Porsche brembo caliper brake swap for 473$

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Glad you didn't weld two pieces together to make that bracket. I look at x-ray's of welds all the time on my job. It's why I choose to trust only (2) of our welders out of the (30) here at work.

I like your ambition and following through to execution. Chalk it up as knowledge learned.
 
This thread is brilliant-nice work on the parts bin engineering and simplified fab. I'm also confident your 3/8" angle iron should suffice given the application. Angle iron is usually made from hot rolled carbon steel or something similar and most carbon steels have great fatigue life and yield/ultimate strength. The suggestion above to check for cracks using either dye pen or mag particle are solid processes and are used every day in aerospace for the same reasons. Any competent machine shop should be able to do them for a reasonable cost.

After you get past a shakedown phase and get it dialed in, it would be supremely cool if you could record/report those findings either in this thread or a new one. I couldn't find any specs for 60-0 braking tests for the stock Dusters of that vintage with a quick search, but I bet they're out there somewhere on the interwebs, and I'm betting it's somewhere around 140-160 ft...
 
txstang84 said:
This thread is brilliant-nice work on the parts bin engineering and simplified fab. I'm also confident your 3/8" angle iron should suffice given the application. Angle iron is usually made from hot rolled carbon steel or something similar and most carbon steels have great fatigue life and yield/ultimate strength. The suggestion above to check for cracks using either dye pen or mag particle are solid processes and are used every day in aerospace for the same reasons. Any competent machine shop should be able to do them for a reasonable cost.

After you get past a shakedown phase and get it dialed in, it would be supremely cool if you could record/report those findings either in this thread or a new one. I couldn't find any specs for 60-0 braking tests for the stock Dusters of that vintage with a quick search, but I bet they're out there somewhere on the interwebs, and I'm betting it's somewhere around 140-160 ft...
Click to expand...

Thanks man! I’m an A&P mechanic by trade, but I have yet to do any NDT on aircraft. Hindsight being 20/20 I should have done a brake test with the original brake setup to get a good comparison. I definitely will post results when it’s tuned in though!
 
txstang84 said:
After you get past a shakedown phase and get it dialed in, it would be supremely cool if you could record/report those findings either in this thread or a new one. I couldn't find any specs for 60-0 braking tests for the stock Dusters of that vintage with a quick search, but I bet they're out there somewhere on the interwebs, and I'm betting it's somewhere around 140-160 ft...
Click to expand...

Mopar Action magazine did a somewhat UNscientific test.
Their "Green Brick" 1969 Valiant....They were doing a Viper caliper swap and after swapping ONE side, they took the car out and did several brake tests. Viper caliper on one side, iron single piston on the other. The car stopped straight each time. There was no braking advantage for the Viper caliper in their limited testing.
Where I suspect the advantage is....Is in repeated hard usage. The iron caliper may start to retain heat and fade while the aluminum caliper would more easily dissipate heat and continue to function. The gains in weight reduction are minor but worth something.
I'll readily admit though that I do like the look of the modern brakes!
 
txstang84 said:
This thread is brilliant-nice work on the parts bin engineering and simplified fab.
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I second that... Great job! I also think the angle iron should be more than adequate. There is usually a decent radius on the inside of the angle that helps with strength. But, as others already mentioned, it's worth keeping an eye on it.
 
Did you do this only on the front or did you swap out the rear drums as well?

I'm surprised they fit under stock wheels. I thought the brembos on my jaguar were large then I saw how big porsche calipers were.
 
phaelax said:
Did you do this only on the front or did you swap out the rear drums as well?

I'm surprised they fit under stock wheels. I thought the brembos on my jaguar were large then I saw how big porsche calipers were.
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I have the same concern.
James was rotating the tyres on the Rolls Royce Ghost prior to my afternoon drive to the vineyard and I observed the Brembo calipers.
I don't see how those would ever fit on a smaller car.
 
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I swapped to the Porsche calipers first while retaining the rest of my brake system as it was to aid in troubleshooting if I had any issues. I’m currently in the process of swapping Jeep disk brakes onto the rear though.

For sure, they are a close fit. But they still have enough clearance for let’s say an out of round wheel.
 
