Two years ago, Midlana’s first Willow Springs track day was cut short due to the fuel filter being installed backwards – my fault. Last event I spun off in T8-9, damaging a couple of body panels and my pride, but nothing serious. This weekend, well, read on…
Saturday morning we ran two skid pad sessions in which I found drifting Midlana to be harder than expected. Due to the size of the circle, Midlana was either at the top of first gear or the bottom of second, neither being optimal. The top of first meant hanging around 6000-7000 for an extended period of time, which I didn’t like doing. In second gear, the car pushes wider than the smallish circle we had to follow. Any time you see videos of cars drifting – on Top Gear for example – they don’t have a set path to follow. The driver’s left to reach the speed he wants, pitching the car sideways and using the throttle to steer the rear for the camera. I think every car has an optimum speed at which to drift and be able to easily control it. Or maybe it’s just my lack of skill…
Anyway, after I’d finished my second skid pad session, a late model BMW M5 went out and threw a rod due to oil starvation; a very expensive weekend for the owner – I would become more understanding later…
They then had us run a short version of the Streets of Willow course and we were only allowed to pass on the one straight. I got stuck behind a BMW that wouldn’t pull over and got annoyed, so I let the newish Porsche GT3 behind me by to beat on the BMW for a while. The Beemer eventually relented and let us both pass so I then got to see if I could keep up with the GT3 – he couldn’t get away and boy was I having fun! Full disclosure: the event was a class; there was a good chance the owner was either new to the car or inexperienced. It didn’t matter much to me as I was not only able to keep up but had to lift so I didn’t run into him. He wouldn’t let me by because he had the “faster car.” And then…
Heading down the straight I had just shifted to 3rd when Midlana suddenly lost some power, like it was running on three cylinders. At first I thought I had blown the gearbox because after pushing in the clutch, it was still idling. I coasted to the side of the course, shut it off, and thought about my fate as I waited for a tow. I realized that things were bad, that one way or another I was going to have to pull the drivetrain, I just didn’t know why. Through the helmet and earplugs I couldn’t hear what the GoPro – mounted to the chassis – heard, the rattling of a connecting rod…
So maybe you’re wondering “what did the ECU datalogs show?” Good question and I wish I could tell you, because the effing ECU datalogger didn’t record it! It did record the car warming up in the morning, it did record the two skid pad sessions, and it also recorded driving from the trailer to the hot pits before going out on-track, and that’s the last recording – extremely frustrating to put it mildly. Posting questions on the manufacturer’s forum has resulted in silence… hmm. Working with what I have for what happened is the GoPro video. It’s not high enough resolution to be able to read the values, but I can see that oil pressure, oil temperature, and coolant temperature were in a green font, indicating that all was well with the engine. It wasn’t until later when looking under the car, we found just how dire it was – a hole through the block and pan. Somewhat surprising, instead of being upset about the cost, the amount of work, or the downtime (all of which will be substantial) what keeps going around in my head is “why?” and “what should I do different to avoid this next time?” I’m completely mystified why the engine failed because:
1. It was built to withstand 9300 rpm – the rev limit was 7700 rpm.
2. The rods can handle 800 hp, I was running 400
3. The pistons are a conservative 9:1 compression ratio
4. The block is sleeved, typically only necessary when running more than 600 hp
5. Boost was 18 psi on ethanol, which is around 400 hp
6. The ECU protects the engine from oil and coolant over-temp, low oil pressure, MCT protection, and knock protect (though I set all of these up).
This evening I sent the picture of the plugs to a buddy who used to build 1000+ hp Honda drag engines. As soon as he saw the close-up picture he immediately said that in his opinion, I killed it due to detonation. A very bitter pill if true and I’ve forwarded the picture to the engine builder to get a second opinion. I’ll post more pictures this week, along with the video of chasing the GT3, which almost made it worthwhile.