVT that Triumph was working on with no steel bands and no shifting cogs was w-a-y ahead technically.
The big problem was the machining of the cavities ( expensive). It actually sounds more like the Audi system in operation that James mentions.

I do know that these systems are still being seriously worked on as I had an enquiry via the board over whether I still had the original CVT unit.
Tony.

[zombeh]

A CVT will generally be more economical at any constant speed since it just pulls the gear ratio up and the engine speed down to get best economy when you lift off the throttle a bit.

Unless the lowest possible ratio on the Perbury was taller than the 1st gear in the normal box it'd be faster too.

[Galileo]

Well, well ! Fame ! Yes I still have the car complete with its history folder and technical details but as has been noted it is now an 1850 standard 4 speed + overdrive.

And I noticed today that you have the sticker on the back of the car to prove it too!

[MIG Wielder]

Ah ! Sorry to have missed you. I was the one wearing the blue jacket but I did spend some time buying oily bits/ shiny bits/ nuts and bolts and accessories. So a belated "Hi there ".
Tony.