Subaru 4 pot front callipers on the front and the rear?

[matteo92065]

Junty, I will look into increasing the rear rotor/caliper size. I will never go smaller!!! I've got so many other little things to take care of, I'll get new pads front and rear for now.

[C.Plavan]

My .02 cents (Again). I keep seeing these brake/caliper threads....... you really do not need to change anything with the brakes.
1. 4 pot Wilwoods front and rear (kit). (12" rotors)
2. Wilwoods are extremely light over the stock stuff.
3. Save your money and do not get the bigger brakes.
4. Do not overthink the brakes, the car is light, and my 818R is heavier than any street 818S (minimum race class weight with me in it (HP/WT) 2266 pounds).

I mated these up with Raybestos ST46 pads(or ST43 cant remember right now). Braking is really, really good (130 mph+ to 40mph many times). I adjusted them with my dash mounted bias control.

[Bob_n_Cincy]

My .02 cents (Again). I keep seeing these brake/caliper threads....... you really do not need to change anything with the brakes.
1. 4 pot Wilwoods front and rear (kit). (12" rotors)
2. Wilwoods are extremely light over the stock stuff.
3. Save your money and do not get the bigger brakes.
4. Do not overthink the brakes, the car is light, and my 818R is heavier than any street 818S (minimum race class weight with me in it (HP/WT) 2266 pounds).

I mated these up with Raybestos ST46 pads(or ST43 cant remember right now). Braking is really, really good (130 mph+ to 40mph many times). I adjusted them with my dash mounted bias control.

Hi Chad
Your advise is worth much more than 2 cents.
I totally agree with you.
I believe you have a balance bar pedal system which allows you to take pedal force from the front and move it to the rear.
The proportional valve only reduces the front and doesn't add anything to the rear.
Is it easy for you to take a picture of your balance bar position to see (count threads) how far it is shifted on way?
Bob

Edit: Chad, I just looked back and see you are using a proportional valve with better pads.

[metalmaker12]

My .02 cents (Again). I keep seeing these brake/caliper threads....... you really do not need to change anything with the brakes.
1. 4 pot Wilwoods front and rear (kit). (12" rotors)
2. Wilwoods are extremely light over the stock stuff.
3. Save your money and do not get the bigger brakes.
4. Do not overthink the brakes, the car is light, and my 818R is heavier than any street 818S (minimum race class weight with me in it (HP/WT) 2266 pounds).

I mated these up with Raybestos ST46 pads(or ST43 cant remember right now). Braking is really, really good (130 mph+ to 40mph many times). I adjusted them with my dash mounted bias control.

Ditto

[DodgyTim]

Just to close off this upgrade, I chose to go ahead for the following reasons:

1 I have to pass a brake test prior to registration. They formally measure deceleration under heaps of conditions include cold stop, fade resistance (15 consecutive 100 kmh stops), and there is a limit on the allowable brake pedal force that can be applied (500 newtons or about 50kg force).

2 They limit the use of proportioning valves to “Proportioning valves can only be used to correct a small imbalance”. One of the tests is performed with the proportioning valve disconnected.

In addition to the 2006 4 pots and the 316mm diameter rear rotors, I’ve opted to swap the master cylinder to the 7/8” diameter unit (The OE Nissan part number is 46010-1M320, thanks to lap_dog) to try and reduce pedal effort.

The backing plates I used were from a Forester that had standard brakes, they were the closest standard fit. The 4 pot front callipers have much longer mounting arms than the 2 pot rears they replace.
IMG_0213.jpg


I machined the calipers a little bit (actually a bit more than is shown in the right hand side of the photo), relocated the holes in the backing plate, and welded in some reinforcement to the backing plate where the old holes were.
IMG_0211.jpgIMG_0215.jpgIMG_0216.jpg

Final fitment was good and the service brake (park brake) works as standard.
IMG_0262.jpgIMG_0263.jpg

Before
IMG_0261.jpg

After
IMG_0264.jpg

[Bob_n_Cincy]

Just to close off this upgrade, I chose to go ahead for the following reasons:

1 I have to pass a brake test prior to registration. They formally measure deceleration under heaps of conditions include cold stop, fade resistance (15 consecutive 100 kmh stops), and there is a limit on the allowable brake pedal force that can be applied (500 newtons or about 50kg force).

2 They limit the use of proportioning valves to “Proportioning valves can only be used to correct a small imbalance”. One of the tests is performed with the proportioning valve disconnected.

