Fair warning, this will be longer than a typical post.
Way back in February, I did something crazy. I entered the Optima Search for the Ultimate Street Car event schedule for the NCM Motorsports Park the weekend of June 10th. At the same time, I ordered my big Weld RT-S71B forged 18×9.5″ wheels. I was feeling giddy. A big name event, actual track time, big sponsors, lots of photo ops, and high-dollar competition that was surely going to crush me, but would be awesome to be able to compete against.
The best part? No work assignments! The second best part? I had five months to prepare! Easy?
Turns out, not so much.
My entire mission the past year or so has been to make changes to the car to reinforce it. After the engine rebuild, it’s been about longevity and reliability. I got new front suspension arms not because what I had didn’t work (it did), but because the new stuff was stronger and had 15 years’ more engineering know-how put into it. I built an engine that can make 500-600 horsepower on race gas and 30psi of boost, and have elected to (attempt) to run it at 17psi on pump gas, because I don’t want it to blow up. Instead of taking the leap to a Megasquirt, I jumped on an opportunity to simply add a blue-tooth enabled connection to my Powerlogger so I can monitor the engine without a lengthy development effort or cutting up the dash to fit more gauges.
So in the run up to the USCA event, it’s all been about evaluating the car and fixing stuff.
The first thing to fix was my new wheels. One of them ended up not being round.
Now, I have no idea how that happened, but Weld took the wheel back no questions asked and fixed it, so good on them. However, they couldn’t get it fixed and back to me in time for the USCA event, so I ran it on my old 245mm Dunlops. Omen #1.
Omen #2 was a trip down to Lexington for an autocross in May. It was hot. 90 degrees. On the way home, I had my handy new Bailey Engineering Scanmaster-G set on the coolant temp, and noticed that I was running 195 degrees on level ground. When cruising uphill at 70mph, the temperature climbed above 200. Not good, especially when I was anticipating having to run boost down a 1 mile long straight at NCM a month later.
So, after I got home and let the car cool down, I popped the radiator cap and looked inside.
Yup, thirty years had taken its toll. The tubes were crusty and full of deposits, the oil coolers were covered in slime. Once I had it out of the car, I found several pinhole leaks that had sealed themselves with corrosion. All in all, this radiator had lived its useful life. So I ordered a new one from GNS Performance. The radiator they sent me was a work of art. All aluminum, dual 1300+ CFM Spal fans. Lovely.
If this didn’t fix my cooling issues, nothing would. Thankfully, it fixed them. I did have a battle with the relays, though. The mounting brackets are crap. If you buy this radiator, zip-tie the relays to the brackets before you attempt to install it. Otherwise, they’ll come off the brackets and drag on the ground.
Omen 2 dispatched.
Omen 3, and the one I should have taken to heart and withdrawn from the competition and gotten my money back, was when I noticed my passenger side axle was leaking. Figuring the bearings where shot, I got new bearings and seals. When I popped the rear cover to get the C-clips out, I found this:
Yes, there was a tooth missing from the ring gear. Conveniently, it had found its way to the magnet on the back cover and not done any further damage.
There’s a lesson here: DO NOT LEAVE OUT THE MAGNETS when you overhaul stuff. They were put there for a reason. There is no way to tell when that tooth broke. It had been at least three years since I popped that cover, maybe more. If that tooth hadn’t stuck to the magnet, instead finding its way back in-between the ring and pinion, the rear would have locked up, then shattered, and the car would have spun off and likely hit something unpleasant.
When my Dad and I pulled the wheel bearings, we found the passenger side bearing had, in fact, spun. Oops. It’s likely that whenever that bearing stuck, then spun, that’s when the tooth came off the ring gear. Or not. Hard to tell.
Anyway, we found this Tuesday night the week of the event. After a judicious application of the plastic wrench (thanks for the metaphor, Rich), I had a new ring and pinion on the way from Summit. It got here by 10am the next morning. Along with a new installation kit.
The next day, as we were installing the new ring and pinion, we discovered the installation kit had come with the wrong side bearings. GAH! Thankfully, a local truck parts house had the proper bearings. My good friend, Tom Bell of Bell Motor Service helped me get stuff pressed off/on, and we got the diff back together Wednesday evening. Summit racing even took back the incorrect bearings and refunded me $58.
Then came the really hard part. Ring and pinion sets must be properly broken in, or they will fail. I needed to put 500 miles on the car by the time I got to Bowling Green – less than 36 hours from the time we buttoned the diff up.
