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Protege5: Harder, not Smarter!


Weight Junkie
so whats next Tamn?
Cleaning up the rear fender area's, still a lot of metal I can cut out and grind flat. Debating on whether too weld up the gas tank cover or leave it for filling the "fuel cell" and then welding up the roofs sunroof hole so I can mold it, cut it off and put in a carbon roof.

Meanwhile I'm still trying too decide exactly what kind of chassis/cage design I want too use, I have several idea's, nothing is totally finalized except that it will be tubular in nature. Whether it is some type of a ladder frame, space frame/main rail hybrid or some variant based on a crossing of both designs is undecided as of now.

I have got the radiator and coolers I will be using as well as most of my engine stuff purchased so I can start mocking stuff up soon too get an idea of what I'll end up leaning towards.

Sandblasting. Paint's waaaay too heavy...

Seriously though, this has got to be the most insane weight reduction effort ever... Can't wait to see it back together!
Oh man, the weight of the paint keeps me up most nights, maybe I need too do some tests on what types weigh less.


Weight Junkie

Cut out most of what is left of the inner rear fenders, 30 something pounds shaved.

Still have to finish cleaning up the edges.

welding some bracing

300 feet of tubing...finally :)

Tacked in temporary bracing

Bracing the car up as I will be chopping the main frame rails off, I estimate they are 80-95 pounds EACH give or take 5 pounds. Totally unacceptable, I will be replacing them with round tubing at about 1/12th the weight. The car will sit approx. 3 inches lower to the ground as a result and I will not be using side skirts as the bottom of the doors will sit flush with the bottom of the chassis.


Weight Junkie
Cut the lower part of the frame rails off, about 15 hours with an angle grinder on my back and a dozen cutting disks. Not having a lift is a real pain in the ass, literally. I really hate sheet metal, its like cutting open an onion, a really difficult steel onion. Once the one side was cut off, the body was balanced on a stack of tires, and that created quite the balancing act as it kept spinning around in circles as different sections were cut, it got pretty weird, but I got it done.

-80 pounds, with another estimated 20-30 pound loss cleaning them up, I have to either flip the body on its front end or lift it way higher too get under whats left in the rails.

Once I'm done cleaning up the sheet metal cut, I'll grind it smooth and then take it outside for acid dipping before I seam weld whats left.



Weight Junkie
Finally ready to go on the chassis fabrication...:)

Heres my first weekend worth of work

hacksaw the tubing because I can't cut flat enough with my angle grinder

Tubing notcher, first attempt...

Wow not bad...

Multiple tube end nodes are a super pain to fit tightly...

Built a jig to hold it when tacking, reduced warping by a large amount

Welcome to Washington, 50 degrees and sunny one day and this the next :p


Weight Junkie
Been awhile since I posted, haven't had a whole lot of time to work on the protege, busy with school and making parts for other people :)

Did get to play around with my bender a bit though and the passenger cell's main tubes are almost done. 2 weeks off for spring break, so I'll be putting in a ton of time on her so hopefully my next post wont be so long.

Made a spare hitch into a bender mount

marks were made before the bend, so I'd say that's some good accuracy :)
2003 Mazda Protege5
wow this thread has gone crazy since i last saw it. i wish i had the balls and the skills to do something like this. props to you!


Weight Junkie
I don't have time, no time to finish some of the things I wanted to pursue further on this car, I just drop some of the plans of stuff I had/was doing when time for a lot more free for me. Sadly the polished engine block is no more, I had 1 half totally done, but I just don't have the time to finish the other side nor the desire at this point.

I still obtained my original plan of smoothing the entire block, both partly inside and out and reduced weight by 4 pounds and reduced the stress risers on the entire assembly so I am more than happy with the results, but time in getting the other side mirror polished is something I must abandon.

Now to clean approx 150 hours over about a year of polishing grime out of this beast.

Brushed out every bolt hole 10-20 times each, phew.

Put some fresh cross hatches down the bores.

All this grime and grit came out of just 2 oil galleries....now most engines won't be this filthy, but still a good show of how much crap can hide in these places.

Rods and Pistons, yummm

Used my leather mallet to split the rods apart.

Knifed/drilled out and balanced/polished crankshaft -8 pounds, had this done about 6 months ago when I ground my cams.

Oh they look funny just hanging there.



Weight Junkie
Okies....lets see if I can remember all the stuff I've done since the last update.

I did a basic mockup of the front end position in relation to the chassis frame and found that the front end box was 2 inches too high on the front end. I also discovered that I had made the main chassis width fairly wide in comparison to the actual unibody shell as I finally had a chance to pick up the shell and try to fit the tube chassis inside it. Part of the difficulty in converting a unibody shape into a tubular shape is the door insets(offsets).

Quick mockup of the engine/transmission in relation to the main box.

I've spent about 30 hours this week designing/searching for part dimensions for the front suspension. I have settled on these 4 pot wilwood dynalites, more to come on the suspension geometry later (shady)

My B pillar hoop ended up being 3 degrees off axis from end to end bends, so I had it held down to a steel table and heated while a 1.5" OD chrome tube was used to tweak it towards the right axis and flat.

Thanks Jason!

So with the front box too high, and the width slightly too wide, I decided to restart from scratch. 2 steps forward, 1 step back. :(

I cut apart the entire box frame and started again, narrowing the width by 4 inches.

I went way overboard on the jigging trying to maintain a perfectly flat and square frame during welding.

Original protege steering rack + column 24 pounds, new pinion and column 12 pounds and I still have a couple pounds I can save on the new column.

Heres the main passenger cell version 2.0 :) Weight comes out to 52 pounds as it sits pictured, estimated weight when the b pillar+a pillars are added is gonna be about 74. Way heavier than I originally planned but I will feel absolutely safe driving this car on the street, these bars can take a massive beating.



Weight Junkie
Between this and the previous updates I did about 40 hours of work into the chassis.

I finished the passenger cell completely minus the roll bar and the bracing, all bracing will be added after the basic framework is completed to minimize warping from welding.

This was a very tricky piece of work getting the the small diameter tubing lined up evenly on the large tubing and then running level across the entire plane. Probably my least favorite part of the chassis so far.

Batteries are used as "clamps" during tacking


Here is the very front of the suspension box being laid out

Jigged it up and tacked it together, I chose to nearly weld this structure too completion too keep the warping down on the main chassis. For anyone unfamiliar with welding, it puts a crazy amount of heat into the metal even with small tacks and if a tube is unsupported you can visually see the tube move 3-4 inches with a 2 second tack weld if not clamped or braced in some way. I basically tack weld the entire car together in wooden jigs for as much as possible and then once everything is braced I run final welds closely varying my locations too reduce warping.

I'm getting better with tig, I could barely even run a bead when I started, and before this project I had never welded anything ever. One of the many things I have gained great satisfaction in doing myself and learning along the way, skills that will last a lifetime. People ask me all the time "where did you learn to do this?" I didn't learn it anywhere, I started started doing it, the best teacher is experience.

This project is incredible, thanks for all of the awesome updates!
I'm glad you are enjoying the pictures :)