07/25/13 Yesterday we took a day off from the regular routine and went testing at ORP. Jonathan Frost came up from California and we brought out the D1, D2 and D4. The goal was to get some benchmarks for the various cars and gather additional data that we can use in development. As I've mentioned before since the cars are faster than I am it is difficult to get good data with me as the test pilot. Fortunately Jonathan is a very capable and professional driver and is a great resource to help us move forward. The 100F temperatures added extra challenge to the mix, so it was bound to be a good test day.
One thing we wanted to see is how some changes to the D4 aero setup correlate with results predicted by SolidWorks CFD. With Jonathan having driven the car in several of its previous configurations we were able to just set it up the new way from the start and get a result. Encouragingly, the real world behavior is as predicted. This is especially good since the prediction was counter-intuitive: raising the ride height by a whole inch was predicted to actually increase downforce. And it does. Jonathan was able to get down to 1:43 flat, clockwise, in his first time at this very technical track.
We also tested the D1 and while Jonathan was just getting started with it (running 1:41) we discovered a maintenance issue that would have to be done at the shop so we parked it for the rest of the day. Once everything is sorted we think getting well below 1:35 should not be an issue. Getting aggressive test miles on the car is very important. It is currently for sale ($125K which is a bargain for what it is) and we need to make sure everything is solid before it finds a new owner. Since I can't push it hard enough to really test all the systems it's great to have a driver like Jonathan at our disposal.
Pete brought his D2 and while the focus was primarily on the other two cars, it got some good track time as well, this being its 9th event since it first turned a wheel in May. Here's a video of Jonathan taking some shakedown laps. He mostly ran in the 1:47s with a best in the 1:45 range which is the fastest the car has gone here so far.
Gratifyingly, all three cars held up to hard use in 100F ambient and much was learned as always.
All that was yesterday. Today it's back at the shop for more progress on all the projects. The bodywork is coming along. Matthew and Robert have been working on the radiator ducts which are now nearing their final shape. The tweaks are getting more subtle and less obvious now. Yes, the round taillights are gone and replacements are on their way. I'll post a picture of those when they get here.
Some may recall the evolution of the D4 design, which all took place in the computer. The D2 is evolving in the flesh but the steps are not all that different. It's just what it takes.
More on the other projects/cars soon.
07/30/13 This is a bit of a milestone - the bodywork is now sitting on suspension and wheels. It's the best way to visualize what the actual car will look like. No need to squint and use imagination for rideheight and perspective. One immediate difference from the staged mockups before is that the car looks a lot more compact. I like it.
It was suggested that the car might look better with exposed rollbar tubes across the top instead of the cover panel, so I tried that. The piece needs to be removable anyway so the customer can decide which way to go for his/her car. I haven't made up my mind either way yet. Need to tweak the shape/details of the cover also.
Headlights and turn/brake signals are still to come, as are fenders. We're in the final stretch though.
08/04/13 One thing I've not been able to find is a compact, reasonably priced set of pedals that would work in all of our cars. The main challenge is that there isn't much (any!) room ahead of the front bulkead to house master cylinders as in a conventional floor-mounted setup. And on some cars (D1/D4) there isn't room vertically to do top-pivoted pedals. So on the D4 which is the tightest package I ended up doing our own with master cylinders mounted under the driver's heels, using Wilwood parts. Yes I know Tilton makes a very nice set that is similar in layout but it was over $3K the last time I checked, if you include the master cylinders.
This design actually works pretty well and that has been our standard D4 pedal set from the start. Adapting it to the D1 and D2 has been held back by some complications so we've just been using an off-the-shelf Tilton set with forward facing masters on those cars, since they have more footwell room. This is also not ideal since it limits adjustment range and has already been an issue for taller drivers. So I wanted to further refine the custom design, make it even more compact and adaptable to electronic throttles such as on the D2. The concept has been done for a while but now I've finally finished the detail design. It only adds 1.75" under the driver's heels and is already accommodated in all our chassis. And, like the D2 shift linkage, the pedals use roller bearings in all the pivots for smoothness and precision.
