Introducing Colin - a Mini-ature WRX

Hahahaha! I never felt guilty.

Pete. (l33t FS) said:

Hahahaha! I never felt guilty.

Then you must have no conscience.  What sort of monster are you?

GasTungstenArc said:

Pete. (l33t FS) said:

Hahahaha! I never felt guilty.

Then you must have no conscience.  What sort of monster are you?

I bend cotter pins over with my fingers, without trimming them.

Heh. Was looking for images of R53 front subframes and I found this.

An R56 Mini, with a BMW V8... and front and rear suspension from a GD STI.

Now, one might look at that and think, "oh! Just plug the Subaru control arms into the Mini lollipops, and you're done!"

Well, that would indeed be nice.   (The Subaru ball joints actually bolt right in to the Mini control arms, too!)  The problem with that is that we shoved the subframe back about 1 1/2" for engine clearance, because we need to mount a Subaru engine to the Subaru subframe.  When using a BMW engine, you can just put the subframe where the wheel centerline is happy and mount the engine wherever.

Still nice to see that I'm not treading entirely new ground.  It appears that they used a shortened T-frame in the back and are using a fuel cell in the cabin, as the thing you see above the mufflers is the stock Mini floor under the seats, where the fuel tank normally sits under.

Very interesting indeed.

EvanB said:

Very interesting indeed.

Thanks Evan.

Or rather.... thanks to your BIL for selling you the Forester so that it was right there in your driveway to take measurements from when I was there staring at the Mini that you'd offered up for this silly project.  If he had a RAV4 we might be trying to stick a 3SGTE in the Mini and look how long THAT could take

I mean, I already owe him a ton of thanks for getting me five gallons of accelerant that day I discovered that the left side fuel sender on teh S60R is not always accurate...

More Mini vs. Subaru trivia: The Mini strut tops are appx. 46" apart, the Subaru are actually a lot narrower at 42" apart.  Likewise, the Mini ball joint holes are appx. 55" apart and the Subaru are appx. 57" apart.  So the Mini setup has a lot steeper steering axis inclination, which would lead to a higher steering axis vs. tire centerline distance.  Subaru used to be real proud of how the suspension on their GL chassis had center-point steering, where the steering axis and tire centerline coincided at ground level, and they appear to have kept that geometry at least through the end of the upside down ball joint cars because they kept everything else from the GLs dimension-wise.

This also means, if you could find a way to plug Subaru axles into Mini uprights, you could use R53 struts/uprights to get like five degrees of negative camber on a Subaru.  Unfortunately, we need to figure out how to mount the struts 2" closer inboard at the top just to get zero camber... and moving the strut towers is not really an option because if we did, we would not be able to service the brake booster. 

The ball joint center-center distance also means we can't simply bung the Mini control arms' weird mounting method to the Subaru subframe and use them, not without lengthening them.  And if we have to modify control arms, I'd rather not start with something that requires that weirdness at the subframe end.

But do you even need a brake booster?  Why not manual brakes?

In reply to ¯\_(ツ)_/¯ :

The Mini booster and master are shorter in overall length than a manual master cylinder, and the strut tower is RIGHT THERE.

Besides, keeping it means less fab needed.

Just caught up and I love this! 

Making thingies on the lathe.

Step 1: Learn how to use a lathe.

Fortunately, we don't need machine shop precision, just something better than using a grinder while holding a pipe between your knees, so these are great for that.

This means evan finally got the lathe running?

Apparently.

Also, I am annoyed.

T frame fits like Mini intended it to be there.  This means the probability is greater than half that the Subaru tank might fit.

Well, at least supporting the diff nose just got a lot easier.

Patrick said:

This means evan finally got the lathe running?

Finally. Now just need to spend some money on tooling.

Weekend 7, day 1 (Feb. 12)

Today we beat target by 300%.  We spent HALF a weekend making TWO brackets!

As noted, Evan got the lathe working, so we were able to chop up some 3/4 OD .12" wall tubing. While I was messing with the T frame and removing more leftover floor with the finger sander and a chisel, he made four thingies.

About that time, I had the dimensions ready for the chassis brackets, and some quality time was spent measuring, cutting, and marking.  Then Evan went to town on them with the drill press and some wild looking drill doodads.

