The engine fired for the first time yesterday… whoohoo!
Unfortunately, while it runs very well, it also is good at spitting coolant out the exhaust, which is less than good. Big sad face.
The likely issue is that the engine overheated in the car it came from and damaged the head gaskets which will cause coolant to leak into the cylinders. This unfortunately means pulling the engine and taking the heads off. On a GT3 motor, only the heads are cooled, so hopefully I don’t need to tare it apart further than that, but I plan to do any sensible maintenance that I can while the motor is apart.
Although this is a big setback, I’m still pretty happy that I was able to get it running. All the wiring and setup was very complex and time consuming, so I’m pretty proud to have been able to accomplish it with zero prior experience. Now it’s on to the next learning-by-doing: rebuilding a GT3 motor.
Anyone wanna learn how to rebuild a Porsche GT3/Turbo engine with me?
In short: functional, not very pretty, but getting better at welding.
So now that I have my awesome new welder, I’ve been putting together little things here and there. They’re things which normally would have been a pain to have to find a way to screw together instead. I’m still working on getting the wire feed speed and voltage settings right for each task, but I can weld stuff together that doesn’t necessarily need to win a beauty contest (i.e. it won’t be visible). On the welder there’s a guide for the settings based on metal thickness, but it clearly states that it’s only a guide.
The first bigger part which I needed to do was to fabricate a mounting plate for the shifter. The shifter has a base that’s about 3″ wide and 8″ long. It somehow needs to be affixed to the top of the aluminum frame under the center console, which is 2″ wide and 4″ high. There are a few different approaches, but I went with one where the bracket is shaped like a “pi” symbol and mounts with through-bolts to the driver and passenger side of the frame (pics below will make more sense…). This of course starts with cutting metal into the three pieces I needed: Continue reading →
This weekend saw the culmination of the cooling system plumbing and thankfully not the start of my comedic career. The fan isn’t installed yet, but it’s a major step to have completed all of the coolant plumbing from radiator to engine to overflow tank – anything involving the liquid itself. It involved quite a bit of problem solving and also required completing various other parts of the build like the water pump housing replacement.
One of the weak points of many kit cars is side impact protection. This is something that’s hard for kit cars to replicate like it exists in production cars due to the vastly different construction method. This requires a brief introduction into basic car construction methods.
Most modern cars are built as a unibody where large portions of the body are actual integral and stressed parts of the chassis. This is in contrast to body-on-frame construction, where as the name suggests, there’s a frame which holds the load and the body just rest on top, unstressed. Body-on-frame is still a common construction method for trucks and buses. To compare, here’s a picture of the body of a Lamborghini Aventador and the chassis of a Toyota Tundra:
Time to update the blog. Sorry for the delays, folks. Going to do this one post at at time, so there should be a few flowing through in the next couple of days. First topic: brakes.
This isn’t a finished project yet because I haven’t mounted the pedals, but it’s done other than that. I’m holding off on the pedals until I can move the telescoping steering column (requires wiring & power), can mount the seat and can mount the pedals. All three work in unison to create a comfortable driving position, so they need to be fitted as one. Plus, I want to fit Stengelita-sized people all the way up to about 6’2″ drivers.
I’ve been able to get most of the rest of the brakes set up though. The brake lines came pre-bent, requiring just a small amount of work to achieve the proper fitment. The front brakes run through the aluminum monocoque which makes for a natural point to create the junction from hard lines to the braided lines between chassis and caliper. In the rear, things are more open, so I had to build some clips which would allow the hard brake lines to mount to the braided lines. Here’s a shot of one of those brackets (on the right):
Rear brake line clip
In the front, I created the connection between the fluid reservoirs for brakes and clutch to the master cylinders. The cylinders are mounted on the pedals inside of the monocoque, so the lines have to go through it. The lines are just a regular hose, so they’re simple to work with, but it did requireda huge drill bit and some very specific grommets to get through the monocoque, be sealed snugly and not rub under vibration. The grommets were the trickiest part in some ways. I spent an ungodly amount of time tracking down a part which costs $12 for a pack of 50. Ugh.
Brake and clutch lines through monocoque
I got the final pieces of the brake hardware, but in the rear the fitment of the braided line to the calipers wasn’t great with the parts I got. Instead, I ordered some new fittings which worked out really well. In the picture below, you can see the bracket I made on the very left, the braided line running to the right and then a shiny 90 degree fitting mounted to the caliper on the very right (the caliper is the dark thing). That piece in the kit came as a straight fitting, not 90 degrees, so the fitment was a bit wonky. 90 degrees worked out much better.
