Poor brake fix

[tmoretta]

I have been trying to decide how to improve the braking performance on my 818S with '02 Subie brakes and Hawk HP+ pads. The car will stop and even the ABS functions but requires a huge amount of pedal force. I am thinking of going to a more aggressive pad on rear brakes only. Maybe that way I could re-open my proportioning valves to the front calipers and gain more overall bite. Anyone know if the EBC Yellowstuff provide more bite than the HP+? I have also looked at the Hawk DTC series, but they are for track only (not street use), and I do use this car on the street and to drive to the track.

[Hindsight]

I had the same Hawk pads... either HP or HP+ I can't remember and they SUCKED! SO much pedal force required.

I swapped them out for Ferodo DS2500 and they were instantly better. I still need to bed them but they are already better just right after install.

Tamra reports the EBC Yellowstuff have great bite and she can easily lock them up on the track. She did say it took quite a good number of AutoX runs to get them fully bedded though.

[DodgyTim]

Another way of lowering pedal effort is to reduce the master cylinder piston diameter
There is a smaller (7/8” diameter unit - The OE Nissan part number is 46010-1M320, thanks to lap_dog)
that is a straight bolt in item

I didn't do a "before and after" to know how much it helps

[Bob_n_Cincy]

Another way of lowering pedal effort is to reduce the master cylinder piston diameter
There is a smaller (7/8” diameter unit - The OE Nissan part number is 46010-1M320, thanks to lap_dog)
that is a straight bolt in item

I didn't do a "before and after" to know how much it helps

Instead of putting a smaller MC piston in, we doubled the size of out rear caliper pistons.
We are running StopTech Sport Brake Pads (CENTRIC 30909290) aggressive friction formulas suitable for track day and autocross use.
No PV on front, PV on rear turned down 4 revs.
After 7 track days and a few hundred autocross runs, very happy with brake performance and pedal effort.
Bob

[Frank818]

Another way of lowering pedal effort is to reduce the master cylinder piston diameter
There is a smaller (7/8” diameter unit - The OE Nissan part number is 46010-1M320, thanks to lap_dog)

Tim, in North America the Impreza got a very small 5/8" master. A least for 2002-2004, I don't know for the other years.

It's true going smaller will reduce effort, however you'll need more travel to get some bite.

[tmoretta]

So how did you double the size of the rear caliper pistons? Also, my original master cyl. is stamped 1 1/16.

[Bob_n_Cincy]

So how did you double the size of the rear caliper pistons? Also, my original master cyl. is stamped 1 1/16.

According to my MC spec sheet impreza and STI are 1 & 1/16" while WRX is 1".

I put standard FRONT Impreza calipers on the rear.

http://thefactoryfiveforum.com/showthread.php?12534-MRG-MotorSports-818S-Build&p=173658&viewfull=1#post173658


http://thefactoryfiveforum.com/showthread.php?12534-MRG-MotorSports-818S-Build&p=218828&viewfull=1#post218828

[DodgyTim]

Or 2006 four pot fronts on the rear :cool:
57716
57717
It was quite a bit of fabrication work though

[Hindsight]

Do you still have an ebrake DodgyTim?

[DodgyTim]

I do still have an ebrake, there is more info on the changeover here
http://thefactoryfiveforum.com/showthread.php?18211-Subaru-4-pot-front-callipers-on-the-front-and-the-rear/page2&highlight=brakes
Cheers

[Hindsight]

Thanks. So you are running the stock diamter rear rotors, but with four pot front calipers?

[DodgyTim]

Thanks. So you are running the stock diamter rear rotors, but with four pot front calipers?
No, I went the 316mm diameter rotors
If I'd kept the stock rotors, the closest I could get the callipers to the axle meant I'd have the pads overhanging the outer edge of the disk
That may have worked, but I'd have never convinced the inspector to pass it

[Frank818]

You too have constraints regarding inspections. :) Australia and Canada have so much in comon for many things. Like Melbourne is a Montreal-like city. :) But your country is so much more beautiful and so much hotter.

Have you had a chance to test the front calipers on the back? Or better, test rear calipers on and then fronts? Maybe I'm asking too much as this stage.

[Hindsight]

No, I went the 316mm diameter rotors
If I'd kept the stock rotors, the closest I could get the callipers to the axle meant I'd have the pads overhanging the outer edge of the disk
That may have worked, but I'd have never convinced the inspector to pass it

Ok I see, that makes sense. So the 316mm diameter rotors still have provisions for the drum parking brakes, and I assume the 316mm rotors came off of the same car that the new backing plates you used did? What year and model was it? And last question, did the WRX parking brake cables plug and play with the new backing plates and drum brakes?

Thanks!

