All kinds of updates!

So lots to unpack here.

DriveAutoX Round 2 at Traders’ World, just north of Cincinatti. I did not win. Not even close. Yet, still close.

The SCN class was much more competitive than it was at UMI Motorsports Park. Eric Brown showed up with is SCCA STR prepped ND Miata, and just laid waste. It was impressive. So, I did not win.

But I was fourth. I had third wrapped up until the last run of Saturday, and a kid that had showed up in an S2000, after consistently running three seconds slower than me, finally figured out his car was awesome and drove like he meant it and clipped me.

So, on to the challenge. I met with Eric in the semi finals, and he beat me. Then he went on to beat the next guy and win the whole thing. So, I lost, but it’s always comforting losing to the guy that ended up winning it all.

Here’s my best Saturday run:

The lot at Traders’ World is BUMPY. Painfully so. By the end of the event, the poor Probe was leaking gear oil from the transmission from somewhere. My holiday weekend will likely involve finding and fixing that leak.

Big props to Eric for a phenomenal outing! I’ll see you at NCM in August!

Eric Brown's ND MX-5 in the winners' lane at DriveAutoX
Eric Brown’s ND MX-5 in the winners’ lane at DriveAutoX

But that’s not all, folks! We have Buick stuff to talk about!

Since embarking on the journey of making a Buick Grand National turn and not just go straight, I’ve been largely successful. Except, I compromised my ability to just go straight. Before I changed the suspension, I could reliably pull at 2 second 60 foot time at a drag strip. Since, then, I’ve been struggling to beat 2.4 seconds. That’s abysmal.

I finally measured the rear suspension and figured out why:

Diagram of the suspension and instance center of my Buick
Diagram of the suspension and instance center of my Buick

54% anti squat! DAMNIT!

Lowering the car had compromised the geometry of the rear suspension. The Watts link had fixed the control issues, but the control arm angle changes had ruined the vehicles ability to put power to the contact patch.

My math told me dropping the rear lower control arm’s attachment point to the rear axle by 1″ would get me to 91% anti-squat. That’s a vast improvement. Anti-squat is a measure of how well the vehicle loads the tires. Instead of the body compressing the suspension, the load goes directly to the tire, resulting in more traction. I was not loading the tires properly, which resulted in horrible lack of traction leaving the line.

Correcting the anti-squat wouldn’t just help with launches. I’ll be able to get on the gas sooner coming out of a corner without worrying about throttle oversteer. I had to fix this.

Now, here’s the thing: lots of places sell brackets that will allow you to relocate that lower control arm pickup. The bad news is all of them are for cars set much lower than mine. So, using an aftermarket bracket would have resulted in 143% anti-squat. That sounds good, but it’s bad. Under braking, the rear end could start hopping with that much anti-squat. Hopping under braking breaks parts. So, I needed to keep it under 100%, and the only way to do that was to make my own brackets. So that’s what I did.

Four brackets for welding

I made four brackets from 8 gauge steel to weld onto the axle LCA mounts. Then I welded them to the axle mounts.

Welded on bracket. My weld beads are getting much better.
Welded on bracket. My weld beads are getting much better.

After smoothing, we locate new hole position and drill.

New LCA hole drilled
New LCA hole drilled

Cleaned it up, bolted it together, and put it on the ground. Bad-a-bing.

A few test hits in front of the house confirmed hookup is much improved. The next event for the Buick is July 12 at NCM. So, we’ll have telemetry to see for sure if this helped! Stay tuned!


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