Final rear brake line mounts
In some ways this isn’t the most special thing the world, but what it did mean is that I now have a fully plumbed brake system short of the final mounting of the pedals. It’s only 15 minutes of actual work to drill and mount the pedals from here, but I want to be sure I get the fitment right before I do that.
Or just making it look cleaner by installing an undertray. I have no basis for knowing whether I’m truly helping ground effects with this addition to the car, but it does make for a cleaner look in my opinion.
Here’s whats going on. The car essentially has a flat bottom all the way from the very front of the to where the engine bay begins. This includes the front splitter, the area under the driver compartment and the area under the fuel tank which is between the driver compartment and the engine. As a side note, I had a special order done on my car to have the same 1/4″ aluminum that’s the monocoque under the driver also welded under the fuel tank. Typically this is a thinner gauge (1/8″), but I figure it’s a good safety measure at a $150 total cost to make it 1/4″ welded aluminum.
Looking further towards the back of the car, I wanted to have the flat floor “undertray” go as far as possible so I decided to add a roughly 22″ square panel in front of each rear wheel well. The reason for not doing a full side-to-side panel is that you want to leave the part under the engine open to allow for air flow around the engine.
Off I went to research how to buy custom cut aluminum and as it turns out what looks to be San Francisco’s premier metal supply shop, Bayshore Metals, is less than 5 minutes from my place. Two hours and $80 later I what I needed: custom cut 1/4″ 6061 aluminum. 6061 is colloquially “aircraft aluminum”, i.e. the stronger variety that isn’t bent as easily. It was recommended by fellow builders to save money and go with a thinner gauge here since it’s not structural, has no safety implications and since it has a greater chance to be banged around a little, replacement is easy. That’s also part of the reason I screwed it in with 3 through-bolts on each side with a layer of silicone between the frame rails and the plate to prevent vibration noise.
That was all. Pretty simple job. Now I have an even longer and cleaner car floor. And zero clue whether this is helping ground effects in any way, but it looks cool, right?
Week 2 has so far been basically consumed with cleaning the engine and also dealing with lots of logistical items. The engine came from a salvage car and they most certainly don’t clean it before they give it to you. Wishful thinking, but I now have much greater appreciation for what ~20k miles does to an engine’s cleanliness. To the right is an example of some TLC given to an intake to bring it back to more or less original form. The one on the left has about 20-30 minutes of hand polishing with a ScotchPad-like pad vs. the one as it came on the right.
Here’s a quick run-down of that project and some of the other current sub-projects.
Alright, the day has finally come and the SuperLite Coupe has safely made it into the garage. Very exciting of course and it wasn’t as tough to get it in there as it could have been. I did get pretty lucky though and I have some really great friends who I can’t thank enough.
The truck came around 8 am and after quickly looking up at the hill towards the general direction of my house, they called me and say “no way we’re gonna make it up there”. I was prepared for that to happen and due to a stroke of luck, my friend Ryan had the keys to our other friend’s Matt’s Ford F-150 Raptor who in turn had borrowed a flatbed trailer from Chris who we race Lemons with. How lucky. Unbeknownst to Matt’s slumbering self, Ryan commandeered the truck and trailer and met me at the shipper’s truck. Fortuitously, the trailer was about as flat as can be and had a very low Porsche on it the prior day, so we knew we could get a car that was sitting at best 2″ off the ground onto the trailer.
I’ve written about the IVI system for the SLC before here, but since then I’ve made a few changes, added a few things and put together a live demo of it. Before you check out the demo below, here is a quick overview of the progress I’ve made:
I bought an embedded computer with the right Intel Crown Bay chipset, but had to return it of a variety of reasons to with hardware support and functionality. Instead I will be using the Nexcom VTC 1000 system, which is the Tizen IVI reference platform. Couple of questions around the display which I need to work out before I order, but that will be the one.
I rewrote the front end from scratch to use jQuery mobile and a different gauge library. This allows various gestures and much more customizable gauges.
I bought a Tire Pressure Monitoring System (TPMS) hub that connects via USB to provide both pressure and temperature of the tires.
Check out the video below – a live demo of what I’ve put together so far. I would really appreciate any feedback you might have on current functionality, features to build, data to visualize (and how), logical organization/flow, etc. Note that things like nav and audio are part of a base system and this app is just meant for the car data. Either comment below or send me an email at tim@timtt.com. Thanks!
A fuel surge tank (a.k.a. swirl pot, reservoir) is an integral part of a modern electronic fuel injected race car. Many modern high performance cars have them as well, especially once with turbocharged engines. Its purpose is to ensure the engine has a constant and uninterrupted supply of fuel even while the car is in a corner which is pushing all the gas in your main tank to one side. When that happens, the main tank pump can’t pick any fuel up and starts pumping air, which is not good and in a worst-case scenario can blow your engine. Continue reading →
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