Competition Automatic Gearboxes

[Dormouse]

Now, how am I going to get back on track and pass muster? By printing out a bit of regulations for the 2019 British Truck Racing.

So, automatics, fluid flywheels and DCT's are banned. Everything has to be basically driver operated, mechanical and a single friction clutch initiated by your foot is all that is allowed when you read further into the regs. So how does that square with modern trucks and transmissions? Answer. It doesn't! It just makes policing the racing easier.
Monster Trucks are pretty much universally automatics and they race a lot. Paris Dakar Raid Trucks are often automatics and more recently automated manuals. So it seems that Trucks could race with Auto boxes - it is just convenient to not allow it. Bit like formula ford for HGV's.

[Dormouse]

Monster truck racers

Rallying winning truck with Allison automatic transmision

[Dormouse]

This is not surprising as, if you remember, I said earlier that automatic transmissions suited certain types of terrains better than manuals. Sort of Horses for Courses, if you like.

[bobins]

I remember the Unimog I used to drive had between the driver's seat and passenger seat - a main gear lever, a reversing lever, a splitter/cascade box selector lever, a cascade box lever with normal, crawler and super-crawler ratios, a PTO selector lever (fore, aft, & both IIRC) and possibly another lever which escapes me*. About the only one I never used in anger was the super-crawler box as I never had the need to drive at full revs doing less than 1 mph
*- the missing one might have been the selector for tea/coffee

[Dormouse]

no. that was only on the models made for Saudi Arabia.

camel mode

[Dormouse]

You mean a bit like these.

If it was a Scottish spec Unimog the bottles would be Irn Bru

[bobins]

Yep, the B&W photo is the one Brings back memories There were also 2 levers on the steering column for front and rear hydraulics for those that thought 5 levers and a switch weren't enough
My boss never could get the hang of all the levers and many's the time I'd climb into it and have to put the levers in their correct position before setting off

[Dormouse]

Yip. the top one is an old style 406. The lower one is it's newer, bigger brother.

[Dormouse]

Some people are just prone to brain fade and aren't safe to be let loose. You could draw dozens of diagrams but they would still faff it.
An old 406 up near Arbroath IIRC had a wire rope winch and hydraulic ground anchors for working in tree clearing. He had tractors and ex army stuff that would have made Heath Robinson proud.

[Dormouse]

I will admit I struggled with the gears until I got the lock out spools idea into my head that limited the number of reverse gears available. After that I wasn't so bad.

[Dormouse]

Now seems a pretty good time to head into tyre technology since it seems I have some extreme/non mainstream views on tyres if you have followed all of my postings.

F1 is awash with theories about Pirelli tyres just now, but in the defence of both Pirelli and the F1 teams, tyre specifications are there to be pushed to the limits ( just, hopefully, not beyond ).

this picture is a good guide of how tyres are made up.

Now, I went for a job where I ended up arguing with the Head of Vehicle Maintenance about tread grip and block pattern during the interview and I got the job in spite of him. Probably ( no, actually ) because no one else wanted it. It reinforced two things - one, when I know I am right I will not back down, and two, it is amazing how many people don't fully understand what they are talking about.

He had seen all these types of pretty pictures but just didn't understand how it all worked and had relied on the mainstream, straight down the middle advice given out to people like him who didn't/couldn't ask more probing questions.

[Dormouse]

What this diagram, and many like it, doesn't detail is side wall construction.

The way a side wall behaves is absolutely crucial to tyre life and behaviour. Everyone obsesses about tread wear, sipe efficiency, block pattern, compound et al, but no one seems to worry about side walls. They batter kerbs. They scuff obstacles. They wear to the point where you can't read the writing. And yet they never get mentioned. But they seem to get blamed for a lot of things.

If they crack, it's their issue.
if they cut, it's their issue.
if they separate and bulge, it's their issue.

It is like they are not part of the tyre.

[NewcastleFalcon]

Now seems a pretty good time to head into tyre technology

There is this active thread you could tag your Tyre info onto if you so desire Dormouse just in case anyone wants to look it up and find it. They aren't going to stumble across it on Competition Automatic Gearboxes!


Everything about Tyres!
https://www.frenchcarforum.co.uk/forum/ ... 30#p690530

Regards Neil

[Dormouse]

Now, if you have followed up on some of the vlogs from Ivan's Shed that I have enthused over, you will have heard Ivan talk about not getting his Golf to handle in corners. As is the way when you are learning your trade, an older stager told him to pump up his outer (circuit wise ) front tyre to 45 psi and his inner one to 40 psi. He did and the transformation was race winning. F1 and lots of the lower formulae take this to an entirely higher plane. Side wall and tread behaviour are both determined by tyre pressure - so why are sidewalls the Cinderella here?

[Dormouse]

Hi Neil. I am not going to put this in the tyres thread as it is more competition experience based than mainstream information.