The reason that the Z3 has the E30 type rear suspension is that there was insufficient room to fit the E36 supension.
Rebody Pingu's Kit Car Project
- Thread starter Pingu
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I've just had another look at RealOEM, and there is something very strange going on. The rear beam (33311090957) says that it is fitted to All Z3s (except the ZMR and ZMC) and all E36 upto 323i (see EDIT below), but when you look at E36 cars, then look at their suspension, none of them are the same as the Z3.
Anyway, my plan is to compare my ZM rear beam with a standard rear beam and strengthen the standard beam. I just hope that mine actually is damaged, or this exercise has been a waste of time.
Edit - the E36 referred to is the Compact. All the other E36 use their own rear suspension.
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Have you considered that the trailing arms themselves might be bent and not the main beam? I've read that of that happening. Anyway, best of luck. I did all of those bushings and welded in a reinforcement for the rear differential. Those bushings can be a real pain!
The compact race/drift guys reckon they can bend the rear arms, even the ‘reinforced’ Z3 wide body arms, so they add more bracing between the casting and the pressed arms. Why I did the same to mine. None have mentioned bracing the beam and there are no commercially available components to do so, that I’ve spotted anyway. Loads of arm bracing pieces though.
I did hear a story of someone bending one of the pins holding the arm, nothing confirmed on that. I braced the little bracket, more because it was there and I had the off cuts sitting about, than a belief it will achieve anything.
I did hear a story of someone bending one of the pins holding the arm, nothing confirmed on that. I braced the little bracket, more because it was there and I had the off cuts sitting about, than a belief it will achieve anything.
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I haven't, but it could be. I really hope not, as a spare will be a fortune to either buy or modify. The beam is pressed steel, but the arm is cast. I can weld reinforcement to the beam, but I'd have to pay someone to weld cast metal.
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What reinforcement did you use?
I'm going to check Google now to see how others have done it.
[edit] I found this adjustable kit which shows one way that I could sort the problem
My preferred route is to strengthen the rear beam
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The arm isn't a full casting Pingu, the inner legs are a welded pressing. I'm told it either bends at the end of one of the legs, or where the casting is welded.
I used 3mm steel, cardboard template from the arm to the damper mount. Dimple die'd, strip welded to form an H. Piece of 3mm from the top of the casting to the arm. Don't have my phone on me, can't post pics.
I used 3mm steel, cardboard template from the arm to the damper mount. Dimple die'd, strip welded to form an H. Piece of 3mm from the top of the casting to the arm. Don't have my phone on me, can't post pics.
The rear trailing arm isn't cast? It doesn't look cast. There's that rim round the edge that looks like it's pressed in two pieces, top and bottom, and welded together.
I've seen at least one post on this forum where somebody is welding reinforcement to the trailing arm.
I've seen posts on this forum where there's holes rusted through which the owner had welded back up. Holes would suggest the trailing arms are hollow ... pressed.
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I'd like to see an image at some time. There's no urgency. TAVM
The arms are two 3mm (I think) pressings welded together with a casting welded on the end. The arms are down the just over 2mm where the metal has stretched during forming.
There are lots of these kind of kits on the bay
Depending on who makes them, these are either 3 or 5mm.
I made mine from 3mm topped with strip, fettled them until I had zero gap, then welded them on with a series of hot tacks, immediately zapping with an air line to cool the weld. It’s not pretty, but there’s no chance of distortion.
There’s a piece of 5mm from the top of the casting down to the arm, but I don’t have a pic of that.
There are lots of these kind of kits on the bay
Depending on who makes them, these are either 3 or 5mm.
I made mine from 3mm topped with strip, fettled them until I had zero gap, then welded them on with a series of hot tacks, immediately zapping with an air line to cool the weld. It’s not pretty, but there’s no chance of distortion.
There’s a piece of 5mm from the top of the casting down to the arm, but I don’t have a pic of that.
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The rear beam was twisted ...
I've cut the old beam, so can't remake the video. The strengthening piece inside the rear beam is very thin. I'm not sure that it does much, but the rear end of the M has a very small factor of safety, so it was probably just enough to bring the FoS back to an acceptable level.
I have some thinking to do. Do I attempt to remake the M beam, but correctly aligned? Do I add some reinforcement to the new beam and add the second exhaust bracket. Either way, I shall be practicing my welding.
I've cut the old beam, so can't remake the video. The strengthening piece inside the rear beam is very thin. I'm not sure that it does much, but the rear end of the M has a very small factor of safety, so it was probably just enough to bring the FoS back to an acceptable level.
I have some thinking to do. Do I attempt to remake the M beam, but correctly aligned? Do I add some reinforcement to the new beam and add the second exhaust bracket. Either way, I shall be practicing my welding.
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I'm in the middle of a dry assembly that will be stripped once I know that everything fits - and aligns.
The new beam fits - so that means that the pins aren't misaligned. It looks like the mounting rubber did a good job and deformed before the load was transferred to the pin.
I've refitted the RHR trailing arm.
I've double checked the LHR trailing arm - it looks to be straight. I've replaced the offset bushes in the LHR trailing arm with standard bushes.
It's too dark now, and I'll continue later.
The new beam fits - so that means that the pins aren't misaligned. It looks like the mounting rubber did a good job and deformed before the load was transferred to the pin.
I've refitted the RHR trailing arm.
I've double checked the LHR trailing arm - it looks to be straight. I've replaced the offset bushes in the LHR trailing arm with standard bushes.
It's too dark now, and I'll continue later.
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Wheels are back on, but the car is still in the air, and it's started raining.
The camber looks good, but I can't tell until it's on the ground. The toe looks to be out, but, again, I won't be able to tell until it's on the ground. I should be able to sort the toe using the offset bushes.
I've got an idea about how I can add the strengthening plate to the new beam. More details later.
The camber looks good, but I can't tell until it's on the ground. The toe looks to be out, but, again, I won't be able to tell until it's on the ground. I should be able to sort the toe using the offset bushes.
I've got an idea about how I can add the strengthening plate to the new beam. More details later.
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It's back on the ground with the full suspension on. The camber looks good, but will be measured tomorrow. I'll also check the toe.
I need to fire up my old XP laptop to check the TIS to find out what the suspension settings should be.
I need to fire up my old XP laptop to check the TIS to find out what the suspension settings should be.
You now have me worried, I have a history of throwing cars sideways off Hillclimb tracks, occasionally backwards.
Do you have any pics of how the M rear beam is reinforced Pingu?
I have 2 spare beams and more adjustable brackets, I may have to look into some method of cross bracing the beam.
Do you have any pics of how the M rear beam is reinforced Pingu?
I have 2 spare beams and more adjustable brackets, I may have to look into some method of cross bracing the beam.
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I'm waiting for some 3mm plate to arrive, and I'll be posting my modification. I cut the beam to see what they did to strengthen it, and I'm surprised at all the fuss. I'm a bit miffed that I cut it before I confirmed the video had recorded, as the video would have shown the problem more clearly than the photo.
To be honest, I think the strengthening in the beam is a token effort, and wouldn't really do much.
You have to remember the car took a hell of a whack at the rear left corner...
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I've decided that I will add reinforcement around the outside of the beam.
It would be too messy to try to copy the M-beam.
Yesterday, I made a dimple die, and tested it on some 1.5mm steel. It works. I still need to test it on the 3mm steel that I will be using for the reinforcement.
It would be too messy to try to copy the M-beam.
Yesterday, I made a dimple die, and tested it on some 1.5mm steel. It works. I still need to test it on the 3mm steel that I will be using for the reinforcement.
- Joined
- Dec 8, 2011
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