In addition to the 2006 4 pots and the 316mm diameter rear rotors, I’ve opted to swap the master cylinder to the 7/8” diameter unit (The OE Nissan part number is 46010-1M320, thanks to lap_dog) to try and reduce pedal effort.

The backing plates I used were from a Forester that had standard brakes, they were the closest standard fit. The 4 pot front callipers have much longer mounting arms than the 2 pot rears they replace.
IMG_0213.jpg


I machined the calipers a little bit (actually a bit more than is shown in the right hand side of the photo), relocated the holes in the backing plate, and welded in some reinforcement to the backing plate where the old holes were.
IMG_0211.jpgIMG_0215.jpgIMG_0216.jpg

Final fitment was good and the service brake (park brake) works as standard.
IMG_0262.jpgIMG_0263.jpg

Before
IMG_0261.jpg

After
IMG_0264.jpg

Great Job Tim
With equal calipers F&R and running 235F and 255R tires, I am very close with no PV. So close I cannot decide where I should put it in. I am leaning toward putting it in the rear.
Are you going to go aggressive on the pads?
Bob

[DodgyTim]

Great Job Tim
Are you going to go aggressive on the pads?
Bob

Not initially Bob, for the pre registration test I need good performance from first stop, I'll look at better ( I have currently got high performance street pads in) if I need more brake when racing

[Tamra]

That sounds like an intense braking test. I hope the rest of the inspection isn't so rigorous! I expect you'll pass this portion with flying colors as long as you get the pads bedded in properly beforehand. Which performance street pads did you go with?

[Innkeepr]

Ok guys,

this build is going to take me a while. My MKII build was 8 years- that's the price of being a single income public servant and raising a family.
Now, with the eldest starting college, and the second not far behind, it will likely be a long term build again ( hope not as long )

I am piecing this together, gathering as I go based on the FFR manual build list.
I purchased a JDM EJ207 complete minus intercooler, has all wires & computer - but will build another mega squirt for mgt.

As I comb the yards around here, what will work best ? mixing/matching and not knowing what will/will not work is going to be wasted cash.
I have read that you should match the MC to the calipers/ ie, use all parts from an 06 ( MC / booster/ calipers )

Seeing how Bob, Plavan, Mechie, & Metal are on top of these cars, it would be great if you guys could start a thread about which parts
you could scavenge, what works best - for those who of us who are putting Frankenstein together without a donor.

So far, I was told to get the 06 steering rack ( better ratio ? ) and get 06 wrx brake system ?

Any thoughts ?

thanks & be safe.
"E"

[DodgyTim]

That sounds like an intense braking test. I hope the rest of the inspection isn't so rigorous!

Much worse actually, I'll post on the chassis torsion and beaming test soon

[Harfang2]

Just to close off this upgrade, I chose to go ahead for the following reasons:

1 I have to pass a brake test prior to registration. They formally measure deceleration under heaps of conditions include cold stop, fade resistance (15 consecutive 100 kmh stops), and there is a limit on the allowable brake pedal force that can be applied (500 newtons or about 50kg force).

2 They limit the use of proportioning valves to “Proportioning valves can only be used to correct a small imbalance”. One of the tests is performed with the proportioning valve disconnected.

In addition to the 2006 4 pots and the 316mm diameter rear rotors, I’ve opted to swap the master cylinder to the 7/8” diameter unit (The OE Nissan part number is 46010-1M320, thanks to lap_dog) to try and reduce pedal effort.

The backing plates I used were from a Forester that had standard brakes, they were the closest standard fit. The 4 pot front callipers have much longer mounting arms than the 2 pot rears they replace.
IMG_0213.jpg


I machined the calipers a little bit (actually a bit more than is shown in the right hand side of the photo), relocated the holes in the backing plate, and welded in some reinforcement to the backing plate where the old holes were.
IMG_0211.jpgIMG_0215.jpgIMG_0216.jpg

Final fitment was good and the service brake (park brake) works as standard.
IMG_0262.jpgIMG_0263.jpg

Before
IMG_0261.jpg

After
IMG_0264.jpg

Hi guys, i have built an 818 S in 2014 and now thats road legal in QC Canada since 2016. I did a lot of lapping on small and big track and this winter i search some upgrade on the forum. I have buy a set of wildwood rally Subaru front brakes kit with 6 pistons and the braking is really better now but the
rear Wrx stock brake is too small and need more cooling (they becoming RED after 10mins).So i found this tread and i found the DBA rotor set but before going further, i want to know if you have good result or upgraded something since 2015 and if the 4 pots on the back braking more/equal than the wildwood 4 pistons set. This is not a race car but you know on the track this car kick a Audi R8 v10 *** hahaha and my brake is my limit for now.
Thanks for the picture and information. I will probably go with a 7/8 master cylinder too if the feeling of the brake pedal is more easy/sensitive than the 5/8 .