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That is awesome nice work. Love the fabrication work! I am a diy kinda guy as well I love to do my own work and fabrication. It may take twice as long and sometimes even cost more but in the end I can say I did that I made that! Not I paid someone to build it for me. I take pride in that. That's very nice work thanks for sharing
 
alex_hockey said:
What made you decide on the Porsche calipers? Great work. What size MC are you running?
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After watching this (11:30)

Seeing how I could use angle iron for an adapter bracket convinced me I could do this swap on my duster. These Porsche calipers seem like a pretty common swap for the import crowd. Probably why they were hard to track down at a good price.

The master cylinder setup is an aluminum manual 1 1/32 inch unit from dr diff. It’s actually one of the things I might change in the future. Because the pedal effort is higher than it was with the stock single piston calipers. I didn’t change anything yet because I’d like to see if the Jeep rear disk brake swap will change the feel.
 
I’m surprised the angle iron was square enough to work as is without machining. Usually when that stuff is formed it is not at a perfect 90° angle. If you were concerned about strength it looks like you have plenty of room to add a gusset between the two legs in the middle of the bolt holes
 
Finally got around to doing my first round of 60-0 stop tests! These are consecutive runs, using the ancient set of 235 front, 255 rear defender sport SR tires mounted on my 15 inch steelies. The rear brakes are late 90’s Jeep Grand Cherokee disk brakes furnished with Powerstop pads and rotors. OAT was around 60 degrees F. The front to rear brake bias isn’t the best. I’m still in the process of dialing it in better. The runs are listed from first to last, and they are all measured in feet.

114
97
114
104
126

For an avg of 111ft

On every run I was fighting with applying the most amount of pressure to the pedal without locking the rear brakes up. Which would ultimately happen during every run. I found myself releasing and reapplying the pedal trying to find the sweet spot during the runs. No noticeable brake fade and had a great feeling pedal for all runs. With more seat time, and continuing the adjustment of brake bias, I think I can shrink that stopping average down.

This won’t be the last round of tests guys. I want to make sure these results are repeatable.
 
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Did another round of tests this evening. Got the brake bias to what I believe to be as good as it’s going to get. Same temp, same road, same tires. Listing from first to last run and all in feet. I’d say there’s an error of +-2 feet just to be safe.


103
104
104
99
97

For an avg of 101.4ft

The extra practice and additional bias adjustment really helped. Brakes felt good and only locked the rear towards the end of a few runs. Interested to see how this stacks up with other cars.
 
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gzig5 said:
Any "before" data? How much improvement?
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No unfortunately. Not exactly a fair comparison because of the weight but I found a test on yt with a RC Dakota equipped with 11 inch single piston caliper front, 10 inch drum rear brakes have a 3 run avg of 168.33 feet.

Weight difference is substantial though. Around 3100 lbs for my Duster, while the Dakota comes in around 4000 lbs.

The same guy with the Dakota proceeded to swap to viper 13 inch rotor/4 piston brembos front and rear with better tires and had a 5 run avg 103.4ft.
 
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Mopar muscle did a rear disk conversion on a '73 Dart Sport and checked the stopping distances between the rear drums and rear disks from 60-0. Their result was that from 60 mph factory disks up front and factory drums in the back the car took 133 feet, 6 inches to stop. After the rear disk conversion, the stoping distance improved to 122 feet 4 inches.

The online article is a total mess now, probably something with being converted over or moved to Hot Rod when MM was bought out. The final distance used to be a caption on the second to last picture, but I don't see the captions popping up anymore. The hardcopy article is easier to follow, but that's the way it goes.

Rear Disc Brakes - All Bound Up - Mopar Muscle Magazine

Now, there are other differences here no doubt, tire compound, road surfaces, driver input etc all make a big difference which makes comparing two different "at home" kind of tests hard to do. But the numbers you're getting are A LOT better than what Mopar Muscle got. And their stock numbers are pretty close to the factory published numbers I've seen. I'll have to look it up but somewhere I saw a drive test article from back in the '70's on a Demon that put the stopping distance around 125 ft if I remember correctly. I'll try to find it.

***Edit***
Here's a Road Test Report on a '71 340 Demon. Not the one I was looking for, as this is a drum/drum car. Neat stuff though. The stopping distances were absolutely abysmal, for anyone that says drum/drum is ok on the street today. The Road Test guys said they expected a 60-0 of 155 to 165 feet. What they actually got was a stopping distance of 169 ft, on a 3,250 lb car with E70's. That was their "best" distance, not an average of their results but a one off. Their Demon had 10" drums and a power booster. They did say their road surface wasn't ideal, but dang.

