4-Pots? Oh yea, they're mounted up.

[deadlydave]

Today, Tom(The guy who now has my old legacy) and I managed to get the mighty 4-pots mounted up on the baja. It wasn't an outright challenge but did take some time. His garage/shed was waaay underheated, but everything went off without a hitch. I'm going to do a writeup(the instructions are pretty easy) that has part numbers in it. Found out I didn't need to buy the 06-07 WRX rotors--the Baja Turbo 2pot rotors are the same freakin' part. Oh well, piece of mind with some new brake hardware.

I also got my Pioneer HU out of the legacy, along with the JDM tails. Still for sale people, great shape and working!

Pics: (Taken with the camera on the LG Chocolate.)
Tom, wrenching on the Caliper bolts.
http://www.cs.sunyit.edu/~trifard/images/bajaturbo/tom2.jpg

Driver's side Hardware mounted (new rotors, calipers, pads, pins, studs, and wheel spacer)
http://www.cs.sunyit.edu/~trifard/images/bajaturbo/mounted.jpg

A shot with the wheel on. The brakes look like they're bulging out of the rather small wheels.
http://www.cs.sunyit.edu/~trifard/images/bajaturbo/mounted3.jpg

[HotBoxer]

looks good dave. do you have some more info on the HU. mine seems to be on its way out.

[_RM_]

looks sweet. how much more braking power does it give you?

[Mr. Sociable]

It's sexy.


Does it help braking by a noticable amount?

[sharky nrk]

it provides LESS braking power. it provides better feel and modulation and bias for superior brake control

[d1giPhux]

^ Doesn't sound like its too much useful for daily driving then huh? I hate having to mash on the brake pedal to get it to stop.

[deadlydave]

it provides LESS braking power. it provides better feel and modulation and bias for superior brake control

Firstly, the roads have been slick since the minute the brakes were installed. Big-time bummer, I haven't gotten to do a 70-0 test

Sharky nrk, are you saying that it takes more power from my leg to get a good result from the brakes? I seem to have noticed they feel the same for light braking, but a little power from my leg and I can feel the brakes biting more. The stock brakes would grip to a certain point, and just kind of hold there, no matter how much more force I put down.

[rougeben83]

it provides LESS braking power. it provides better feel and modulation and bias for superior brake control

Firstly, the roads have been slick since the minute the brakes were installed. Big-time bummer, I haven't gotten to do a 70-0 test

Sharky nrk, are you saying that it takes more power from my leg to get a good result from the brakes? I seem to have noticed they feel the same for light braking, but a little power from my leg and I can feel the brakes biting more. The stock brakes would grip to a certain point, and just kind of hold there, no matter how much more force I put down.

Best way to describe it is less slack in the system since it's a mono-bloc caliper and not a floating design. It's similar to putting SS lines on the car.

What pad did you end up getting? I'm running Hawk HPS's...I may switch to a more aggressive pad later.

Looks nice btw Dave :wink:

Don't forget to change your fluid now :)

[deadlydave]

What pad did you end up getting? I'm running Hawk HPS's...I may switch to a more aggressive pad later.

Looks nice btw Dave :wink:

Don't forget to change your fluid now :)

Thanks. Right now, just stock pads. I'll be driving these until the stockers are shot. I did a full system flush with brand new Valvoline V-power fluid.

I'm still trying to figure out what to do for the rears--WRX 2-pots of the same origin would fit and look good, but the STi Brembo Rears might shift the braking balance to the rear a bit and brake harder.

[d1giPhux]

I would be interested to see what they feel like. How much you pay for them? They look great no doubt! =]

[deadlydave]

I would be interested to see what they feel like. How much you pay for them? They look great no doubt! =]

For all parts including pads, pins, etc: $780, everything new in the box. I have a very good friend who works for a dealer. I didn't need the rotors either, could have saved almost a hundred fifty bucks if I didn't buy them.

[Sarra]

I would be interested to see what they feel like. How much you pay for them? They look great no doubt! =]

For all parts including pads, pins, etc: $780, everything new in the box. I have a very good friend who works for a dealer. I didn't need the rotors either, could have saved almost a hundred fifty bucks if I didn't buy them.

Too bad I'm stupid broke from having to fix the Legacy, or I'd ask you to hook me up with some WRX front brackets, calipers, pads, and BH rear brackets, calipers, and pads. :-(

[Mr. Sociable]

it provides LESS braking power. it provides better feel and modulation and bias for superior brake control

Can you explain this? Common sense dictates to me that (and this is without any research mind you) these should have more pad surface and pressure being applied to the discs, therefore increasing the stopping power by increasing friction. I understand where the additional feel and modulation comes from, but I don't get the less power part.


Help a noob.

[d1giPhux]

^ +1 .. and why would that be a good thing for normal daily driving? Or would it not be..? :shock:

[sharky nrk]

[quote="sharky nrk":1m1811yi]it provides LESS braking power. it provides better feel and modulation and bias for superior brake control

Can you explain this? Common sense dictates to me that (and this is without any research mind you) these should have more pad surface and pressure being applied to the discs, therefore increasing the stopping power by increasing friction. I understand where the additional feel and modulation comes from, but I don't get the less power part.


Help a noob.[/quote:1m1811yi]

deadly dave, I am saying that for the same leg force you exert the front brakes will exert less brake torque.

Mr. Sociable, well its all in the piston sizing. brake torque can be calculated from several variables. these include total piston area, effective rotor diameter, pad friction coefficent, ect ect. the rotors are exactly the same so no net changes from the rotors, the effective radius is effectively the same, the pad material can change from pad to pad but stock 4pot pads are not much different than stock 2 pot pads neither in area or compound (we are looking at change in torque from 4pots not pad so if you are running non-stock pads it is a different change). Pedal ratio is the same, master cylinder is the same. Now what is different is the total effective piston area.

