Project Starlet: Drivetrain-Related Things

 
Somehow, there are only 2 posts about this car even though I feel like I've done a bunch of work to it. It turns out that I've started on a lot of different parts of the car, and since I haven't really done anything to completion, I don't feel ready to report on it. Well, too bad for me; I've done some stuff and if I don't write about it, I'll forget about what it was. On with the story.

Uh...where did I leave off...?

Engine and Transmission

I went through a lot of my trademark waffling when trying to pick a drivetrain for this car. My first thought was to do a 4AGE, since it would be kinda period correct and it's a solid motor, but it's pretty ancient by now. At the other end of the spectrum, it'd be cool to do a small block Chevy because they apparently go with everything. However, an LSx is pretty heavy. I know that's the cliché that people cite when they say that builders are "removing the soul" from some lightweight sports car, and then somebody points out that it's only a 50 lb weight gain over stock or something. Admittedly, those motors are light for what they are, but modern four-cylinder motors are still substantially lighter. In addition, the Chevy V8's need huge transmissions and the giant torque numbers will require something like an 8.8" rear axle (and if you've been following along, you've seen that I've already decided on a dinky little 7" thing).

So with these points considered, I ended up deciding on a Ford Duratec/Mazda MZR inline four cylinder. It's a very light all-aluminum engine with efficient head design and it's ridiculously common. This engine architecture is used in the Ford Focus, Fusion, Escape, Ranger and Transit Connect as well as the Mazda 3, 6, Tribute, B2300, and even the MX-5 Miata (there are probably a few I'm forgetting there too). It also comes in a whole bunch of different variants, ranging from a 2.0L in the Focus and MX-5 up to a 2.5L in later Mazdas. I decided on the 2.3L variant because it seemed like a good size for a turbo motor, and because it's readily available in a RWD configuration from the pickup trucks and those pickup motors don't have balance shafts, so they're a little lighter and more efficient. Uh...so it wasn't super well thought out, but these engines are popular and frequently used in swaps and in motorsport applications...though mostly in Europe. So I bought an engine out of a 17K mile Ranger from a junkyard. I'd put a picture of the acquisition phase here if I was significantly better at documenting what I do, but I'm not so instead here's a picture of me trying to stuff it into the car!

I also needed a transmission, obviously to do transmission-y things, but also so I could determine fitment in the vehicle. For this, the only longitudinal manual transmissions that bolt right up to your average Duratec are the Ranger 5-speed and the MX-5 5-speed and 6-speed. I decided against the Ranger trans because it has truck-y gear ratios, and decided on the MX-5 6-speed because they're apparently a lot sturdier than the 5-speeds. Heavy though. So I got one of those too.

And even took a picture of it and the box that it arrived in on my doorstep

Eventually, I bolted those two things together, and tried positioning it the way I wanted it in the car. Unfortunately, that transmission is gigantic, so I had to do a lot of uh...clearancing to make it fit.

This gets less ugly later. Not much less though

I bought some polyurethane bushings from some off-road shop, machined a couple of billet mounts for the engine and fabricated a steel thingy for the back end of the transmission. Oh, another detail of this particular transmission is that it uses what Mazda calls a "powerplant frame" or PPF, so instead of attaching the transmission to the body, it runs a huge beam down the length of the tunnel to attach it to the diff nose. My RX-8 actually does this too. What that means is that the mounts on the transmission are weird, so the interface I made for it is weird too.

That tunnel brace will have to be a lot beefier. Also, these photos suck

That's cool. I have a different engine firmly bolted into this vehicle now! Somehow, I also did this in the middle of winter with this much space in the garage:

I suppose I could have turned on the lights for this photo op

Oiling

Very quickly, oiling became a serious problem for this particular engine/chassis combination. The first problem is that the Ranger uses a rear-sump oil pan, while the Starlet uses a front sump. That means that the Starlet's front subframe (really just a crossmember in this case) exists in space where the oil pan would like to be. The other issue is that the MX-5 transmission demands that the engine be tilted ten degrees toward the passenger's side of the car, so the oil pan would be crooked anyway. The MX-5 pan would be oriented correctly, but the sump clearance problem is even worse. So those pictures of the engine in the car also show the engine with no oil pan. Clearly a problem.

