Drive shafts that take big power??

[rally_master]

Hi all. Hope some one can help??

Ive read of people putting big power through std 325 shafts and very rare breakages.... Well...

The story so far

E36 compact rallycar fitted with std S50b30 engine and box. medium case diff and 18"wheels and proper tyres.
In two years of using the car (with a 3.91)we've had 2 output's from the diff shear and 2 CVjoints shear.
I've just fitted a 4.45 and got 2.5miles and sheard the shaft(bar).

Idealy looking for an uprated shaft or proper motorsport item? Anyone got sugestions for a UK supplier? My searches have turned up zip.

What about info on conversions to the largecase(210)diff,as in what shafts ect to use?[/b]

[leeparkes]

What shafts are you using now? compact?

[leeparkes]

Z3 may be an option.

Im still on 318ti shafts on my compact with no issues.
Its M52 b2.8 with M50 inlet manifold and big bore TB, est 220hp. still using the 318ti box with 7kg fly then its 325i prop up to a medium 188 E30 diff (3.46 ratio) down to 255 Falkens.

Never heard of drive shafts failing on big power E30's either, prop seems to go first.

[rally_master]

300bhp and proper 9"wide slicks driven hard dosen't like std 325shafts.

[leeparkes]

Nice Have you looked into Z3 M shafts?

Any pics of this said chariot?

[fuzzy]

i never had a problem with driveshafts . my problem was always with prop shaft bearings.

[DanThe]

Centre bearing failure usually comes from misaligned gearbox/diff

How about these E46 outputs-



The only real way to stop it is to go bigger

[Duke137]

Centre bearing failure usually comes from misaligned gearbox/diff

How would you check/rectify that one out of interest?

[DanThe]

Straight edge down the prop would give you a good idea I imagine, its likely to have been fuzzys problem as the engine/box were not even BMW so your pretty much guessing where the output of the box needs to be

[Duke137]

Straight edge down the prop would give you a good idea I imagine, its likely to have been fuzzys problem as the engine/box were not even BMW so your pretty much guessing where the output of the box needs to be

Plus the extra power he had over standard I guess.

[ross2009]

300bhp and proper 9"wide slicks driven hard dosen't like std 325shafts.

mines running 300 bhp and 9 inch wheels granted not slicks but never had any trouble with mine before i changed them ive got custom ones on there now with uj joints they aint braking anytime soon

[rally_master]

Idealy looking for an uprated shaft or proper motorsport item? Anyone got sugestions for a UK supplier? My searches have turned up zip.

What about info on conversions to the largecase(210)diff,as in what shafts ect to use?

Anyone with info on a replacement heavy duty shaft to replace my 325 shafts or info on large case diff conversion, please??

Hey ross thanks for pics on your shafts. Where did you get those beasts made?

[ross2009]

i never had them made i know a guy that drag racers a e30 he had these made cost him about 1500 quid i think then he changed the drive chain so he couldnt use them any more i bought them off him for about 300 quid

there isnt really anything you can replace them with tbh with out having some thing like mine made or serious surgery to change the rear end

[GeoffBob]

Hi all. Hope some one can help??

Ive read of people putting big power through std 325 shafts and very rare breakages.... Well...

The story so far

E36 compact rallycar fitted with std S50b30 engine and box. medium case diff and 18"wheels and proper tyres.
In two years of using the car (with a 3.91)we've had 2 output's from the diff shear and 2 CVjoints shear.
I've just fitted a 4.45 and got 2.5miles and sheard the shaft(bar).

Idealy looking for an uprated shaft or proper motorsport item? Anyone got sugestions for a UK supplier? My searches have turned up zip.

