GR86 GR86 - Brake Upgrade Guide

AdamST205 said:
WRX STi calipers seem a lot more plentiful and could pick up a full set for about a grand. Refurbish them, new discs, pads, lines and shield and I should have a decent setup for around 2k.
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And a setup that's bolted into leading position instead of trailing position (or vice versa) as it was designed resulting in bigger of two pistons coming to the contact with the pad first.
FYI "PP Brembos" come with 4 40mm pistons, older STI ones with 38 and 42mm iirc. What might be the result: Longer braking distance, pad taper, improper brake pressure distribution and incorrectly working ABS ?
There's plenty of good and inexpensive (inexpensive as BBK goes) kits abailable in UK (Reyland, Brembo themselves, AP).
 
MrSkubi said:
And a setup that's bolted into leading position instead of trailing position (or vice versa) as it was designed resulting in bigger of two pistons coming to the contact with the pad first.
FYI "PP Brembos" come with 4 40mm pistons, older STI ones with 38 and 42mm iirc. What might be the result: Longer braking distance, pad taper, improper brake pressure distribution and incorrectly working ABS ?
There's plenty of good and inexpensive (inexpensive as BBK goes) kits abailable in UK (Reyland, Brembo themselves, AP).
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Bleed nipples can be reversed and calipers turned around and then it is a non issue though?
 
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AdamST205 said:
My GR86 isn't even here yet but brakes are going to be the first thing I will change for something a little more beefy. From what I have seen from pictures I have looked at is that the "Brembo Performance Pack" for the old GT86 bolts straight up to the GR86? Also these calipers look identical to Subaru Impreza WRX calipers from 2008 onwards so they should bolt straight on?

WRX STi calipers seem a lot more plentiful and could pick up a full set for about a grand. Refurbish them, new discs, pads, lines and shield and I should have a decent setup for around 2k.
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Never a popular choice on the old car. 12% loss in braking power on stock sized discs and shifts the brake bias backwards. I imagine this is the same on the GR86 as they share the same setup.
 
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ZN8 said:
Never a popular choice on the old car. 12% loss in braking power on stock sized discs and shifts the brake bias backwards. I imagine this is the same on the GR86 as they share the same setup.
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I am confused how do you lose braking power with bigger calipers. Also apart from the tapered pistons it is exactly the same as the performance pack for the GR86 unless I am missing something?
 
AdamST205 said:
I am confused how do you lose braking power with bigger calipers. Also apart from the tapered pistons it is exactly the same as the performance pack for the GR86 unless I am missing something?
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I just found the thread, sorry I'm getting confused with the older generation calipers!

https://www.gt86.org.uk/forums/forums/topic/7369-impreza-wrx-brakes/

Here are the Brembos fitted to a GT86

https://www.gt86.org.uk/forums/forums/topic/1620-brembo-sti-front-brake-kit-fitted/
 
AdamST205 said:
I am confused how do you lose braking power with bigger calipers. Also apart from the tapered pistons it is exactly the same as the performance pack for the GR86 unless I am missing something?
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The issue is not with the braking performance, its brake balance. With the larger pistons on the STi Brembo's, you transfer more brake torque to the front axle which causes issues with the cars braking ability and brake force distrubition, stability control, etc.

The STi Brembo's (Gold & Black versions) have 40/46mm pistons, this creates an approx 8% difference in brake balance over stock.

They Reyland AP and PP Brembo's are approx 2% difference.

If you want to do a BBK on the cheap, get a set of the Megane 3RS Brembos, as these have 40mm pistons which is the same as the PP Brembo's.
These are the calipers Misha is running on his/Gapped GR86.
 
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Will300 said:
If you want to do a BBK on the cheap, get a set of the Megane 3RS Brembos, as these have 40mm pistons which is the same as the PP Brembo's.
These are the calipers Misha is running on his/Gapped GR86.
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Do they fit directly or are other discs and/or mounting adapters needed?
 
Will300 said:
The issue is not with the braking performance, its brake balance. With the larger pistons on the STi Brembo's, you transfer more brake torque to the front axle which causes issues with the cars braking ability and brake force distrubition, stability control, etc.

The STi Brembo's (Gold & Black versions) have 40/46mm pistons, this creates an approx 8% difference in brake balance over stock.

They Reyland AP and PP Brembo's are approx 2% difference.

If you want to do a BBK on the cheap, get a set of the Megane 3RS Brembos, as these have 40mm pistons which is the same as the PP Brembo's.
These are the calipers Misha is running on his/Gapped GR86.
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I got you so Reyland AP and STi rear calipers would be the perfect setup whilst maintaining OEM brake balance? Would the performance pack dust shields fit behind the Reyland discs or are they too small?

Also what is the noise like with the AP kit as I noticed you have them on your car? I have grooved 320mm discs and Carbotech XP10's on my Celica GT-Four and the noise would be unbearable unless piping hot. The breaking performance however is obviously superb.
 
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AdamST205 said:
I got you so Reyland AP and STi rear calipers would be the perfect setup whilst maintaining OEM brake balance?
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It should be very close to the OEM balance, i.e. less than 1%.

AdamST205 said:
Would the performance pack dust shields fit behind the Reyland discs or are they too small?
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No idea, there might be some interference as the front PP discs are 326mm, where as the Reyland discs are 330mm.
I no longer run the dust shields and I've not come across any adverse effects.

