Alot of activity over at Miata.net about the 2006 car, the problems that were discovered, and some accounts from the actual team members. Note that the 2006 MX5 is running against the new Civic Si, at least in this NASA series.
A few pics from the event
There were teething problems to be experienced, as expected on a totally new platform:
Another team member here.
We had actually asked for the Miatas to be classed in E1 instead of E2 to give us stiffer competition. The Miata was slower than others in the class - such as those Civics - but we figured there wouldn’t be much pride in winning E2 and no shame in losing E1
Our biggest problem was the suspension. The cars were prototypes for the upcoming MX5 Cup (or Pro MX5, I’m not sure of the name) spec series. The specification hasn’t been finalised yet, but in their prototype form they did 25 consecutive laps at Thunderhill that were 3 seconds faster than the Spec Miata record. Unfortunately the special shocks that were used for that weren’t available to us and we had to run the stock Bilsteins to our surprise. The spring rates were in the 700/350 range to start and the cars were bouncing all over. We also had problems with them bottoming out hard. Oh, and one car oversteered while the other understeered. After a crazy day on Friday of trying to set the cars up, we ended up with two different setups on the two cars. Number 55 (the oversteer car) had the rear bumpstops removed and seemed to handle the bumps on turn 5 better than number 19 (the understeer car). For spares, we had a pile of parts that had been pulled off a new MX5 by Mazda for us along with random bits and pieces. An exhaust manifold heatshield and one right headlight, for example.
Also, it looks like the transmission in in the new Miata has a flaw, as both of the factory cars had problems:
So, the race began. We weren’t lapping as fast as much of our E1 competition but we were ahead due to better fuel economy and fast, clean pitstops. The marshalls were being really strict about pit stop violations and this was hurting Honda fairly badly. Then the problems started. 55 came in with a smoking differential (literally) and the crew dove underneath to figure out how to remove it. Both side seals had been torn up and it’s likely the extra travel from the removed bumpstops caused the halfshafts to bottom out on the seals. That’s the best we could figure anyhow. The car went back out.
Then 55 came back in with a charging problem. We thought it was the alternator so that was changed out. The car went back out but the problem wasn’t solved. We were distracted by the fact that 19 came in stuck in 3rd gear.
Now, during testing we’d had a transmission fail and stick in 3rd. The cause was a broken shift fork. It looked like a fluke. Well, we started to pull the tranny out of 19 and 55 pulled in with the exact same problem. Perhaps not a fluke then. Since all hands were working on 19 and we only had one spare tranny, we fixed the charging problem (a failing kill switch) and sent 55 back out to circulate in 3rd gear.
19 was finished and sent back out. We opened up the damaged box and manually shifted it into 4th. 55 was brought in, the transmission was pulled and the single-speed box was installed. We joked about not installing a shift lever as it was still possible for the driver to mistakenly go back to 3rd, but the tranny had to be pulled to put it back in 4th. I don’t know exactly what happened, but it turned out the car was running in 5th or 6th. Did the driver hit the lever? Did we have something misaligned in the transmission? Regardless, that’s the gear it was going to be. We pushed the car to start it moving down pit lane.
Another note about penalties here. After the car left, a marshall dropped by to talk to us. He wanted to thank us. A bunch of cars had been given stop-and-go penalties for excessive speed in pit lane. Despite the fact that our car was in high gear, the driver took it through the pits at or below the limit. That’s the sort of thing that helps win enduros. In fact, after a total of 90 car-hours of racing over two 25-hour races the Mazdaspeed team has not taken a single penalty.
19 came in for the same charging problem and was sent back out fixed. Now we knew that the transmission had a lifespan of about 200 laps before it would break. After 100 laps with the new tranny, we told the driver to stick it in 4th and leave it there. The flexible nature of the new 2.0 meant that this wasn’t a huge problem and the lap times didn’t change much at all. We were a long way back - about 30 laps in 19, much further in 55 - but at least we were moving again.
And that’s what went on all through the dark hours. The cars drove around and around in 4th and 5th (or 6th, we’re not sure) respectively. They did manage to get good gas mileage and were working back up through the ranks as other competition failed.
More on the failures, and why it is good to have a manufacturer that supports motorsports:
I went up on the roof of our trailer to get some pictures of the sunrise. Once it was light enough, I decided to watch 19 handle the bumps on turn 5. There was a Factory Five Cobra moving slowly going through 5 in the center of the track - he was low on fuel. The MX5 was coming up fast and went to pass on the left, just as all the passes on that corner had been taking place for 19 hours or so. Just as the MX5 came up on the Cobra, the driver turned to head for the access road at the left of the track. Totally unexpected and he had no idea the MX5 was there. I never even saw the Cobra turn in so there was no chance for our driver to do anything. It was rolled over a couple of times and the MX5 went tumbling across the infield. The Cobra driver thought he was already in the access road at the time of impact but the marks on the track don’t say so. The Cobra driver was really lucky as there was a big skid mark on his roll bar right above his head. He was unhurt. Our driver went for one heck of a ride but only had a painful broken thumb. Three cheers for AWR cages! The car could not be towed back to the pits so it was left in the midfield like some sort of anti-drunk-driving ad.
The 55 car droned home. I don’t know the placing, it was a fair way down by this point due to the high gearing and all the time we spent working on it overnight. The Honda that had been 2 laps behind us finished 4th overall. There were a lot of Mazdas running at the finish - mostly 1st generation RX7s and Spec Miatas.
The vultures came out for the wrecked car almost immediately. One of the drivers for the 55 car wanted the transmission. I wanted the car for product development. Frank wanted it to fix. In the end it went straight to Mazda.
If you read the comments in that blog, you’ll see one of the VPs of MNAO was going to talk to the program manager for the MX5 about the transmission problems before the race was even over. You don’t get much faster response time than that to problems! From what I could see, it looked like a poorly designed part with a stress riser in a sharp corner. Both broken transmissions had identical failures.
We were there for R&D. We did that
vq30de
December 7, 2005, 9:58pm
3
Very good read, and an excellent example of a manufacturer truly using motorsports to better their product. :tup: to mazda IMO
…we figured there wouldn’t be much pride in winning E2 and no shame in losing E1.
that’s the spirit, lads. very jaunty :lol:
the '07s will probably have the revised fork. I’m with stupid, definitely a great read!
Daddie
December 8, 2005, 7:50am
5
Great read. I really do love Mazda
Rx3
December 9, 2005, 1:07pm
6
Do Miatas always run spring rates that far apart front to back? No wonder the car was bouncing. What was the final spring rate they agreed on for the race?
Actually those are almost exactly the same spring rates that they use for Spec Miata (700F/325R). However, Spec Miata also uses a matched shock for that spring rate. These guys were stuck using the stock Bilsteins which are set up for the stock springs, around 150lbs in the front and 100lbs in the rear.
Spec Miata and other track driven versions generally run much higher springs in the front than the auto-x cars do. For example, the rates I plan to run in CSP are 550F/350R. Keeping the same front and rear bars that I use now, my balance should remain exactly as it is, as the front to rear ratio is the same as stock.