I wanted to see what people think about the t3 steering rack. I really would like a rack from mtheory and I know its probably better, but It is also 3x more expensive, and he may not make/have any when I go to swap mine.

 

You "get" what you "pay" for!

 

I think anything is better than our stock recirculating ball steering that can be compared to an old truck -lol. My steering wheel play went from 11 to 1 o'clock to now being at 9 to 3 o'clock -lmao. This is most likely from installing the coilovers that have an aggressive 2.5+ drop all around. I would give t3 a try as their parts seem to be well made for the most part when I've seen them in person on people's cars.

 

yeah, there manufacturing looks good. And the only area of concern would be steering geometry right? From my knowledge even a monkey could get that right with simple math. Is there something else people dont like about it?

 

This thread below on the T3 kit is the "only" information I've seen on the the T3 kit for RX7 SA/FB cars on this forum, and it may be worth reviewing before making a decision on what route want to take as far as your steering options are concerned for your project. The information on the T3 kit has been "anecdotal" at best, and not very informative as to final results of the installed kit. You have taken on a huge project with a lot of moving parts and money is "always" and issue resurrecting an RX7 however, a steering kit, in my opinion, is not one of them. I will do without but when it comes to my GSL-SE I've had for thirty-two years cost has never been the determining factor. Only what best fit's the needs for my car to be it's best version of what I want it to be. Almost twenty-eight years of having progressively sloppier steering, the lack of wheel feedback at eighty-plus on the freeway was not what I wanted from my RX7 experience. The MTheory rack & pinion kit changed all that, and I've never regretted spending the money for it. There are other forum members who have installed the Mtheory kit on their cars and have commented on their experiences with the installation, and the results. I hope I don't sound like a "broken record" on this issue but knowing what a difference this kit made, and what a joyful experience driving my RX7 is now. can't be understated. Was it easy paying for it? No! Do I regret buying it? No! Make the best decision you can make in your situation, however, just make sure it's an "informed" decision. I will get off my "soapbox" now.

(https://www.rx7club.com/1st-generati...1168978/page3/)

 

Good post. With age and experience comes wisdom that you can't buy. I don't own anything from MTheory, but believe that he already has a solid enough reputation that even having one of his racks on your car would help its resale if/when it came to that.

I used to hear guys on here wish that they had purchased the re-speed unit when it was available and were kicking themselves for passing on it. I'll bet that in the future, you will see the same thing with the MTheory kit.

 

Good points, I read what scott said about it and it seems not great. Especially the possible exhaust interface for a turbo setup. Ill just go with mtheory.

 

The respeed kit was not great either... lots of U joint bind and the left tie rod was like half the length of the right... can you say bump steer?

The biggest issue with ANY rack and pinion setup is that the inner tie rod pivot needs to be inline with the control arm/strut rod axis when steering straight ahead. The inner almost goes under the engine at full left lock. So for a rack to work the quill will have to be under the engine!

This is why FCs have the rack in front of the engine and extremely short control arms. The engine is just too dang wide at the bottom!

Now, if I were to design a kit, it would replace the steering box with the idler arm from a RHD model and then use a center takeoff rack to move the center link. Steering geometry is retained.
Another idea is like the Australian rack setup for Falcons (the 1st gen is remarkably like a Falcon up front) where they use a center takeoff rack (from a Chevy Cavalier!) and a large bar attaches to the rack's inner tie rod mounting points - this becomes a kind of dummy centerlink that the inner tie rods attach to. I installed one of these in a Torino (very similar to XB Falcon) and it worked exactly as advertised. Also pretty much the only way to get power steering when you have a big block and headers.




The easiest approach is to adjust your driving technique. Cars like this are driven with steering pressure and not steering position. In this respect the stock steering is amazingly GOOD, it is very communicative as to what the contact patches are doing.

I drove my RX-7 (with 46 year old gearbox) for the last two weeks and switched it up today to drive my Mk7 GTI. The GTI has steering ultra precise in position and a very fast ratio. It is also so dead feeling that I don't feel like exploring the car's limits, you cannot feel what the tires are doing... Pressure is more important than position.

 

A lot of the issue is the steering geometry is engineered around donut shaped tires. Tires that have long canoe shaped contact patches. Stock is 165/80R13 with 185/70 as an option. These tires are fairly resistant to change based on road irregularities and such - what is known as self aligning torque. If you go to wider, lower profile tires, the steering geometry built around tires that handle themselves as far as staying straight will now allow the steering to get pulled every which way. This "feels" like loose steering when the real issue is the wrong tires are on the car.

Now, unless you want to buck up for some $300 Vredesteins, we are kinda screwed for performance tires that meet the needs of the steering geometry.

I think a better fix is not in replacing the box with a rack, which will still wander all over the place with modern rubber, but attacking the issue at the source and using new or modified steering arms to shift the strut on the steering arm to change the amount of caster trail. Now the geometry will handle modern rubber a lot better. The stock trail was minimal to keep the steering from being too heavy with those canoe shaped contact patches.

If you could shift the strut backward on the steering arm, trail will increase and it should track straighter with low profile rubber without changing caster.

 

Hmm one could probably 3d print a test piece, and then have it cnc machined. But they would also have to understand the geometry, and i dont. of course I could always learn. Then just to fix the leaking seals.

 

It is way too simple to bother with CNC, a manual mill can handle it or even just a drill press and files... CNC is great if you want to run a batch of fifty.

Depending on how far it needs to be moved, you could even just engineer it into a roll center corrector plate. Or plug the holes in the steering arms and drill new ones.

 

Wouldnt that interfere with the top of the balljoint, i like the sound of the roll adjuster situation. But that sounds above my machining skills currently.