Summit Point Motorsports Park is tucked deep into the pocket of eastern West Virginia, just miles from the borders of Virginia, Pennsylvania and Delaware. Having four distinct tracks , it offers a variety of challenges, but the original Summit Point Circuit is still held as the premiere track to be at. Just 2 miles long, it has some rolling elevation changes, over a half mile front straight and a series of esses and hair pins that test the suspension and tires to their fullest capacity. Summit Point 2017 was looking good on the horizon.
AER @ Summit Point 2017
We took our 9-3 SS race car out into the wild for the third time for the American Endurance Racing 18-hour endurance series. We had several known challenges to overcome since the New Jersey race in May and a few that would present themselves during the race-prep week. The known challenges would be to work on the cars setup to make the car feel less like a FWD four-door sedan, and more like a high-performance drivers car. Being a FWD four-door sedan, this meant trying remove the built-in understeer by biasing the tire grip to the front as well as removing as much weight as possible. Every component, bracket, clip and screw was analyzed for weight savings. Even adding back some components for aero and ease of service, we managed to strip another 75lbs out of the already stripped tub to a total wet weigh-in of 2800lbs. Front grip was provided by some new 17x9in Team Dynamics Motorsports wheels allowing 255/40/17 tires for the front and 245/40/17 in the rear.
Another challenge was just to get the engine into a consistent performance. Previously we were plagued by erratic limp-modes due to both the ESP system and Trionic 8 engine diagnostics. I believed I had sorted all of that out, I just needed to get the engine to a final dyno tune to flatten out the fuel curve and get some baseline at the power levels. The day before the race I had the car loaded up on the dyno doing some pulls when disaster struck. A backfire on the release of throttle at full-bore caused the turbocharger oil feed line to come off, spraying oil everywhere and instantly catching fire to the blistering hot downpipe. The fire was put out quickly, we cleaned up, re-tightened the line, checked the oil and tried another pull. Our 320whp was now 118whp – something was very wrong.
Our Mamba 20T TDO4 turbo had seized from lack of lubrication while probably spinning at 150,000 rpm. Knowing we had to swap turbos before we loaded up that night, we packed up and got back to the shop. Not having another custom turbo, we swapped in the stock Aero 14T and called it a blessing in disguise. That night I worked on a tune using the stock turbo applying all of the parameters that we’ve been tweaking over the last 5 months in hopes for some solid performance. During our test/qualifying day, a few more tweaks were made and the car became a solid runner.
We qualified for position 1 in class 3, which proved that the car was capable and competitive. We’d be in a swarm of E36 and E46 BMWs as well as our favorite frienemies, the Krabby Krauts. Our 6-speed manual transmission with WaveTrac LSD was performing flawlessly along with the suspension changes that improved the cars handling. An experimental front splitter was implemented to further improve the fast sweeping corners and aid the new brake cooling ducting.
With lots of changes for Summit Point 2017, it’s always a nail-biter to know if there was some sort of unintended consequence that will ruin the weekend. This time everything worked so well, that consequence was a lot of fast , consistent laps which highlighted the weak points in our current setup – Axles. Originally, we started off with four good OE axles and several aftermarket ones.
The OE axles were certainly strong enough, but seemed to suffer from boot and ultimately joint failure do to lack of lubrication. The aftermarket axles seemed to be a gamble. We had one last a whole day of racing in New Jersey and then some last only 1 or 2 laps. We ran all day a few test days and all day practice/qualifying on our aftermarket axles, but a race day is a different story. After our first failure happened on one of the axles that had lasted in previous races, we swapped it out with another in a brisk 14 minute stop. Unfortunately, that axle only survived another lap before it had given out again. Chalking that up to just a manufacturer error, we threw in another.
Three laps later, same deal. My theory at this point was that putting a fresh newly manufacturered axle into race conditions was outside of its design specs. Tolerances on these new axles were very tight and adding a ton of abuse at them without great distribution of axle grease was just compounding the heat problem. The decision was made to try and clearance the joints the last of the new spare axles we had and pack them with some high-quality Red Line CV2 grease. We also had a very nicely rebuilt (by Kyle) OE axle that needed to be just booted. Matt went out to purchase a Dremel and some sanding rolls and Kyle and I got to work on breaking down these axles in order to prep them. Several hours later we had one axle that was de-burred, clearanced and reassembled. Using the best of what was available to us, I had pretty good confidence that this would work. If nothing else, we should get more than 3 laps out of it.
We set out Sunday race day all the way in the back of group 3. Lee Carpentier, who knows his way around the pedals, worked his way through traffic back up to podium position. After about a hour into the first stint, a full-course black flag which brought all the cars back to the hot pits. While waiting for the track to restart Matt noticed one of the inner CV boots had come off! Everything was still intact but we had to pull back into our paddock space to try to get the clamp back on the boot. It took some time to find a the right size clamp while navigating around scalding brake rotors. But we made it back out on track and kept close eye on these boots for the rest of the day.
Everything seemed to be going great until we heard over the radio of a heavy vibration on the right front. We brought the car in and checked it over. Nothing looked out of the ordinary, however the tell-tale click-click-click of the outer CV told us it was a ticking time bomb. Still we managed about 7.5 hours of racing of the 9-hour day and decided it would be better to do the autopsy of the failure before a complete and utter meltdown. We could still drive the car on the trailer and we all got at least one and a half hours behind the wheel at the end of a very long race weekend.
Back at the shop I took apart both axles to inspect the failure and get a reading on the longevity of both our OE and modified aftermarket axles. It seems that the failure was simply due to not enough lubrication. The modifications seemed to work, but without enough grease, the parts started wearing into each other and generating more and more heat which further boiled off the lubrication. The OE axle although needing a good re-greasing, looked like they were holding up just fine. The plan is to find some more of those axles and do complete tear-down and rebuild of those, as well as playing around with some friction modifiers to keep internal temperatures down and improve the longevity. Stay tuned for more info about this in the near future.
