1985 Series 3 restomod with s5 13BT on LPG, R&P steering

[KYPREO]

JPEG_20170405_200427_669276453.jpg (76.4 KiB) Viewed 6299 times

This is what a 30+ year old unrestored Australian RX-7 looks like underneath

[MelloYello]

Where is all the brown flakey stuff?

[Threesevens]

you have been done mate. Brown flaky stuff comes as standard

[ian65]

that is clean
Looking forward to seeing how you get on with the new steering setup... are you doing an FC subframe swap to mount the rack?.... the woeful steering is the one thing I hate about these cars and really spoils the driving experience for me... 100mph on the motorway is a real scary experience.
I've got the parts to do the swap from a TII but the issues with alignment and camber puts me off.
Interested to see how you get it to work... I might be inspired to do mine then!

[KYPREO]

Don't worry, I do have brown flaky bits, but thankfully concentrated around the hatch drain holes. This is the usual spot where RX-7s first rust here.

that is clean
Looking forward to seeing how you get on with the new steering setup... are you doing an FC subframe swap to mount the rack?.... the woeful steering is the one thing I hate about these cars and really spoils the driving experience for me... 100mph on the motorway is a real scary experience.
I've got the parts to do the swap from a TII but the issues with alignment and camber puts me off.
Interested to see how you get it to work... I might be inspired to do mine then!

You're spot on about the woeful steering. In reevaluating what I wanted to do with this car, I basically asked myself "if I was to re-release this car as a new car today, what would I most like to change?" My answer was that the looks are pretty much 100% perfect but (a) the engine is significantly underpowered for what you can accomplish with the chassis; and (b) the steering sucks big-time. So I'm really just setting about fixing those things. Oh and upgrading the drivetrain (lightened flywheel, heavy duty clutch, 4.1:1 Torsen diff and s5 turbo box already installed years ago) and brakes and suspension.

I'm doing the FC subframe swap. The benefits of the FC setup are manifold (pun intended):

- relatively easy to locate the parts and convert
- rack and pinion steering (manual or powered, choose your poison)
- bigger FC 4 piston 276mm brakes bolt on (although I'm going bigger again to 294mm FD brakes which will help with inner wheel clearance)
- choice of any off-the-shelf FC adjustable coilover strut (although 1st gen strut top is needed)
- heavier duty stub axles
- range of adjustable steering arms/tie-rods are available off-the-shelf for tuning the front suspension
- rear-mounted engine for better support and rigidity compared to front-mounting
- for us RHD guys, a nice big space to fit bigger turbos with more compact and responsive short manifold runner design. A standard s4/5 turbo and manifold will work as a bolt-on mod.

There is a cheap/nasty one of doing this which a lot of the guys in the US (on rx7club) have done. From memory, it involves bolting the subframe directly onto some of the existing mounting points without modification. This moves the front axles forward, changing the geometry and requires you to cut the inner guards and fit flares due to wheel clearance issues.

Adsy from ACBron Motorsport has done this conversion about 5 times now and has pretty much perfected it. He will be fabricating an adapter plate that allows fitment of the FC subframe using all of the original 1st mounting points but retains the original axle position and track. I sourced 4x114.3mm alloy hubs from the bottom spec series 4, which even allows me to retain the original wheel bolt pattern and offset (although some people might prefer to convert to 5-stud at this point).

I will be sure to post details of how this is done in future updates. (there is also a chance my conversion might be used as a mule for a conversion kit, but I can't promise anything as this is out of my control ).

Another option which a guy on AusRotary has done is to use the steering rack from a Holden Barina - which is the same as your Opel Corsa. This also retains the standard crossmember and struts, allowing one to retain the front-mounted 12A. The Opel Corsa has a manual rack but uses has an electric motor on the steering column itself. These are a very popular conversion in British rallying circles and you can get aftermarket Opel Corsa power steering motor controllers.

More info on the Barina conversion is here: http://web.aanet.com.au/arran/car/projectpart7.html

[Hobbawobba]

I would definitely say the steering is the main issue with these cars aye. I've seen a few people on Facebook over the last few days saying they're in the progress of making a R&P kit for us. Probably only LHD though :x

[KYPREO]

I've seen various R&P kits come and go over the past 15-20 years. The first used a rack from a VW Rabbit (US version of the Golf). It was a rear-mounted rack but the angles were all wrong and it suffered from horrible bump steer (apparently). Then there was another one that attempted to use an OEM style rack and wasn't that great either.

Finally, ReSpeed released their rack and pinion kit. This was a properly designed conversion that completely replaced the front crossmember, control arms and steering arms etc. The only problem is that it used a Fox-body Mustang rack. The theory was great - pick a rack that is common place, cheap and easy to find. It had a heap of aftermarket versions, including billet power steering ones made by hotrod companies. Only problem is that this style Mustang is pretty rare outside the US and I don't even think it was ever made in RHD. ReSpeed had the best intentions to make a RHD version - a bunch of us on AusRotary tried to get it off the ground about 6-7 years ago, but then ReSpeed sold its business and the new owner abandoned rotaries altogether. No more ReSpeed parts.

The attempts to get R&P kits back off the ground have largely turned around trying to get the ReSpeed kit re-made. This won't help us RHD guys.

Now, what ACBron does is modify the FC subframe itself to weld on some new tabs for the front mount and then (I think) a custom bracket weld on as a rear mount for the subframe. These then bolt onto the factory 1st gen chassis points (rear mount is where the steering gear and idler arm usually attach on each side). This means it is a completely reversible modification and does not require need mounting holes or anything (although I think we insert some crush tubes - I'll confirm that once we're done). These modifications sit the subframe 20mm further back than if it was simply bolted to the 1st gen chassis, effectively restoring the factory 1st gen geometry.

If a conversion kit is made available, it will be supplied with the required bits and instructions on how to modify the subframe. It will require some welding skill however. It would not be economical/affordable to supply a kit with the subframe pre-modified.

My subframe is done now. I'll post up some pics when I get a chance.

[KYPREO]

Here's one that was prepared earlier (not mine) which shows the mounting points...

adsys s2 engine bay.jpg (225.81 KiB) Viewed 6248 times

adsy subframe 2.jpg (225.65 KiB) Viewed 6248 times

[DB RX63]

That's neat that is, looks better than my home built set up:

[Hobbawobba]

That does look very nice . Swapping to an FC subframe and whatnot.. I don't know if the FC brake setup would fit under my 14" wheels. I'm also running the standard 4x114 bolt pattern. Unless I could track down some 114 FC hubs. Does anyone know if we got them in the UK? Also engine mounting? Hmmm hahaha.

I'll be keeping an eye on this. Although I won't be paying ACBRON anything until a final product is released. After paying for my coilovers and still waiting (over a year ). Thankfully I know he has a great reputation for what he does!