This is the best shot I have of the stock Ranger pan. It's maybe a little ominous

What do you do when nobody makes a pan that will allow you to do the engine swap you want? I don't really know for sure, but my guess is that you cut up the existing pan until it fits and then fix the problem with welding (the way I fix most of my problems). In the photo above, I needed to remove almost everything above that green tape line. Here's a view from the bottom of the car with the pan hacked up to fit:

 Note that you can see into the engine around the middle of the photo

I also had to cut off everything else that was left so I could put a sump up front. I then got to work reconstructing the whole thing.

Incidentally, the oil pickup also had to be relocated from the back to the front, so I left the bottom off the pan so I could see where it was going.

 

I finished off the bottom of the pan and filled it with water to determine how grossly short of my desired capacity it was. The sump is very small because it's a lot shallower than stock for ground clearance, and the crossmember eats up a lot of the volume I'd like to use. I ended up with something like 3.1 quart capacity, which is less than the 4 quarts that I'd like to see (based on no real science).

Looks nice, but sadly too small

The only option I had at this point to add volume was to add wings to the sides. Wings are a bit of a pain because they make it very difficult to access some of the bolts for attaching the pan to the engine block, so I tried to make sure that I left a decent amount of clearance for fishing bolts in and out. I simply cut some slots the sides of the pan with a plasma cutter (to let oil flow in and out of the wings), bent up some C-shaped things and welded them on.

I also needed a drain plug, and I rather liked the stock arrangement, so I cut that corner off the old sump and welded it on.

A dipstick is a nice thing to have too, and you may notice from two photos above that the dipstick hole in the side of the pan leads to an area that is not inside of the pan itself, so I turned a dipstick bung on the lathe and welded that in...

I then closed up all the holes, checked for leaks and checked capacity again to find that I was just a little over 4 quarts. I'll be running an oil cooler and maybe an Accusump too so I'll have a bit of extra capacity with those. The pan still needs some baffles and a windage tray, so it's not done, but it's at a point where it keeps crap out of the engine and tells me what I need to know about fitment.

Probably the most complicated fabricated aluminum thing I've made to date

On to the next oiling problem! You may or may not have noticed in this picture:

 

that there is a machined spot with some oily holes in it by the U-joint at the end of the steering column (that thing that looks like a rusty funnel on the right side of the photo). That's where the oil filter take-off used to be. It wants to be right where that steering shaft is, and the filter itself wants to be where the steering rack is. Obviously that won't work either, so a remote-mounted filter is in order. Unfortunately, most filter relocation kits still attach to the existing filter mount, so I would have to make something once again. I also didn't have a whole ton of clearance to the steering system, so it would have to be fairly low-profile. I did some measuring of the stock part, made a CAD model, stuck a chunk of aluminum in the big machine, bought some AN nipples, did some welding and made myself a cool filter take-off. I still need to buy some expensive hoses and a filter mount, but at least I know that the engine fits! Naturally, I have no photos of it installed...

I've done a bit of other stuff too, but this has gotten quite long, so I'll leave it here for now.

Project Starlet: Rear Axle Build-Up

 A lot has happened on the Starlet since I introduced it like a year ago, but not really as much as I'd like. During the autocross season, I don't really get much done, so now that that's over, I've been digging into it a little more. I'll get to a major-ish update later, but since I just built up the rear axle, I'll post about that now.

The Starlet comes with a solid axle utilizing a tiny little 6" ring gear and it's held on with a triangulated four-link suspension. This is the same kind of suspension as the "quadra-link" that was used on Mustangs up until the S197 was introduced in 2005. Unfortunately, it is also not-so-affectionately known as "quadrabind" because it demands a lot of deflection from its bushings in both roll and ride motions, so stiffness would increase significantly with suspension travel, causing all kinds of dumb handling problems. The Starlet is no different, except that it's an economy car so nobody cares.

Well, I care. So part of the plan for this car is to basically scrap the rear suspension in favor of a different design. Incidentally, I'm following what Ford did with the Mustang and replacing the four-link with a 3-link and a Panhard bar. While I'm at it, I'm also changing out the dinky little Toyota axle for something that won't explode when subjected to more than the 60 hp that it was designed for.

