TheDrip

I did end up having the manual transmission rebuilt under warranty, due to bearing failure. No one said a word about the trailer hitch.
 
 

It drove me crazy on my last road trip thinking about not having a spare tire with me.
I bought a takeoff spare on craigslist, jack and lug wrench on amazon, and $20 in various hardware at Home Depot.
An hour later, my trunk looks 100%, but my mind is at peace.
Cut an 18" wood disc, drilled to bolt it to the stock 4 mount points, and 2 studs to hold the spare The spare sits toward the front of the car to make room for the jack at the back. If I ever have to change a tire, I will not be able to put the flat tire back into the spare tire well. It was a decision I made to be able to fit the jack under the floor.

The stock foam sheet, and the red scissor jack tucked against the rear of the spare tire well, it gets held down by the tire.

Spare tire held down with two wing nuts.

Tools to the left, stock compressor and foam tucked into the spare just in case.

Hardboard to provide a flat and sturdy trunk floor. Double thick in the middle over the wheel.

and finally, a stock looking trunk. I hope I never have to see whats under that carpet again, but it makes me feel warm and fuzzy that it is there. Total investment was around $75. The snow brush lives in my trunk, I found one that matches Jalepeno Green perfectly (although my phone camera does not represent colors well).

A good sunday morning, and a good rest of the life of my Spark!

Car is over 60k miles now, and still gets beat like a rented mule. I did finally have a "major" failure though.
 
Bearings in the transmission had to be replaced. The final diagnosis is that the manual trans was not designed for high-rpm down shifting with heavy engine braking. Covered under warranty.
 
For anyone who thinks the trailer hitch doesn't cause abuse, hook up 800 pounds to the back of your car and try driving some of the mountain passes in Colorado or California. 3rd gear, full throttle at 5000rpm to maintain speed. Turn the A/C off because you will need that extra 3hp. Dallas TX to Denver CO, and Dallas to San Diego with an 800 pound trailer. Neither was a pleasant drive.
 
My car should be retired into a museum of automotive abuse!

My car has 52k on it. I've done the suggested oil changes and put an air filter in it a few weeks ago. I had a wheel bearing issue that was a factory QC issue out of the gate, and the whole A/C debacle everyone went through. I would have no qualms about buying a 50k mile spark for my wife. 
 
My car also has a pretty brutal life as far as Sparks go. 17" wheels and tires since 14k, lowered since 30k or so, also has a hitch and tows on a semi-regular basis. 85mph commute to work + stop and go at either end. #1 issue is the loose nut behind the wheel!

My car has 52k on it. I've done the suggested oil changes and put an air filter in it a few weeks ago. I had a wheel bearing issue that was a factory QC issue out of the gate, and the whole A/C debacle everyone went through. I would have no qualms about buying a 50k mile spark for my wife. 
 
My car also has a pretty brutal life as far as Sparks go. 17" wheels and tires since 14k, lowered since 30k or so, also has a hitch and tows on a semi-regular basis. 85mph commute to work + stop and go at either end. #1 issue is the loose nut behind the wheel!

It drove me crazy on my last road trip thinking about not having a spare tire with me.
I bought a takeoff spare on craigslist, jack and lug wrench on amazon, and $20 in various hardware at Home Depot.
An hour later, my trunk looks 100%, but my mind is at peace.
Cut an 18" wood disc, drilled to bolt it to the stock 4 mount points, and 2 studs to hold the spare The spare sits toward the front of the car to make room for the jack at the back. If I ever have to change a tire, I will not be able to put the flat tire back into the spare tire well. It was a decision I made to be able to fit the jack under the floor.

The stock foam sheet, and the red scissor jack tucked against the rear of the spare tire well, it gets held down by the tire.

Spare tire held down with two wing nuts.

Tools to the left, stock compressor and foam tucked into the spare just in case.

Hardboard to provide a flat and sturdy trunk floor. Double thick in the middle over the wheel.

and finally, a stock looking trunk. I hope I never have to see whats under that carpet again, but it makes me feel warm and fuzzy that it is there. Total investment was around $75. The snow brush lives in my trunk, I found one that matches Jalepeno Green perfectly (although my phone camera does not represent colors well).

A good sunday morning, and a good rest of the life of my Spark!

