Stock Front Brakes On Rear

[bogan393]

Its looking like the kit I may have to go, just got a price on sone 4 pistons rears, $3550!!, 1550 more then the 8 piston fronts.

[bushuteF6]

It is a painful process. On my track car I changed from twin piston fronts to 4 pot AP Racing and moved the original 2 pots to the rear (lost my handbrake in the process Doh!). I ensured the piston area ratio between front and rear was maintained but forgot about the extra pistion area I created. As a result I have to push the peadal further. I still stop the same no doubt but the pedal travels further.

This would not cause an issue on the street but when doing "heel toe" on the track it sucks as I'm used to a certain "style" and foot position. I now have to put in a bigger master cylinder to compensate and get the "hard feel" back in the pedal - means more force is reqd though - good for "heel toe".

My track car has no power assist so it is realtively straight forward. An educated guess tells me a power assist setup with ABS would a different story completely. Maybe someone out there has a better idea than me re setup on XRs??

Also - a larger rotor diameter will have an effect on brake force too and must be taken into account.

Bottom line - do an all corner job if you do it.

[bushuteF6]

Forgot to mention - check out Competition Friction in the ACT (AP Racing stockist for Australia). They do big brake upgrades for lots of HP cars, esp HSV etc. I get all my race gear though them and I'd be happy to help out with pickup etc as I know the guys and live in the area.

If there are a few people interested I might be able to work out some sort of "package deal". I could probably talk to them about a "kit" (if they don't have one already). Thoughts?

[Evil F6]

So is it deffinately not possible to put these brakes 8 piston brakes on without upgrading the rears? if not what are my other options that arnt too pricey, preferably under $4000, other then the pbrs, I havnt heard good things about that upgrade.

←

Not necessarily. I can attest to the fact I had a large brake upgrade on my VT on the front and stayed with the stock single piston rear brake setup. People were telling me it will be unbalanced. Well it it wasn't, not in the least. Braking performance was massively improved. Brake pedal feel was improved as I went from rubber to braided lines losing the sponginess of the stock setup, but stock master cylinder. So I would try it first and see how it behaves. At worst you can get a decent rear brake upgrade without going to 4-piston setup.

Having said that, a year later I fitted a 4-piston rear kit and the braking was improved again. It's intersting FPV use a huge 4-piston caliper and rotor on the front but a single piston on the back.

Why don't you talk to a brake shop. Racebrakes in Sydney are a good shop and set you straight.

[ms700]

I had the 6 piston AP setup on the front of my car for probably about 6 months before I upgraded the rears, the car's brakes worked fine...

If you put the front brakes on the back, it can be done, but kiss your handbrake goodbye.

[ZAP]

I think people are applying Racing logic to street applications.

The ONLY reason the stock rears would not be suitable is due to heat.

The stock brake have no issue with stopping the car currently. If the front calipers were upgraded, I do not think you will need to worry about the rears, unless you want to do some racing. A few laps around the track will not cause consern, unless you are really hard on the brakes or you are planning to run slicks.

The clamping force applied by the rears have nothing to do with the fronts.

The only consern I would have is would your master cylinder be capable of providing the pressure for such a big caliper and are they street legal.

My opinion is do not worry about the back calipers.

P.S I thought there was a little drum brake setup for the handbrake and thet it was not reliant on the rear caliper. (I could be wrong as I have never looked closely at the handbrake setup)

[Evil F6]

I think people are applying Racing logic to street applications.

The ONLY reason the stock rears would not be suitable is due to heat.

The stock brake have no issue with stopping the car currently.  If the front calipers were upgraded, I do not think you will need to worry about the rears, unless you want to do some racing.  A few laps around the track will not cause consern, unless you are really hard on the brakes or you are planning to run slicks.

The clamping force applied by the rears have nothing to do with the fronts.

The only consern I would have is would your master cylinder be capable of providing the pressure for such a big caliper and are they street legal.

My opinion is do not worry about the back calipers.

As an extreme example we had the brakes on our Lancer upgraded on the front from the puny little POS they had to Evo III brakes and calipers, while still retaining the purile drum brakes on the back. Yet again we had no issues with the setup being unbalanced. Stock master cylinder coped perfectly and again pedal feel was good with no extra travel distance etc.

I would say that at least upgrade your rear pads and fit a slotted rotor though.

[XR06T]

I think the handbrake cog thingo is on the inside of the rear disk and the front disk wont have this, so it is defn goodbye to handbrake

[bogan393]

This is all very useful info, thanks heaps for the replys, I think im going to go with this front set up to start off, im guessing in the worste case scenario, they will still be better then my stuffed warped std brakes now that wont stop me over 120. I will deffinately do the rear in the up comming months but will start off just with the fronts. Thanks again for the replys. Ps I dont think my car will every see a racetrack, probably a drag strip but never a track.

[BAturb]

then why the expense of the 8 spot fronts? why not use the money and go for an all round package? just a thought