[DodgyTim]

I'm happy with the setup, I still run it as seen in the photos above, with virtually no bias adjustment.
I haven't tested any other setup to compare with, there was a local 818 with the wilwood setup, but unfortunately I didn't get a drive
These brakes are quite heavy, if I was doing it again I'd look seriously at the Cadillac CTS kit too. Those kits got popular after I completed my mods

[Harfang2]

Thanks for the inside! I will take a look to the cadillac caliper too... I have already find a potential seller for the 4 pots subaru and i have found the disc like the dba on KNS brake website for less and thats the same buisness that making disc for DBA. And for the 7/8 master cylinder have you found a big difference on the pedal brakes because i have buy the kit without the wildwood dual cylinder option .
Thanks

[DodgyTim]

Sorry, I didn't try the standard 1" master, I've only used the 7/8", so I can't tell you how much difference it made
Pad selection is important to pedal effort too. I'm still running performance "street" pads, the pedal effort is OK
Cheers

[prematureapex]

Instead of those expensive conversion rotors, I think I'll buy a set of those modified/thicker parking brake shoes and run stock STI rear rotors. Generics are like $30 a piece.

[prematureapex]

Just to close off this upgrade, I chose to go ahead for the following reasons:

1 I have to pass a brake test prior to registration. They formally measure deceleration under heaps of conditions include cold stop, fade resistance (15 consecutive 100 kmh stops), and there is a limit on the allowable brake pedal force that can be applied (500 newtons or about 50kg force).

2 They limit the use of proportioning valves to “Proportioning valves can only be used to correct a small imbalance”. One of the tests is performed with the proportioning valve disconnected.

In addition to the 2006 4 pots and the 316mm diameter rear rotors, I’ve opted to swap the master cylinder to the 7/8” diameter unit (The OE Nissan part number is 46010-1M320, thanks to lap_dog) to try and reduce pedal effort.

The backing plates I used were from a Forester that had standard brakes, they were the closest standard fit. The 4 pot front callipers have much longer mounting arms than the 2 pot rears they replace.
IMG_0213.jpg


I machined the calipers a little bit (actually a bit more than is shown in the right hand side of the photo), relocated the holes in the backing plate, and welded in some reinforcement to the backing plate where the old holes were.
IMG_0211.jpgIMG_0215.jpgIMG_0216.jpg

Final fitment was good and the service brake (park brake) works as standard.
IMG_0262.jpgIMG_0263.jpg

Before
IMG_0261.jpg

After
IMG_0264.jpg

Thinking out loud...

Do you think I could run a spacer on the hub to center the rotor vs. machining the caliper ears?

And along those same lines, you don't happen to recall how much you took off do you? Or the resulting thickness of the ear?

[DodgyTim]

The main point of machining the ears, and relocating the holes in the backing plate, was to move the caliper in closer to the axle centerline.
Otherwise the pad would overhang the outer edge of the disk.
I can measure the final thickness this weekend if you like

[prematureapex]

I knew part of it was to accomplish that, I just thought you thinned it down to center the rotor as well. Based on my initial measurement, looks like 2.5-3mm puts the rotor in the middle of the caliper on the stock ear thickness. Then again, with a 20mm rotor, maybe there is enough extra room that you don't have to center it really at all.

Sticking point being, I can crudely clear material away radially with a grinder, etc. but without a mill, I couldn't do the depth cuts. While I can get to a mill, I think a grinder and a 3mm spacer could get the job done.

[prematureapex]

Tim/Bob,

Any tips for locating the holes accurately? I'm finding it tough to clamp the caliper in place with the rotor on (and still be removable) to ensure pad alignment. Maybe mark the back of the caliper with the rotor on, remove the rotor, and then clamp/mark hole/drill according to the marking? But that doesn't seem too accurate.

I'm probably missing an easier way to do it...

