Baller on a Budget BBK (BBBBK)

Cuttyman9

New member
well don't quote me but rock auto has 1996 porsche 911 calipers for 230 each reman'd (1996-1998 are the same except turbo's)
That's not too bad for brembo's. I use the pads out of those calipers and their dimensions are very similar since i dont have one to put right next to mine I cant say for 100 percent but I buy my repair parts (dust boots and seals) through a porsche place lol so between that and the pads being porsche pads I would thing there is a connection haha prolly like a 75-85 percent certainty.

just an idea.
 

underscore

Well-known member
Are you sure those calipers are Brembos tho? Also I'm curious if anyone else running the 2004 STi front rotors is running into balljoint rubbing issues.
 

Cuttyman9

New member
they use the same pads, same mounting style but different hold down (because of the top brace) but the faces are the same, the piston sizes for most are the same depending on application the stoptechs were purchased for.


anyways heres some pics

old stuff back when i was aiming for the porsche brembos but ended up buying 986 calipers vs the 911 ones i needed.
still have those if someone is in need.





new stuff



















The future





Using a wilwood rotor blank I designed a hat that could be made from 6061 to match the is350 rotors but shave a good deal of weight and keep the heat off the hub.
 

ALLensTRAC

New member
How about an OEM full floating 2 piece rotor with the same hat offset as the IS and same pad swept area but 355mm instead of 334mm? Oh and at a price of 59$ per rotor cost! Would that spike your interest?
Next to an OEM alltrac rotor:
ImageUploadedByTapatalk1397909665.083221.jpg

Mounted in a vise with an IS350 caliper:
ImageUploadedByTapatalk1397909737.716367.jpg

I am not an engineer but I'm planning on running this setup once I'm able to make mock up brackets. So far I have only 330$ into this for 2 piece rotors and mono block aluminum calipers.
 

ALLensTRAC

New member
It probably does have full contact but the IS pad contact area is very large(55-60mm IIRC). As long as the pad is not over hanging on the edge it is fine. But at the same time it isn't using all the rotors potential friction area.
 

Cuttyman9

New member
The rotor doesnt fully need to be covered, you will gather the most force at the farthest position from the center based on the increased moment arm. The reason why the sweapt area is farther out is because I accidentally stumbled on this whole layout, I need to mill off a bit from the bracket to drop it down a hair.

I don't want 355's because I don't want to be forced to run 18's only.
Now if you find me hats and 334 rotor blanks for that price sure.


Not trying to make a pissing contest out of this, was just stating what I had into it to show that it's not some high dollar build. I'm still in school so i don't have cash like that to throw around.
 

Cuttyman9

New member
I'm waiting on your reply allenstrac, I want to know where you get those parts for cheap because I'm leery of them actually being that cheap.


bajallaman did you consider cressida rear rotors? ive been trying to find some that are vented, my plan was to use 300zx rear calipers because they are super super cheap in the junkyards. I'd use is300 ones if I found them cheap, what are you using for a bracket on the rears?
The cressida rotors are a slight bit smaller in diameter than the stock celica/camry stuff but are vented and fit the drum ebrake bits.
 

ALLensTRAC

New member
Cuttyman9":18pmg0jb said:
I'm waiting on your reply allenstrac, I want to know where you get those parts for cheap because I'm leery of them actually being that cheap.


bajallaman did you consider cressida rear rotors? ive been trying to find some that are vented, my plan was to use 300zx rear calipers because they are super super cheap in the junkyards. I'd use is300 ones if I found them cheap, what are you using for a bracket on the rears?
The cressida rotors are a slight bit smaller in diameter than the stock celica/camry stuff but are vented and fit the drum ebrake bits.

The rotors come from the 2013-2014 Lexus GS350 F-sport RWD. I work at a Lexus dealer and when we are bored we price things out in the parts dept. to see how cheap they are. To my suprise the rotors were 59$ cost. I paid 71$ each with tax(10% over cost). I thought it was a typo so I ordered them as fast as I could!!! This is the biggest reason I went 5x114.3 because of all the cars that use this PCD with big brakes.

For the rear have you looked at the ISF rear rotors? They are around the same height as alltrac but are 28mm thick so they can support some of the larger Brembo options from other manufacturers. They use 190mm parking brake shoes just like the supra but I'm working on a solution for that. The IS300 calipers will not work as they are used with non vented rotors and they have only 12mm total rotor thickness clearance.

To the OP: sorry for the thread jack but I figured since you two are engineers I could use this as a place to bump ideas off you guys. If you want me to delete my posts I will.
 

bajallama

New member
ALLensTRAC":18tp6snc said:
To the OP: sorry for the thread jack but I figured since you two are engineers I could use this as a place to bump ideas off you guys. If you want me to delete my posts I will.

No worries, I like the input and what you guys came up with.

Cuttyman9":18tp6snc said:
bajallaman did you consider cressida rear rotors? ive been trying to find some that are vented, my plan was to use 300zx rear calipers because they are super super cheap in the junkyards. I'd use is300 ones if I found them cheap, what are you using for a bracket on the rears?
The cressida rotors are a slight bit smaller in diameter than the stock celica/camry stuff but are vented and fit the drum ebrake bits.

I never did cause I got the legacy rear rotors to fit perfect with very little machining. The parking brake works and they are a large vented rotor. You can most likely run the upgraded rear rotor from Brembo (If you look at the first page, another user stated the option available) and run the bolt on 205 rear caliper. That would probably be the cheapest route, however it is not confirmed this works.

