Why Do I Need Rear Brembo's in R180 Swap!?

[ViperWRX]

I have searched alot of places and couldnt find the Exact reason why, and I have a JDM STI V8 6 Speed setup just not the R180, STi axles, sti hubs or Brembo's yet. Now I am wondering if I had the R180, Sti Rear Axles and STi 5x100 Rear Hubs Why would I need the rear Brembo's/Rotors when I have the PowerSlot Oversized Rotors W/ Bracket for the rear stock 02 WRX brakes? It would clear as they are very similar to the size of the Brembo Rotors. Please if anyone knows I would appreciate it. Thanks for any feedback!

(Update)
This is the info I have so far:

Rear STi Brembo Rotor- 12-12.5" <-- Can Someone confirm this?

Powerslot Big Rotor- 12"

[stoke]

Originally Posted by ViperWRX

I have searched alot of places and couldnt find the Exact reason why, and I have a JDM STI V8 6 Speed setup just not the R180, STi axles, sti hubs or Brembo's yet. Now I am wondering if I had the R180, Sti Rear Axles and STi 5x100 Rear Hubs Why would I need the rear Brembo's/Rotors when I have the PowerSlot Oversized Rotors W/ Bracket for the rear stock 02 WRX brakes? It would clear as they are very similar to the size of the Brembo Rotors. Please if anyone knows I would appreciate it. Thanks for any feedback!

(Update)
This is the info I have so far:

Rear STi Brembo Rotor- 12-12.5" <-- Can Someone confirm this?

Powerslot Big Rotor- 12"

The reason most people go with the rear Brembos is that the rotors for those brakes are made to fit the 190mm parking brake that works with the STI axles. R160 cars have a 170mm parking brake and different axles. That's one good reason you need rear Brembos: the rotors you have won't fit over the parking brake you'll need to install with your STi axles.

Also, rotor size is not the only factor in braking performance. The Brembo calipers, which are two-piston fixed units, can likely generate more clamping force and thus more brake torque than your WRX brakes. This means that if you run Brembos up front and your stock rear brake setup, your brake bias will be thrown off and you will not be fully utilizing your rear tires' ability to slow the car because your brakes are front-biased. Thus, your braking will not be as good as it could be... which seems a waste of all your effort, doesn't it?

[piddster]

SVX backing plates can be used along with redrilled rotors to use sliding calipers, but what's the point? Unless you are trying to run smaller wheels.

[ViperWRX]

True, and I realize now that the rotor is made bigger on the rear side to accomodate the parking brake, and I read that the stock parking brake line will connect to the sti hubs. But anyways I am planning on upgrading to Brembos and all the goodies, but, I am on an Extremely tight budget for a little while and was hoping to be able to go with a stronger rearend since I am pushing around 380chp or more, I guess I could just granny shift for several months and no launches/tracking/autoX till I can raise enough money for the swap. I was just looking for a cheaper way to get the R180 in there. Have only really heard of 2 ways to do the R180 swap. 1 is of course the whole works with brembo's and the other was kinda sketchy with the DSS or something modified rear axles but were really expensive and not really effective but is still something a couple vendors are trying to figure out.

[wheatpaste]

The R180 rear axles are totally different than the R160 rear axles. You cannot use regular R180 axles with WRX rear hubs. They do not mate to the WRX rear hubs.

To solve this, you need to either just swap over STi rear knuckles, or use the DSS hybrid axles that allow you to use WRX hubs with the R180. These are probably not much cheaper than just getting a used set of 04 STi rear hubs and brembos. There have also been mixed reports of the quality of the DSS products.

Since the STi rear knuckles are completely different from the WRX knuckles, you cannot use your stock rear brakes. At least, not easily.

Using the DSS hybrid axles allows you to keep your stock rear hubs and brakes.

Keep in mind that if you go to Brembos, you will now have fewer wheel choices, especially if you stay 5x100.

[Dubstar112]

I went 5x100 sti rear knuckles with my r180 with DBA 4000 series rotors (sti parking brake, for 2 pot subie brakes). I think that is a minimum best upgrade. And from what Ive heard the subie two pots with brembo fronts provids a better bias!

[kpluiten]

Originally Posted by ViperWRX

True, and I realize now that the rotor is made bigger on the rear side to accomodate the parking brake, and I read that the stock parking brake line will connect to the sti hubs. But anyways I am planning on upgrading to Brembos and all the goodies, but, I am on an Extremely tight budget for a little while and was hoping to be able to go with a stronger rearend since I am pushing around 380chp or more, I guess I could just granny shift for several months and no launches/tracking/autoX till I can raise enough money for the swap. I was just looking for a cheaper way to get the R180 in there. Have only really heard of 2 ways to do the R180 swap. 1 is of course the whole works with brembo's and the other was kinda sketchy with the DSS or something modified rear axles but were really expensive and not really effective but is still something a couple vendors are trying to figure out.

Don't worry about it dude. I'm putting nearly 380 WHP through my R160 and while the vlsd is toast, the diff is holding (a bit noisy, but holding fine for now). That's a good deal more than your 380 CHP (no offense). I beat the hell out of the car on shifts at times. We're talking flat foot shifting and hearing the diff smash th underside of the car. You'll be fine. And if it does break, R160's are stupid cheap (like <200).

[ronzogonzo]

Originally Posted by Dubstar112

I went 5x100 sti rear knuckles with my r180 with DBA 4000 series rotors (sti parking brake, for 2 pot subie brakes). I think that is a minimum best upgrade. And from what Ive heard the subie two pots with brembo fronts provids a better bias!

I did the same, Ken from WRXBrakes sells a "Gravel rotor" that will fit the 190mm parking brake with the 06-07 wrx 2pots. The rally guys use this setup because they use the Group N 4pot/2pot setup for rally racing

I think the model number for those rotors is DBA656SL/R
that would be for the DBA standard series slotted rear set

[ViperWRX]

Originally Posted by wheatpaste

The R180 rear axles are totally different than the R160 rear axles. You cannot use regular R180 axles with WRX rear hubs. They do not mate to the WRX rear hubs.

To solve this, you need to either just swap over STi rear knuckles, or use the DSS hybrid axles that allow you to use WRX hubs with the R180. These are probably not much cheaper than just getting a used set of 04 STi rear hubs and brembos. There have also been mixed reports of the quality of the DSS products.

Since the STi rear knuckles are completely different from the WRX knuckles, you cannot use your stock rear brakes. At least, not easily.

Using the DSS hybrid axles allows you to keep your stock rear hubs and brakes.

Keep in mind that if you go to Brembos, you will now have fewer wheel choices, especially if you stay 5x100.

I wasnt planning on using the wrx axles if I got the R180, and for the price of the DSS Axles (500 each I think) I could have the F+R brembo's and just spend a couple hundred more for the rear axles and R180. I am also already running 18" rims so I will not have a problem with clearance.

Originally Posted by kpluiten

Don't worry about it dude. I'm putting nearly 380 WHP through my R160 and while the vlsd is toast, the diff is holding (a bit noisy, but holding fine for now). That's a good deal more than your 380 CHP (no offense). I beat the hell out of the car on shifts at times. We're talking flat foot shifting and hearing the diff smash th underside of the car. You'll be fine. And if it does break, R160's are stupid cheap (like <200).

As far as power goes I just said 380chp since I havent been tuned yet and I dont have a rearend yet to drive the car, I am running a VF37 twinscroll with a 20G wheel and Fully Ported and upgraded WG. I would hope to be in the 320+ whp area, but we'll see.