Slow Car Fast
LIFE OF A GT
March 7, 2010 - In order to fit the radiator, I had to remove some structure from the nose.
Of course.
I'd already cut the frame horns in half to fit the engine. There was a box that joined the remaining bits in half that was fairly nicely built with big lightening holes. However, these holes were too tempting for someone who had to tow this car at some point, so the box was rather torn up. Since I'd cut into it to fit the radiator, I decided to remove it completely. This had a fairly dramatic effect on the structural integrity of this part of the nose!
I still need these frame horns, however. That's where the bumper mounts. And I needed a way to mount the radiator as well. Now that I had all the parts in hand, I was able to figure out how to build a frame extension for the nose. First, a piece of 2x3 tube to replace that box. I'll extend that further to the sides and tie it into the suspension uprights then drop some steel down under the radiator to support it.
I'm pretty happy with this. It was one of the unanswered questions of the build, and it's good to have it figured out.
The two jackstands closest to the camera are the ones that were supporting the radiator, so you get an idea of how it sits relative to the frame.
entry 305 - tags: structure
March 7, 2010 - The structure at the front of the car is now finished.
Not fully welded - that'll happen when the engine is out - but complete. I'm really happy with this. The end result looks pretty obvious, but it took me a while to come up with it as I kept thinking "no, that's too complicated" and taking another look. This is simple, fairly light and should be decently strong. Might make a good sway bar mounting point in the future as well!
I was originally thinking of leaving the ends of the rail open (as can currently be seen on the cross bar) but realized that closing it off wouldn't just look better, it would also add some strength. So I closed 'em.
One detail you can't see on that cross bar is a couple of holes with nuts welded in the backside. Those will be alternate bumper mounting holes, since the originals are now trapped inside the cross bar.
It's quite easy to picture the location of the radiator in this shot, as it's actually in place.
entry 306 - tags: frame, radiator
March 7, 2010 - As usual, everything's tight.
A bit too tight, in fact. When I had the new frame horns and decided to install the rad to show off to Janel what I'd accomplished, I discovered that the radiator outlet was right into the kink in the horn. Argh. So I cut that one off again, chopped 5" off the back end and spliced it into the middle. You can see the ground-down welds in this shot. There still isn't a lot of room for the radiator outlet, but there's enough. That's all I ask.
On the other side of the engine, the alternator has a massive half inch of clearance. Ha, that's miles of room.
Speaking of clearance, I realized that my thought about using pusher fans and moving the rad back wouldn't work. The coolant outlet on the block would get in the way. So nix that idea then. I've decided I'm probably going to use 11" fans instead of the pair of 12" I was trying earlier, as then I can mount them side by side low on the rad. It'll mean most of the airflow will be concentrated on the bottom 2/3 of the core, but since it's a dual-pass setup it'll still hit all the coolant. This gives me more room.
entry 307 - tags: fans, packaging, frame
March 15, 2010 - The finished driveshaft.
Okay, not a terribly exciting picture. But I'm pretty happy with how easy and inexpensive this was.
entry 308 - tags: driveshaft
March 15, 2010 - I dragged the plasma cutter home to chop out the stock frame rails.
It was a very quick and easy job as I'd hoped. I had my welding helmet set too dark so I couldn't see where I was cutting, but it only took a little bit of cleanup afterwards to make everything work well.
Plasma cutters rock.
entry 309 - tags: frame
March 15, 2010 - The frame rail pass-through tacked into place!
Compare the wall thickness of my new pipe to the picture of the removed part. I suspect the car is now stronger. And more importantly, the exhaust construction may now commence.
entry 310 - tags: frame
March 15, 2010 - First step on the exhaust.
This is the section that goes through the new pass-through. Clearances are tight (no, really) but it works. The wide section at the bottom is the front half. I'll build the back section first, then start working on the header design. I'm thinking there will be rapid visible progress with this part, which is always satisfying.
entry 311 - tags: exhaust
March 16, 2010 - With the X located, I figured I needed to identify the other end.
So I hung the first muffler under the car. It took a bit of fiddling around to get the location sorted, but a couple of hangers and some careful placement and it was in place.
entry 312 - tags: exhaust, muffler
March 16, 2010 - I needed a way to attach hangers to the bottom of the car.
The flat floor is a bit tough to weld to, so I welded the hanger to a small plate. The hanger itself is a piece of 1/2" bar bent to shape. I tried both a small kink and a bead around the end to keep the rubber from sliding off. Both seem to work pretty well.
entry 313 - tags: exhaust
March 16, 2010 - Once the muffler was in place, I was able to figure out the routing of the rest of the piping.
It's fairly straightforward. The only problem is the trailing arm bracket on the rear axle housing. It's nicely in line with the outlet on the muffler. The muffler is also higher than the axle at full droop.
A 45 degree piece out of the muffler, rotated about 45 degrees from vertical and mated to another 45 degree piece wiggled the pipe nicely around the obstacles. Nice and simple. I used jack stands to support the exhaust under the car - lots of jack stands. Once I figured out how, it went pretty quickly.
entry 314 - tags: exhaust
March 16, 2010 - With one side of the exhaust done, now I have to do it all again - and make it symmetrical.
