Race Cars and Motorsports

First off, what is 24hrs of Lemons - Well it's explained here.
[24hoursoflemons.com]

I bought the SD1 caged, it having completed in lemons several years previously, but it was a dog, and the last time it raced, it lost a few valve heads and one piston (under the previous owner).

I spent a few years fixing it up in slow time, adding much larger front brakes from a S430, rear discs, heim joints, and stiffer springs, 22 gal FIA fuel cell, Maxima radiator/fans, coolant swirl pot, race seat, quick release wheel, etc, etc

And the important item - a junkyard issue serp 3.9 from a 1995 disco.
The engine had great compression, minimal leakdown and had at some point had the heads freshened up. I checked the mains, and they had typical wear, but were fit for more service, so they went back in (but i did modify the lower shells on the center three to 270 degree oiling, knowing the crank driven pump has tons of reserve volume so may as well use it)... I also modified the SD1 oil pan (sump) adding wings on each side to add another 3 quarts of fluid and prevent cornering starvation (no extra baffles or trap-doors

I also installed a mustang T5 with Camaro concentric release bearing, using the bell from a 4.0 discovery (suitably modified).

To the race at the NCM track in Bowling Green KY. This is an endurance race, 8 hrs on Saturday and 7 on Sunday.
A very complex and technical track, but an absolute blast. Here is a video of the track if anyone is interested.
[youtu.be]
Racing is exhausting, so there is a crew of us - four total in our case, and one extra crew guy along to see what its all about.

Race started with light rain on the Saturday, and I was out first. Driving very gently to shake the car down, I bought it in after 45 mins to get it up on the stands and give it a once over, then sent out our next driver. Next driver went out and did another 45 mins, and same with the next. We didn't have any radio comms, and pretty much decided to just drive, and have fun learning the track, and not go all out for being heroes in our 42 year old racecar.
So driver changes ended up being a casual 10/15 minute affair, instead of the high speed pit lane changes of 50 seconds (or more if adding fuel), which made for a low stress weekend... We did just two hot-pit driver changes over the weekend, both where we added fuel as the track pumps ran out of 93!

The only somewhat significant issue we really had on the weekend was an increase in the amount of clunking coming from the steering rack; the bushings in the housing (that the rack bar itself linearly moves in) had developed a lot of play and i decided to get it changed out. There was probably 3/16" vertical movement at the pinion end of the rack, so was not far from the teeth climbing and disengaging!!! Luckily, I had a backup de-powered rack with me, so that was pressed into service, but we lost an hour of racing in changing it. I will strip and rebuild this rack, and put some more suitable bushing element in there going forwards.

Even without a LSD, the rover cornered like it was on rails, courtesy of the very stiff front springs. It had excellent balance, with no understeer, and the rear end would step out very slowly and be easy to reel back in with a little lock even under power. in the Turn 2/3 hairpin, it would corner as well as many of the very fast cars.

The junkyard engine sounded fantastic, but was running crazy rich in areas (which did lead to fouling plugs, and a slight misfire by the end of Sundays race), but we took the chequered flag on Sunday, which was a fantastic achievement. I don't even know where we finished - maybe 40th in a field of 80 cars? We obviously could have been a lot faster, and positioned higher, but every driver loved the experience.

While we did not win any lap time or class awards, we were bestowed the coveted "IOE" award; a massive $600 and free entry to another race. What is IOE? This is the blurb from the lemons pages:
"The I.O.E. (Index of Effluency) is the grand prize awarded at each 24 Hours of Lemons race. Using a proprietary calculation of how bad a Lemons entry is versus how high it finished, race organizers bestow the award on only the most worthy teams. Winners of the I.O.E. enjoy the highest honors (a low bar, we know) of any Lemons trophy."



What's next? Well there was a weird resonance in the driveline at the "transition" phase between driving and over-run. I'm not sure if this is excess backlash in the torque tube, the bearing in the torque tube, from the UJ angle in the prop shaft, the (probably excessive) play in the tailshaft bushing in the T5, or the T5 itself. I also need to get it dialed in a little more on the fueling so a dyno session will be coming up at some point, and the tire pyro revealed the pass side front needs a little more caster. That's really not all that bad considering a hard weekend of running!!!


So to answer the question in the title, yes, this was a success. I think the SD1 chassis with a few tweaks is a cracker, and the V8 sounded great. Everyone got a lot of seat time, and everyone had a lot of fun racing.



If any of you guys are thinking of going racing, or want to send that old dog of yours that you used to race back in the day out for a little more fun, I strongly recommend this series.

More pics. One of these shows the corvette factory in the background. And the stock disc vs the slightly larger one we used!

So very, very cool!

Congratulations!

Great write-up and photos. Thanks for sharing them!