Stainless can be tough to bend; the new tank uses 18 gauge material which is 0.045″ thick, and at nearly four feet wide it’s just too hard to do properly in a garage environment.
For the first time ever I searched around for a local sheet metal shop that could help out, but initially it wasn’t promising. Most small shops have aspirations of grandeur, looking for small production runs. People like me are a waste of their time – the dreaded one-off project that takes as much time as it takes their CNC machine to make 20 of something. Though I did my part, having cut, drilled, and marked the stainless, it wasn’t anything they wanted to do.
Finally, one shop took pity on me and gave me the number of another shop, “It’s a small place, basically a one-man show that does all sorts of one-off stuff for off-road vehicles.” That sounded like “my people” and sure enough the guy and a couple helpers were working on all sorts of interesting things, all crammed into a small shop. They had an autocross car in there, an MG Midget with a turbocharged 3-rotor Mazda engine on race slicks, a national championship car. Anyhow, I explained what I wanted and they said no problem. My sheet was sheared and bent within a day at a price that I was happy to pay.
He knew I was making a fuel tank and asked how I was going to make the flange around the hatch. I said it wouldn’t be easy but that I’d cut, drill, and file an 0.125″ plate to fit. He said I really needed to talk to another little shop near by with a water jet machine. Like them, they do all sorts of interesting stuff, mostly inlaid ceramic patterns for expensive home flooring and wall sculptures. However, it’s a water jet machine – it can cut nearly anything. They said, “give us a sketch of what you want and we’ll make it next week.” Well, okay, we’ll see how that goes; they’ll be handed a drawing Monday.
This is a new experience for me – actually getting help making stuff. As long as it’s for items that I can’t easily do myself, it’s a luxury that’s hard to pass up.
Yesterday a bolt-on engine bay floor was fabricated. The advantage of accessing the engine bay from below is so great that the riveted panel had to go. Since it was already off as part of installing the dry sump, and because it had been damaged by the suspension bottoming, this was the time to do it. Even though the shocks and springs have been stiffened, skid plates will be added so that the screw heads don’t get removed in a shower of sparks. The plates will get added soon enough but I wanted to get on with today’s project.
Today the “fuel tank V2.0” project continued. Most of the bits are already here, fuel doors, pump, stainless sheet. The sheet was cut, trimmed, and drilled, but the trick’s going to be bending it. What I would “like” is only one weld seam, which basically means finding a place that can make four bends in a sheet, forming a box. Hopefully there’s some place with a large brake that’s narrow enough that it can reach in and make the last bend. The thinking is that the metal is springy enough that even though it’s attempting to close on itself, it’ll allow the brake to exit. If this proves impossible, then the sheet will be cut somewhere and I’ll end up with two long weld seams.
The reason I’m trying to avoid any more welding than possible is that stainless heat distorts something terrible – the less welding the better. If two seams are necessary (and even if there’s only one), I’ll be a lot more careful this time around, making short welds and cooling the assembly in between welding sessions.
Anyhow, some local sheet metal shops are being contacted to see what they can do and what it’ll cost me…
First event of 2015 was again at Fontana Autoclub Speedway, where there were about 100 other drivers including my brother with his LS3-powered Stalker and my buddy Lee and his Mallock. Both were out for their first track tests (my brother’s first track event since the engine transplant, and Lee’s first track drive with his car). Lee signed up for the race group while I and Scott signed up for the “pass anywhere” group. To be honest, I was a little uncomfortable doing so, having never run in this type of group, not so much for me and my car, but others. If you’ve ever driven on-track, you know about the “kill mode”, the I-must-catch-that-car-in-front-of-me switch in you brain. That’s fine when championship points are on the line, or million dollar sponsorships, but there’s none of that here. Nothing, not even $5 plastic trophies. So while that should mean that no one’s going to dive-bomb you into a turn, things can get clouded in the haze of war. Then there’s the not-so-little detail of the likely consequences should a sedan bump into my essentially open-wheel car, which would probably end badly for me more so than them. That said, both my brother and I are tired of how obviously slower drivers don’t always point you by – a requirement for any passing in typical track day events. You’re all over them, making it very clear that you have the faster car, yet they either don’t see you (a problem in itself) or they’ve just decided they deserve to be ahead of you. Worries aside, the day went fine, Midlana did well, nothing broke or fell off, though things could have gone a little better. The issues:
Either I don’t know how to operate the GoPro 4 or it has some quirks – probably both – so I didn’t record nearly as much as expected. Sometimes it wasn’t clear when it was recording and when it wasn’t. Some of the “scrap” video snippets found during editing showed me puzzling over the camera, saying “I can’t tell if it’s recording” yet obviously it was. Not seeing any activity (no blinking LED or LCD indications) I kept messing with it, and after finally seeing an indication, I headed out since I’d configured it for “one-button record”, which turns it on and starts recording immediately. Push the button again and it stops and powers down. It worked during testing but later I found that the first session was completely missed, me thinking that it was recording when it was not.