With a junk backing plate, I tried Bob's way of opening up one of the holes, and relocating only the other. But with the 4-pot pad shape, that doesn't seem to work without a bit of pad overhang (which isn't the biggest deal, but not ideal).

Thanks!

[DodgyTim]

It's been ages since I did the mod, but from memory I temporarily bolted the backing plate and rotor to the spindle, trial fitted the caliper (with worn/without pads) and aligned the pad retaining pins to the outside of the rotor, checking the inner clearance on the rotor hub too.
I then center punched the backing plate and drilled 2 slightly oversized holes.
I re-assembled everything with the weld-on washers + bolts etc and positioned it exactly as I wanted it, snugged up the bolts and tacked the washers in place.

The calipers bolts were a close fit to the washer holes, not the holes in the backing plate
Cheers

[prematureapex]

OK, finally finished welding this up. Thanks Tim for the above, my issue was the step between putting the rotor on, and center punching the holes. As you have to take the rotor off do do that, but taking the rotor off meant moving the caliper and losing the hole location.

When it was said and done, my holes were more like rough slots from the factory holes to their final resting place ( I was using hand tools in an inappropriate manner). In view of that, I used 3/16" stock and an angle grinder to make thick patches vs. using thinner washers as you did. Overall, I think it will be AOK.

At full thickness, however, the inner pad just barely doesn't fit...so I'm thinking I'll need to space the rotor out via a wheel spacer at least until the pad wears a bit (then I can move to a shim on the outer pad).

At $40/piece for STI rotors, $190 for e-brake shoes, and $112/per for reman calipers. This is certainly the cheap way to give yourself PLENTY of rear brake with cheap consumables. Same pads F/R is also a nice plus. The more I think about it, even many of the expensive aftermarket solutions are designed for the Subaru, which means they still don't provide enough clamping force.

I'll post pictures of my awful work later...

IMG_20190307_111252861.jpgIMG_20190313_121805617.jpgIMG_20190307_111231252.jpgIMG_20190313_152431966.jpg

[tmoretta]

I am looking, with much interest, at this thread about using the 4 pot calipers in the rear of the 818. I already am using the H6 rear rotors on my car and am still unhappy with the braking. I have '02 WRX front calipers on the car now. A few questions/concerns: What model/year of subie 4 pot calipers should I use on the rear? Can I continue to use the H6 rotors, or is it best to source some others? Will worn brake pads pop right out of the wider 4 pots when used on the narrower (non vented) rotors? How much modifying needs to be done to the backing plates and/or rotor hubs?

[Bob_n_Cincy]

I am looking, with much interest, at this thread about using the 4 pot calipers in the rear of the 818. I already am using the H6 rear rotors on my car and am still unhappy with the braking. I have '02 WRX front calipers on the car now. A few questions/concerns: What model/year of subie 4 pot calipers should I use on the rear? Can I continue to use the H6 rotors, or is it best to source some others? Will worn brake pads pop right out of the wider 4 pots when used on the narrower (non vented) rotors? How much modifying needs to be done to the backing plates and/or rotor hubs?

Tmoretta,
At one point I was running H6 rotors, with 04FXT front calipers. I took an old pad backing plate and welded it to the new outside pad. this prevented the pad from falling out if worn out. Changing to the DBA rotor eliminated this issue.
Bob

pad.jpg

[tmoretta]

What is the DBA rotor? Same diameter? Uses E brake?

[Bob_n_Cincy]

What is the DBA rotor? Same diameter? Uses E brake?

https://thefactoryfiveforum.com/show...l=1#post218828

DBA2657 are 5 x100mm lugs, 170mm e-brake, 20mm thick.
see attached. Available from summit.


dba_2657_cat_a_2004_sti_rear.jpg

[DodgyTim]

The original 4 pot calipers I used suited a 295 dia x 25 thick rotor. They were sourced from 2006 or 2007 WRX's, though they do come on some other Subaru models too.
The DBA 42657 is 316mm diameter and 20 mm, thick so if my pads got down to less than 2.5mm thick, they'd be further out than standard fitment

The good features of the DBA rotor is that it keeps the standard 170mm dia handbrake and 5x100 stud pattern.
Overall this was a good mod for me because the
calipers were free
pads are the same front/rear
The downside is they are quite heavy. When I did this there wasn't much chatter about the Cadillac CTS caliper swap, if I was doing it now I'd look at that too

[prematureapex]

As I mentioned before, the other option is to use a stock 2004 STI rear rotor (190mm ebrake drum), and buy/have made thicker shoes to maintain the ebrake. Godspeed brakes makes them out of the UK.

https://www.godspeedbrakes.co.uk/276...-adapter-kits-

If you're going to track the car, you're going to go through rear rotors. So for me it made sense to spend the $200 on the shoes up front, so I can buy $80/pr. generic STI rotors vs. the unique $300/pr. DBA conversion rotors.

