Secrets of the Mirage

[Loren]

You might have heard that some bozo is trying to autocross a 3-cylinder Mitsubishi Mirage in FAST S5 class. That would be me! It is neither the least powerful nor the lightest car that I've autocrossed. That title goes to the FASTiva. By the numbers, this car should be somewhat quicker than the FASTiva.

So, what are we talking about here?

2015 Mitsubishi Mirage
40,000 miles
Purchased for $6800
5-speed manual
1.2 liter 3-cylinder engine
78 hp, 73 ft/lbs
~1900 pounds

So, as I did with the FASTiva, this thread will be a sort of progress log. I'll update the first post with the latest info, and discuss things in the thread as we go. It's really more for me than for you. I forget stuff if I don't document it.

The Big Picture:
A Mirage is a silly car to try to autocross. I knew this going in. But, eventually, I learned that with stock suspension (even with good shocks and a rear swaybar) and sticky tires... the car is dangerously unstable. It wants to roll over. If you're going to seriously autocross a Mirage (or anything like it), you need to go modified with it. Lowering springs at a minimum. But, for this car, even that wasn't enough. I had to modify the front suspension to fix the roll center after lowering it. That required some custom fabrication, because nobody makes those parts for a Mirage. After doing that, it was a lot better... but, eventually as we really started trusting the car, we started getting it up on two wheels again. Dangerously so. The latest iteration has added much stiffer front springs and lowered the car another 1.5". It's barely streetable now (by my reckoning), but it handles quite well. Is it stable? Honestly, we're afraid to push it hard enough to answer that question any more!

Stuff do do soon:

Stuff to do a little less soon:

Stuff to do eventually: (somewhat prioritized)

