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Login to post Forums » Grassroots Motorsports » Fun with the sawsall: roadstering an RX-7

Dec. 26, 2009 10:37 p.m. Jeff Dork

So I was working on the RX and I'm not happy with the cage. It will be fine for autoX and HPDE, but I'm not real happy with it for wheel to wheel. It's a bolt in and it anchors to the flat part of the floor. Looks like it's just waiting to punch through.

It got me thinking about a new cage. And what makes a new cage easier than cutting off the roof . Who here has done this? I've always thought an open car would be cool. I'm trying to sort out what classes this would be legal in. I'm leaning toward building to production specs. The rules talk about open and enclosed cars, but don't say if you can convert one to the other.

I realize it might be simpler to find a convertible 2nd gen and move my parts over when ready. Any thoughts?
Dec. 26, 2009 11:08 p.m. P71 SuperDork

There were near-factory 1st Gen RX-7 convertibles They were built by an aftermarket company but supplied directly by Mazda and had bespoke 1/4 panels. They are beautiful but RARE!! I've often thought of doing up a 1st Gen Porsche 914 racecar style, taking out the hatch, roof, and windshield; but leaving the "targa" band.
Dec. 27, 2009 7:49 a.m. WLB New Reader

It's fairly common practice to remove the roof when installing a cage on an oval track car.
Dec. 27, 2009 8:58 a.m. Jensenman MegaDork

P71 wrote:

There were near-factory 1st Gen RX-7 convertibles They were built by an aftermarket company but supplied directly by Mazda and had bespoke 1/4 panels. They are beautiful but RARE!! I've often thought of doing up a 1st Gen Porsche 914 racecar style, taking out the hatch, roof, and windshield; but leaving the "targa" band.

I saw a picture of one once, it really was a cool looking car. I wish more of them had been built.
Dec. 27, 2009 6:40 p.m. aussiesmg SuperDork

They are called the Pacifica and are awesome.

Before you cut the roof make sure you brace the body really well.

A rally car builder back in OZ used to cut holes in the floor, weld the cage up on the ground, inside the car, then raise the cage up to the floor level and weld up the floor holes, it was a great way to do it as you can lift the cage as often as you please to get a nice tight fit.

Much easier than removing the roof and risking the body twisting.
Dec. 27, 2009 6:42 p.m. mad_machine PowerDork

oh neat idea
Dec. 27, 2009 6:47 p.m. Jensenman MegaDork
Dec. 27, 2009 6:56 p.m. Nitroracer Dork

That looks good! Is that one of the factory jobbers?
Dec. 27, 2009 7:17 p.m. Buzz Killington Reader

we cut off the roof of our MR2 Lemons car to make it easier to do the cage, and to provide additional cage height/helmet clearance. with a full cage the body is still plenty stiff.
Dec. 27, 2009 7:37 p.m. MrJoshua UltraDork

IIRC the RX7 vert conversion used something like a Mx6 trunk with a few inches added to to lower lip. The conversion is talked about in a book with a title something like "Mazda RX-7, Sports car color history" (I used to have it and loaned it out like an idiot)
Dec. 27, 2009 7:45 p.m. dyintorace Dork

This is an FC, but check out the fabrication on this set up!

http://www.rx7club.com/showpost.php?p=8378170&postcount=604
http://www.rx7club.com/showpost.php?p=8378188&postcount=605
Dec. 27, 2009 8:55 p.m. Woody UltraDork

Jensenman wrote:

Damn, that's nice looking.
Dec. 28, 2009 9:02 a.m. mad_machine PowerDork

Jensenman wrote:

Just think.. if Mazda themselves had done that conversion and it had proved popular.. they might not have built the Miata
Dec. 28, 2009 9:06 a.m. Rza HalfDork

dyintorace wrote:

Dang, I didnt know that the FC had a swivel drivers seat!
Dec. 28, 2009 9:29 a.m. GlennS Dork

Lol. Who doesnt own that blue harbor freight floor jack? That thing rules.
Dec. 28, 2009 9:56 a.m. 4cylndrfury Dork

Buzz Killington wrote:

we cut off the roof of our MR2 Lemons car to make it easier to do the cage, and to provide additional cage height/helmet clearance. with a full cage the body is still plenty stiff.

HEERRRMMM...Elan much?
Dec. 28, 2009 10:42 a.m. bamalama Reader

GlennS wrote:

Lol. Who doesnt own that blue harbor freight floor jack? That thing rules.

Anybody else break theirs? I lost the button that holds the handle together.
Dec. 28, 2009 10:55 a.m. mad_machine PowerDork

I drilled mine and put a bolt through it.. as far as i know it is still working.. my father stole it two years ago
Dec. 28, 2009 11:09 a.m. tuna55 Reader

That car won Lemons South this year - clearly it works OK on the track
Dec. 28, 2009 1:00 p.m. CLH New Reader

dyintorace wrote:

This is an FC, but check out the fabrication on this set up!

http://www.rx7club.com/showpost.php?p=8378170&postcount=604
http://www.rx7club.com/showpost.php?p=8378188&postcount=605

Sadly, he cut up a pretty solid GTUs to make that car. There was quite a vocal contrarian chorus on rx7club when he was first talking about it...
Dec. 28, 2009 1:23 p.m. Xceler8x Dork

mad_machine wrote:

Just think.. if Mazda themselves had done that conversion and it had proved popular.. they might not have built the Miata

The Miata is an improved first gen Rx-7. I owned an 85 RX-7 and sold it because of the numb steering. I then bought a 1st gen Miata. They could've been the same car EXCEPT the Miata fixed all the issues I had with the RX-7.
Dec. 28, 2009 1:55 p.m. Jeff Dork

Thanks for the inspiration. I have to admit, I forgot about the big open boot I'd have with the hatch gone. I'd need to fab something.
Dec. 28, 2009 4:15 p.m. Jensenman MegaDork

Yeah, I wonder about the loss of rear storage access as well. How would you get to the spare? But it sure looks cool.

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