I ended up deciding on an axle from an '84-'85 Mazda RX-7 GSL-SE for a few reasons: It can handle a decent amount of power, it's not as heavy as common axles like a Ford 8.8, a GM 10-bolt or a Toyota 8", and it's a lot easier to find than an AE86 axle. There are other little factors like the fact that it shares a bolt pattern with the Starlet and comes with a nice clutch-type diff from the factory. That's probably true of the AE86 axle as well, but like I said, the RX-7's are a lot more ubiquitous especially in the midwest.

Check it out; a real ramped clutch-type diff!

I ended up finding a local guy parting out a GSL-SE, so I was able to just drive a few miles, stuff it in the back of my Fit and bring it home for a very reasonable price. It just sorta sat under my bench in the garage for a while, but I just recently took it out and slid it under the car to see what it looks like. It turns out it's waaay too wide, as it's about 5" wider from hub face to hub face, so on top of having to cut off all the brackets and weld on new ones, I also have to narrow the housing and get the axles cut down and re-splined.

So let's get to it. First, I stripped out the diff and axles and ground off all the tabs on the axle housing except for the pair used for mounting the sway bar which I've decided I'll keep for now. This took a long time and turned my garage floor black.

Then, I made all the tabs. Oh, I guess somewhere in here I also designed the suspension. That is surprisingly uninteresting though. Basically, I guessed at target values and saw how close I could get to them in a way that would be somewhat easy to implement. So I picked a super low ride height, decided that I would re-use the lower control arm mounting points and figured out the rest from there.Here are some of the tabs and things. I welded the panhard bar mount together off the axle to make life easier. I also have no confidence in my design, so I put in extra holes to allow for (very) coarse adjustment to things like roll center, anti-squat and roll steer.

These are lower control arm tabs (windowed for lightness!)

This is an adjustable toothy plate for mounting the panhard bar at various heights

After that, I hit the point of no return when I lopped the ends off of the housing. This is scary because they carry the wheel bearings and need to be nicely aligned to the center housing area, so they're not going back on without some work. I was smart enough to measure the angle of the brake mounting bosses first so at least I could get one thing right when I pieced it all back together.

One of my rare thinking-ahead moments

The final disassembly step was to lop off the extra width on the housing. I decided to take 2.25" off of each side based on some crude measurements that I took with the axle under the car. This was done in a crazy looking way by putting the entire axle housing in a bandsaw.

Can you tell that I love my digital angle finder?

That was a little scary, but after measuring 19 times and cutting once, it turned out about right. Meanwhile, I smoothed out the faces of the axle ends/bearing carriers on the lathe so I could weld them cleanly to the axle housing.

It wouldn't be one of my updates without a picture of this lathe

While I was on the lathe, I also made some dummy bearings to clamp into the diff carrier as well as to press into the wheel bearing carriers. These dummy bearings all had a matching hole in the middle through which a big straight solid steel shaft was passed through to ensure alignment.

 

I saw this great tip somewhere of using a factory scissor jack to level out the housing

After measuring another 100 times, I welded the ends on.

And then I welded on all the suspension tabs.

I made a lot of little plates to box them in too.

  

The panhard mount also needed some little tubes to give it some lateral stiffness since all of the rear axle's lateral load is transmitted into it.

A giant pain both to miter and to weld

And all of a sudden, a finished axle!

 

Actually, this took a ridiculously long time

I knocked out the alignment rod...and oh wait, the axle is super crooked!

For reference, the yellow end of the rod should be in the middle of that hole...

I was a little alarmed because I don't have the heavy equipment normally used to straighten axle housings. That usually consists of a gigantic I-beam, some big chains, a bottle jack and an oxyacetylene torch. Well, I guess I had a bottle jack in my truck, but those other things are important too. I had also heard of using an OA torch to heat up part of the housing and then quenching it with water to shrink that area and pull the axle straight. I liked this idea, but again, no OA torch. So I instead used the TIG welder torch to strike up an arc on the housing. Wandering the torch around a bit was enough to get a decent chunk of the housing cherry red.

And then a quick quench with a wet rag.

   This is a boring looking photo

A few iterations of this on each side, and I was able to slide the alignment rod in and out by hand. And there you have it, a narrowed and custom tabbed RX-7 axle housing.

I unfortunately can't cut splines on the halfshafts, so those will be sent to Dutchman Motorsports to get shortened. Then, with some work on the chassis end, and some money sunk into decent shocks, I should be able to bolt this thing up and have some rear suspension!