Autox Log:
8/11/2017 - Purchased with new OE tires, 165/65/14 Dunlop Enasave
8/12/2017 - 7 runs, 1 Driver (Loren), Duel format, one win (what?)
9/1/2017 - Installed 195/50-15 Bridgestone RE-71 on 15x7 Kosei K1's
9/30/2017 - 7 runs, 2 drivers, Loren - 3/9 in S5, Steve 5/9 in S5 (in the rain)
10/8/2017 - 6 runs, 1 Driver (Loren), 2/6 in S5. 16/40 overall.
10/21/2017 - 4 runs, 1 driver (Loren), 1/7 in S5, 37/100 overall.
11/4/2017 - Didn't drive the Mirage
11/18/2017 - 4 runs, 1 driver (Loren), 1/4 in S5, 21/103 overall.
12/2/2017 - 2 runs, 1 driver (Loren), 20/27 overall.
12/2/2017 - 2 runs on skidpad, 1 driver(Loren)
12/10/2017 - 10 runs, 2 drivers (Loren, Philip), 1/2 in STS, 30/93 overall.
12/17/2017 - 10 runs, 2 drivers (Loren, Ben), 1/4 in M4, 17/99 overall.
12/30/2017 - 7 runs, 1 driver (Loren), 2/5 in M4, 24/44 overall.
1/13/2018 - 4 runs, 1 driver (Loren), 2/6 in M4, 43/98 overall.
1/27/2018 - 8 runs, 1 driver (Loren), 1/4 in M4, 12/32 overall.
2/10/2018 - 4 runs, 1 driver (Loren), 2/5 in M4, 39/107 overall.
2/24/2018 - 20 runs, 2 drivers (Loren/Steve, 1 & 3 in M4, 15/48 overall.
3/11/2018 - 5 runs, 1 driver (Loren), 1/4 in M4, 19/87 overall.
3/24/2018 - 9 runs, 1 driver (Loren), 1/3 in M4, 24/50 overall.
4/7/2018 - 7 runs, 1 driver (Loren), 1/4 in M4, 18/87 overall.
4/11/2018 - Installed 195/50-15 Dunlop ZIII on 15x7 Storm S1's.
4/22/2018 - 8 runs, 3 drivers (Loren, Philip, Ron), 1/3 in M4, 16/37 overall.
5/5/2018 - 5 runs, 1 driver (Loren), 1/7 in M4, 20/78 overall.
5/19/2018 - 6 runs, 1 driver (Loren), 1/3 in M4, 27/49 overall.
6/3/2018 - 5 runs, 1 driver (Loren), 3/4 in M4 (had the raw time for 1st, coned it), 27/92 overall. (would have been 18th)
6/10/2018 - 4 runs, 1 driver (Loren), practice
6/16/2018 - 8 runs, 2 drivers (Loren, Jean), 3/3 in M4 (rain), 21/40 overall.
6/30/2018 - 5 runs, 1 driver (Loren), 2/3 in M4 (rain again), 44/90 overall.
7/14/2018 - 6 runs, 1 driver (Loren), 2/5 in M4 (by .1), 19/47 overall.
7/28/2018 - 7 runs, 2 drivers (Loren, Steve), 1/4 in M4, 28/96 overall.
8/12/2018 - 6 runs, 1 driver (Loren), 2/5 in M4 (coned), 25/46 overall.
9/8/2018 - 16 runs, 2 drivers (Loren, Dan), 1/2 in M4, 16/46 overall.
9/15/2018 - 4 runs, 3 drivers (Loren, Steve, Ken), practice.
9/23/2018 - 10 runs, 2 drivers (Loren, Dan), 1/6 in M4, 27/95 overall.
10/6/2018 - 6 runs, 1 driver (Loren), 6/7 in PAX, 11/48 overall.
10/20/2018 - 2 runs, 1 driver (Dan), car broke.
11/17/2018 - 10 runs, 2 drivers (Loren, Dan), 2/7 in M4, 35/113 overall.
11/18/2018 - 18 runs, many drivers, 9/16 overall.
11/21/2018 - Installed 205/50-15 Dunlop ZIII on on the front.
12/1/2018 - 12 runs
12/9/2018 - 6 runs (PCA)
12/16/2018 - 10 runs
12/29/2018 - 33 runs (EnduroDuel w/ 2 drivers)
1/6/2019 - 12 runs
1/12/2019 - 10 runs
1/27/2019 - 8 runs (in the rain)
2/9/2019 - 10 runs
2/23/2019 - 8 runs
3/3/2019 - 8 runs
3/9/2019 - 15 runs
3/23/2019 - 8 runs
3/23/2019 - 10 runs (on Ben's Miata)
4/7/2019 - 12 runs
4/20/2019 - 12 runs
5/4/2019 - 12 runs
5/9/2018 - Installed New 205/50-15 Dunlop ZIII on on the front.
5/26/2019 - 8 runs
6/15/2019 - 10 runs
6/29/2019 - 12 runs
7/27/2019 - 10 runs

Total Runs to date: 469
Total Runs on 165/65-14 Dunlop Enasave (8/2017): 7
Total Runs on 195/50-15 Bridgestone RE-71 (8/2017-4/2018): 109
Total Runs on 195/50-15 Dunlop ZIII - Front Only (4/2018-11/2018): 125
Total Runs on 195/50-15 Dunlop ZIII - Rear Only (4/2018-8/2019): 353
Total Runs on 205/50-15 Dunlop ZIII - Front Only (11/2018-8/2019): 198
Total Runs on 205/50-15 Dunlop ZIII - Front Only (5/2019-???): 30

