I can't expect everyone who does this stuff to be an engineer, so I am passing on a suggestion to you and others who may read this thread. Whenever you make a cutout in a structural member, sharp corners should be avoided because they cause stress concentration when bending loads are applied. As an example, the cutout you made in the frame rail for the steering link could be a half circle. If you have a junk driveshaft lying around, that would be about the right radius. Cut out a half circle or maybe a little more, cut and grind out the frame rail until the curved piece fits with minimum gap, and weld it in. This will look neater, have more of a factory appearance, and will be much stronger. In this case there are no really big loads forward of the cutout, so it won't make a lot of difference unless you get into a accident.

I realize you may be planning to weld on a doubler to the cutout. If so make it with a rounded cutout to increase the strength.

When I was a Service Engineer at Boeing I did hydraulics, and we had cases of components failing in the 3,000 psi hydraulic systems because they were incorrectly machined with to small a radius in some areas, and fatigue cracking resulted. The most famous example was the De Havilland Comet, the world's first jet airliner. Back in 1950 there had not been many pressurized airplanes, and fatigue failures were not well understood. The airplane was designed with square windows and after a few thousand hours service, there were two mysterious crashes. It is interesting to read about it and how they solved the problem.

A Great British Air Disaster, Channel 4, review - Telegraph

 

While I appreciate your efforts to save others from problems, I disagree.
First, to get it round, it takes either an oxyacetylene torch, which is undesirable even beyond the jagged results, or a plasma cutter, which is costly and difficult to use. Everyone can afford an angle grinder, $15 at Harbor Freight. A nibbler isn't a practical option here, nor any other sort of snips nor shears. certainly not any saw I've ever seen.
Second, there was no way to know in advance where the center of a half-spherical cutout would need to be located. Except now anyone can ask me for measurements at no cost.
Third, any concerns about weakening the structure can be addressed with a few bracing bars welded in. How you execute that should factor in your beliefs concerning how you want the front of the car to crumple in an accident. That's your crush zone.
I had considered what you call a doubler, I could make cardboard patterns or templates now that I'm this far along, but that brings us back to how that area will collapse in a wreck. The general public, including me in this case, has no access to computer modeling programs that can adequately illustrate alternative ways of finishing the area in question.
I do care about the driver's safety, but in this case I know the driver, and how she will use the car. It's only 175-ish HP at this elevation, with massive overkill brakes, and should swerve well enough to avoid most crashes.
She has already scheduled a course at the Bondurant school, so little risk of her standing on the brakes while trying to swerve.

 

I like your ideas, I was pondering something similar in case the TB doesn't clear. Thanks!

 

The V6 is sitting in the RX-7, left it that way all night, decided to quasi-mount the trans before tacking my fabbed mount pieces together. Pics then.

 

right mount from front


left mount from front


right underside from front


left mount under rear

 

left mount rear under


transmission mounting I fabbed


progress on clutch release


right mount from rear

 

fabbing exhaust system


ULEV catalytic converter

 

 

 

I've been progressing on the rear axle swap, still not ready for pics, but I'll make some ASAP.

 

superbriteleds provided the bulbs to upgrade the gauges.


My spring pads are only tacked for now, no shock brackets yet, trailing arm brackets are thoroughly welded, as are the Watt's link stubs. Sway bar mounts from '80s Camaro not snugged yet. That's the '83 RX-7 bar.



PCM location shown, intake ducting and alternator relocation mounting bracket both in progress.

 

PCM location again, and heater hoses.


heater hoses again


working on accessory belt routing


trying ideas for third link, note bracket only spot welded

 

not happy yet


had to order this to match the HTOB


I'll splice the center of this to the RX-7 hood to clear the throttle body.
I'll give credit to whomever gave me the idea as soon as I can get it right.

 

 

 

Now that I have my "new" daily driver all legal and fully functional, I can get back to ye olde '83 RX-7.

 

Getting the rear brakes figured out, red shows where I cut to accommodate the larger diameter rotors, welding will be required.

 

There are 2 ways of doing a Watt's link behind the axle. Either center pivot on the chassis, outer ends on the axle, or center pivot on the axle, outer ends on the chassis. These cars came with the latter, while I've been working toward the former. Now that I've made a bunch of brackets and done many mockups, I've learned a few things.

Assuming keeping the stock fuel tank, If you're going to do a panhard, the chassis end will need to be on the right, putting the axle end to the left, much like an '82-'02 Camaro. If you insist on Watt's link, as I do, then the center pivot must be mounted to the axle. It just can't be packaged any other way with the stock tank.

Pics to follow very soon.

 

I realize my progress isn't pretty yet, but very little is finalized, either. Anyway,...







Sorry the flash isn't working, and that's an '86 Camaro driveshaft shortened 5.25 inches and re-balanced.

 

 

Ordered a Summit radiator, 2 row, 2.5" thick, 19" x 27". It's all I think I can fit, and probably overkill. Now to mount it and adapt the hoses.
Also trying to splice the GM single-outlet p/s hose to Mazda's dual-inlet p/s rack. I'm using a y-block, all -6 AN, with 2 different adapter fittings, and 3 identical 13-inch lengths of PTFE-lined braided stainless steel hose.
For anyone who may ever try this with any GM engine that uses a metric pump, and an FC steering rack, you need a -6 AN / 16 mm x 1.5 o-ring style male adapter, for the GM pump, and a pair of -6 AN / 16 mm x 1.5 inverted flare style male adapters, for the Mazda rack. I used a Fragola brand 491963, and 2 Fragola 460616s. I'll report back if I ordered anything that proves to not work. So if you try to copy this part, keep reading to see if I later correct myself.

 

Also, now the alternator is relocated and mounted, I had to find a belt. I used the Napa website to search by length and number of rows, the first thing I tried fits great! I'm putting an identical spare in the car, just in case.

 

 

just a general mockup there



PCM mounted



How I did it, with 1/4-inch panhead bolts, lockwashers, and double nuts.



Made the p/s bracket by cutting and welding what it had, then drilling the car.

 

Mods for fitting under stock hood.



Mockup showing p/s reservoir



Progress on keeping it Watt's link rather than a Panhard bar.