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      05-19-2020, 08:38 AM   #1
sikedsyko
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Welded a rollbar into my E85.

I've been wanting to get harnesses mounted into the Z4 for track use. I met with a local cage builder and we discussed a couple of different options. We thought about leaving the factory rollover protection and just adding a harness bar, but ended up deciding to just weld in a 4 point rollbar and removing the factory rollover protection.

Anyways, here's how it turned out. Pretty happy with it. The convertible top still works perfectly. I initially had the thought of trying to put most of the rear interior back in the car after putting the bar in, but this car is primarily a track car, so I really don't think there's any point in all that effort and cutting up my pieces to get them in around the cage. I'll probably just try to sell them to recover some cost.











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      05-19-2020, 10:37 AM   #2
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Assuming the bars actually go through the bulkhead as opposed to terminating there?
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      05-20-2020, 10:33 AM   #3
Michael9218
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Nice looking rollbar.

Using those plates is probably structural enough for the down bars. The outboard portion of the bulkhead is fairly structural.

The question I have is why keep that heavy bulkhead at all for a track car? Let alone the speakers. Maybe you want to blare The Flight of the Valkarie as you rip around the track...��

I suppose the answer is your designed purpose evolved...
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      05-21-2020, 08:36 AM   #4
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#In4cageMeasurements

... I may also want to do this, as my limiting factor on holding of on a half cage has been not having a hardtop. How much did it run by the way?
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      05-21-2020, 06:39 PM   #5
sikedsyko
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Yeah I'm pretty convinced (and my cage builder was too) that the bulkhead is structural enough to mount the bars to with the reinforcement plates. He said this is pretty common practice in Miatas that want rollbars without losing the convertible top. Going with this setup vs the factory bars also moves the rollbar several inches further above the top of my helmet, assuming it functions properly.

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Originally Posted by jns_e85 View Post
#In4cageMeasurements

... I may also want to do this, as my limiting factor on holding of on a half cage has been not having a hardtop. How much did it run by the way?
It was about $900 for the hoop fab, paint, and install. I did all the interior stripping work myself before dropping the car off. Then he also made some 6 point crotch mounts that would attach to the VAC Motorsports seat mounts for $75. I also bought two Ultrashield 6 point harnesses from him. They were a little pricey to buy through him, but I thought the rollbar was such a good deal I was happy to buy the harnesses through him.

And yeah, my plan is to run the car like this for a year or two. If I can ever source a reasonably priced hardtop for the car I'll ditch the softtop and get a full cage welded in, with proper rear bars extending down to the chassis in the trunk. If I can't ever find a hardtop without spending $5k+ for it, I've also thought about having some kind of bimini top made that could replace the factory softtop, cover a full cage without ruining the lines of the car, and provide a minimal level of rain protection. At this point, this car is pretty much a dedicated track car, so fuck it? I probably should have sold this car and bought a coupe, but its too late for that.

Something like the Porsche Boxster Spyder


Last edited by sikedsyko; 05-21-2020 at 07:01 PM..
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      05-21-2020, 07:38 PM   #6
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$900 is a fantastic price. And your bars definitely extend higher than the one on my old coupe...
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      05-22-2020, 12:07 AM   #7
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That is a great price. I've considered doing the same thing... also thought "shoulda bought a coupe" .... but then I love driving with the top down
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      05-22-2020, 09:25 AM   #8
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DAMN! That is quite reasonable for sure!

I agree, we should ALL have bought coupes when the "gettin' was good" so to speak, BUT I'm already too far down the rabbit hole with my roadster as well. Plus, I would have a hard time cutting up a clean, collectible, $30k+ coupe when the roadsters are such a deal and readily available!
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      05-23-2020, 12:31 AM   #9
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Quote:
Originally Posted by jns_e85 View Post
DAMN! That is quite reasonable for sure!

I agree, we should ALL have bought coupes when the "gettin' was good" so to speak, BUT I'm already too far down the rabbit hole with my roadster as well. Plus, I would have a hard time cutting up a clean, collectible, $30k+ coupe when the roadsters are such a deal and readily available!
As a former coupe owner, I actually prefer the roadster + hard top (best of both worlds).
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      05-25-2020, 11:48 PM   #10
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wow! cool setup nicely done, i also LOVE the floor mount, where your main hoop connects to, that looks sturdy as heck!

Good job.
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