Tire Wear:
8/18/2017 - Installed 195/50-15 Bridgestone RE-71
12/1/2017 - Rotated tires front-to-rear at 21 runs
1/11/2018 - Rotated tires front-to-rear at 52 runs. Will need to be flipped soon. These tires wear fast!
3/2/2018 - Flipped tires and rotated again at 88 runs. I'll be surprised if these make it to 150 runs. Maybe.
4/11/2018 - Installed 195/50-15 Dunlop ZIII
7/28/2018 - I should rotate them, but I think I'm going to leave it and just flip the fronts at some point. Goal: put 205's on the front and keep running the 195's on the rear.
9/11/2018 - Had the front tires flipped. Should be good for close to 150 runs. Noticed center of tread is a little fat a couple weeks ago. Raised front cold pressures to 40 from around 36.
11/18/2018 - Front tires are done at 125 runs. Could get another event or two out of them, but wouldn't want to drive them in the rain. Only the two center grooves are left, no visible tread on the corners. But, no cord!
11/21/2018 - Installed 205/50-15 Dunlop ZIII on on the front.
2/24/2019 - Had the front tires flipped. They're actually wearing pretty evenly, there's just a little more meat on what was the inside shoulders. Should easily go another 80 runs. The rears are finally showing some wear. Could have flipped them today, but opted to let them go.
4/20/2019 - The fronts are just about dead. Couple more events maybe. Not expecting them to make it to the end of July with 2 drivers though.
5/9/2018 - Installed New 205/50-15 Dunlop ZIII on on the front.
8/6/2019 - Removed autox wheels and tires.

Stuff that's been done: (overview)

• Wheels & Tires (195/50 & 205/50 on 15x7)
• Suspension (coilover kit, rear swaybar, custom front suspension bits)
• Exhaust
• Kinda sorta tuner (not a real flash tuner, did advance timing and improve throttle curve)
• Lighweight Crankshaft Pulley
• Lightened Flywheel
• Updated to 2017 spec engine (CVT version with dual roller cams)
• Rear Seat Removed

Stuff that's been done: (full details)

• Tires: 205/50-15 Front, 195/50-15 Rear
• 15x7, 35mm offset Storm S1 wheels
• 450g stainless steel shift knob
• Accelerator pedal extension
• Custom 22mm Hollow Rear Swaybar (.122" wall)
• Godspeed coilover kit (4" 9kg front w/ 2" soft tender / 3kg rear w/ tall bump stops)
• Front bump stops from a VW (Uro 1H0 412 303B)
• Custom Caster plates to add +2 degrees
• Engine torque strut
• Removed front swaybar
• Removed rear wiper
• Modified front control arms, 1/4" longer, fits screw-in Chrysler #772 ball joint
• QA1 Lower Ball Joint - it's 0.5" extended, but it's 1" taller than the stock Mirage ball joint
• Custom Bump Steer Correction kit. About 1/2", could use more.
• SuperCircuit exhaust header
• Custom full header-back exhaust. 1.75" mandrel-bent with high-flow Cat, standard muffler and resonator.
• Works Aluminum Crankshaft Pulley - 1.03 lbs (stock was 2.8 lbs)
• Engine Oil changed 3/9/2018 at ~35k - 0W20 Synth
• Trans Fluid - Redline MT-85 75W85 at ~38k
• Brake Fluid flushed with Valvoline synth at ~38k
• Power Stop (Z23-1731) front brake pads at ~38k
• 2017 engine from a 20,000 mile CVT Mirage at 41k
• 2017 brakes, front and rear
• Wagner (Z924) rear brake shoes at 41k
• ETZ10S motorcycle battery at 41k
• Lightened flywheel and new clutch at 41k
• Rear Seat, seatbelts, brackets, spare tire cover and cargo cover all removed (38.8 pounds total)

Suspension Reference Info:

• Current Suspension mockup (updated 1/1/2019)
• OE Ride Height: 14-1/8" from center of hub to fender lip. Front and rear.
• OE Front Strut Length: Installed static length = 17.5"
• OE Front Spring Diameter: 2.5" tapered diameter at each end (fatter in the middle)
• OE Front Spring Length: Installed static length = 8"
• OE Front Spring Length: Installed fully extended length = 10.5"
• OE Front Strut Stroke: 5.5"
• GodSpeed Front Strut Stroke: 4.5"
• GodSpeed Front Bumpstop: 1-5/8" very stiff, but progressive. 1.5" OD, .75" ID.
• OE Rear Shock Length: Installed static length = 22.5"
• OE Rear Shock Stroke: 8"
• GodSpeed Rear Shock Stroke: 5"
• Stock Corner Weights 9/2017 - Front: 573/648, Rear: 362/474, Total: 2057
• Corner Weights 11/2018 - Front: 666/601, Rear: 443/414, Total: 1936
• Total Weight 11/25/2018 - 1901
• Current Ride Height:, 11.75" front, 11.75" rear (center of hub to fender lip)
• Current Ground Clearance: 4"
• Control Arm Torques - Inner bolts 80 ft/lb, Ball Joint thread into control arm 130 ft/lb

Some weight info for reference:

• Transmission (including upper trans mount and bracket) = 73 pounds
• Engine (all accessories removed, no manifolds, fuel rail or coil packs) = 112 pounds
• Intake Manifold & Fuel Rail = 7 pounds
• AC Compressor = 9 pounds
• Alternator = 10.5 pounds
• Flywheel = 15.1 (lightened to 14.3)
• Pressure Plate = 6.0 pounds
• Clutch Disk = 1.6 pounds
• 2015 Front Rotor - 7.55 pounds - 229mm (9") OD
• 2015 Caliper Bracket - 1.22 pounds
• 2017 Front Rotor - 9.12 pounds - 251mm (9.9" OD)
• 2017 Caliper Bracket - 1.45 pounds
• Brake Pads, one wheel (barely worn at 20k miles) - 0.91 pounds
• Brake Caliper - 4.38 pounds
• Caliper Pins - 0.26 pounds
• Brake Hose - 0.35 pounds
• OE battery = 34 pounds (525 CCA, absolute overkill)
• ETZ10S AGM motorcycle battery = 6.11 pounds (+.1 for lug terminal adapters)
• OE battery shelf/tray/tiedown = 2.8 pounds
• Modded battery shelf/tiedown = 2.16 pounds

[Loren]

Reference Photo #1 courtesy of Philip:


Completely stock with crappy 30,000 mile factory shocks, and a brand new set of OE tires. Tires have no grip. Shocks provide no damping. Engine has no torque below 4k. It's fun in its own way, but pretty awful in the current condition. You have to slow down SO MUCH to take any kind of turn that you're bogging 2nd gear pretty much all the time. Better tires (much wider RE-71), better shocks, and the addition of a rear swaybar should allow it to corner a lot faster, and thus not be at the bottom of 2nd gear everywhere. It still won't be fast, but it should be a lot more fun.

[Loren]

So, here's the coilover kit that I've ordered it. It's already shipped FedEx (from China, of course ) and should be here in a week.

Godspeed Mono SS

Typical Asian cheap coilover kit.
16-position adjustable dampers.
4k front / 3k rear springs (I'm installing it with the STOCK springs until/unless I decide to run M4)
Adjustable shock body length and perch height (I'm setting it to STOCK ride height)
Front Camber plates (setting to 2.0 degrees camber for S5)

Pretty cool kit for $600.

The rear shocks are easy, as they are separate from the shocks. So, I just install the shocks. Done.

The front struts will be a little more complicated because the front factory springs have tapered ends. So, I'll need to fab a set of adapters to fit those springs to the flat spring perches. Since the OE shocks are dead, I'll probably cut the perches off of them and use that somehow. Will take a little bit of creativity, a little bit of scrap metal, and a little bit of Joe Brannon's welding skill.

End result will be a set of adjustable shocks on stock springs at stock ride height with 2 degrees of negative camber... everything you want for FAST Stock!

[Loren]

The rear swaybar, like a lot of aftermarket parts for this car, is available... in places like Malaysia and the Phillipines. Getting them here is a bit more difficult. And for the price (would end up being around $230 after shipping), the bar is simple enough that it would be easier to just make one.