If anyone is further interested in this project. I have DXF and STL files of the adapters, and measurements on everything. I'm a little wary of sharing them publicly, as someone will surely think they can actually drive with 3d printed plastic brake brackets and then blame me.
I am looking for someone with a CNC mill to cut these out of steel. I'd rather support a hobbyist I can really explain the important parts of the maching work to than blast drawings off to the shop and hope what I get back is what I meant. The needed machining can be done completely one sided, though some creative fixturing would be needed to keep from having to refixture halfway through the process.
Shoot me a PM if you're interested in finishing up this project with me. Also if enough people want brackets (at their own peril!) it may become financially reasonable to have a larger shop produce them.

Guaranteed they give you free time. There is an ongoing promotion for buyers of used cars to receive 6 months (I believe) OnStar simply by calling in.
As far as fixing it, the previous owner may have been wearing a tinfoil hat and pulled the fuse or unplugged the unit under the driver's seat.

And we finally have some progress! I found a friend who was willing and had the time to machine the parts from steel. Here is a better rendering of the assembled product (minus bolts) from Fusion 360.

And photos from my friend of the raw pieces fresh off the Mill! I will be tapping the 12-1.25 holes when they get here, as well as painting.
There are a few notches in the outline, they were run using off-cuts, and the outline just barely intersected with holes in the material.


He also posted a machining video of cutting the outer profile of one of the pieces. I'm geeking out over all this. I figure maybe one other person in the entire world would be interested in this product, so it definitely won't be going into production, but I will hang on to the drawings just in case.

I've driven 12 hours straight normally cruising about 75-80mph. My daily commute includes a stretch of 25 miles I do at 85mph.
The car will take it, but say good by to your gas mileage. At 85mph cruise, I get about 28mpg. At 55-60mph I get over 40.
5 spd 2013 car. 85mph = 4500 RPM.

If anyone is further interested in this project. I have DXF and STL files of the adapters, and measurements on everything. I'm a little wary of sharing them publicly, as someone will surely think they can actually drive with 3d printed plastic brake brackets and then blame me.
I am looking for someone with a CNC mill to cut these out of steel. I'd rather support a hobbyist I can really explain the important parts of the maching work to than blast drawings off to the shop and hope what I get back is what I meant. The needed machining can be done completely one sided, though some creative fixturing would be needed to keep from having to refixture halfway through the process.
Shoot me a PM if you're interested in finishing up this project with me. Also if enough people want brackets (at their own peril!) it may become financially reasonable to have a larger shop produce them.

I would keep the outline of the caliper adapter pieces, I would keept their drill hole locations. I could move the wheel in by removing the rotor adapter, and move the caliper in the same distance by adding a spacer in between the caliper adapter halves. For strength reasons I didnt want a 3rd piece, so I added the 'spacer' to the spindle side of the adapter.

I mocked up the adapter with a spacer, that looked good. I drew up modified adapter halves in CAD, they looked good. I changed from a 5 hole center pattern to a 3 hole center pattern where all 3 would be bolts. Through holes in the narrower piece and threads in the thicker piece with the 4mm bump.



And that's almost the end of the story, you have almost caught up to me. I designed one last thing. During the last fitup and trying to figure out how to fix the 4mm spacing issue, I may have used some pieces from unneeded 3d prints to try and solve the issue. The end result was that my smartly engineered rotor adapter with the locations for drilling the rotor with a retaining screw hole was no longer usable. Knowing I would need to mark and drill any future rotors on this car, I designed up a little drill template. It keys into the center bore of the rotor and a single wheel stud hole. This is enough to locate the correct location for the retaining screw hole. Another good friend printed this for me. It's in the mail somewhere, but he sent me a picture before sending it.



A last single simple detail. With no rotor adapter, I now no longer had a way to center the rotor on the hub. A quick websearch found me a vendor who carries a hubcentric ring with the odd dimensions of 59.1x64.1mm. Perfect to center my BMW rotor on my Chevy car. A fun side note about the rotors I ended up ordering. They're from AC/Delco and have a GM parts number. I can buy my 12.5" rotors for my Spark at my Chevrolet Dealership!

And that is all. You're caught up. My design is finalized. I have some parts in the mail. A bag full of 12x1.25 10.9 bolts for the final bolt-up. All I need to do is have the final relocation bracket design cut from steel. I have a vendor that can do it with a 1-2 week lead time, but its quite a bit of money. It gets a lot cheaper per set if I have more than one made, but how big is the market for Spark brake upgrades? I'm guessing about 1 person.

I will leave a post or two reserved for final pictures. In the meantime, don't hate on my write up too bad, and don't tell me why this whole thing was a useless idea. I know. It won't improved brake performance 60-0. It will probably hurt my 0-60 times from the extra rotational weight. I'm never going to track the car. I did it to see if I could, pure and simple!

