Greetings fellow endurance racers. I've searched high and low for a forum that specializes in endurance racing the Miata but haven't had any luck finding one. That being the case I thought this seemed like a really good place to start a forum thread pertaining the the specific technical challenges likely to be encountered when enduance racing a Miata. I've been racing my Miata for 11 years now, starting out in SCCA sprint racing then moving on to Lemons, Champ Car, SCCA and AER endurance racing. The setup of my NA Miata is based fairly close to the west coast Super Miata with NB suspension, NB2 VVT motor w/coolant reroute, MegaSquirt ECU, 4.77 rear gear, diff cooler, 5 speed trans, Sport Brakes, and fiberglass doors and top.
The most significant challenge we've faced when racing 9 hours a day has to be heat. We've experienced and seen many, many failures through the years and I'm convinced that I can attribute the large majority of those failures to the build up of heat taking its toll on the equipment. Here's what I've done to mitigate the heat issues:
- Header - I sent our Racing Beat header to JetHot and had it coated. I've tried header wrap but found it to be to fragile plus I do believe it makes the header susceptible to cracking. JetHot says their coating knocks down 60% of the heat and I believe them.
- Transmission - The header is pretty close to the trans so I fabricated a heat shied that fastens with a couple aluminum straps.
- Diff - I did wrap the exhaust pipe where it comes closest to the diff. I'm not as concerned about it causing cracks in a fairly cheap piece of exhaust pipe and I also painted it with the product recommended for this purpose.
- Diff Cooler - With only one quart of gear lube, heat build up is a huge problem when racing for 9 or even 24 hours. After seeing multiple diff failures, all heat related, coming late in the race day I decided that a diff cooler was really the only option. I've only had it for one race weekend and that was in February but I've fairly confident that it will prevent future failures.
- Foot well - insulating the foot well is a must, I actually had a driving shoe fail because the foot well was getting so hot.
That's it for now, time to head the shop to start installing the Penske shocks I just purchased for the Miata.