A swaybar is a simple device. A "swaybar" for a twist beam axle is even simpler. It's not a "real swaybar" in that it doesn't actually attach to the chassis with end links to the suspension. It merely bolts to the twist beam axle and acts as a reinforcment to it to further resist the twisting force... which gives a net effect that is the same as a swaybar.

Benefit of doing a DIY bar is that it's going to be cheaper (maybe $100-120), and I can make the bar section hollow rather than solid, so it will be 30-40% lighter. Will be a simple bolt-on part that will require minimal cutting and welding to construct.

[Amphoteric88]

I am so excited to see this build through! Looks like we'll have to step up my game, big time for S5! Ed and his Tercel could probably learn from your twist beam sway bar configuration.
I think having those paper temp plates really shows the "race what you got" attitude

[CaptainSquirts]

What are your expectations of the coilovers? I always read that getting anything under a grand for coilovers(even up to under 2k) are usually crap. Now I'm pretty damn sure the struts that come on that Mirage are going to be pretty weak as well, but think those coilovers will be that big of an upgrade of the stock?

P.S Should've gotten an Evo.
P.S.S Please... don't get an Evo, or any fast car for that matter.

[twistedwankel]

You know seeing that they actually make performance bolt on's for this lame econobox reminds me of a couple years ago when we went to Kefalonia, Greece and the kids there were pulling wheelies racing on hopped up Mopeds burning 95 octane gas = the only gas they sold there.

Loren, there is a reason they call it Mirage (not the jet fighter). It's imaginary. It's okay I have an imaginary race car or two myself.

As usual it will be fun to watch.

[Loren]

What are your expectations of the coilovers? I always read that getting anything under a grand for coilovers(even up to under 2k) are usually crap. Now I'm pretty damn sure the struts that come on that Mirage are going to be pretty weak as well, but think those coilovers will be that big of an upgrade of the stock?

My stock shocks have 30k miles on them and have lost any "edge" that they may have originally had. (surely not much) Street ride is okay, but they feel dead and floppy when pressed. So, any new shock would be an improvement. Having some adjustability, and a shock that's spec'd for a higher rate spring, I expect I can run them near the low end of their adjustment, as as they wear, I can go stiffer with them. I don't expect them to be "great" shocks, I just want something that at least somewhat does what it's supposed to do. A little bit of turn-in crispness, and damping of suspension movements. No expectation of "fantastic" performance. But, hopefully adequate for the task at hand.

[mymomswagon]

oh snap there goes my fantasy of winning s5, down the toilet.

not to mention my dream of winning dorkiest looking ax- mobile

[mymomswagon]

will you need to mod the spring perches on the front to deal with stock springs?

that tire diameter change will help with second gear

[Loren]

I'm not so sure this car's going to run away with S5 or anything. I suspect we're all going to get beaten by the open-diff Miatas... or will we???

Here's what the new tires and wheels look like:

[mymomswagon]

well maybe not run away.
but
F=ma, Re-71 and you.

[twistedwankel]

Never ceases to amaze me how great a visual improvement a decent set of wheels/tires make a car look!! It actually looks sporty now.

[CaptainSquirts]

So is this car going to be a DD or just pure autox?

[Native]

oh snap there goes my fantasy of winning s5, down the toilet.

not to mention my dream of winning dorkiest looking ax- mobile

No, and yes.

[mymomswagon]

oh snap there goes my fantasy of winning s5, down the toilet.

not to mention my dream of winning dorkiest looking ax- mobile

No, and yes.

it's even the same color!!!

[Loren]

So is this car going to be a DD or just pure autox?

I just drove it to dinner, I guess it's a DD in as much as I daily drive. Being a driving instructor, I'm always in the DE car during the week, I don't drive my own car much.

So, it's mostly an autocross car. But, it needs to remain streetable, and reasonably comfortable.

[Solar]

I don't see it.

[Rawkkrawler]

Not gonna lie, I kinda like it. Just needs some fender flares, just because.

[Loren]

I don't see it.

I see what you did there.