The D2 configuration is shown above, with the GM electronic thorttle sensor mounted and it will give us a full 4" of pedal adjustment range. Cable hookups can be accommodated by simply using a different bracket on the end of the assembly. The Stiletto will use this design as well. The pedal set and its derivatives will be available for purchase separately once it's all done.
The last few weeks have been heavy on the bodywork, which still continues, but in the next week or so I'm going to do a bunch of machining as well.
08/14/13 It's been 10 days since the last post and a lot has been done in that time. Today is an example - we were out at ORP again testing Pete's car. The primary focus today was to continue testing the dash that Pete and Josh are developing, derived from Pete's CMS Lap Timer. The progress is very good and I'm happy to report that it's very readable in bright sunlight with sunglasses on. Pretty much all the functions are working well now, just some minor tweaks remain.
All the features of the CMS Lap Timer will be included, complete with at-the-track video with data overlay between sessions, detailed data analysis, etc.
Another thing we're testing is a temporary windshield. One concern with a flat glass is reflections so we installed a coated lexan piece to simulate the production glass. Fortunately I seem to have gotten the angles right because it completely disappears and is not an issue at all. The buffeting is greatly reduced. We drove around the track at street speeds up to 70 mph with no helmets and were able to carry on a conversation (not all testing we do is going all-out ;). The windshield also seems to contribute to high speed stability - the car is now very tolerant of a stiff crosswind cresting a hill at 110+mph, something that was a bit uneasy without.
I even managed to have some fun and drove the D2 a few sessions. Normally I'm too busy with logistics, test planning and other duties to allow myself the luxury. But, I need to have first-hand seat time in the car too so that's what I did today (thanks Pete for insisting on it ;). Really rusty at first, then more relaxed and finally able to get into the groove and play. It is a VERY fun machine and with all the minor tweaks we've been making, like spring rate changes, it just keeps getting better. I'm told the D4 is much improved now too. I should try it sometime. LOL.
Other items back at the shop, in no particular order - G96 mounts and shifter for Adam's car, showroom all filled with company colors, testing potential LED turn signals and bodywork nearing its final shape,
More to come, of course.
08/16/13 One more item checked off - pretty much figured out the windsiheld wiper. Complete with variable speed intermittent, two preset speeds and a washer integrated in the arm.
A lot more sanding this weekend (I think 16 gallons of bondo so far?), Then the bodywork is off for final priming/polishing and we're on to other things - not that the other projects ever stopped, just sometimes progress is more visible/tangible on one versus the others.
08/20/13 Big milestone - we're done with our part on the main bodywork and it has been handed off for finish surfacing and mold prep. In preparation for it being picked up we rolled the plug outside. Of course being able to see it from various angles outside the confines of the composites room led to a few last-minute tweaks. Jay and Tristan had to do those, I was feeling pretty spent. If I never do another bit of bodywork it'll be too soon. And I may not have to, due to a new piece of equipment that just showed up, but more on that separately. In the meantime this is what it looks like.
Yes, fenders and a few miscellaneous bits are still to come but the main parts are out of our hands now. It's a huge relief but of course so much more still left to do. And there are other designs in the pipe too.
Separately but related, we now have a source for a sequential gearbox that is made by a major manufacturer and is fairly reasonably priced ($13K-ish). A D2 with one of those and an LS3 would run about $70K for manual shift or $75K for fully electronic paddle shift version. Considering how quickly the car goes through gears I really think a sequential is going to be a great match for it. Orders placed now should see delivery around January timeframe....
08/25/13 Now that the bodywork (well, the main part of it) is out of our hands more progress can be made on other bits. Pedals are the next major item. Adam fired up his engine in the car a couple days ago but he and Alex both need pedals before the cars can be driven. The other two D2s are running with Tilton setups which are OK but are limited in adjustability within the packaging constraints of our cars. So now it's time to get the production bits done. It's always fun to turn a rectangular block of billet into a useful part.
Of course the art component of CNC machining is figuring out the toolpaths, which tools to use and how the part is going to be accurately fixtured in various orientations. It's still very far from 'automated' and I do enjoy the challenge.
