Aircooled VW South Africa

Piet wrote: ↑Mon Aug 14, 2017 9:06 pm Many years ago I wrote a bit of software for a company that develops chips for modern cars, and build their own dyno's too. They have a theory that you accelerate on the rollers as hard as you can, until you hit the limit. Then you close the throttle and let the wheels decelerate in gear while you keep on recording. You can then calculate the drag of the drive-train (the longer the wheels keep on spinning, the less drag). By adding the drag to the torque you get to the "real" output of the engine. Does that make sense?

maybe with the clutch pedal pushed in. But if in gear with the throttle closed, then you are decelerating due to compression as well

The gearbox is broken....
Doing about 160 in 4th and I put my foot down, there was an almighty bang and then a continuous rubbing sound. At first I thought the clutch had delaminated and was rubbing on the bellhousing, but after I stopped and pushed the car, it proved to be something a bit more serious.

I've pulled out the engine and the gearbox is on a pallet on its way to JHB for a rebuild and to find out what broke.

I didnt notice any chunks in the oil, but there was a lot of shiney stuff and the oil was particularly black for a gearbox.
Pushing the car around, after a few cm, the rear wheels lock up and then release with a loud bang/clunk like someone hitting a hard metallic object with a hammer.

On a positive note, this gives me a chance to neaten up and re-route some oil hoses as well as attend to some small oil leaks which I cant get to with the engine in the car.

Eish.... sorry to hear Tony

Tony Z wrote: ↑Sun Jan 14, 2018 4:19 pm The gearbox is broken....
........

Sad to hear Tony, and these gearboxes can be expensive to rebuild....

Good it did not happen on its way to George........ OH !! wait... she's a trailer queen.....



Jokes aside, are you going to George. ??

Herman

yea, the box broke on a trailer....

I wont be in George this year, I'm heading to Florida in a couple of weeks for 2 months

Tony Z wrote: ↑Sun Jan 14, 2018 9:48 pm yea, the box broke on a trailer....

I wont be in George this year, I'm heading to Florida in a couple of weeks for 2 months

Bonn-voyage and come home safely

Herman

Eish, thats not good. Hope you get sorted soon.

Tony Z wrote: ↑Sun Jan 14, 2018 4:19 pm The gearbox is broken....

I've pulled out the engine and the gearbox is on a pallet on its way to JHB for a rebuild and to find out what broke.

Sorry to hear of your unexpected gearbox trouble, but you certainly aren't wasting any time in getting it sorted!

You've spent a lot of money on having a bulletproof gearbox built... I will also need a strong gearbox for my car, so would be very interested to know what went wrong, and what will be done to prevent the same from happening again.

you can start by not driving like a goon the way I do...

lol, then why oh why spend all that valuable money on the car in the first place?

Tony Z wrote: ↑Mon Jan 15, 2018 9:00 pm you can start by not driving like a goon the way I do...

Don't think anyone has that level of restraint... How do you not use an engine like that, to its full potential?

tyres are for smoking... (or is it clutches are for smoking?)

Going for cross cut gears this time?

It turns out that I havent updated this thread to show what happened to the gearbox

Bugger took the box apart and his comments are that my engine makes too much torque

Apparently what happened is that 4th gear bend the circlip that holds it in place and pushed it off the main shaft, leading to all sorts of grinding noises...
Bugger has upgraded the retaining system on this shaft to prevent 4th from pushing itself off again

4th gear

Ouch Tony! But shows that you have a monster of an engine