AdamST205 said:
Also what is the noise like with the AP kit as I noticed you have them on your car? I have grooved 320mm discs and Carbotech XP10's on my Celica GT-Four and the noise would be unbearable unless piping hot. The breaking performance however is obviously superb.
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I don't experience much noise, the only occasional issue I have is when reversing, there is a slight squeal.
Disc and pad selection also plays apart in this. I'm aware that XP10's are quite prone to squealing.
 
AdamST205 said:
I got you so Reyland AP and STi rear calipers would be the perfect setup whilst maintaining OEM brake balance? Would the performance pack dust shields fit behind the Reyland discs or are they too small?

Also what is the noise like with the AP kit as I noticed you have them on your car? I have grooved 320mm discs and Carbotech XP10's on my Celica GT-Four and the noise would be unbearable unless piping hot. The breaking performance however is obviously superb.
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Its very much dependant on the pad compound. I had no issues with squeal on my AP kit with Ferodo DS2500 pads.
 
Hi all,

I'm no pro driver, but I love a track day. After testing a lot of different pads over the years I've been really impressed with Pagid pads, most recently the RS14 grade.

They're not as initially bitey as some track pads I've tried, but they're fine from cold, they have higher friction than regular road pads, they have superb longevity and they give superbly consistent pedal pressure through the temperature range.

I couldn't find Pagid options for GR86 so I contacted their technical line and got the following feedback, I thought might be helpful to add here:

"Thanks for your request. Unfortunately I cannot see the pictures you attached. The GR86 uses the same pads for front and rear like the GT86. These are the PAGID Racing shapes 8174 and 8175. We list them as on inquiry on our website but we have stock of RSL1 pads for the front which is a similar compound to RS14. The RSL1 has a longer pad life but is a little bit less progressive in friction level development over temperature. For the rear we also have RSL1 pads available.

The part number you need to request are:

S8175L01001 and S8174L01001

1000038848.webp

1000038850.webp


We also have pads for this car available in our Street Plus range which is our compound for street cars with a small amount of track use.

https://www.pagidracing.com/en/products/street-brake-pads.html

Here you can have a look at the article numbers:

T8047SP2001

1000038852.webp



1000038851.webp

T8065SP2001"
 
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Can anyone confirm whether both front and rear pads are interchangeable with standard (non performance pack) GT86 pads?
 
@Will300 that's a very good insight on braking system and parts.
Although I am not a GR owner, I am a gt86 owner I would like to share my experience with different pads and setups.
All these setups are with braided lines, Millers racing oil and Porsche 964 brake cooling ducts.

Oem calipers setup:
I have used Dixcel ES type front and rear with OEM discs I can say that this is very capable for street use only. Bite is strong from cold, balance is good but even with good oil, these pads will fade after short time of hard driving. They are NOT good for trackdays, my front pads completely desintegrated after 10 minutes session due to overheating.

After that, I used PMU HC800+ both front and rear with OEM discs, they are decent for road use, decent bite from cold and very good after warm but they unbalance the car a little bit.
Due to this unbalance, I then changed to PMU HC800+ in the front and Dixcel ES type in the rear and although the brake bias was more to the front, I felt this setup extremely strong and never felt fading even after multiple 30/40 minute sessions in a row. These PMU pads are extremely durable and after 2 years of use with 4/5 trackdays and many spirited miles, I still removed them with 50% plus of life.
Downside of these pads, they produce considerable amount of dust. And it will definitely f**k your wheel paint job.


Following to the latest setup, I upgraded to performance package Brembos with oem brembo discs.
With Brembo front and rear pads the setup is very streetable, good cold bite but starts fading when hot. The pads are durable but also start wearing much faster when overheated, as expected.

Was then upgraded to lastly and current setup PMU HC800+ front and rear, extremely strong setup for street up to intermediate trackdays and a well balanced setup. Strong bite from cold and it grows stronger and stronger as you make the pads hotter.
Very durable as they withstand multiple sessions of 30 minutes with minimal wear.
Downside once again is the amount of dust produced and the aggressiveness of this dust on wheels paint jobs.

The part numbers I have for performance package brembo PMU pads are
F906 for front and F506 for rear.
Same part numbers as for Subaru STI Brembos.
 
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I used both the PMu HC800 and their Club Racer (££) on my gt86, both excellent and I just couldn't kill the club racers on track, amazing, however, they instead decided to kill my discs . Somethings gotta give I guess! Excellent pads though, even hc800 I was more than happy with and couldn't get to fade. Would recommend for those really pushing it on the 86 platform and who want to try something a little different

Sent from my Pixel 8 Pro using Tapatalk
 
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AdamST205 said:
Have seen these. Seems like a good option than paying £600+ for a set of used STi calipers. £290 for the pair.

www.ebay.co.uk

ICP LH RH 2 Pot Rear Brake Calipers Fits: Subaru Impreza WRX STi 07-17 Brembo | eBay UK

ICP Quality Assured Parts. Subaru Impreza WRX STi GR/GV 2007 To 2014. Subaru WRX STi VA 2014 To 2017. LH & RH Rear Brake Caliper. Subaru Service Parts (1102). 1 x LH Rear Brake Caliper. 1 x RH Rear Brake Caliper.
www.ebay.co.uk
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I have a pair of these sat in my shed. I bought genuine Brembo hardware and it all fits nicely. ICP are definitely capitalising on these reverse engineered brembos. I bought a pair for £179 off amazon a couple of years back.
 
Anyone knows if the Reyland Track 330 BBK fits either of these wheels?
- OEM 18x7.5 ET48
- OZ Alleggerita 18x8 ET48
- Enkei RPF1 17x9 ET35
 
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