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Gear
For a race and a half, our third gear synchro has been playing dead. The shifter drops into third with almost no effort and an inevitable GRAUNCH every time. This is the kind of thing we might have tried to repair between races if we weren't doing two back-to-back enduros. Instead, we've been taking our time with every shift, matching revs as much as possible, and trying to keep the graunch lowercase.
Half an hour into my stint, trying desperately to make up for almost an hour of unscheduled pit time, I do a 4-3 downshift, and as I let out the clutch the shifter bounces back at my hand like a missed shift. Instinctively, I get back on the clutch and try again. The shifter feels like it's in neutral, but it won't move. Crossing my mental fingers, I let out the clutch again and find I'm still in third. Great. Three and a half hours to go…
Third is clearly the best gear to be stuck in at Streets of Willow. Given a full gearbox, you only use 4th twice (on both straights) and 2nd is optional, but not really necessary coming out of the skidpad. Other than going down the second half of each straight cruising just below the rev limiter, the loss of our gearbox doesn't change much. The chase for first place, though, is over. The BMW we've been chasing notices our change of pace and parks itself on our rear bumper. If they follow us, we can't lap them three times to take the lead. We finish the race in second place.
Turbo
Turns out you can't just spit a screw head through a spinning turbo without anything bad happening. When the turbine wheel hits the screw, it kicks it back into the turning housing, where it has to gather its courage and try again. Based on the damage we found on our turbine wheel, it took a lot of trial and error to find its way out.
The damaged turbine wheel led to an imbalance that lead to bearing wear that led to contact between the turbine wheel and the housing that led to more bearing wear that probably has something to do with the chip missing from the compressor wheel.
The bearings were so shot, you could rock the turbine wheel back and forth about a quarter inch. Amazingly, we didn't really notice any loss of performance and only discovered this problem weeks later when we finally started prepping for the next race.
Fixing it
Despite the fact it somehow still worked, we clearly needed a new turbo. A new Mexican Dodge Stratus turbo. For free.
LeMons accounting conventions allow for money to be spent on repairs, but only with approval. Say your car starts a race as a $500 heap, but “loses some value” on the track. Send some pictures and a descriptive sob story to LeMons Czar Jay Lamm, and he'll assign a residual value to your car, leaving you with some budget to fix things back up.
Problem is, we knew exactly how little sympathy Jay would have for our car having broken itself at a ChumpCar race, so we had to figure out how to fix our turbo for free.
Luckily, we have three former turbo engineers on our team. Realizing that the Mexican Dodge turbo was supplied by Mitsubishi, and that Mitsubishi built this turbo from a Lego-like toolkit of TD-04 parts, they went digging for a similar turbo that might be more common in the States. Through an incredible stroke of luck, it turns out early WRX turbos used the exact same turbine wheel as the Mexican Stratus. This meant we could replace the CHRA (that's the center housing and spinny bits of a turbo) while maintaining the turbo's exhaust housing. Since all the most difficult manifold and downpipe fabrication is on the exhaust side, this would save us a tremendous amount of effort and money. Not only are used WRX turbos abundant and cheap (~$70 used), I actually had one sitting in my garage, a leftover from SCC's Project WRX almost 10 years ago.
The WRX turbo (on the right, above) did use a larger compressor wheel, so we had to use the WRX compressor housing.
(By the way, being free and found on your shelf isn't always enough to qualify as worthless in LeMons accounting. After announcing our clever repair during judging at the next LeMons race, we were given 3 penalty laps for the value of the turbo. That was discounted from what technically should have been 7 laps, at one lap for every $10 of the $70 street value of a used WRX turbo. Presumably we got the discount because we were honest enough to actually point out something they wouldn't have noticed in the first place.)