Thank you for reading through my 20 pages of ramblings. This wasn't a terribly hard project. If you wanted to you could make the brackets needed with an angle grinder, a drill and a tap. They wouldn't be pretty, but they would work. I just hope that new guys who would never think of a project like this can realize that its not rocket science and everyone should try a project to stretch their limits now and again. Its amazing what you can do with a measuring tape a pencil and a napkin!

SATURDAY MORNING

...again, or HURRAH! depending how you think this will go.

I slowed things down, and tried to be a little more methodical. First I compared the old rotor to new. This seems better, looks like a little more than an inch extra material on each side. Good so far!



Next I tried the new rotor adapter on the hub, again looking good. You can see that the small hole for the rotor retaining screw is in the right location, the retaining screw fit like it should. Then I tried the rotor on the adapter, after removing the same dust shield as before. It occured to me that this was a sizeable brake rotor. The last time I had a 12.5" rotor on a vehicle, it was rated to 14k GVWR. That is a lot of brakes for a car that weighs 2300lbs.



One more step before we get too excited, I bolted the relocation bracket in place. Thats a lot of smurf blue. I think I will paint the final parts something other than bright blue.



And then I got too excited. I removed the caliper, fit the rotor, and put the caliper on. I will need to grind about 1/8" of material off for a perfect fit, but its 1/8 of steel coming from a piece thats over an inch thick. This will work. Finally, THIS WILL WORK! I forgot to take a picture. I got the wheel on and bolted up and all of a sudden, it was picture time like your mom watching you leave for the prom.

First, to remind everyone what this looked like when I started, followed by the glory of my work.



What a difference! The crowd goes wild! And then I found the problem. My car doesnt have 4mm to spare in the wheel well. 17x7 wheels with 205/40R17 rubber. The wheels have +38 offset. If they had +42, I would have been ok. As it is, I have a feeling there is barely a hair between the fender and the sidewall when I go over bumps as my car is also lowered.

It works. I know moving the caliper out 30mm from the centerline is perfect, I just need to figure out how to save 4mm in width. I'm sure someone out there is yelling the solution at their computer screen, but it took me the rest of the day (in between chores) to commit myself to a new design.

SUNDAY of redemption.

OK, that title is a bit dramatic, but I did get over myself long enough to at least find the close end of the tunnel, hoping there would be light at the other end. Fewer pictures now, and more badly written words.

I started by going back over my inital math. Now it was a 256mm stock rotor, plus the same 56mm for enough offset. 312mm at a minimum. I thought I would start with the same vehicle, a Cooper Mini. The John Works packages cars always came with bigger brakes, so maybe a later year car would have even bigger brakes. I managed to dig up that an 08-12 Mini JCW car had 316mm rotors, with otherwise identical dimensions to the 294mm rotor. Not only did I find the tunnel, there was light at the end of it after all!

I headed back out into the garage yet again, quickly tore the brake rotor off the car and measured for depth, thickness, offset and sketched it out to match my Mini rotor drawing. I should have done this the day before, but I wasn't thinking straight out of frustration with myself.

The rotor adapter wwould work, it just needed to be 4mm thick instead of 2mm thick. An easy enough change. I went back into the house, and sat down for a few minutes of CAD. I added a couple things to the rotor spacer. A hole that correlated with the retaining screw hole in the Mini rotor. A hole that correlated with the retaining screw hole in the Spark rotor. I also added two holes that would line up with these positions but were only drawn at 3mm so that I could use a 1/8" diameter center punch to mark the hub face, or rotor to be drilled out later.



I also revampled the relocation bracket design. I went from pushing the caliper out 29mm to pushing it out 30mm, an easy enough change. I also changed the alignment and plug welding holes in the center. WHen gluing the plastic halves together, I realized one bolt is a terrible way to hold parts in alignment. I laid out a 5 bolt pattern. the two outermost holes were in the spindle side of the bracket for plug welds, the center hole in the caliper side for the same reason, and two more holes that would be threaded on one side to use bolts to align and clamp the parts together for gluing or welding.



I sent off my designs to my friend at Multirotor Superstore who printed them up for me. MRSS doesn't do 3d printing for their business, but they are a terrific vendor of Multicopter (drone) and other flying R/C hobby parts.

SATURDAY MORNING of broken hearts...

A warning before hand, you may cry from empathy for how I felt 20 minutes after walking into the garage Saturday morning. I woke up cheery, ate a good breakfast. Ready to get out there and see how terrific everything looked. I got the car in the garage, stripped off the same corner, and got to work.