Just keep in mind when you're doing this the unsprung weight you are introducing. The cars the brakes come off of all have aluminum uprights. We have heavy cast iron ones and adding a heavy rotor does not help at all. This is where a two piece rotor will shine, but cost you. Also keep in mind practicality. Those brakes look beautiful ALLenTRAC, but I feel they maybe slight overkill for most applications. If you are doing an event like REDLINE Time Attack or similar, I can see that as helpful, but most of those cars are full on race cars with fully dependent brake systems. Going anything larger than equivalent to an STi seems unpractical. Also these rotors are rotating mass. Larger rotors = larger inertia = slower acceleration. These are all things to consider and I have put a lot of thought into.

I will be sharing my calculations soon once I finish the excel sheet. You guys can use it to analyze your different setups and see what works best. For my combination I got a 171% improvement for the front with around a 70% front and 30% rear bias(Stock came out to 74% front and 26% rear). Thats assuming I can find a 2 piston caliper in the rear to fit. I am most likely just going to make a bracket to get the Legacy caliper to fit. I will be deleting the ABS pump and installing a Bias valve to adjust my proportion to get 4 wheel lockup.
 

Cuttyman9

New member
If only those rotors were 13" vs 14" cuz I don't want to have to get 18's only.
to tuck those under the 17's would be difficult to say the least.

The drum portion is small on the celica's so I'm rather limited unless i go with some other sort parking brake arrangement.
 

Cuttyman9

New member
Yup well where my brake system adds to the weight, the wheels and tires take away from it. I am currently down 8lbs a corner vs stock.
This brake setup provides confidence, I learned a long time ago that before you can go fast you must stop fast.
when you drive something with 4 wheel drum brakes you learn that very quickly.

Those 14" rotors prolly are lighter than the subie ones, if they are the same layout as my is350 ones then they move the rotor away from the ball joint gaining a greater advantage. Also note with aluminum hats they shed the heat into the atmosphere quicker keeping that heat away from the bearings.


so to give credit where credit is due, that rotor is a great find.

good job on your setup bajallama, sounds like its just what you needed for your car.
 

bajallama

New member
Cool, at least your saving some weight through the wheels. But know that inertia is multiplied by the square of the radius. Meaning that although your wheels maybe lighter, you have a higher inertia. Not only because you are now running a larger diameter wheel, but because most of the mass is at the outer portions. It's like spinning in your chair with your arms and legs spread out. When you bring your extremities in to you(the center) your rotational speed increases. Just something to keep in mind.

ALLEN those rotors are amazing if you can really get them that cheap. I might have to use them on a future project 8)
 

Cuttyman9

New member
Hahaha so why aren't you building 2 piece factory sized rotors with light 4 pots? You know instead of heavy rotors and massive factory calipers?
 

ALLensTRAC

New member
I do have the numbers and will post them shortly. Things have been a bit hectic so I haven't been able to respond to this in a bit. Lexus also came out with a TSIB updating the rotors for a clicking sound on slow speed turns. This has to do with the hat to rotor hardware. I will post the updated numbers in a bit.

I'm also working on a solution for the small parking brake shoes our car came with (170x39.9). Most of the 5x114.3 big rotor options have a 190mm diameter parking brake. I'm working on either a compatible backing plate or shoes that will fit ours with increased diameter.
Once I've done all the work on this I will post my brake set with cost front and rear as well as what's needed. I hope everyone does this as we all have different goals for our cars requiring different components. My personal goal is 200mph in the standing mile and that is why I'm working with 14inch rotors and 285/30r18 tires. I need all the stick and stop I can get!!!

Maybe I'll trade a set of these rotors to you guys who have access to solid works and machining equipment for my brackets lol.
 

bajallama

New member
Cuttyman9":1lv4aj1q said:
Hahaha so why aren't you building 2 piece factory sized rotors with light 4 pots? You know instead of heavy rotors and massive factory calipers?

Well mostly because it's a budget build. 2 piece rotors are going to have a minimal effect on inertia, since the material you are removing/saving is in the center. They DO help with unsprung mass. Other than the unicorn rotors that Allen found, 2 piece's were going to blow my budget out of the water. Although I didn't weigh the original 165 calipers, they are the same if not heavier than the UCF30 calipers. At 9 pounds, you can't get much better than that and they are not rotating mass. So in all reality, changing to the larger caliper made no effect on my handling/acceleration. I went with the heavy rotors because the stock rotors lack thermal mass, that's why the brakes suck. It was a sacrifice you have to take in order to make the car perform in a racing environment.

Your setup looks great and I'm sure it will perform well, but I was only stating the physics just so you know. It's that old saying; robbing peter to pay paul. It's never really a win win, but you can try to keep a good balance by doing the right calcs and building a system that performs well with out hindering other performance characteristics of your vehicle.
 

Cuttyman9

New member
Lol just being an ass back haha
That is all, cuz if interita was your largest concern along with unsparing weight it's quite obvious that stock sizing is ideal.



I look forward to seeing the part numbers on those rotors.
They are worth givin a shot.

I knew the physics, I disregarded it because wide/light/cheap wheels and wide/cheap tires are far more important to me than the inertia and added mass.

Can't do diddly with big brakes (or the entire car for that matter) if you don't have the grip to attach it to the road.
 

MWP

New member
Inertia is of almost zero concern.
Sustained braking power and unsprung weight are the important ones.
 
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