AP Formula 4 piston - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

brn12345 · 10-20-2013, 02:06 PM

Just finished installing the AP 4 Piston Formula kit (Thanks Essex parts!) Install went smoothly and all parts needed were in the kit. Took it out for a test drive and the brakes are much more responsive and feel just like the Brembos on my Evo X. The only thing I did notice about them is that the pedal travel has increased a bit. My first assumption was that we didn't bleed it right so I redid the bleeding but still same pedal travel. Has anyone installed these and gets the same longer pedal travel before it gets hard? My other thought is that bigger surface area of the AP pistons require more fluid hence the longer pedal movement. Here is a picture of the install.

Ro_Ja · 10-20-2013, 03:43 PM

FYI Keep an eye on clearance with the wheel weights. I've had the weights hit the caliper.

Dezoris · 10-21-2013, 04:51 PM

When you bleed the fronts the reservoir goes dry fast keep it super full. A little bit of extra travel is normal but if its much deeper, bleed again just to be sure.

Team STILLEN · 10-21-2013, 06:02 PM

Anyone looked into a different master cylinder that might work better with BBK's?

wparsons · 10-21-2013, 09:32 PM

A properly designed BBK won't need a different master cylinder... just because there is more pistons doesn't mean there's more volume since each piston is smaller than stock. Most of the BBK's keep the fluid volume required very close to stock from what I've seen.

post_break · 10-21-2013, 10:55 PM

I had super long travel when I missed the step about bleeding the inside nipple first then the outside. I only did the outside. Make damn sure you bleed inside first, then outside.

Now my pedal is a rock and more like an on off button.

ZionsWrath · 10-21-2013, 11:04 PM

I tried asking in the official thread for these. Are these able to handle a car with FI on the track with wide sticky tires or is the Sprint or Endurance needed for that?

I like this kit because I can keep 17" wheels and want it but if it won't stand up to increased power and grip I guess I'll have to settle with a sprint kit and 18" :\

Team STILLEN · 10-22-2013, 01:33 AM

The AP Kit should be able to handle FI and sticky tires just fine. The limits of the power in these cars is still fairly low and the chassis is light. There are a lot of factors that could change that statement but for all intensive purposes it should work fine.

OrbitalEllipses · 10-22-2013, 01:43 AM

No long pedal here. ROCK hard actually. Like something else...

CSG Mike · 10-22-2013, 12:54 PM

I am so jealous...

brn12345 · 10-22-2013, 12:54 PM

Will try bleeding inner then outer and get back to you guys. Otherwise I am loving it. Braking is out of this world. Amazing kit would highly recommend.

wparsons · 10-22-2013, 03:13 PM

Quote:

Originally Posted by ZionsWrath

I tried asking in the official thread for these. Are these able to handle a car with FI on the track with wide sticky tires or is the Sprint or Endurance needed for that?

I like this kit because I can keep 17" wheels and want it but if it won't stand up to increased power and grip I guess I'll have to settle with a sprint kit and 18" :\

Depending on your driving skill, you're probably 100% fine with stock rotors and calipers, just upgrade to better fluid and pads.

Boost won't magically make you faster on a track, so you might not be carrying that much more speed into braking zones over a better driver with much less hp.

Dave-ROR · 10-22-2013, 04:04 PM

Quote:

Originally Posted by wparsons

A properly designed BBK won't need a different master cylinder... just because there is more pistons doesn't mean there's more volume since each piston is smaller than stock. Most of the BBK's keep the fluid volume required very close to stock from what I've seen.

If there were larger MC options then it'd be ok though.. lots of OEM upgrades on other cars end up that way but aftermarket solutions usually don't.

My essex kit (not the formula of course) still has a solid pedal

Dave-ROR · 10-22-2013, 04:06 PM

Quote:

Originally Posted by Team STILLEN

The AP Kit should be able to handle FI and sticky tires just fine. The limits of the power in these cars is still fairly low and the chassis is light. There are a lot of factors that could change that statement but for all intensive purposes it should work fine.