I started with the same approach as the paper templates, each side individually, then glued the brackets together to check for interference from the overlap.



A great day so far, I tried out the rotor without adapter. Again, fitment looked perfect except for some minor interference with the dust shield. 3 screws fixed that problem, and I had the rotor on with the adapter this time with one minor change. The Spark's spindle has a step from 57.1mm where the wheel indexes to 59.1mm where the brake rotor indexes. No problem, scrape some plastic out and we're back in business. I wonder why the rotor drawing didnt show the correct center bore?



Feeling the confidence of a boxer with his opponent on the ropes, I bolted the adapter on and the caliper to that, and slid on the rotor adapter. The world is a great place this morning!



Let's carry this through all the way so we can get to the celebration right? Heres the 294mm rotor installed, with the caliper hanging off the plastic bracket. I am the greatest engineer in history. I have conquered nature, made metal and plastic bow to my whim. See where this is going yet?



That looks fantastic! That looks terrific! That looks... wait, why does that caliper seem to be stock way to far out?

WHAT HAVE I DONE?

With my victory stolen from me by an unknown foe, I calmed down and started measuring parts, double checking my drawings, questioning every part of my design.

I found the problem.

Remember back at the beginning when I found a drawing of the Spark rotor? It wasnt for a current generation Spark. I broke out my meauring tape, and sure enough my car didnt come with 236mm rotors. It came with 256mm rotors. So that 20mm difference in diameter means 10mm for the caliper offset. No wonder my caliper stuck out to far.

Back to the drawing board. My design was based on caliper at least 56mm larger than the OEM one to simplify the bracket design. I would have to start all over again!

I put the car back together, packed up the rotor to go back to the vendor, tucked my tail between my legs and sulked around the house for the rest of the day.

My design had worked perfectly, I made one major mistake at the very beginning: I didnt measure the stock rotor. I made an assumption, and I made an ass out of me. I don't know where the U went, but it doesnt matter.

SATURDAY MORNING

With the energy that accompanies good initial progress on a new progress, I headed back out into the garage first thing in the morning, armed with the latest paper templates. Everything went smoothly. I got the car into the garage and the drivers front corner stripped down in no time at all.

I made sure to take the time to photograph the fitup this time. I knew I was getting close, but that any minor dimension changes would be easier to get right with pictures to refer to.

First I tried the fitment against the caliper bracket. The half of the adapter which will attach to the caliper bracket first, followowed by my template showing both halves to see if anything would interfere. Fitment was good with a millimeter here or there that needed tweaking.



I did the same with the spindle side of the adapter. First the half that bolts on, then the combined print.



This fitment went even better. The only changes needed were changes already in line from the caliper bracket side fitting.

I called it a (very short) day in the garage, cleaned up and set about my honey-dos for the weekend. Later in the evening, I sat down and finalized revision one of the bracket design.

The changes were so minor I didnt even save my renderings, I couldn't see a difference. I sent files out to a couple good friends with 3D printers, and planned on a new round of mock-ups the next weekend with plastic brackets and a real rotor.

I wasn't going to make any progress beyond this on sunday, so I let the whole project rest.

Big Brakes for the Little Spark
---------------------------------



Here I lay down the tale of how I toiled night and day for weeks on end, simply to equip my spark with (unneeded) larger brakes, or, how I learned to love the bomb.

**NOTE: Sorry for the giant pictures, this board won't let me specify image dimensions for thumbnails, it will take some time to go through and replace them all. Give me a day or two!

These are me memories of the last 3 weeks or so, working for a couple hours each day on the weekends, and the few minutes I could sneak in on week days after work. I think writing this thread took almost as long as all the CAD work put together!

But really, I thought i would lay out the process I used and went through fitting larger brakes to my spark. With no specific purpose other than to do it. The Spark's brakes are exceptional, and put it in braking territory of sports cars of recent years past. Motortrend gave the spark a 60-0 stopping distance of 116ft when they tested a '13 model. This puts it on par with early mid 90s Corvettes, Acura NSX, RX-7s, and all but the newest Miatas. Not the best of the best now, but certainly more the sufficient for an economy car.

So why do it? Because I think I can.

My basic approach was this:

Using the stock caliper, just pushed 'out' from the rotor centerline to account for the larger disc.

Find a rotor with the same wheel bolt pattern (4x100), and a large enough increase in diameter to make the relocation bracket design easier.

Mock up designed with 3d printed plastic parts to verify fitment.

