Saturday: Mazfest 2017
Finally! Time to go stretch the car’s legs and see how it runs. This weekend was the first big shakedown. This is pretty much a completely fresh build at this point, and so you have to expect to discover issues and there’s a long teething process as issues are sorted out, items fixed and improved, etc. once it’s being used at the race track. This weekend was all about getting the car out there and running it as much as possible to discover those issues and to take home a long but focused to-do list for how to improve the setup.
Saturday was Mazfest at Auto Club Speedway and I had a great time showing the car when I wasn’t on track.
On-track was special, after this much time building the car it was great to just feel the thing doing what it is built to do. There is a lot of power on tap and the engine is super smooth and worlds better than the old turbo setup. Torque is just always there if you want it. I’m delighted to find the car is still very “Miata” with great balance and drives just like it should just with much more motor attached to the right pedal. That was the biggest goal with going with this engine package over alternatives that might weigh a bit more.
Here’s a run-down of notes on each system and any issues that did spring up.
– Engine (max temp 225 water / 265° oil): no issues to report. Ran like a dream, makes power everywhere. Currently running with no oil cooler, just the factory filter housing. Oil cooler will bring oil temp down a good chunk once I have that in and working.
– Transmission (max temp 200°): Grinding on upshifts. I believe it’s a pedal/rod length issue. Bled the system after 1st session with no effect. Drove around it the rest of the weekend by trying to be VERY patient on shifts to let the rpms drop to where they needed to be on the next gear… which was somewhat successful. Gearing is good. Used 3-4-5 at this track which has a really low speed ~50mph tight right at the end. 3rd pulled right out of it, I won’t ever be using 2nd on a road course.
– Differential (max temp 180°): puking fluid out of the vent on top. V8R says running a breather line will fix this. Otherwise, the limited slip characteristics feel great.
– Power steering (max temp 190°): leaking fluid from the cap. We’re suspecting it’s from high-G right-hand turns which effectively submerges the left/lower side of the non-sealed cap. I’m implement a fix in the next couple days. Steering feel with the NB power rack is good and I’m much less worn out at the end of a session than with a manual rack. I think I’ll be keeping the power steering for a while.
– Ergonomics: new seating position and controls are all perfect. I did accidentally hit the fuel pump switch to off when shifting once. Might need to move the switches or add a guard.
– Display dash: I’ve already forgotten how I lived without one of these. The dash is set up to monitor all the temperatures and pressures without me having to do anything. If something is amiss, it lights up a warning light and lets me know. Otherwise, I just drive.
– Suspension: the spherical bearings and Feal 442 shocks are butter. I haven’t even begun making adjustments here yet, just set compression and rebound to dead center of the available range and left them there while I focused on everything else.
– Brakes: The V8R/ST four wheel kit has some serious stopping power and is easy to modulate.
– Powdercoat: powdercoating has a “squish” in the coating that prevents proper torque on bolts. I lost a spindle to caliper bracket bolt on track which prompted checking every bolt on the car that was in a powdercoated surface. Several had loosened. The rest of the weekend I re-torqued bolts after every 2 sessions. Will be adding split lock washers to most of those bolts this week since the lock washer will cut through the coating.
A great thing about the temps listed above for steering, diff and transmission is this confirms what we suspected – these items are all way under-stressed in a small lightweight Miata. Zero need for diff or transmission coolers.
Joe working the pedal while I bleed brakes:
Chatting with Sean about something. Probably about how something tried to fall off the car:
It was great fun to see so many friends at Mazfest who were there for the track day portion or who just came up to check things out. Being back out on track in my own car with fellow Roadster Cup guys felt great:
Spent all of Saturday with a passenger riding along and sorting out issues, and got absolutely no clean laps without traffic but I still ended up setting the fastest time by a Mazda at Mazfest with a 1:11.x.
Quite honestly surprised by how much pace the car had out of the box with zero time spent on dialing things in. Since it was still running well I signed up for the Redline Time Attack competition coming up the next day and grabbed a hotel for the night.
Sunday: Redline Time Attack
Sunday morning first practice session in the cool air I went out with no passenger and did a 1:08.763. That is a new lap record for a Miata at this track (Auto Club Speedway Infield) by a gap of almost 3 seconds.
Time sheets after the practice session revealed that not only was it looking like I could take the win in my Limited Rear Wheel Drive class, I was actually within range of contention for the top overall time with the unlimited cars. There’s no way I could ignore that carrot dangling out in front of me so “I’m just testing things this weekend” went out the window at this point and it was game on. I did a little research around the paddock to scope out the cars that were at the top of the time sheets with me:
At the top of the sheets, this 500hp BMW M4 built for NASA ST1 competition running in Unlimited RWD:
Bulletproof Automotive’s 750hp GTR in Limited AWD:
Time Attack veteran Amir with a 660hp aluminum V8 swapped E36 M3 in Unlimited RWD:
In true Time Attack fashion, Redline has just two Time Attack sessions where it all counts. Only three laps in the session, do or die time. Cars are pre-gridded by lap time from practice so I was third in line behind just the GTR and M4.
That lap took 1st overall by a gap of just 0.08 seconds ahead of the M4.
By the second afternoon time attack session temperature had climbed a lot and some teams didn’t run because they knew they wouldn’t go faster. The GTR and M4 both went out to try to take the top spot. They both went slower. I did a 1:08.8 again, so that lap would have been even faster in the cool morning.
SO… first shakedown weekend with the car… fastest Mazda at Mazfest, 1st place Limited RWD and Top Time overall at Redline Time Attack, and a new Miata Lap Record.
We’re on the right track here. With some more track and tuning time this car is going to rip.