Uhoh. The first step is to position the muffler in exactly the same place. It's the most visible part of the system so I have to get this right. I won't weld hangers on this one until it's hooked up to everything else, to make sure I don't accidentally put a bit of variation in the system.
entry 315 - tags: exhaust, muffler
March 24, 2010 - I can't do any work on the car for the next little while that involves flying metal, which is surprisingly limiting at this point of the build.
So instead, I took advantage of a nice sunny day to cast a spare intake manifold in aluminum. At least, that's what I'm hoping the result looks like. I figured the engine looks a little too plastic for the old car, so I shot my spare intake manifold with paint.
After some test sprays I decided a light hammered finish looked the most like metal. I think it'll be pretty good. I have to find some way to hide the coils that look appropriate. The proximity of the brake booster makes this a challenge. Maybe if I mount them remotely...
entry 316 - tags: intake
May 3, 2010 - Work has finally resumed.
I took some time off for lasik eye surgery (highly recommended), some engine work on the Targa Miata, a trip to Laguna Seca with three days at the track, etc, etc. But it's time to dig back into things.
I didn't get a lot of work done tonight - I repositioned the muffler in the perfect location again, then figured out how to snake the exhaust pipes past the Panhard bar mount on the axle at full droop and cut a couple of pipes - but it was a start. Expect more progress! Will the car run by the end of the month? It's possible...
entry 317 - tags: exhaust
May 10, 2010 - This was a fun little section to do on the exhaust.
The pipe has to twist around the Panhard bar mount on the axle and wiggle up to the muffler. And I had to do this while putting the muffler in the perfect place. The end result did have me welding up a bit of a gap - you can see the ugly resulting weld - but it'll do the job! It's just tacked together now, I'll clean everything up later.
Next step: hangers for this muffler. Then for the X-pipe. Then I do the headers.
Janel has a new job that keeps her traveling quite a bit during the week. This has shifted the timeframes I have available to work on the car - evenings are much easier to do, but weekends are pretty much out. I'm figuring it out now, so work should continue apace.
entry 318 - tags: muffler, exhaust
May 12, 2010 - Exhaust work continues.
I now have the system complete up to the entrance to the x-pipe. Now I have to figure out the headers. My collectors have a 3" outlet and the rest of my exhaust system is 2.5", so I plan to use these ball flanges to neck things down while also providing a good spot to disassemble the exhaust. The problem is that the whole assembly is pretty long as you can see. I've cut down most of the parts and taken a significant amount of length out since this photo was taken. You can see the conical insert from Dynatech that should drop the sound level by around 2-3 dB.
I'd prefer to be using a slip-on collector as they're a lot easier to deal with than this minimalist one - but unfortunately, I don't have any. So I'll have to cope with it.
entry 319 - tags: exhaust, collector
May 12, 2010 - I'm also looking at laying out the fuel system and the packaging involved.
Not a big problem, really - more on that later. But first, I need a bracket for my fuel pump.
The pump is a Pierburg unit that should have no trouble with the big engine - I hope. It's a round piece with no mounting points. So, with the help of a short piece of exhaust tubing cut in half, I made this little doodad. I'll weld it on to the car and let it cradle the pump.
entry 320 - tags: fuel pump
May 12, 2010 - The pump is secured to the bracket with a clamp.
That's why the round bars connecting the two "hoops" for the pump. Sharp eyes will notice that the previous photo only had one bar. The reason is that the pump was able to rock too much with the clamp in place. Adding the second took care of that problem.
This is what it's like to build this car. Solving one small problem after another. It's fun. Now, where to put it?
entry 321 - tags: fuel pump
May 16, 2010 - Time for the headers!
I've built a couple of headers before - most memorably, the one for the Targa Miata - so I have a fairly good idea what I'm doing. In this case, packaging is my biggest problem. I'd love to do a nice equal length, long-tube header for maximum power but I simply don't have the room for it. So I'm going to settle for simply fitting everything in place. I figure it'll be lower restriction than the stock stuff (hopefully) and it's certainly not tuned length.
The key to making this relatively easy is the Ice Engine Works "header lego". It's a box full of little blocks that snap together. They come in straight and in 2", 3" and 4" radius bends. Each block is 1" of tube, which really helps when it comes time to make primaries of a particular length. In this case, I'm just trying to get things to fit. There's a fairly massive length difference between the front and the back cylinders.
The initial mock-up was done on the car and transferred to the work bench.
entry 322 - tags: header, exhaust
May 16, 2010 - With a wave of the magic welder, the plastic mock-up has been transformed into metal!
Well, the magic welder, magic chop saw and magic sawzall. I tweaked the design a little bit to make it work better and to take into account the various diameter bends I actually had on hand. It worked out well, there's a bit of art to the way the front two tubes work together and it all comes together nicely. These are 1.75" tubes, by the way.
entry 323 - tags: exhaust, header
May 16, 2010 - All four primaries come together nicely.
The next step is to fit the collector on. Since my collector is a cheap bent piece of pipe instead of a nice slip-on, I'll have to weld up the hole in the center as well as make sure they seal well in the deep gaps between the tubes.
This is the driver's side, which has the steering column and the brake booster to deal with. When I think about it, I didn't really have to do anything to cope with those parts, so I could probably make the passenger's side as a mirror image of this one. I don't know if I have enough 2" radius bends to make that happen, but it might be worth trying simply to avoid problem-solving a second time.
entry 324 - tags: exhaust, header