So the plan is, the subframe has 16mm-ish IDs in the mounting bushings, that plugged into locators in the body.  The box tube I am using is 2" tall by 1" wide by .125" wall.  So the thingies have an overall length of 3", the bottom 9/16" cut down to about .625" OD, and the box tube has a 3/4" hole on top and 5/8" hole on the bottom. 

I left my 135mm long bolts at work (d'oh) but Evan had some long enough 12x1.5 bolts from the Mini, and some lug nuts to thread on.  The brackets were reefed down with all the torque to compress everything as much as possible, then the thingies were welded in place and painted with weld through primer.

I have come to the conclusion that the chassis is slightly twisted.  

And so...

Weekend 7, day 2 (Feb. 13)

So, interesting thing.  Last night I found a PDF copy of the Subaru body manual... the one with all of the different datum measurements: the distances between all sorts of different hard points, vertical and horizontal, X, Y, and Z axes.

Nice.

Armed with that, I measured, calculated, and guesstimated that the front subframe was mounted 3/4" higher in the Mini than in the Subaru.  This is fine because Subaru floors sit a bunch higher, so the body drop is welcome.  The other interesting thing is that the front and rear subframes sit at the same height.  Neat.

Another interesting thing is that the center to center distance of the rear subframe holes is almost exactly one inch narrower than the inside width of the chassis in the Mini.  Just enough to be a real bastage to try to get up in there, and it kept getting hung up on some lips in the Mini that I did not want to trim off.  After several iterations of wrestling it in, swearing, hammering, prying, dropping it out, cutting, grinding, wrestling it back in....  we get to here.

More cursing and hammering as I try to get the tubes even in position in height, longitude, pitch, and roll.  One side is like 1/8" further forward than the other, which should not really be possible, making me question the parts of the body I am measuring from.  Finally I decided that I wasn't going to get it any better than where it is, the T brace clears the floor section perfectly, let's just put it in here.

I have decided that weld through primer sucks.

With the crossmember permanently mounted up, it was time to put an upright in and see about what was going to happen at the trailing arm.

Hmm.  This could work.  The T bar and the trailing arm bracket both attach to the same plane, appx. 5" lower than the plane of the crossmember.  (Whatever 206mm minus 76mm is.  Smells pretty close to 5" to me)  The T bar bolt hole is 8" from the rear bolt holes on the WRX, by some wild coincidence that will also center the wheel in the wheelwell, on this side at least...

Pete. (l33t FS) said:

I have decided that weld through primer sucks.

It certainly does suck.  And I think it is just a clever name.  I tried it once and never used it again.  

This is all looking good.  Remember: if you need any TIG welding done, I know a guy close to you.  Very close to you.  In fact, typing right now.  

Having just played a few rounds of "cards against humanity," the phrase "smells pretty close to 5"" struck me as rather funny. 
 

Carry on. This is the kind of ambition I need to see right now. 

barefootcyborg5000 said:

Having just played a few rounds of "cards against humanity," the phrase "smells pretty close to 5"" struck me as rather funny. 
 

Carry on. This is the kind of ambition I need to see right now. 

it's 5" but it smells like a foot

I wanna see how this competes against an AWD converted wishbone era Civic hatch.

In reply to clutchsmoke :

I'll be ecstatic if it can handle two people driving it back to back without overheating any of its systems (fuel, oil, power steering, transmission, or coolant) or requiring regular deep maintenance.  Which would make it better than a wishbone Civic, as it should have a more reliable engine, and it doesn't have stressed ball joints to blow apart or blow the threads off of the retainer nut.

Locally there are no C cars and all of our MA big hitters have moved on to different classes, so it'l just be us out there having fun while the car stays mobile.

Makin' brackets.

Harbor Freight benders do NOT like 16ga.

Pete. (l33t FS) said:

I believe this is the part where you list it on craigslist for $6000 and claim "the hard part is done"

In reply to Patrick :

No way.... then I'd have to deal with yahoos who want to drive it home and get belligerent when told that it is not mobile.

I'm not thrilled with how wide those brackets are, but they are exactly wide enough to support the diff bar bushings, which forensic analysis suggests was how the Subaru was.