So, Thursday was a driving day. My daughter packed up some books and videos and her MP3 player, and we climbed into the Buick early Thursday morning. We took the back roads to Newport and ate lunch at the Haufbrau Haus, then took I-71 back home. That got us 350 miles.
Friday morning, I packed up and headed for Bowling Green, again taking the back roads to extend the mileage and vary the speed. I arrived at the track just past noon, having put just over 500 miles on the ring and pinion. I paid $100 for a garage and parked the car so it could cool off. If you’re ever doing a track day event, pay for a garage. Being able to get out of the sun is worth every cent.
While it was cooling off, I took some time to walk around the event.
The equipment present was fantastic. It was also HOT. I don’t think it go below 90 degrees at night.
Anyway, I changed the differential fluid at the track, and thought all was well.
The next morning was the Speed Stop challenge. We started on a section of the road course, accelerated down a hill, up another hill, and had to stop the car in a box just over the crest. Much tougher than it sounds. I got one good run, then the car started stalling and sputtering. It wouldn’t rev past 3000 rpm, which, coincidentally is when the fuel injection system switches from sequential to batch fire. That’s important. Remember that.
After making a few more attempts at runs, I finally limped it back to the garage. I pulled the logs from the runs out of the Scanmaster and found that, curiously, when the engine burped, every single sensor spiked. This was good. It meant this was a problem internal to the computer, not a problem with the engine. So I pulled the computer out.
It was so hot to the touch, I nearly dropped it. After setting it on the concrete floor to sink some heat out of it, I opened it up. I wish I took a picture, but what I found was amazing. A ground had completely burned up inside the ECM. Now, since these ECMs sink a lot of current, they have a bunch of ground pins on their connectors, since one pin with a single 16ga wire isn’t enough to handle the multiple amps that ground through the computer. One of those pins had overloaded and melted, leaving the ECM with insufficient ground capacity. The epoxy that’s used to weatherproof the unit had melted in places. It had gotten hot, and likely had one or more internal short circuits.
This is where the 3000 rpm thing comes in. The car was stalling at 3000 rpm. When the fuel injection switched from sequential (1 injector grounded at a time) to batch (6 injectors grounded) the current overloaded the ECM and caused it to reset. At best, the car stumbled. At worst, it stalled completely.
Now this is where a small miracle occurred. Where do you get an ECM for a 1987 Buick Grand National on Saturday? In Bowling Green? Not at a store, that’s for sure. I called them all.
But wait, each year Bowling Green hosts the Buick GS Nationals! There had to be somebody nearby that raced Buicks that had an ECM on the shelf. I called my friends at Boost Crew Motorsports, and within an hour, a kind soul brought me a loaner ECM.
So, while my Speed Stop runs were poop, I had a new ECM and an afternoon of autocrossing to get done. I also had the Design and Engineering portion, which I crushed. Top Ten finish in that section. Go me.
The autocross was HOT. The Dunlops didn’t like the heat and washed out halfway through my first run. I got two more runs done before the brand new cooling fans quit.
That’s right. 98 degrees and I had no cooling fans. It was at this point I threw in the towel. It was too hot and I was too tired. Racing further risked damaging the car worse or me losing my temper. I wasn’t having any fun. It was time to go home.
My good buddy Dave happened to be at the event working, and he’d brought his truck. A quick call to U-haul for a car trailer and we were loaded up and headed home.
Ironically, this would be the second time Uncle Dave had bailed me out of a racing-induced failure two hours from home. He was the one that got me home in 2014 after I blew my head gasket at IRP. I really need to get my own truck and trailer.
Once I got home and had time to properly troubleshoot, I found the root of the problem:
Let me take a paragraph to explain what you’re looking at. It’s a ground, melted into a loom. The ground had gotten hot, probably from working loose and arcing after I installed the new fans (which grounded through this ring). As it melted the plastic, the plastic eventually encased the ring and separated it from the bolt head that was grounding it to intake manifold. This severed the ground and disabled the fans. I think it also re-directed a bunch of current through the ECM, which is what burned it up.
Needless to say, this particular ground has been fixed, and fixed right. A reman ECM was sourced and a spare I had in the garage has gone into the trunk “just in case.” The entire weekend, including the radiator, ring and pinion, entry fee, and hotel cost me over two grand.
That said, I didn’t do too badly. Thanks to my top ten Design and Engineering score along with Autocross and Speed Stop times that were above the bottom third, I managed to not be DFL despite scoring a big fat 0 on the road course portion. That’s a big deal.
I plan on trying again next year. I think with my big wheels on the car and all these other gremlins sorted, the Buick should turn some heads next year.