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OS Giken’s Grand-Am Spec TR Series clutch & flywheel going into Project #YAE92 at European Auto Source. OS Giken’s proven clutch kit gives us a lot more reliability and the rotational weight savings will help us on the acceleration end as well!Since we had most of the driveline out of the way it was a good time to remove the transmission and install a new clutch from OS Giken. Although we aren’t going with a ton more horsepower than stock, replacing the clutch is still a must-do in endurance racing. While the stock clutch could handle our expected power output, we wanted something a lot more durable to withstand not only the amount of shifts that will occur during the course of a 25 hour long race, but also the heat that goes along with it. We looked no further than OS Giken’s Grand-Am spec TR clutch and flywheel as it has already been proven by many of the teams running E92 M3s in Grand-Am (now United Sports Car Series). Of course, we will also reap the other benefits of swapping out the clutch such as it being lighter weight which in a clutch, also helps with quicker acceleration. We will also be running OS Giken’s tried and true Super Lock Limited Slip Differential, but unfortunately we are still waiting on it to arrive.
The Ultimate Clutch Pedal is a really cool and seldom thought about upgrade that sits lower to the floor, won’t wear out and get sloppy, and features adjustable tension and travel. All incredibly cool and useful features for something that will be used thousands of times during every endurance race.While we’re on the subject of clutches, we will also talk about our new Ultimate Clutch Pedal! This replacement clutch pedal has a lot of features but what really drew us toward it was reliability. I know what you’re thinking and yes a clutch pedal can be a source of weakness very easily on an endurance race car, or any track car for that matter. Think about the number of times that clutch pedal is slammed to the floor during a 25 hour race. What about during an entire season of endurance racing? When building an endurance race car, these are the things you must think about and fortunately for us Ultimate Clutch Pedal has a solution. The stock clutch pedal is plastic with a nylon bushing at its pivot point which means that over time it will wear out and being that the arm is plastic, it may even be prone to breaking. The Ultimate Clutch Pedal is 6061 aluminum utilizing a self-lubricating bronze bushing at its pivot point. Not only that, but it has a host of other cool features; for instance it sits about 15mm lower than stock so it’s less effort for the driver to get his foot to it, especially cool if you’ve removed all of the factory carpet and insulation under the driver’s feet like we have. It’s also two-way adjustable meaning you can adjust the pedal travel as well as the tension which are very useable options for something that you’re going to be using thousands of times during an endurance race.
Despite having a dual pickup system, BMW’s S65 V8 engine can still suffer from oil starvation in race conditions. In our opinion a baffled oil pan like this one from VAC Motorsports is a must if a full dry-sump system isn’t in the budget.Another big source of failure within the E9X M3 comes from the rod bearings in the S65 V8 engine. Long story short, the bearings wear pre-maturely. The exact cause of the problem is unknown and unfortunately BMW issued no TSB or recall on the problem and now that the engine is not being used anymore we doubt they will take the time to look into it. Since this is a known issue, we decided to perform a bit of preventative maintenance and swap them out. Upon inspection it’s good that we did as our stock bearings were already showing signs of excessive wear. To help combat the problem we’ve gone with a set of bearings which have been WPC treated and if you don’t know what that means you haven’t been reading MotoIQ long enough! If you want more education on it, read the “WPC is Neat Stuff” article written by Mike Kojima.
Here you can see some of the used rod bearings with excessive wear, a problem that is becoming more and more common as the E92 M3s get older. Our M3 chassis only had 36,000 miles on it.In addition to the WPC treated rod bearings we also changed out the bolts for stronger ARP replacements since we were already in there. While we had the oil pan off the car, we decided to send it out to VAC Motorsports to be baffled. Oil pan baffling is the next best thing to an uber-expensive dry sump oil system. Baffling keeps the oil pickup surrounded by oil which of course keeps your engine lubricated and running. Without it you run the risk of the g-forces seen while racing moving all of the oil away from the pickup which can result in temporary oil starvation and that of course leads to a bunch of smoke and oil billowing out of the new hole in your engine.
So there you have it! After a long period of time with an immobile chassis, we’ve finally begun re-assembly on Project #YAE92. The project should be moving along quickly now so I don’t expect it to be too long before we reveal part 3 of the build journal! If you missed part 1, click the link below.
Yost Autosport #YAE92 M3: Part 1 – We Officially Void the Warranty
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