Produce the design in steel once it was verified.

SUNDAY NIGHT ... and the week following.

I sat down to do some deep thought, research, designing, and internet forum browsing.

Over the next few days I poked and prodded at my brain trying to kickstart some activity.

My first stroke of genius was realizing my wife's car had the same bolt pattern as a Spark. I started looking for a database of rotor dimensions to narrow down possibilities.

First I found a drawing for a Chevy Spark rotor, measuring 236mm in diameter. Included in the drawing I found were overall height, hub thickness, center bore diameter, and other useful dimensions.

Next I started poking around rotors related to my wifes car, a 2005 Mini Cooper S. And yes, the Chevy Spark is our large 4 door family car. I knew from my initial measurements that an offset of at least 28mm was needed to allow the caliper to move directly outboard from the stock mounting point. This meant an minimum overall diameter of 292mm.

I quickly found two possibilities, a 02-06 John Cooper Works edition Mini with a 294mm rotor and approximately the same height/thickness, or an archaic Renault application that is 300mm. Being practically minded for such a ridiculous project, I quickly found the Renault rotors would fit perfectly, but cost $125/side and were essentially unavailable.

It was getting toward the next weekend, so I moved forward with the Mini cooper rotor and ordered one from an online vendor to have ready for fitup.

Here is the stock Spark rotor vs the Mini rotor



I fired up my CAD program and got to making my design work with the car's parts. I couldnt have two identical parts, so I split into caliper side and spindle side designs.

These are the paper templates I printed out to test out the next day. The top is the caliper side, or rather the piece that bolts to the caliper bracket. The middle is the piece that bolts to the spindle, and the bottom is the two combined, so I could see if one interfered with the other in any way.



I was happy enough with the design to save a couple of 3D renders as well.



I moved on to comparing the details of the two rotor drawings. I wanted to make the centerline of the thickness of the rotor match the old rotor since I was only moving the caliper out from the spindle. I decided that I only needed an offset of two MM. I drew up a 2mm thick spacer that also included a spacer ring to adapter the Spark's hub diameter to the rotor's center bore. For good measure, I also included little index rings around each wheel stud to the the larger holes in the new rotor.



I put down my thinking cap for the rest of the week and waited for the weekend.

Over 1k miles on city streets and in-city highways now. Plenty of pot holes and construction. There are definitely jars at times, but no $$$ problems yet.
The car's light weight helps a lot when it comes to pothole strikes.
I don't think anyone lowers a car and steps up on wheel size while expecting a smoother ride as an end result.
As far as looking silly, these cars look 'silly' to the vast majority of the population anyway. I'm sure everyone on this site has been the butt of jokes like "do you take that inside with you?" "wheres the rest?" "where does the carry handle go?" and such. Maybe someone thinks your hair looks silly, but you chose it and you like it.

That is partially kind of true.
The insurance thing depends on the company and can be fought. Liability would not be affected, but collision/comprehensive could be.
The warranty is only invalidated if the dealership can prove direct causation. Engine/trans warranty would be in question, the A/C would not.
Another load today,

1000 lbs behind a 2200 lbs car? Really slow.
Roadtrips, homedepot, and even moving to a new house. Little car gets it done!

If you want to take of quickly (which you do if you're leaving the line at > 1000rpm), try a little more throttle. You're talking about 84hp, that right pedal is going to need some tough love, and you're going to have to slip the clutch a bit more than something with torque. I have noticed some clutch chatter when its cold/damp/wet out, but thats probably my left knee acting up and not being able to clutch smoothly, rather than the car itself.

I installed a Curt brand hitch a couple weeks ago... 45 minutes from opening the box, actually read the directions to completed install. It would have been 15 minutes flat, but I fiddled around with elongating the holes. I didn't take the time to find the right tool, and it took me 5 times as long as it should have.
Elongating those holes is the only gut wrenching part of a hitch install. Cutting into brand new car metal is sure a lot easier when it's someone else's brand new car.

The radio was designed around 8 ohm speakers in front and 4ohm in the rear. Your replacements are 4ohm all the way around, so there is now effectively twice the current being delivered to your front speakers.
Party on.

I have the chevy rubber mats in my spark, and weathertechs in my mini. The chevy mats are just a flat rubber mat with some texturing, the weathertechs will basically hold 3" of water. If you want a mat to keep your feet off the carpet, the gm rubber is great. If you want a mat to keep monkey poo (my wife is a zookeeper, and drives the mini) and other nasties completely contained, get the weathertech