Project Starlet: Introduction

Toward the beginning of 2010, after graduating from grad school, getting a job and moving to a house with a proper garage, I got hungry for a project car of my own. Turns out, I already have a project car; it's a 1983 RX-7 with a Ford 302 swap.

I started on this project waaaay back in 2004 with my good friend, Chris Szutu. It was the summer after our freshman year in college, and for some reason we thought it would be a good idea to get a project car even though we spend most of our lives about 2300 miles apart. We found a non-running RX-7 GSL (that's with 4-wheel disc brakes and LSD) for $300, which included two blown motors. The original not-very-fleshed-out plan was to rebuild one of the motors and get it running. Then maybe we'd sell it or...like I said, not much of a plan. We eventually found both engines to be completely useless as one had been ravaged by a broken apex seal and the other had warped housings due to an overheat.

We went back to school, leaving the car in Chris's parents' driveway, and somehow it remotely escalated into a V8 swap. We ended up as the proud owners of a hideous '88 Mustang GT convertible and proceeded to drop that engine into the RX-7 the next summer.

Wow, that thing is ugly.

This was basically the pinnacle of our automotive achievement

That was pretty cool, but just because it's in the car, doesn't mean the car runs. We were too daunted by wiring (and the spiders that live in the car's mirrors) to really tackle it seriously, and so it's really just been sitting. In Chris's parents' driveway. For...5 years now?

This post is titled something about my Starlet, so all this must seem pretty unrelated. Well, just over a year ago, Chris was trying to get the RX-7 out of his parents' driveway like any good son would, but he had no place to put it, so the plan was to ship it out to me. Due to some really shady shippers (partially a result of our own cheap-ass-ness), that fell through. So I had gotten all excited to have a cool project and then it just didn't happen, so I started looking for one.

My introduction to the Toyota Starlet was seeing a couple of really cool looking ones autocrossing in the Bay Area way back in 2002. Apparently, one of the better ones belonged to Tito Solis of Red Star Racing.

My Inspiration!

Little did I know, Starlets don't look or act anything like that when they're stock. Not. Even. Close. But now that I was starting from scratch, I was determined to get one because they're unique, rear wheel drive and weigh about 1800 lbs. I started searching in earnest, finding that Starlets are ridiculously rare in the Midwest and clean examples are VERY expensive. I finally found a 1981 in Chicago that claimed to be rust-free, had new paint and a 2TC swap with dual Weber DCOE's. I don't know anything about old school Toyota motors or carburetors, so none of that mattered to me. I also made a really strong point to the seller that I was driving a long distance to get the car so I wanted to be reassured that the car wasn't a rustbucket. The lesson that I learned is that people are jerks, because the car is actually pretty rusty. It also ran like crap, so I drove it about 250 miles across Michigan at about 55 mph, with the exhaust backfiring violently if I ever broke that barrier.

The Starlet is the brown one on the right

This thing has pushrods?!

Since getting it into my garage almost exactly a year ago now, the car has run a few times just to get it positioned in various directions in the garage so I can cut out the MASSIVE amounts of rust on the car and repair them. So far, I've replaced large chunks of both rockers, both front frame rails where they come under the front floor, and most of the floor.

The floor looks suspiciously like my garage floor...Much better

Once I get the passenger's side floorpan buttoned up, I should be done with most of the rust repair, with only minor stuff up front that is neither structural nor visible. Then, following Dmitriy's lead, I'll probably get the thing up on a tiptisserie to strip and paint the bottom.

What, you don't know what a tiptisserie is?

I'm moving soon though, so I have to wait until I have my new garage setup before I can pull the motor and suspension to allow it to be supported sideways by plywood.

SO, the long-term plan is something like this:

1. Make car not rusty: Getting there...
2. Engine swap: Current plan is 2.3L Duratec/MZR with turbo + NC MX-5 6-speed. Maybe 240 whp?
3. Full custom front suspension: Decouple sway bar from suspension location, Koni 8611's, really really low
4. Full custom rear suspension: RX-7 rear axle and custom 3-link + panhard or watts link, more Koni dampers
5. Big wheels and tires: It came with 155/80/13's (!), but I have it sitting on 225/45/15's right now. It seems appropriate, but maybe a 275 Hoosier is in its future
6. Race it wherever it fits: One thing that sucks about this car is that it will not fit nicely in any ruleset that I know of. That's ok with me for now though, I'm just having fun building it!