The inner chassis-side of the toe-link has these two triangulated tabs welded to the chassis for strengthening. This is where the commonly produced “anti-toe brackets” unnecessarily reinforce. They do not eliminate the toe deflection because it deflects at the outer knuckle.The next step is to remove the lower rear wheel bearing bolt and remove the cotter pin and toe link nut.The long toe arm does not have much material or triangulation to the rest of the knuckle and acts like a lever arm, bending at the joint to the knuckle from all of the load going through it.With the bolts removed we are ready to install the Toe Stiffener.Installation of the toe stiffeners is very straight forward. The parts are marked “L” and “R” (left and right) as well as the bags they are packaged in. Use the supplied Mil-Spec bolt which is longer to compensate for the added width of the stiffener, and reuse the toe link bolt. Erik recommends using a bit of high temp “Copper-Kote” anti-seize on the bolt and threads and Red Loctite on the toe link nut before torquing everything down to factory specs. *The factory cotter pin is not reused and the Red Loctite holds the nut in place. Erik has never had an issue with this process over decades of doing this on many street and track cars.
Great article! Any chance you could place a link up top as to where to get the stiffeners? They sound necessary and I’d love to buy them for my GTS as well. Thanks!
Wow; kind of concerning that the stock uprights were that marginal. The brace seems to take care of things but I guess it highlights stuff that didn’t get caught in the design stage.
… I swear, every time I see a new update in this series come up I start checking ebay.
He doesn’t wrench, but he can wheel better than any of the aforementioned names. Can relay what effects the setup changes made better than most and that is more signal and less noise.
Billy can wrench and he is pretty damn good. I have seen him do it. Why do some of you feel that you have to pick this article apart in such a dumb sniveling way? Wouldn’t you rather have the car on a lift with good photography rather than some weird angles and lighting on jack stands?
I would rather take better photos of the install on a lift and give credit to a friend and owner of a great shop than to show how cool I am for working out of my home garage with jackstands and a small, 10 gallon air compressor tank.
Hey Billy, I know exactly what you are feeling from damper testing I did with a certain company as a consultant a few years back. I was able to get rid of most of it through spring rate and damper tuning but some was still there. Now I know what was the issue. If we had these, I bet I could have backed off on some stuff and gotten more mechanical grip. I was really impressed by how well the Viper did on the track. Pounding really hard in the Arizona summer heat and no heat, tire or brake issues. When we were done, the car was a sweetheart to drive too. Tamed the bobbing and twichyness and went a few seconds a lap faster to boot. We tested and developed settings with Pirelli and Michelin slicks as well as the OEM tires.
I would say no since quite a bit of the load is torsional. Square section tubing is stiffer in straight bending though. It is also about 20% heavier for equivalent strength.
Just curious how does one measure/find out on the toe deflection. I can understand what a driver feels when it deflects but how did you measure to amount that was deflected?
I’m always fascinated by this. Keep up the great work/articles guys.
I believe Erik had the chassis on a kinematics rig and loaded the suspension to measure the deflection and/or had strain gauges & potentiometers on a car to measure the deflection.
This deflection is due to a lack of stiffness. This deflection is also (thankfully) lower than the yield point of the arm, at which it has been known to snap and not just deform.
I was not aware that aluminum could bend so much, so often, without breaking more easily than it does.
I’ve seen one or two similar products for Miatas (ND in particular), the front knuckle of which weighs like 2.x pounds. I’ve never heard of any breaking, but… has anyone else?
Great write up and wow… I knew the rear toe was an issue but never considered the upright. Makes perfect sense and I’m sold on Eriks solution. Attempting to contact him now, if only to save my uprights before I get more wild in my 99 GTS.
23 comments
Great article! Any chance you could place a link up top as to where to get the stiffeners? They sound necessary and I’d love to buy them for my GTS as well. Thanks!
Wow; kind of concerning that the stock uprights were that marginal. The brace seems to take care of things but I guess it highlights stuff that didn’t get caught in the design stage.
… I swear, every time I see a new update in this series come up I start checking ebay.
You brought it to a shop for a 2 bolt nothing comes off bolt on????
Should we all start bribing Dave Coleman and Eric Hsu to write again?
Miatabusa………………
That is a pretty lame statement. Would you rather have no photography and no article?
He doesn’t wrench, but he can wheel better than any of the aforementioned names. Can relay what effects the setup changes made better than most and that is more signal and less noise.
Billy can wrench and he is pretty damn good. I have seen him do it. Why do some of you feel that you have to pick this article apart in such a dumb sniveling way? Wouldn’t you rather have the car on a lift with good photography rather than some weird angles and lighting on jack stands?
I would rather take better photos of the install on a lift and give credit to a friend and owner of a great shop than to show how cool I am for working out of my home garage with jackstands and a small, 10 gallon air compressor tank.
Exactly!
I’m with Brad. Where can I get a set of these? Thanks!
Hey Billy, I know exactly what you are feeling from damper testing I did with a certain company as a consultant a few years back. I was able to get rid of most of it through spring rate and damper tuning but some was still there. Now I know what was the issue. If we had these, I bet I could have backed off on some stuff and gotten more mechanical grip. I was really impressed by how well the Viper did on the track. Pounding really hard in the Arizona summer heat and no heat, tire or brake issues. When we were done, the car was a sweetheart to drive too. Tamed the bobbing and twichyness and went a few seconds a lap faster to boot. We tested and developed settings with Pirelli and Michelin slicks as well as the OEM tires.
That brace would work better made from square tubing.
I would say no since quite a bit of the load is torsional. Square section tubing is stiffer in straight bending though. It is also about 20% heavier for equivalent strength.
Just curious how does one measure/find out on the toe deflection. I can understand what a driver feels when it deflects but how did you measure to amount that was deflected?
I’m always fascinated by this. Keep up the great work/articles guys.
What I have done in the past is to make a simple fixture for a magnetic based dial indicator.
I’m assuming you’re measuring this after a session or doing a tear down to see if if the part/knuckle has deformed.
I can’t imagine you’re using that with a camera pointed at the whole dial jig whilst it’s on track. Haha
I believe Erik had the chassis on a kinematics rig and loaded the suspension to measure the deflection and/or had strain gauges & potentiometers on a car to measure the deflection.
This deflection is due to a lack of stiffness. This deflection is also (thankfully) lower than the yield point of the arm, at which it has been known to snap and not just deform.
I was not aware that aluminum could bend so much, so often, without breaking more easily than it does.
I’ve seen one or two similar products for Miatas (ND in particular), the front knuckle of which weighs like 2.x pounds. I’ve never heard of any breaking, but… has anyone else?
Where can one purchase the stiffeners??
Can someone please advise where these can be purchased? I am eager to install these and track test it.
How do I purchase a set for the rear on a 1997 GTS?
Great write up and wow… I knew the rear toe was an issue but never considered the upright. Makes perfect sense and I’m sold on Eriks solution. Attempting to contact him now, if only to save my uprights before I get more wild in my 99 GTS.
how does one get the EMI Toe Stiffener.
That is a very good question…