Vintage Road Test: 1971 Dodge Demon 340 – Road Test Magazine Takes A Real Devil For A Spin
 
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Here's another one. This is for a '76 Dart Sport with a 360, which would have had the BBP brakes. Only problem is that it's a 70-0, not a 60-0.
1975 Dodge Dart and Swinger cars in detail

Screen Shot 2020-09-19 at 10.47.47 AM.png
 
72bluNblu said:
Mopar muscle did a rear disk conversion on a '73 Dart Sport and checked the stopping distances between the rear drums and rear disks from 60-0. Their result was that from 60 mph factory disks up front and factory drums in the back the car took 133 feet, 6 inches to stop. After the rear disk conversion, the stoping distance improved to 122 feet 4 inches.

The online article is a total mess now, probably something with being converted over or moved to Hot Rod when MM was bought out. The final distance used to be a caption on the second to last picture, but I don't see the captions popping up anymore. The hardcopy article is easier to follow, but that's the way it goes.

Rear Disc Brakes - All Bound Up - Mopar Muscle Magazine

Now, there are other differences here no doubt, tire compound, road surfaces, driver input etc all make a big difference which makes comparing two different "at home" kind of tests hard to do. But the numbers you're getting are A LOT better than what Mopar Muscle got. And their stock numbers are pretty close to the factory published numbers I've seen. I'll have to look it up but somewhere I saw a drive test article from back in the '70's on a Demon that put the stopping distance around 125 ft if I remember correctly. I'll try to find it.

***Edit***
Here's a Road Test Report on a '71 340 Demon. Not the one I was looking for, as this is a drum/drum car. Neat stuff though. The stopping distances were absolutely abysmal, for anyone that says drum/drum is ok on the street today. The Road Test guys said they expected a 60-0 of 155 to 165 feet. What they actually got was a stopping distance of 169 ft, on a 3,250 lb car with E70's. That was their "best" distance, not an average of their results but a one off. Their Demon had 10" drums and a power booster. They did say their road surface wasn't ideal, but dang.

Vintage Road Test: 1971 Dodge Demon 340 – Road Test Magazine Takes A Real Devil For A Spin
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kick ***!!! Thanks for the posts! Hindsight truly is rearing it’s ugly head right now. Wish I would have tested the stock stuff. Because I could have duplicated some of my testing variables to make a good comparison.

Got the idea to do the swap and jumped in head first with blinders on lol
 
Next evolution I might embark on is power assisted brakes. The manual master works fine during hard braking and I didn't really notice any high brake pedal effort needed during any of the runs. But I believe it’d improve comfort for everyday driving.

I have a 2018 scat pack challenger and I love the brake pedal feel in that car. Come to find out mopar utilizes a vacuum pump to supply the booster, not engine vacuum. Which is extremely cool to me. So it got those oh so dangerous new project gears turning, “what if I can swap the booster and assembly from a challenger onto the duster”.

First thing I wanted to do is verify P/N’s between the different models. And from the best that I can tell, mopar uses the same booster/pump/MC setup from the base car all the way to the hellcat in 2018 lol

I ended up finding a booster setup off eBay with 2740 miles for 30 bucks shipped. At that price it is worth the risk that it’s not correct, or will not be able to work.

I have zero idea when I will get around to attempting this. There’s also a ton of variables that could potentially stop this project dead in its tracks. I still need to get into the D/O of my FSM and figure out how the booster supply system actually functions, I could be wrong about the pump setup. If this swap does happen, if it ever does, I’ll be sure to post up the results in another thread.

1EF65851-A3F8-46C6-8EAE-A5A3F29F91E0.png
 
Update post: Fair amount of miles driven on this setup now, and all is good! Here’s some pics I shot after welding in subframe connectors and the Z bar reinforcement bracket

1EB9408E-4D84-4B1D-8D70-C20CF738BE32.jpeg


DD049CEB-888E-4C6E-9C13-F8FC9FA49DED.jpeg
 
Any updates? Still doing routine inspects for cracks or other issues?

Curious how the angle iron is holding up.

Thanks.
 
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