foggyjames wrote:The problem which Anjo was mentioning is that the steel prop they'll make will obviously be heavier than the standard ally one (hence the interest in a centre bearing for support). I take the point, but am tempted to suggest that it will be ok, given that Iain's (Huskyracer) was fine.

You are missing something there James, though I take the point you do make too.

The thing that makes our cars different is where the gearbox is, not just that it's bolted to the boot floor. In almost all applications of a transax, you find they use a torque tube, so lets start there and work out why. Alignment seems to be the obvious one right? Well, no. Not to me really. Torque tubes are big fat and heavy, why didn't all manufacturers use a UJ'd prop from the beginning (I'm thinking Porsche, Corvette, Alfa and 360 here at the mo). It'd be lighter than the torque tube, easier to manufacture and perfectly good for the power.

Well, I'm not sure it would. Ok, the prop shaft would be lighter than a torque tube setup, but the actual rotating mass in a torque tube is naff all. Look at the 360's inside spinning bit and it's about an inch in diameter, same as a 340's clutch shaft but about 6ft long. Same with the other manufacturers.

So why? Well... think about the loadings applied to the syncro mesh during gear changes. You know how much I complain about GLS's having way to big a flywheel to allow a quick gear change and for proper rev matching, more weight in the prop will cause the same problem but more so. You'd take out the synchro's in a matter of 10,000 miles, if that I'd guess and given nearly all the other transax cars are "sports" cars, a slow gear change would make them unsellable.

The 340 prop is amazing at being the lightest thing in the entire world, you can lift them with a little finger. It would have been cheaper for Volvo BV (who were Daf lets remember) who are known for not being able to spend pennies as they were nearly bankrupt for so long, to make a "normal" propshaft out of steel, where the parts existed, rather than learn how to get involved with rubber bonding to ali which again isn't the worlds cheapest metal. There must be a reason why.

Chris' thought, is that if a propshaft upgrade is needed, it pretty much has to be a torque tube, but it's only a theory and I don't want to stop others experimenting and trying things, there is always a way to sorting problems.

i love hearing other peoples ideas keep them coming as i can miss things and its nice to see things through a different set of eyes
Chris i would love to fit a torque tube and be done with it much cheaper easier stronger but that would throw me out the 8 point system so i would technically need to be re registered at a cost of hundreds

back to the prop im assuming that all the engine mounts are mint and it is correctly aligned
I was thinking of mounting it solidly like they do on american v8s so it wouldnt move but vibrations would be present never run one so not sure any ideas it will be a diesel so even worse may just run hockey pucks again

most views seem to say a two piece with a sliding joint would be the best option but it adds extra cost, weight and harder to fit, needs a bracket welding in to support the middle bearing

were as a single piece prop with two ujs with a built in sliding joint would do the job just fine it would be cheaper, direct replacement (no special tools), Now weight a steel one would be heavier than the rather light alli one but it would be a hell lot stronger. I think thats the only way unless you spend alot on a ally one

i keep swinging both ways as there is good support for both sides but the only rely successfully uprated prop was a single prop with two ujs and no slider and thats worked with no props well as much as i know about it

so i think a single piece prop with a sliding joint just to take up some more adjustment would do the job without a problem plus it would look completely standard to any vosa/dvla inspectors just awaiting funds it will probley be after xmas now or if i can get back in work soon as job seekers is crap and rely rely boring even with college

what do you think to that guys?

I might take a few days to mull over... I didn't realise you were getting close to the 8 points, that certainly changes the game!

yer chris what with suspension, steering and engine mods i need to keep the body, axles and transmission standard or standard looking to keep 8 points

Surely they only need to know about the engine...? I mean who's going to check? I'm not even sure there is a number on the box.

Interesting point about mass between the clutch and box, Chris. The theory certainly makes sense. I wonder if this actually had an effect on Iain's car in practice.
I still think alignment was the primary motivation, though...the reason Volvo went for it on 360s being that the greater torque capability of the B19/B200 were more likely to result in "dynamic misalignment" than the Renaults. It is a good point about the weight of the 340 prop though. Not that it really matters...as long as we're considering all the angles.

cheers

James

james is not the point i want to be fully legal so if /when i get pulled they cant say crap to me so ive got to stay with a prop

Yeah, VOSA really love to impound cars for things like that. Regular roadside Police won't do it (mostly because they'd agree it's stupid) but VOSA have been turning up more lately to local cruise meets, booking people for minor things. They'd have a field day if a car was found to be "unroadworthy".

Another little pointless update but a update none the less,had a spot of luck over on RR 4x145/70/13 easy 6-7mm of tread £40 quid so ive got them and there on but while we had it on the ramp at a mates work noticed that the front springs dislocate massively and werent the right springs for the car and the boots weren't fitted properly or have come off when in use either way so today yes today i jacked the car up removed the front springs and chucked them to one side and grabbed my proper lowering springs -40mm -two coils that i had on my other volvo, so fitted them jubile clipped them in place so the spring cant dislocate, fitted the boots cable tying them in place. Replace a top mount and sat it back down on the ground. The new springs are slightly softer its rolls now haha so i may look at taking my spare front arb and doubling it up. its got the dreaded MOT tomorrow so hopefully it passes.
sorry i didnt get any pictures i started raining half way through so i didnt have time heres something from my cool pics folder

It'll be interesting to see how the new MOT rules affect situations like this. From what the tester I spoke to a couple of weeks ago said, springs that need to be clipped into place will be a fail. I see Dai's shorter shocks being in demand!

cheers

James

No, they are not. There's much confusion over it and it's been discussed (at length) on RR. If they dislocate = fail. If they stay in place, either assisted by ties or not = pass.

It's basically the same as before except they've now defined it exactly for cut/sports springs. Nothing has really changed.

Even if it was a fail not to hard to get around as all you would have to do is move the travel stopper up on the damper fingers crossed it passes

It FAILED on some welding to the O/S/R i knew about it but though i may get away with it never mind. Im just hoping for some good weather friday to get it fixed and moted again i promise to pictures next time

mat_91 wrote:It FAILED on some welding to the O/S/R i knew about it but though i may get away with it never mind. Im just hoping for some good weather friday to get it fixed and moted again i promise to pictures next time

No other fails?

PICS!!!!

nope just that so i let if off haha and ill get pictures up friday of the turd as i havent got any up to date ones

mat_91 wrote:nope just that so i let if off haha

Bzzt bzzt then dude. Winner!