BMW Rallying Forum

Hi Guys,

Im looking for an upgrade to my axles and possibly rear arms etc. I'm currently running an S54 in my 318ti making 280 rwhp (what torque I have.... I'm not sure). there is more power to come out of out of it and I'm also looking at a supercharger system for the future so want a set up that can handle up to 400 rwhp.

I have two question areas, if you have any of the answers I would love to hear from you.

1: I currently have a medium case 6 bolt 3.91 diff and E30 325i axles (same as E30 M3). What power/torque can these handle before they give problems? Is the 8 bolt 210mm diff an over kill? Has any one put one of these in a ti? What diff did the E36 Z3M S54 use?



2: Since my engine upgrade from 180 to 280 rwhp I have not surprisingly broken the stub shaft off the outer CV. I see there are lots of options of using custom axles like here:
https://www.pureperformancemotorsport.com/index.php/bmw/cv-axel-800hp/bmw-e30-custom-4340-half-shaft-axle-s.html

The only problem i see is the area where it broke wont have changed.

I know little of the Z3M upgrade, Does this give you you a larger axle? I believe the off set in the arm is larger. I use a 20mm spacer on the rear so this shouldn't be a problem other than it being very expensive option.



The car is only raced on tarmac roads and I can be pretty rough on my drive line. I'm looking for something strong and reliable.

Thank you in advance

Steve

I have gone down the route of fitted hubs into e30 arms and then 108mm CV's after breaking LOTS of shafts with my 3.0 M3 which is much less HP than yours...

I then broke the stub in the diff so now going 210mm diff!

Pure performance dont have any shafts! I got them on back order for over 1 year! .



The way i have gone has cost me A LOT of money tho!!!

This is a good option, but not tried them >>>

http://www.driveshaftshop.com/import-ax ... t-in-axles

Where did you get the hub from? Did you machine it from a standard 325 axle?

Thanks

Might Declan's combination of bespoke and standard parts be a good solution to driveshaft issues?

viewtopic.php?f=6&t=3976

Has anyone tried this?

Mine is declans shafts

mrfuzzyfelts wrote:I have gone down the route of fitted hubs into e30 arms and then 108mm CV's after breaking LOTS of shafts with my 3.0 M3 which is much less HP than yours...

I then broke the stub in the diff so now going 210mm diff!

Thanks again for the photos, I was in a rush so didn't say so previously sorry. Is the spline much bigger than standard? in the photo below its hard to tell. I haven't seen the other half to this but this is what you run? I like the idea.

red325 wrote:Might Declan's combination of bespoke and standard parts be a good solution to driveshaft issues?

viewtopic.php?f=6&t=3976

Has anyone tried this?

Great info thanks. My old man has a replica E46 GTR he track races and he has a similar setup, just a little bigger. I didnt really want to go down the road of making a hub up to find it didn't work but if some one has already made one for the E30/36 ti and proven that it works then great!

mrfuzzyfelts wrote:I then broke the stub in the diff so now going 210mm diff!

So your having problems with the 188mm diff? The internet can be a confusing place, I was told by a local BMW motorsport specialist (knows his stuff) that I was on the limit on what the 188mm diff can handle for rallying. But then I went on line and people have been saying you can put 800HP through them! There strong but definitely no ford 9".

gartrac wrote:http://www.bmw-rallying.co.uk/viewtopic.php?f=3&t=4178

Thanks but its a bit out of my budget but could you tell me if the Z3M arms are 20mm wider or 20mm skinnier? Ive read both reports online.

As far as I know, I must stress I have never fitted one, the Z3M is overall the same width as a standard Compact, the Z3 is wider

If as you say you intend to super charge in the future with 400 rwhp I think you really need a good plan for the axle otherwise it will just keep breaking

210mm diff is a must but finding one is the problem, the 210 case that fits was only used on a few older BMW models, mrfuzzyfelts has just fitted one so he can probably tell you more but I don't think they are just a drop in fit you have to modify the cross member to the rear of it and make your own mountings plus motorsport crown wheel and pinions for them are a fortune

Driveshafts you need Declan's shafts or similar again not a straight fit, I'm pretty sure you have to move the shocker mounting to accomodate them into the hub

Have fun

Ended up getting off road axles in from the states and using Motorsport GKN cvs coupled with a custom outer hub that utilised a larger bmw oem inner hub. Bullet proof.