Cornering Stability - Part 1

Cornering Stability - Part 1

On the last track event at Thunderhill West I noticed that I was not comfortable running the car very hard into the corners. From the data that I pulled from RaceChrono it appears that I'm getting around 1.8G of force in turn 3.

In comparison my buddy Barry in his CRX is able to get ~3.2G of force in the same turn. Honestly the issue with this is that I dont feel comfertable pinning the car that hard in the corners, it feels as if the ladder structure of the unibody is rocking. I recalled Twitsted46 stating that he really liked the stability improvements that came from the T3 bracing setup.

Let me backtrack, when I first started looking at some type of chassis brace I was actually considering to get a TEP Brace.

I thought the design was simple enough, especially for the vintage look. I wanted to make my own, I'm not sure why, but I think it comes down to doing everything on the car from this point, why stop now.... So after getting this cheap tube bender on ebay, I started making a brace that was similar to the TEP design.

I got to the point where I was planning to weld the firewall rods to the strut bar when I realized that this was going to be a pain in the ass to service, There would have to be a removal of bolts, and the fitment to the studs on the strut brace is very snug. So snug that it might ruin the threads as you try to pull off the brace to get into the valve cover. So I never finished the mount. I went back to the drawing board.

The T3 brace (STB) is more complex that the TEP counterpart, the STB uses rod ends and radius rods to inter connect all the legs of the triangle that is formed. But it makes servicing the motor easier to access, and less chance of ruining the studs... plus its shiny. There is a direct corollation over here with the amount of shiny and the price you pay, just the front is $300 the rear is another $300. So like always I think how can I build this myself?

I started off with some designs in fusion-360 to make the mount that side on the strut top, I used the 3d prints to mark the steel and make the cuts on the porta-band saw.

V1, not enough space on the left side.
V2, more spacing for the mounts on the left.
Made in ~3mm steel

The center hole was made on a plasma cutter that I HAD to buy (so much for saving money). I later realized that you can also get the hole cut with a milwaukee 2" bi-metal hole cutter, which is the EXACT size of the cap cutout in the center. :(

not too bad.
Note the side of the falage that holds the rod end, this will be changed.

Four of strut tops were made in total, all the exact same dimensions, some tabs were cut cout out in carboard after referencing some of the rod dimensions from [RodEndSupply](  One firewall mount was made which has a 0.5" drop to a wing that holds the radius rod end.

The nice welds are where you cant see them.
Test fitment of the radius rods into the mounts.
Cut the falanges to make sure i can run the OEM caps, something T3 does not do :) 

Mock up of the radius rods after welding the falanges.

Winkle Black paint, 5min intervals, 15min till heatgun, 48 hour dry, 20 min cure on oil heater.
Front is done. 

Not bad if I say so myself. The rear still needs to be triagulated, I have the rods I need to make a mounting bracket.

Now the cost breakdown...

Rodends $190 shipped (front and rear)
3mm plate $20 (but it was scrap in my hoarding pile so $0)
Additional Hardware $20
Plasma Cutter $400 (not needed at all, but now i have a plasma cutter >.>)

So if this was you making the brace, and you had around 30 hours, you can have all this for maybe ~$250 because the plasma cutter is not really needed.

In Part 2 I'll talk about the rear triangulation, and how the car feels.

The track event is on Dec 6, 2020.