It’s been an absolutely crazy couple of weeks. The challenges and minor setbacks have been too numerous to even think about, we’ve just been powering through them. The exact dates are a blur but below is the last few days’ worth of progress.
We have been stressing over this car, and Rodney has been worried. The small delays have really been adding up. Over the weekend the last of the wiring was finally completed. Even though it’s a relatively simple car as far as AWD performance cars go, there is still a fair bit of complexity to the systems.
This ‘only’ left front and rear wings and all of the paddle shifter installation. The latter is complicated by the fact that we are using different actuators for the shifter and throttle blipper than we’ve used before. Many other parts are different as well.
The wings took a fair bit of work (the skins were first parts from a new vendor and we had to experiment with layups and such). Now, on Friday, they are finally done.
The shifter has been more difficult. Figuring out, designing and machining a mount for the shift actuator wasn’t too bad. I have all the parts in CAD and once done, everything fit perfectly on the first try.
I did have to make a custom ‘rodend’ which has an M10-1.25 internal thread to mount on the cylinder, and an M6 spherical bearing to connect to the geabox. Some CAD work, a small piece of aluminum, about half an hour of actual machining and all is good.
The throttle blipper proved to be more difficult. When I was finally ready to tackle that part, it was almost midnight on Wednesday. Keeping in mind that we leave for the race at 5AM on Saturday, I was ready for an all-nighter and that’s exactly what it took. Haven’t done one of those in some time and don’t look forward to ever doing another. The main challenge with the blipper is that the throttle body assembly is not in CAD, it has odd shapes, limited access space, and taking anything apart is not an option at this point. Whatever I do has to be installed on the car as-is.
The part to hold the actual blip actuator was not too bad. Just measured the spacing, eyeballed where it has to live relative to things, some CAD, some machining, and it’s in. Figuring out a way for it to actually activate the throttle was much harder. It took many iterations with guessing at the shape of the throttle cable pulley (it is NOT a circle), the location of the couple holes that I could possibly put a bolt through, making a drawing, printing it on a piece of paper, test fitting, then adjusting and repeating.
With paper being really fragile it only got me so far and I finally had to make an aluminum prototype then repeatedly modify that. At this point it’s 4AM and I have to be really careful not to make mistakes that could crash the machine and break things. All goes well and by 5 I am ready to make the final part. By 6 it’s all on the car. It’s a weird shaped part but it fits and it works. All that remains for the shifter now is calibration and testing of the control system.
This takes a while since the car initially doesn’t start. I eventually trace it to a wire I left out of the harness, I add it, the engine fires up. But now I realize I can’t talk to the shifter control unit. It’s a serial connection and neither of the old USB-serial adapters we have seem to work with Windows 10 which is on all the computers. By now Chris comes in and I ask him to find a store that’s open and has the cable. He does, and I can now talk to the GCU. It’s 11am. The rest of the guys are in and ready to finish up the car. Jonathan has already left for ORP with the D2 but I’m still hopeful we can take the D1 out today as well.
The finish work takes a couple more hours. We service this car on its side, just like the D4 and regular D1 models. Convenient and effective.
At 2PM all is ready. Unfortunately it’s a 2.5hour drive to the track and there won’t be much time left to test, then a 2.5hour drive back. I have other demands on my time at this point, so I schedule a Friday morning test at Pats Acres kart track nearby. Since we are leaving Saturday morning, that doesn’t allow any time to fix problems that may be discovered. And, we hear from Jonathan that there were issues in D2 testing so tomorrow will be spent on that. And packing. I go home and get some sleep while the rest of the crew goes over the car again and loads it in the trailer for me.
This morning it’s raining at the house but fortunately dry at the track. I take the car out with Chris taking some pictures and video with his phone.
This thing is a BLAST! Even in my dizzy sleep-deprived state, on a super-tight kart track, I absolutely love it.
This is a huge relief. Everything seems to be working. Only adjustment that I can tell it needs is a tweak to throttle blipper intensity, a simple thing to do. Unfortunately we didn’t bring tools so I’ll have to leave it till we’re back at the shop. Still lots of minor things to do but at least it runs. Rodney is relieved to hear the news, and I am relieved to deliver it.
When we were testing on the Mountain, I talked with the officials and they approved removing the vertical firewall behind the driver’s head, IF we extend it horizontally by making a fireproof engine cover. Jonathan flew in for two days of testing but we are not ready on the first day, so he got handed the task of designing and fabricating the cover. I briefly described what I had in mind, handed him some cardboard for prototyping, then got back to working on the D1. The coolant overflow tank had to be relocated first. With that done, the fabrication could begin.
Tristan and Jay assisted with some of the fabrication but Jonathan did the bulk of it himself.
Now we’ll have much better functionality from the wing, and less drag too. All good things. We made some other tweaks and Thursday Jonathan took the car to ORP for testing. Jake, one of our new interns, met him there to do crew duty. About mid-day I get a call – the wing broke. The new aero is much more effective without the barn door firewall, so the loads on the wing are much higher. This was the first prototype with foam ribs. We now use machined aluminum ribs (see D1 wing pictures above). So we’ll have to make a new wing since I won’t know if this one can be fixed until I see it tonight. Further complicating things is that I’m going on zero sleep at this point and dealing with emergencies is difficult. A frantic call goes out to Mike at M&W Fiberglass. It’s late in the day but they might be able to infuse a set of skins and have them ready tomorrow. Two hours later it’s confirmed. Fortunately we have a set of wing ribs onhand and I can make the machined mounts tomorrow.
So that brings us to this morning when the wing skins are picked up, trimmed, and the wing is bonded. Some adjustments are necessary to the car and we need to check all the suspension settings. In the meantime Tristan is making vinyl stickers and Morgan is getting them ready to apply.
Christopher brings by his regular D2 for some service and it’s quite a contrast between old bodywork and new. Looks like a totally different car, even though it’s just some fiberglass. Christopher will be upgrading to the new body when it’s fully sorted.
In the meantime it looks like another late night and an early morning to follow, but barring any last-minute issues we should be on the road shortly after 5AM. Wish us luck. Of the good kind.