What about info on conversions to the largecase(210)diff,as in what shafts ect to use?[/b]

I can’t help with up-rated parts I’m afraid, but I thought I would just mention that it is worth looking at your differential and sub-frame mountings. Under hard acceleration the diff will tend to pitch backwards (nose up, tail down) in reaction to the wheel torque, as well as tend to roll anti-clockwise (left side down, right side up) in response to the torque transmitted by the prop-shaft. This problem is exacerbated by traction. If the diff housing isn’t held rigidly in place (that is to say there is excessive flex in the mounts) then you have a recipe for broken shafts/joints as the diff moves around. The sub-frame mounts are of course an issue due to the fact that the diff housing bolts rigidly not to the car body but to the sub-frame. Just thought I’d mention this just in case you were unaware.

FYI, changing from a 3.91:1 to 4.45:1 diff ratio you have effectively upped your wheel torque by 14%, which can only increase the likelihood of a failure occuring.

[fuzzy]

^^^ thats just jogged my memory, i did have a problem at one stage with the diff mounting plate and it cracking around the 2 high level bolts holding the diff in place, right enough, as you say the rear axle/subframe mounts were knackered allowing play on hard acceleration and also leading to centre bearing problems.
i used to hammer my car on a 3.91 but never had a problem with the actual driveshafts. that extra 1.5" width on your wheels must be straining things hard.
2.5 miles worth of use would be a right pain for sure.

[HairyScreech]

are you regularly lifting wheels under load? as some of this may be a hammering issue rather than a pure torque issue, i assume from the fact its a rally car this may be the case.

[e21Jason]

A few options, go for a e34/28 210 diff, and modified e28 hubs in e30 trailing arms with modified drive shafts basically the same as the prodrive e30 m3 setup.

A set of z3m drive shafts stronger than e30 straight bolt up and i have a spare set £200

Or get a set made up from some like drivelink

http://www.drivelink.com/contact_Drivelink.cfm

Also GKN do of the shelf Motorsport uprated e30 CV joints but they are about £200 each

J

[e301988325i]

I recall that to fit the 210 diff to an E30, that an E30 & E34 rear beam has to be cut and shut, not impossible by any stretch.

[DanThe]

What is the wheel end of those shafts made up from Ross? Just that the outer spline can twist as much as the inner -

[ross2009]

it's just a normal spline mate to go in to the hub the spline is just on the end of the tube not like in your pic

[GeoffBob]

What is the wheel end of those shafts made up from Ross? Just that the outer spline can twist as much as the inner -

I see your point Dan. Spline chilling stuff, to say the least.

[SteveR]

Nice Have you looked into Z3 M shafts?

Any pics of this said chariot?

[cypriot_boy_2k7]

Nice Have you looked into Z3 M shafts?

Any pics of this said chariot?

owww a edirty6, good luck with your search

[rally_master]

I'll bring this back to the top.
Can you give me any more info on this Jason?

A few options, go for a e34/28 210 diff, and modified e28 hubs in e30 trailing arms with modified drive shafts basically the same as the prodrive e30 m3 setup.
J

The car and driver are really coming on now. Last rally running top 10 all day, 4th fastest on 1 stage. Last stage of the day it stripped the pinion 2xCWP's in 3rallys GRRRRR.

Now thinking along the lines of above or maybe chopping out rear section of floor from rear of E36 M3 evo and fitting full rear end!! The amount of effort on everyones part with this car is emmense, it's heart breaking that we aren't finishing.
Steve overtook an Escort mid stage that I knew changed hands recently at 60grand!! And it was mid-corner too!!

[e21Jason]

If your up for a bit of fabrication cut and shit an e28 rear axle to fit, that's what have in the back of my e21, same size diff and cv's etc as the e36 evo rear end and less work.

The prodive set up was basically a e28 diff (210) in a e30 rear beam and trailing arms an e28 hubs, there is a bit of info on s14power as one of the guys has an ex prodrive rally car and is building a second to the same spec.

I tried a z3m drive shaft on an e30 trailing arm a few months back and it does not fit as the spline is bigger.

Also GKN do cv joints from stock to fit inc one with a greater angle.

[rally_master]

Thanks for the Info Jason, much appriciated. I keep you informed on the outcome!!