The MR2, like most cars, has some custom rubber intake plumbing running from the air filter and air flow meter to the intake. My MR2, like most 30 year old cars, has an intake pipe that's full of cracks and splits. I've helped it along with some duct tape patches, but they don't last long and living down a gravel road, I'd rather not have leaks for dust to get into the engine through.
I searched a forum to see how people were replacing them and discovered a post from myself 4 years ago asking the same question. 4 years ago, the answer was "call up a Toyota dealership and fork over $100 for a replacement." 4 years later, and every dealership I checked didn't stock the part anymore...
Time to figure out an alternative. Ebay is full of folks selling turbo intake parts...maybe I can do something with that. I ended up picking up a couple of 45 degree elbows and a 3" piece of 2.5" diameter aluminum tubing with the idea that I'd figure out what to do with it once I had all the parts in hand. The tricky part is that there's a vacuum hose that comes off the intake -- you can see the hole for it to the right of my thumb in the picture above. That had cracked about 3/4ths of the way around and was really not easy to patch.
I cut a couple of elbows down to size and put them on the end of the aluminum pipe...not too bad!
I put it in the engine bay and kind of eyeballed where I'd need to cut the elbows to fit the intake, then marked the cut positions with hose clamps. They form a handy guide for cutting the hose in a circle (more or less):
Seems to be turning out well so far:
Time to hook up the vaccuum hose. I bought a brass hose barb and some silver solder and an O/A torch setup. Drilled a hole in the hose, held the hose barb on the end of some MIG wire so as to not burn my fingers, and tried to solder it up...and failed miserably. It just would not flow onto the aluminum, and the flux just turned to soot. I looked up the solder online (the stuff I got just came with an MSDS sheet) and discovered that it didn't work on aluminum.
At this point I have fewer pictures because I was a little frustrated. I dug around and found a piece of 2.5" stainless steel tubing that I had completely forgotten and decided to use that instead. Lacking a bead roller, I decided to make one with an old pair of vise grips that never worked right. I filed a piece of 1/4" steel into a rounded shape, then used a die grinder to cut a rounded trough into another piece. (By the way, if you do not have a set of carbide bits for your die grinder and you do any amount of metal shaping, you're missing out. The stones that die grinders come with don't cut worth a damn compared to these.) I welded these bits to the jaws of a pair of vise grips, then fine tuned the fit with a file.
Unfortunately the vise grips had too much slop in the mechanism to squeeze a bead into the tubing, so I used a vise to squeeze the jaws together instead!
This worked surprisingly well once I heated the tube a little. Here's one bead, plus the tube set up in the lathe so I could cut it to length:
I broke the tip off my cutoff tool immediately after I finished the cut, so no pictures of it, but it's just a tool bit ground thin; probably a 3/32nd kerf.
I rolled the second bead on, then cleaned up the tool marks and heat yellowing with some emery cloth:
The beads are about 0.005" shorter than the beads on the tube I bought; not too shabby. I'm not really worried about the hoses coming off, but I wanted to have something for the clamps to hang on to.
Drilled a hole in the tube and this time the solder flowed just like a dream:
Cleaned up the flux with some isopropyl alcohol:
At this point I discovered that the intake side of the hose is 2.5", but the air filter side is 2.75". So I bought a 2.75" elbow and used a piece of the 2.5" elbow cuff as a spacer on the end of the stainless steel tube:
The finished product, right before installation:
(Check out my cool wheeled stool in the background that's definitely not a tank off a dead air compressor.)
I also needed a bit of hose to connect the hose barb to a T joint for the vaccuum system:
Here's where the intake pipe goes:
And here it is, after quite a bit of fiddling to get everything lined up right and tighened down:
Tip: I like to make jaw protectors for various pliers out of bits of hose I have lying around. They're handy when you want to grab something without marring it, or if you need to, close a fuel line so you can remove a filter or something. Here's an example on my big channel locks, which I don't use often, but when I need 'em, I need 'em:
I cleaned up the brake rotors with some emery cloth on the lathe, since they had rusted from sitting:
Hmmm, there's a car shaped hole here:
I forgot how GOOD this car is! It's so tiny, and it's so nice to have a proper hydraulic clutch and a short shifter...it's like driving a street-legal go-kart.
Unfortunately, the oil pressure dropped off after I ran it a bit, so I carefully nursed it back home from my test run. I'll have to figure out what's up; it may just be a wonky sensor, or it may be a bunch of crap clogging the oil pump intake. Hopefully it's not the pump itself since that's a pain to replace.
Omitted: a 1500 word essay on how I think this MR2 is the best car on the face of the earth.