Does anyone have access to a tri-link set up? Need some measurements of the arm. \___
I have some pictures but I could always use some more.

 

82transam has done a few. If he doesn’t chime in, he did my 83 tri link, i can crawl under there one of these days when i have motivation to do anything in the shop.

 

Thank you that would be greatly appreciated. Any pictures would also help a lot.

 

What’s your timeline and what are the important measurements to you?

 

measurements of the arm itself. My time line is whenever it's convenient for u.

 

I am guessing by your little symbol of \___ that you are referring to the curved/bent arm that G force engineering (possibly others?) used to make. The one that fits under an unmodified transmission tunnel. If so, then I (and swbtm) cannot provide measurements of that. The Tri link that I have built for my FB's uses a link that is straight and the same length as the stock lower control arms - with the trans tunnel cut modified to accommodate it.

I had a G Force setup long ago, but sold it. Sorry!

 

Do u have any pictures of where u cut into the trans tunnel? I was thinking this was a better to do the 3 link. From what I understand. The G force kit was made to work around the scca rules for a specific class. I have a few pictures of the Mazdatrix 3 link in one of my old catalogs and a few others I found online. But all it shows is how it's mounted to the floor. Nothing pictured of how big of a hole in the tunnel or where it is located. I already have the mount on the axle done. Was going to use 3/4 rod ends with inserts to fit 1/2" bolt through. That I had laying around.

 

I made my third link the same length as the lower control arms. As for the hole that needs to be opened up that depends on allot of factors. Like how low is your car going to be and whether or not the chassis end of the link is going to be adjustable. In my case, I knew that my car was going to be very low and I wanted to be able to adjust squat/anti-squat. I have installed two three links - one in my RX7 and one in the Mustang autox car I had before. I adjusted the Mustang's 3 link allot chasing various issues and it was an effective way to tune the car's forward bite. The Mustang also had allot more torque/hp than my RX7 and 12" wide rear tires.

Here is a link to mine: https://www.rx7club.com/build-thread...-build-992966/ Rear suspension and third link discussion starts on Post #13. Note that I went through three rear end mounts - I broke the first two. I never included a photo of the last mount but it is made out of 5/16" material and the top of the diff housing was plated in 1/8" before I welded on the mount. For rod ends on the third link I used Aurora XM series with a 1/2" hole and a 5/8" shank. Lower control arms also use Aurora rod end but with 5/8" hole and shank.

Here is a link to a really nice install by someone else: https://www.rx7club.com/1st-generati...d-but-1171965/ Three link starts on post #19

 

The link Mustanghammer posted above of rk970's build looks very similar to mine so I won't bother digging for pics. I made the "box" slightly larger because I have an adjuster on my tri link to dial in pinion angle - the larger box section gives more room to make the adjustment underneath the car. Overall though very similar result as his.

 

https://www.summitracing.com/parts/c...TAQbKoILQFRmXv

In my never ending attempt to overthink things, only thing I might change on the 5/8 hiem joints 82transam put on my upper adjustable bar would be to use something like the link above. The thought was to improve nvh and help the possibility of unscrewing the jam nuts by taking more of the articulation. No clue if it will actually make a difference though.

 

Too bad Mazdatrix doesn't make there 3 link kit anymore. Looks like it doesn't cut such a big hole in the tunnel t5y⁵ and easy access to the link bolt in the car. But looks like there's no adjustably and that the 3rd link would be mounted farther forward. Than the lower links. Making it uneven.

 

Too bad Mazdatrix doesn't make there 3 link kit anymore. Looks like it doesn't cut such a big hole in the tunnel and easy access to the link bolt in the car. But looks like there's no adjustably and that the 3rd link would be mounted farther forward. Than the lower links. Making it uneven.

 

I remember that kit. I think it appeared in the Mazda Motorsports catalog around the time SA/FB RX7 was added into SCCA E Production as a limited prep car.

I have a friend with a similar installation in his EP RX7 under the guise that it fits in the drive shaft tunnel he had to modify to fit a 3" drive shaft. Another famous racing driver put a short third link in his very fast EP car (similar dimensionally to the one that Ford used on the S197 Mustang). His evaluation was that a longer arm would be better.

As 82transam mentioned, the need to access and adjust the third link is a real thing. Solid suspension elements like rod ends are prone to coming loose over time. So it is important that access is easy at both ends of the link. This is why I offset my third link so that the drive shaft isn't in the way.

Lastly, the old G-Force Tri-Link worked very well. It was designed to take advantage of SCCA Improved Touring rules that allowed for the addition of a "traction device" on the rear suspension of a RWD car. That's right, the Tri-Link was a traction aid.......not a trailing arm.....on a legally prepared ITA or IT7 race car. On cars with stock port engines and 13" DOT racing tires, the Tri-Link really helped an RX7 rotate through a turn and put the "power" down on corner exit. It was only when this traction aid was used on EP RX7s with twice the HP that the Tri-Link was found to be less than ideal.

On a street car with street tires, a Tri-Link could be made to work. Just like on a Three Link, the connection points have to checked often because they will come loose.