Pro Touring '69 Chevelle build thread

[Derek69SS]

Spring of 2021, I decided to finally do a project I had wanted to do for about 12 years.

I bought a fiberglass hood from Glasstek, and modified it for functional heat extractors that I moulded into the hood and tied into the shape of the SS bulges. The holes are right behind the radiator, located in a low-pressure area and will help pull high-pressure air out from under the hood, significantly reducing aero-lift at high speeds, reducing under-hood temperatures, and increasing air flow through the radiator.

The fiberglass hood also removed 40 lbs of high-centered weight off the front of the car. (Stock hood 72.3 lbs, FG 32.3 lbs)

[Derek69SS]

Over the years I had changed my opinion on a few things, and wasn't real fond of the smoothed rear tail panel painted body color anymore, so in 2021 I added the trim back on, and painted the panel satin black like a factory SS car.

I also moved the battery to the trunk to help balance the car, and bought a fiberglass trunk lid to help shed some weight.

I wanted to take advantage of the aero allowances for the classes I intend to run with. What you see here is a ridiculous looking 10" SCCA CAMT-legal spoiler. I also made an 8" version for USCA events. It will be easy enough to swap out size and adjust AOA depending on use... Big one at steep angle for low-speed events (autocross) and smaller ones laid back more for higher speeds (roadcourse)

I don't expect everyone to like it, but it is there for a purpose, and I will take any performance advantage I can get.

[Derek69SS]

As usual, completely changing the car meant re-learning how to drive and set it up the following season. The 3-link took a few events to get dialed in, but when I did, it really helped the car everywhere.

Having conventional spring/shock in the rear was limiting my ability to take advantage of the adjustable rear roll center as I could only find "rear" springs up to 250lb rate. I discovered that I could use a "front" spring from a QA1 hybrid coilover setup, which opened up a lot of options for spring rates. I moved to 350lb with great results.

Changing anti-squat from 180% down to 110% really helped in both braking and driving off the corner. Eliminating all of the roll-bind made it more predictable mid corner.

I ran a few events with the steel hood and trunk back on it as I ran out of time doing the body work on the fiberglass parts.

Still a street car doing street car things...
Drove my Chevy to the Levee but the Levee was dry... stopped at the Buddy Holly crash site on the way home from Goodguys Des Moines.

[Derek69SS]

I was signed up for UMI Autocross Challenge 2021, and decided if I wanted a shot at winning an invite to KOTM, I'd need the fiberglass parts and the spoiler mounted. I didn't have time to get blocked smooth and painted, so I shot them with black epoxy primer and installed them unfinished for the rest of the summer.

Fresh 295/35/18 squared Yokohama A052s, as well as taking 40lbs off the front, 18.5lbs off the back, and adding the spoiler did the trick, as I won the invite by 0.059 second over 2 days.

[Derek69SS]

Summer of 2021 I decided with all the uncertainty in the world, I had to do some things while I still could... I didn't want to be that guy in 40 years saying "I wish I would have..."

I registered for my first Ultimate Street Car Association event at Road America. I put my old tires back on for Road America, so I could save the Yokes for KOTM. This hurt my times quite a bit, but being my first time on a big roadcourse, I was more concerned with being smart and keeping the car together than my finishing position. Of 21 cars in GTV class, I finished 11th overall. 6th in the Autocross, 7th on speed-stop, 13th on the road course, and dead-last on Design & Engineering judging... that was kind of a kick in the pants, but I knew having no radio, horn, or reverse-lights would hurt the score there.

My best lap at RA was a 2:56.379 (full course + the "bend" motorcycle chicane instead of running the "kink") Ran over 130mph in 3 places on that track (138mph on the front straight, 135mph down into T5, and 132mph into Canada Corner.)

My last lap, I was finally comfortable enough to put down a flyer, but accelerating up the hill out of T5 the car started billowing smoke. I thought I blew it up, but oil pressure was good and no knocking sounds... I had less than a week to fix it before KOTM, but hadn't really figured out the problem yet. I thought I filled the catchcan and burped oil onto the header, but was wrong about that...

One other highlight of the Optima event at Road America for me was the karting enduro. My team didn't win it, but I narrowly beat out pro-driver Billy Johnson on lap-time, scoring the fastest lap out of everyone!

[Derek69SS]

The night I had to load up and leave for UMI King of the Mountain 3.0, I discovered the real reason for all the smoke. The rear seal on the T56 was leaking really bad on acceleration, and the driveshaft was throwing trans fluid onto the exhaust. I didn't have a new seal, but I loaded up anyway and headed to Pennsylvania. Thinking about the problem on the way, I realized I'd be driving right past Summit Racing in Talmadge OH, and would have no problem getting a new seal on short notice there. I replaced the seal at UMI Motorsports Park, but also discovered another problem. The lower brace connecting my 3-link upper frame mount to the lower mount was starting to buckle. I had made it out of too thin of metal for the stresses I was putting it through, and braking into T5 at Road America from 135mph had pushed the driveshaft too far into the trans, wiping out the seal.

It was too late to fix the brace, so the decision was made just to replace the seal and run it for the weekend and weld in a new brace when I got home.

I finished 14th of 33 in the vintage class at KOTM among some really fast competition, being the fastest A-body there.

[Derek69SS]

The decision to run KOTM with a buckled chassis brace probably wasn't a smart one, but I had already towed 14 hours to get there before it was discovered... When I got home after the event, the brace had fractured on both ends and was laying loose on the floor of the trailer. Putting the car up on the lift revealed that repeated flexing was tearing the rear crossmember away from the frame rails. The rain on Saturday, with the last runs of the weekend being in the wet probably saved me from more serious problems.

I built a new brace out of much heavier material, and added some gussets. I now paint all of my chassis modifications in light colors (white or silver depending on what I have on hand) to make inspections for cracks easier.

[Derek69SS]

The end of the 2021 season was an awesome local event in Wisconsin Dells. It was a 2-day event with a "CAM Challenge" shootout at the end of each day, and some of the fastest CAMT cars in the upper midwest were in it. The host club used a picture of my car from the previous year on the "big check" to the winner.

On Saturday I qualified for the shootout, but in Round 1 went too hot into one element, lost the back end, and wiped out a wall of cones, so I didn't make the final.

On Sunday, I qualified, went top-2 in round one, and ran my best lap of the day to win the final, taking home the "big check" for $25, making me a semi-professional racecar driver.

[Derek69SS]

Winter of 2021/2022 Dad and I traded cars for the season. Neither of us wanted to work on our own junk, but we both were able to get stuff done on each other's cars.
His skills, garage, and tools are better set up for paint and body, and I'm better set up for chassis and mechanical work.

He got my Chevelle hood and trunk painted while I installed power steering and did some suspension work on his '68 Camaro.

[Derek69SS]

Spring of 2022, with the new hood/trunk and no stripes.