I got it running for the second session, but during editing I found two videos from the session. Apparently hitting a small bump on-track caused it to start a new clip.
For the third session, the GoPro appeared dead as if its battery was done. However, when I got home and downloaded the videos, the camera reported that it still had 75% battery life… grrr.
Other issues. The way the track event was run confused me. I heard the call “10 minutes to pre-grid”, got my gear on, headed over and got in a very slow line where a guy was asking each driver if they had a transponder (so the cars could be grided according to expected time). By the time I got in position, it slowly dawned on me that the line was for the next run group and that I’d wasted half of my track time. It happened again for the next group but this time I thought “Fine, I’ll just run with these guys and get a full session.” That worked well, passing everyone left and right :).
The bright spot of the day was that the dry sump worked great. The last time here, oil temperature got as high as 250 degrees F. Due to that temperature and the resulting thin viscosity, oil pressure dropped to as low as 45 lbs at-speed. This time oil pressure stayed right around 60 psi and better yet, oil temperature stayed much lower, 205 degrees maximum. There was a small leak in one oil fitting but it wasn’t a big deal, apparently it’s a defective AN-10 coupler since tightening it didn’t stop the dripping.
The water/meth worked fine, until it didn’t. The controller has adjustable thresholds for both too-much and too-little flow. For some reason it kept tripping on “too much flow”, which disables the system. Unfortunately I forgot the cable necessary to reconfigure it, so boost had to be backed off to keep the engine safe. Sigh, oh well, another day. In my mind though, it’s just another reason for going to a flex-fuel ECU, closed-loop boost control, and no water/methanol.
My brother’s LS-powered Stalker was very fast, hitting 160 mph down the front straight, though of course I claimed that his speedometer was way off. He was fastest in our group, though when he tried backing his car out of the garage for the third session, it wouldn’t go into gear. Something in his clutch circuit had failed, either the master cylinder, slave, or clutch itself. He’s really hoping it’s the master cylinder because getting at the slave is a real bitch, an internal unit that’s built into the throw-out bearing and means pulling the engine and transmission to gain access.
Lee got one session in and seemed fairly happy with the Mallock, though it may have worked too well. The rear section of floor panel pulled away from the chassis(!) due to generating more downforce that expected, and they spent the rest of the day working on that. I asked why they were working on it there instead of calling it a day, since it was supposed to rain on Sunday. Lee said “What!?”: he didn’t see the same forecast that I had checked. As I type this on Sunday it does say it’s raining in Fontana so I don’t know if they’re still up there or not.
Speaking of rain, it started raining at the start of the third session, not a lot, but enough to make me wonder if I really wanted to take the car out – answer: sure. If you haven’t tried it, driving on a wet or damp track is an excellent way to find out at relatively low speed how it handles at much higher speed. It was very educational balancing it through the turns, front/back/front/back constantly slipping slightly. Of course I was unwilling to try that in Turn 2, the 130 mph left hander with its very solid concrete wall along the top right edge. Having the unexpected rain reminded me that I need a bottle of Rain-X to be in the box along with the other supplies…
My brother bought a “Stig” key chain. To keep it from rattling around and getting in the way, he stuck it above his ignition key as shown below, and headed out on-track. About half way through the session his ignition cut off unexpected. Apparently the cornering load was enough to cause “Stig” to switch off his ignition – we though that was pretty funny. (Either that or an electrical issue that’ll become more apparent with time…) Here’s my video and my brother’s.
In the pictures below, the notables are the Mercedes SLS, the Tesla(!), the 999 custom racer, and the very diverse types of cars showing up is what keeps me coming back and enjoying track day events so much. There wasn’t time to get pictures of all of them.