In a sliding caliper design, a resultant force equal to the force of the two pistons is exerted on the non-piston size of the caliper. so take the piston area x2. On four pots the four pistons oppose each other so take the total area of the four pistons

wrx 2 pot piston area x2 > sti 4pot non brembo piston area -> therefore wrx 2pots brake torque > sti non brembo 4 pots brake torque.


Now this is not a bad thing. subarus (like most other cars) tend to be overly front biased. The rears can do more of the work, take thermal load off of the fronts, and improve stopping distances through better balance. the 4 pots do have far far better feel and modulation than the 2pots as well.

lets be clear on this - it is a worthwhile upgrade, but it does not provide "more" stopping power - just better stopping power

also for the rears h6 or first gen legacy turbo brakes will provide even more bias to the rear, more thermal capacity, and generally better brakes. if bling is not the most important thing you get basically all of the performance of the 2 pot rears out of an older legacy turbo setup

[Jedi Taxi]

^
+1 Entirly correct, I'm just going to reiterate

The main way one can actually increase thier stoping power is by decreasing the brakes hard line length or increase rotor size. Or knowing you parts functions. However, this involves knowledge of materials, thermal dynamics, somemore basic mechanical engineeringness, and generally phancy math. (yes, with a PH infront. Only minus the D, because you can't have a PHD in the mechanical engineering degree, at least at the college im at. That and PHDancy doesn't make any sence)

The more effiecent brake design would be better for every application, road racing, street, autoXXX, or just daily driving. Better control and efficency is better than lack off. More effiecent modulation control is better than brute force with so much as a tap of the brake.

But don't get me wrong! those 4 pot calipers kick ass man!

[Mr. Sociable]

Well I learned something today.


Thanks! :grin:

[sharky nrk]

^
+1 Entirly correct, I'm just going to reiterate

The main way one can actually increase thier stoping power is by decreasing the brakes hard line length or increase rotor size. Or knowing you parts functions. However, this involves knowledge of materials, thermal dynamics, somemore basic mechanical engineeringness, and generally phancy math. (yes, with a PH infront. Only minus the D, because you can't have a PHD in the mechanical engineering degree, at least at the college im at. That and PHDancy doesn't make any sence)

The more effiecent brake design would be better for every application, road racing, street, autoXXX, or just daily driving. Better control and efficency is better than lack off. More effiecent modulation control is better than brute force with so much as a tap of the brake.

But don't get me wrong! those 4 pot calipers kick ass man!


lol I paid alot of money to get that mechanical engineeringness, but am thinking I need to get some of that PHancy math lol. where are you going to school at? Just curious - I am not sure if Texas A&M (where I got my degree) offers a phd in ME

[Sarra]

I just want brakes that will completely fill up my wheels (IE, WRX brakes under WRX wheels, with "H6" rears, or STi Brembo's under 17" wheels). I just feel that having a bunch of empty space under there is wasted potential...

[Reason]

I just want brakes that will completely fill up my wheels (IE, WRX brakes under WRX wheels, with "H6" rears, or STi Brembo's under 17" wheels). I just feel that having a bunch of empty space under there is wasted potential...

Wouldn't the idea of upgrading brakes is to increase stop power/distance rather than looks?

[danci1973]

Wouldn't the idea of upgrading brakes is to increase stop power/distance rather than looks?
Increasing stopping power / decreasing stopping distance - sure, that's the idea.

But most cars (in fact, all cars) I've ever driven had enough braking power to lock the wheels at any speed. So how much more braking power do you need?

Now sustaining that braking power over a long period of abuse (ie. racetrack), that's another story. That's why there are big rotors, holes and other tricks to help dissipate the heat.

IMHO 'improving' braking power without improving other stuff (tires, suspension, front/rear bias, weight distribution) will just help lock the wheels sooner with less leg-force.

D.

[deadlydave]

AHHHH, thank you Sharky Nrk. I understand now.

My autocross style is a kind of "whale on the car to get it to go where I want it." So me having to use my leg more will definitely fit in with that....awesomesauce! :grin: As far as the rears go, this thing may already have the H6-style rears. I'll have to hunt around to verify this.

I was thiking about going to RacingBrake or Stoptech rear calipers as well--Do you think their 2-piston rears shift too much braking force to the rear? I may also go with the STi rear brembos(checking fitment), or matching 2-pots. Definitely some better brake lines in the future though.

[d1giPhux]

I didnt understand what you meant ? :roll: SO.. basically you have to mash on the brakes more if you want more stopping power other than normal. Do they actually have less stopping power when applied normally over stock? :?:

[deadlydave]

Do they actually have less stopping power when applied normally over stock? :?:

It doesn't feel that way, the light stopping power feels the same.

[Huffer]

Tires before brakes.

If you want stopping power, you need to grip the road, not have the wheels stop and the tires be so slippery that they are like skates.

But we digress.. the 4 pots are sweet dave...

[deadlydave]

Tires before brakes.

If you want stopping power, you need to grip the road, not have the wheels stop and the tires be so slippery that they are like skates.

But we digress.. the 4 pots are sweet dave...

LOL Roger. Actually, tires are coming, but wrapped around something more than stock wheels. I needed new pads and to bleed my brakes anyway--"I may as well upgrade." was what I was thinking at the time.

[Jedi Taxi]

Tires before brakes.

If you want stopping power, you need to grip the road, not have the wheels stop and the tires be so slippery that they are like skates.

But we digress.. the 4 pots are sweet dave...

Too true, tires before brakes. No sence in having great stoping power if it breaks the tires limit of adhesion