Although either option is good.

As far as machining goes, you can get it done with an electric angle grinder and a drill if you're handy...but you'll want to have some washers or patches welded on when you're done. Took a few hours in the basement.

+1 on the caliper weight, that's the drawback. But if the car needs more brakes, and you don't want to drop a ton of money...this is a good solution imho.

[walt555]

I am looking, with much interest, at this thread about using the 4 pot calipers in the rear of the 818. I already am using the H6 rear rotors on my car and am still unhappy with the braking. I have '02 WRX front calipers on the car now. A few questions/concerns: What model/year of subie 4 pot calipers should I use on the rear? Can I continue to use the H6 rotors, or is it best to source some others? Will worn brake pads pop right out of the wider 4 pots when used on the narrower (non vented) rotors? How much modifying needs to be done to the backing plates and/or rotor hubs?

If your still having high pedal force to stop, I think it has more to do with pedal ratio than more or bigger brakes. For stock wrx pedals "Hindsight" drilled holes 7/8ths inch up and 1 1/4th inch up. The 7/8th was better than the ffr 1/2 inch and the 1 1/4" was spongy. So I'm thinking 1 inch up from stock. Better yet talk to wilwood about a pedal box for you application. Hope this helps!

[Bicyclops]

Howdy,

I read all this stuff three years ago and made some of my decisions based on advice gleaned. I went with Cadillac Brembos on all four with 04 STI front rotors. I'm using, so far, generic Delco ATS brake pads. Might go to better pads as I get it dialed in better. I added Wilwood cable actuated E-brakes to get legal. I drilled the FFR hole higher up the pedal and following Hindsight's advice, another hole higher than that. Like most I found the brake pedal very hard and couldn't lock them or even really panic stop even with every thing I could do on the pedal. Been so busy having 500 miles of canyon road fun, where I didn't really use the brakes much, I ignored the lack of braking ability. Today I tested with the clevis pin in the top hole and it made a world of difference. I was able to lock the rears @ 40mph. I put my bias valve in the rear circuit. I've turned the bias out 1 full turn and have yet to test that.

Got back from test drive. Brakes are awesome. Very happy with them.

Ed

[blomb11]

Howdy,

I added Wilwood cable actuated E-brakes to get legal.

Ed

How did you get an e-brake with the Cadillac brembos and STI rotors? I don’t think my line lock will pass the CA inspection.

[prematureapex]

How did you get an e-brake with the Cadillac brembos and STI rotors? I don’t think my line lock will pass the CA inspection.

You can order thicker ebrake shoes from the UK. I believe I posted the link earlier in this thread.

[blomb11]

You can order thicker ebrake shoes from the UK. I believe I posted the link earlier in this thread.

Ah yes I see it now...I should have read the whole thread. My google skills are not working well to try and figure out the pad wear surface dimensions of the DBA 2657S conversion rotor (170mm ebrake). I have 5x100 STI front rotors on the rear now so I will measure the wear area, see if I can try to compare it online, or maybe just buy a DBA rotor to measure. It seems like as you and others have done adding material to offset the Cadillac caliper could work. My question/concern is the front and rear pads are usually different sizes with the rears being smaller. I can't remember if this is a pad height or length difference. If the pad height is the same front to back then I think it will work just need to modify the OEM caliper bracket. Sucks that when I moved I tossed all of the rear brackets and ebrake stuff.

[Bob_n_Cincy]

to try and figure out the pad wear surface dimensions of the DBA 2657S conversion rotor (170mm ebrake).

rotor.jpg

[Bicyclops]

I used '04 STI rotors front and rear and the Caddy Brembos. With no hat section, you can't do drum E-brakes so I went to the Wilwood units. I think they might be kart brakes. I don't have the model number handy, but I did find them by searching the Wilwood site. The cables are also Wilwood. I used an aftermarket brake handle, Lokar I think. I'm very happy with this setup.

Ed

Rear brake resize.jpg