Project Valtezza

[tractor]

mmmm i spy a nice bonnet scoop in the background

[Guest Paddy1970]

You do indeed, that will be glassed into the bonnet soon.

[Guest Paddy1970]

Did you sell your seats by the way?

[tractor]

havent sold them yet but another member does have first dibbs i do like to follow forum etiquette unlike some other members

 

you know who you are

 

 

 

 

im not bitter

[Guest Paddy1970]

No probs I fully understand, keep me in mind if it falls through.

[Guest Paddy1970]

Big milestone today, now a fully rolling chassis, long way to go but a big step forward.

 

 

[tractor]

looking good

[Guest Paddy1970]

Lots happening on the Valtezza at the moment, lots of little jobs but nothing picture worthy, so in the meantime i've just bought some old skool Image split rims for the Robin Hood.

 

 

 

 

Also managed to cure this cars handling issues thanks to the North East chaps advice, camber correction plates added to the rear, softer suspension springs and it has transformed her, thank you both Alans and Pintogogo.

[Guest Paddy1970]

Still no good pics to show but the gearbox mounting is done, and Altezza LSD mounted, my propshaft and driveshafts are now with the friction welders to mate Altezza to Mx5.

 

So it should be a complete drivetrain by next week.

[brumster]

driveshafts are now with the friction welders

 

I have to chip in here just to say my experience of frictional welding of driveshafts is NOT good. Despite being assured by the well-known manufacturer that competiton use wouldn't break them at the weld, they both popped straight across that very point after very mild use on-stage. If you go this route, I would suggest you be very gentle with them... maybe for sensible road use, without sticky tyres or any clutch-dropping antics, you'll be fine, but.... well... just saying

 

Yes, I am talking for experience....

 

[Bob Tucker]

Is that a butt joint? The friction welding I have seen done used a cone shape

on one side and a recessed cone? on th other side. The weld area is far bigger that way.

The other way I have seen drive shafts done is to machine a cone on both sides,

jig it up so its straight & can spin, then weld from the narrow part towards the wide end.

 

Many moons ago, so things may have changed....LOL

[Guest Paddy1970]

I have to say in my job I regularly get shafts friction welded and have built some pretty high torque engines going through them, so far we have a 100% success record with no problems at all.

 

Are you sure it was friction welding? The process is widely regarded as reliable and safe in our trade.

[brumster]

Definitely friction welded. Well, it sounds like you've got better experience than myself, so I'll sit back down !! Maybe I was just well and truly conned with some cheap knock-offs...

[Guest Paddy1970]

No thanks for sharing your experience, it's just odd as we have some 325bhp/300lbs.ft engines running on some friction welded shafts without issue, in particular a Lotus Elise i put a V6 engine into (before Lotus brought out the Exige i may add) which still has the same friction welded shafts to this day, the process itself should make the whole shaft as strong as it was before as they are fused across the entire cross section, it does sound to me like they weren't done properly.

[brumster]

Maybe so. Basically, the story is this. Due to revised suspension geometry, my rally car needs slightly longer shafts but thankfully the Peugeot 309 had ideal shafts - they were 10mm longer than the 205. But the OE stock has dried up and they are no longer available. So in trying to buy some brand new shafts, I was told the best they could do would be to take some new shafts from another model (ie. way too long), cut them to the desired length and then friction weld them together. I'm no engineer, but I distinctly remember saying to them (via my supplier contact) that they did realise these were for use in a competition vehicle, right, and I was a bit worried that the weld would present a weak spot. They assured me the weld would be strong, in fact the shaft would break elsewhere before on the weld.

 

On my first loop out (thankfully the last stage prior to service) the shaft snapped while absolutely tickling it through a tight, nadgery spot - it basically hit a bump in the road and the shock snapped it in half right on the weld.

 

You can see in here (fast forward to 6:05, it happens at 6:15 but you can see at this section it's really bumpy and we were taking it really easy!)

 

 

We got back to service, swapped for the other one, and then later in the day it did it again on another stage in equally mundane circumstances.

 

After that I moved to hollow shafts from a Peugeot 306, shortened, sleeved and welded around a joining insert (V-grooved around the join) and those have been reliable.

 

I've since spoken to Dave Mac (who are making my new shafts, so it happens!) and they are not surprised. Don't rate friction welded shafts at all. My new shafts being made up for my new gearbox are solid shafts but they're F1-grade S155 steel, with a lifetime warranty from Dave Mac so I guess I'll just be breaking CVs now lol

 

It sounds like you're genuinely happy and having better experiences, which is great, I just figured I'd chip in in case it was all a bit "new" to you - which clearly it isn't !!

Edited August 6, 2018 by brumster