Rear strut brace? From an E30 for a Z3 roadster

[Anthony Cherry]

Also there are loads of MX5s. All either 1.6 or 1.8. Relatively level playing field. Lots of turbo and supercharging options. And they handle well for the price. That all adds up to a good cheap track day racer.
The Zeds will follow now though. Great value and the price of MX5 mk1's are beginning to creep up.

 

[Dino D]

I take your point Dino, but when you watch the "rare" MX5 races on Eurosport and the like they're almost all convertibles. So do they use the coupes for racing rigidity or roll over safety?

Tony.

There was no Mx5 coupe hence you only see MX5 roadsters, no choice like with a Z..

 

[t-tony]

There was no Mx5 coupe hence you only see MX5 roadsters, no choice like with a Z..

You missed the point there Dino, what I meant was, the open roadster is up to the job, so why don't more people use Z3 roadsters?
A few do have the hard tops on but not many, obviously no strength in those, but surely more aero dynamic? MGB had the GT (coupe) version but there are more open cars on the classic racing scene.

Tony.

 

[Dino D]

Ah I see Tony, I think that is simply because the Mx5 was very cheap and plentiful as well as having a massive tuning market for it (was/is it not the best selling roadster of all time?).

I had go to an Mx5 specialist for my suspension set up...He set up years ago after seeing how many Mx5 race cars were out there and never looked back.

The Z3 has only now become cheap, still not much tuning options though. It still also has competition from the e36/46 cars which are even more plentiful and cheap and arguably make better and safer track cars.

I think it's budget and availability if custom parts and tuners that influence peoples track car choice, it's a lot of work to prepare a car so better to start with a base that is well known with expertise available already.
The Z3 will probably get there too once people see more about on track..

 

[t-tony]

Absolutely Dino, I hope it's a long time before mine ends up as track fodder, unless I'm driving. One day I might be tempted to have a go even though it's auto, in sport it does go well. You never know eh?

Tony.

 

[Dino D]

@ Anthony Cherry - make sure you do the rear subframe bushes, massive difference to the rear end.

 

[Anthony Cherry]

Ireland or powerflex?

 

[Dino D]

I have Poweflex purple fitted a couple if months ago. Very happy so far.

 

[Dino D]

Ps I believe they have just launched a yellow insert bush that you push into place to stabilize the holes in the OEM bush. I believe it's done without removing the subframe.

 

[Anthony Cherry]

Ok.... Rear strut update.
I have modified the E30 rear strut to fit the Z3. It needed shortening and re-welding.

When we got down to the cutting and welding it was noticed that the E30 strut had 4mm Aluminuim brackets (I think steel would be better) and the tubular steel strut was thinner than I expected (strength was good though as a wide diameter).

Now to fitting and testing it.
Simple to fit. Just unpop the plastic fastenings on the carpet below the roof. Pull back the carpet. Undo the 4 nuts. Fit the brace. And tighten the 4 bolts. This takes in total a maximum of 15 minutes.
The hood operated perfectly. Tight on closure. It could do with further modification. But still fully closed.

Road testing... This was fun.

I drove 60 miles on mixed roads before fitting the brace and 60 miles home after fitting.
I defiantly felt more feedback and the rear felt less loose. Less rear body roll and the car generally felt more planted. I was a little sceptical before fitting it as the existing bulkhead runs between the top mounts. But the additional bracing really seemed to add rigidity to the back end.

I was so impressed I decided to draw up some plans with the fabricators to make a batch of 10 x Z3 specific rear braces.
These will be of a thicker, stronger oval tube with a lower top profile than the one I modified. To allow a greater tolerance for the roof to close. Also 3mm thick steel end brackets (double the strength of the 4mm aluminium brackets) All tig welded together. This will be a very solid brace. Finally finished in black. (Although you won't see the brace as it will be under the carpet and below the roof.) this first batch will be ready next Thursday.
I intend to sell them for £99 UK delivered. But will bring some down to the London/Brighton where I will sell them for £80 take away on the day.

I'm pretty excited with the results! As soon as I have some pictures I will start a dedicated thread.

 

[Dino D]

Very interested to see it.
I have damper adjusters coming out of my rear top mounts, wonder if that will affect fitting?

I'm assuming no reason it can't be fitted over the carpet instead if under?
Looking forward to seeing it!

 

[Anthony Cherry]

I don't see why it won't fit.
One of my concerns are if the positions of the bolts are the same in all the Z3's? I have tried it on a 3.0. And will check to see if they fit the M. But I only have two 3.0's and an M in my Bertini garage.

Cutting the carpet would make fitting it really easy. I guess that can be the choice of the owner. It might be cool to see the bar when the hood is up.
I will take loads of pictures with the brace installed both ways.

 

[Anthony Cherry]

I have been driving it for a few days and I can defiantly feel an improvement in the normally lose back end. I'm really looking forward to getting my hands on the first ten rear strut braces on Thursday afternoon.

 

[Brian H]

Very interested to see it.
I have damper adjusters coming out of my rear top mounts, wonder if that will affect fitting?

It should fit no probs Dino the standard shocks protrude as much as your BC shocks, the adjusters you have will just fit through the hole in the brace.

 

[Anthony Cherry]

i am going to pick up the rear braces today! i should be able to post some pictures this evening. If you want one then let me know.
Im really pleased with how the prototype is performing.
Happiness really is just around the corner!!

 

[Anthony Cherry]

 

[Brian H]

Now that I like

 

[Anthony Cherry]

Yours is in the post tomorrow Brian.

 

[t-tony]

It looks very nice.

Tony.

 

[oldcarman]

Another home run Anthony! JIM