We're getting ever closer to delivering the production spec cars and everything we're learning from the development cycle is being incorporated (Pete's car now has 14 track events on it and many demo rides and drives, like this one). The next batch of orders is coming together. As soon as we have 5 we'll pull the trigger on the frames. The reason for the number is that it's currently the best compromise between using the available space/manpower in the shop and building things in quantity for efficiency.
08/30/13 Test-fit a full pedal set in the D2. It works great with track shoes but when I tried it with my wide street shoes it was a little tight. So I'm redoing the base plate somewhat to get an extra 5/8" spacing, since this is a streetable design.
Speaking of streetable, congratulations to John on getting his D2 road legal and licensed in Illinois. He did what he had to do with temporary lights and windshield... gives me additional motivation to get the production bits finished and delivered to him! Gotta turn that 'ugly duckling' into something more presentable :)
In other news, now that the messy work of building the D2 bodwork plug is done, we cleaned up the composites room and made space for a new piece of equipment - a CNC router for cutting foam patterns. Now, future composite parts will be less of a manual process. The router is actually not ours. It is owned by a friend who wanted to have the capability for making his own parts for his formula car but didn't want to set up or run the machine. We want to run it but didn't necessarily want to buy one. Works out perfectly.
We're waiting for the dust collection system to arrive and are building a steel stand for it. Will still be a few days before we have it set up and running but it'll be a cool capability to have inhouse.
And yes, that's Stiletto bodywork in the back - we're redoing the windshield with what we think will be a much better (and better looking) approach.
09/06/13 The first set of pedals is done (and the second will be done Monday). It took us a while to figure out how to machine all the various pieces and we had to do some experiments with fixturing and tooling. As always learned quite a bit in the process. This should work, but testing will tell.
The unit is pretty neat, only needing 1.5" below driver's heels and giving us a full 4" of adjustment range in the D2. A single remote reservoir will feed the 'manifold'.
Other items are progressing as well. We're now starting to design and build wiring harnesses and to facilitate that Tristan made a dedicated wiring cart.
This is going to be a whole other process and learning curve (already has been). Fun stuff. Never ceases to amaze me just how much goes into making a car and how much more goes into reliably and repeatably making several of them.
09/12/13 Yesterday was a significant day, out at ORP again. Adam drove his D2 for the first time (Alex is waiting for the bodywork before coming up to drive his, but it's drivable also). It was great to see two D2s on the track at the same time! Looking forward to seeing many more. To that end, a prospective customer who flew in for the event was so impressed that he ordered a D2 for himself.
The new pedals in Adam's car worked very well so another success there. Pete will get a set installed shortly as well, in place of the temporary Tilton setup he's been running.
This was the 17th track event for Pete's car which continued to generate great data as a development vehicle. As a result of all the testing I'm making some changes to suspension parts to improve durability under heavy loads and of course all our early customers will get their cars updated with the latest items as part of the lead customer program.
The dash development is progressing as well. It now has separate street and track modes, a variety of display options and lots of analysis and connectivity features. For example this morning it emailed Pete all his run data via our shop's wifi connection and then later in the day we updated the software with a new revision that he created back home in Seattle. Yes the black/white can be inverted, units can be changed on each channel individually and there is a variety of programmable alerts.
In the top window of the analysis display, the width of the line indicates lateral g and color indicates longitudinal g so you can easily see what the car is doing at a given spot on the track. Individual channel plots as well as an overall track map are in separate windows below. Of course the screen can be reorganized as needed.
All the features are operated via the touch screen interface (the steering wheel is removable to make it easier and the dash is too, if you prefer to tinker with it while not sitting in the car).
Anyone who has read my blogs on the Mini, Elise and other cars I've tracked knows that I consider datalogging and analysis to be a vital learning and driver development tool. This is why we're integrating all this into the car as standard and are taking it further by making analysis (with full video overlay) available right there in the pits, between runs. No need to upload to a PC, run software and mess with video syncing and integration. Of course you can stil do all that, too, if that's the preference, but the goal is to let the customer just focus on getting the most out of the car and not have to mess with gadgets. And yes, when finished the dash will become standard on D1, D4 and future offerings as well.
Really pleased with how the car is turning out. This is getting to be more fun every day :)