HU41 moves under its own power for first time since I acquired it from Derek Harling 4 years ago! It has been 6 years since it was on track.
Some of you may recall my many posts as I went thru the car and sorted things that I wanted to improve upon over the last 4 years. I would have had it out much sooner but between COVID and moving across states a couple years ago, and still waiting for a garage build to start at the new house, I was delayed or full of excuses why I couldn't get more done sooner.
But alas, the opportunity to head to Wisconsin for perfect weather and a great track day format (open track all day, no assigned sessions, high caliber drivers) put some emphasis on being ready this past week to get it running again.
Here is some short video:
https://youtu.be/TamScYws5LM
Here's the breakdown of the day:
Started the car up at the trailer. Couldn't get it to free rev past 5500rpm when slowly applying throttle. I didn't recall this behavior during any of the times I had warmed it up in the garage over the last few years, but not sure I ever really tried to get rpm's that high either. Motor didn't sound weird or anything, it just wouldn't rev higher under light to medium throttle. Just acted like it was hitting a wall, something amiss with air/fuel ratio it seemed. Or a very soft rev limiter in play, that I am pretty sure does not exist in the ECU. The only rev limiter I know of is programmed to 7200rpm. If I very quickly stabbed the throttle I could get the rpm's to go higher but couldn't hold them there.
So I decided to try a single lap and see how it behaved. That's in the video link above. Motor was incredibly strong and really wanted to run. No apparent issues and would rev past 5500 under load it seemed.
I brought it back to the trailer and put in 20 gallons of fuel, intent on running 10-15 laps before lunch. This time out, the motor shutdown going into turn 5. I tried to restart it while coasting in 4th gear but it would not fire back up. It coasted in gear without any apparent issues. I went thru the run-off area and then got towed back to my trailer. It started right back up there while on the jump battery and sounded fine. But now it was lunch break.
After lunch, I tried again, but was a bit too anxious and didn't fully warm the car up before heading out. Temps were probably 140F or so.. I have alarm triggers for "too cold" which started going off as soon as I went over the mph threshold for the alarm. I drove slowly around at 60-75mph and pulled into the pits, planning to let it idle a bit longer and ensure the thermostat was open before going back out. As soon as I stopped, smoke was evident and it smelled like oil. I quickly drove back to the trailer and the oil pressure warning came on 100' from parking it!
It seems the LH Cosworth Oil Pump is leaking, badly. So 2.5 laps / 10 miles total time on track this week.
Haven't downloaded data yet, I will this weekend and report what else I find. And I'll start removing things to further diagnose. Perhaps a line came loose. Perhaps o-rings have gone bad. It never leaked in the garage anytime I warmed it up past 200 degrees every 6 months or so. So we'll see.
Hope you enjoy the video, albeit short! I'm miles ahead (literally) of where I was with the car a week ago, so all is not lost. Confident I'll get this thing sorted soon enough and have another attempt at it. It's been 6 years since I drove my last formula car (Pro Formula Mazda) and I've been endurance racing a Corvette in the interim so I have a lot to do to reset my brain! Pretty much even forgot how to shift a dog-ring box! I also think I need taller gears as this one with rev-limit 5th gear @ 156mph. It was immediately apparent that gearing is too short for this much motor!
Cheers,
mikey