Depends

I agree that they will work (as long as they can lock up those sticky tires blah blah blah) but if the car is fast enough it might overcome the ability of the formula system to hold and remove enough heat.. but that's going to be very car, driver and track specific so there's no "right" answer.

10-20-2013, 02:06 PM	#1
brn12345 Senior Member Join Date: Oct 2012 Drives: BRZ Location: Bahrain Posts: 254 Thanks: 101 Thanked 137 Times in 63 Posts Mentioned: 6 Post(s) Tagged: 0 Thread(s)	AP Formula 4 piston Just finished installing the AP 4 Piston Formula kit (Thanks Essex parts!) Install went smoothly and all parts needed were in the kit. Took it out for a test drive and the brakes are much more responsive and feel just like the Brembos on my Evo X. The only thing I did notice about them is that the pedal travel has increased a bit. My first assumption was that we didn't bleed it right so I redid the bleeding but still same pedal travel. Has anyone installed these and gets the same longer pedal travel before it gets hard? My other thought is that bigger surface area of the AP pistons require more fluid hence the longer pedal movement. Here is a picture of the install. Attached Images

10-21-2013, 04:51 PM	#3
Dezoris Senior Member Join Date: Aug 2012 Drives: FR-S Location: IL Posts: 2,857 Thanks: 519 Thanked 2,997 Times in 1,095 Posts Mentioned: 159 Post(s) Tagged: 1 Thread(s)	When you bleed the fronts the reservoir goes dry fast keep it super full. A little bit of extra travel is normal but if its much deeper, bleed again just to be sure. __________________ SAVAGEGEESE

10-21-2013, 06:02 PM	#4
Team STILLEN Mark @ STILLEN Join Date: Dec 2012 Drives: 2015 Subaru BRZ Location: Costa Mesa, California Posts: 170 Thanks: 201 Thanked 148 Times in 73 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	Anyone looked into a different master cylinder that might work better with BBK's? __________________ \| Mark Dorman \| Performance Specialist \| markd@stillen.com\| IG @Mark_STILLEN \| www.STILLEN.com

10-22-2013, 01:33 AM	#8
Team STILLEN Mark @ STILLEN Join Date: Dec 2012 Drives: 2015 Subaru BRZ Location: Costa Mesa, California Posts: 170 Thanks: 201 Thanked 148 Times in 73 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	The AP Kit should be able to handle FI and sticky tires just fine. The limits of the power in these cars is still fairly low and the chassis is light. There are a lot of factors that could change that statement but for all intensive purposes it should work fine. __________________ \| Mark Dorman \| Performance Specialist \| markd@stillen.com\| IG @Mark_STILLEN \| www.STILLEN.com

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10-20-2013, 03:43 PM	#2
Ro_Ja Senior Member Join Date: Aug 2012 Drives: TOYOTA Location: CA Posts: 401 Thanks: 191 Thanked 225 Times in 134 Posts Mentioned: 8 Post(s) Tagged: 0 Thread(s)	FYI Keep an eye on clearance with the wheel weights. I've had the weights hit the caliper.

10-21-2013, 11:04 PM	#7
ZionsWrath Thanks Join Date: Apr 2013 Drives: BRZ Location: NY Posts: 4,163 Thanks: 5,989 Thanked 3,100 Times in 1,498 Posts Mentioned: 38 Post(s) Tagged: 3 Thread(s)	I tried asking in the official thread for these. Are these able to handle a car with FI on the track with wide sticky tires or is the Sprint or Endurance needed for that? I like this kit because I can keep 17" wheels and want it but if it won't stand up to increased power and grip I guess I'll have to settle with a sprint kit and 18" :\

10-22-2013, 01:43 AM	#9
OrbitalEllipses Banned Join Date: Jan 2012 Drives: Attitude Location: MD Posts: 10,046 Thanks: 884 Thanked 4,889 Times in 2,902 Posts Mentioned: 123 Post(s) Tagged: 4 Thread(s)	No long pedal here. ROCK hard actually. Like something else...

10-22-2013, 12:54 PM	#10
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,533 Thanks: 8,920 Thanked 14,178 Times in 6,835 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	I am so jealous...

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