Intrax suspension failure

[TANKSLAPPER]

At the Ring last weekend and my mates intrax rear suspension failed

[Jeff]

Intrax are the ones that use coils on struts at the rear unlike the standard setup which has the springs separate correct?

This therefore doesn't surprise me given the tower isn't necessarily designed for the extra load - as it would have only been designed to hold a shock, not the cars full weight.

My 2 cents. I think others had mentioned their concern over this previously?

[thegingerninja]

These failures are quite common - they can only be used if a full weld-in cage has been fitted to the rear top monuts to take the extra loadings. You have to stick with the seprate spring and damper unit if you want to stay standard. Imagine if it had completely pushed through while mid cornering - major shunt!
Iain - was it Nathans?

[deleted_user_0_csl]

Failure

It seems like the suspension did not fail, but the top mounting fork punched through the sheet metal of the car. So the car failed :thumbs:not the suspension. I would weld a small strenghtening plate in the car. Or go back to the original spring position. But then you loose the advantages of the coilover system.

[TANKSLAPPER]

Iain - was it Nathans?

Yes, NathanCSL

[TANKSLAPPER]

It seems like the suspension did not fail, but the top mounting fork punched through the sheet metal of the car. So the car failed :thumbs:not the suspension. I would weld a small strenghtening plate in the car. Or go back to the original spring position. But then you loose the advantages of the coilover system.

What, either way you look at it, He walked home LOL

Original position is best with the lower springs taking the load onto the chassis.

Like "thegingerninja" said you need a fully weld cage with strengthening on the turrets for intrax

[NZ_M3]

It seems like the suspension did not fail, but the top mounting fork punched through the sheet metal of the car. So the car failed :thumbs:not the suspension. I would weld a small strenghtening plate in the car. Or go back to the original spring position. But then you loose the advantages of the coilover system.

Actually looks to me that the rear top mount have failed and it's punched through the the sheet metal on the top mount and the rear shock carrier - so it's the suspension that's failed not the car - how can you fail something that wasn't designed to carried such a load in the first place? That's like driving your car into water and saying the car failed.

I've said many times ... those Intrax should not be used without a roll cage - a full rear coilover setup on these cars are just plain stupid without a roll cage or related structural inhancement.

[s.mac]

a full rear coilover setup on these cars are just plain stupid without a roll cage or related structural inhancement.

What make/set up should be looked at then ?

[Thorney]

Whilst its not right to say I told you so it does validate an opinion we have mentioned (and been criticised for) over an over again. Glad to hear he was OK. The chassis was not designed for a rear coil over, period.

We have designed this to address the issue should people not want to go for a full cage (the only alernative if you want to run rear coil overs)



You cant see from this picture but the brace/harness bar has a top plate that fits over the suspension tower and the suspension bolts to it directly. The lower portion bots directly to the chassis floor.

[Thorney]

What make/set up should be looked at then ?

three options:

1. Fit a full cage
2. Fit a rear tower support (as pictured)
3. Run rear spring and strut

We run rear spring and strut on the CSL Cup cars and not much get near them in terms of handling, we run KW 2 way or 3 way race.

[NZ_M3]

Thorney ... may I suggest that perhaps you can come up with a bolt in solution to help prevent the rear subframe mount tear (if that's at all possible) - I think you'll sell thousands of them :hahaha: especially to the Yanks across the pond.

[thegingerninja]

Look at the photo again and read his post - it is a bolt in brace!

[NZ_M3]

Look at the photo again and read his post - it is a bolt in brace!

Read my reply again - I am refering to the rear diff subframe mount not the rear shock mount - 2 different weaknesses in the E46 chassis.

[Thorney]

All of our cages had diff mounts integral as well. Whilst I've heard of numerous suspension tower failures with coil overs I've not heard of any diff mount problems unless you run slicks where the extra lateral grip causes the issue.

[NZ_M3]

All of our cages had diff mounts integral as well. Whilst I've heard of numerous suspension tower failures with coil overs I've not heard of any diff mount problems unless you run slicks where the extra lateral grip causes the issue.

https://nam3forum.com/forums/forum/csl-register/csl-register-main-discussion-centre/380183-csl-bodyshell-stress-crack-warning