[Frank818]

And for those like me who have the rear 310mm disc from Wilwood, maybe we just need to fab some caliper brackets in order to fit the front calipers on. I just don't know the result about pads overhang, they already overhang with Wilwood's kit.

[DodgyTim]

Ok I see, that makes sense. So the 316mm diameter rotors still have provisions for the drum parking brakes, and I assume the 316mm rotors came off of the same car that the new backing plates you used did? What year and model was it? And last question, did the WRX parking brake cables plug and play with the new backing plates and drum brakes?

Thanks!
The rotors are a special item made by DBA, Part No DBA 42657 or 2657. They are 316mm diameter and 20 mm thick. They keep the standard 170mm dia handbrake, so no mods to cables, e-brake pads etc required. The rotors were originally developed to suit Subaru WRX (5x100) pattern to allow a Brembo Conversion.

There are a pair on ebay at the moment (in the USA) for $175 USD each but on Australia ebay they are about $252 AUD a pair (about $190 USD)

[DodgyTim]

You too have constraints regarding inspections. :) Australia and Canada have so much in comon for many things. Like Melbourne is a Montreal-like city. :) But your country is so much more beautiful and so much hotter.

Have you had a chance to test the front calipers on the back? Or better, test rear calipers on and then fronts? Maybe I'm asking too much as this stage.
Hi Frank
I lived in Vancouver for a couple of years and really enjoyed the Pacific Northwest. Nice to have proper seasons instead of "hot and Dry" and "hot and Wet" like here. I also commissioned a copper mine in Williams Lake in winter. Fun times when they give you a V8 F250 and a fuel card, drives to the water recovery dam became something like a round of the WRC:D

I tested the front callipers on the back, but whilst they were still on my donor WRX. They certainly changed the brake bias rearward:rolleyes: but I can't give feedback on ultimate performance on the 818. Bob's setup is similar, but different callipers and I believe he's liking it.

[Hindsight]

Thanks Tim. Very cool.

[Bob_n_Cincy]

Do you still have an ebrake DodgyTim?

I also have and ebrake.
I used a Locar handle. It is smaller and less mechanical advantage than the OEM brake handle.
So I just hooked one cable to one wheel.
Bob

[ehansen007]

Thing about these cars is that were putting on brakes that are built for boosted systems. While wilwoods and Baer are great systems they are pricey. On both of my first two cars (the 33 and the 818) I tried the Hawk pads with the stock rotors. Great when warm but man you didn't want to need to stop quickly on the way to cars and coffee!

We did a lot of discussion on the 33 forums about this and one guy had stumbled on the brakemotiv store on ebay. Cheap cross drilled, slotted rotors and ceramic pads from China for like $159. Man what a difference. I used this setup on both the street and track (mostly autocross) and never needed more for these light cars. I could lock them up all day long if needed. I've also used this setup on my daily drivers. For my other cars, meh, they lost a bit of braking but still worked. I put them on the 818 and it solved my braking problem instantly.

My theory is that for these pads, they are softer and with the crossdrilling and venting you get more bite unless weight overcomes the pad. They wear out quickly on heavy cars but I doubt I'll ever wear them out with the limited mileage we do in our FFRs. I would really like to put them on the cobra but you can see the discs through the wheels and I prefer the vintage look. So for now it's the kit rotors with the cheapest Napa Semi Met pads which work fairly well.

But for under $200 for rotors and pads front and rear, you might consider brakemotiv on ebay. The only problem is you have to find the exact model to reference which can be tricky on these cars. Just my experience!

[flynntuna]

Thanks for the tip. :cool:

http://stores.ebay.com/Brakemotive/SUBARU-/_i.html?_fsub=15607918&_sid=170279225&_trksid=p4634.c0.m322

[Wayne Presley]

I use the Hawk Street race or DTC30 compounds or Yellow Stuff EBC pads with very good results.

[Hindsight]

Wayne, do you use EBC Yellow Stuff on the track (road race, not AutoX)?

[Wayne Presley]

I use DTC 30 or DTC 60 Hawk on the track. Haven't tried the EBC orangestuff pads yet.

[Hindsight]

Thanks

[Frank818]

This is interesting info to keep forever.

Can those Brakemotiv work great with only the pads on upgraded Wilwood's discs? OR do we need pads and discs to make them work properly?

[freds]

Thing about these cars is that were putting on brakes that are built for boosted systems. While wilwoods and Baer are great systems they are pricey. On both of my first two cars (the 33 and the 818) I tried the Hawk pads with the stock rotors. Great when warm but man you didn't want to need to stop quickly on the way to cars and coffee!

We did a lot of discussion on the 33 forums about this and one guy had stumbled on the brakemotiv store on ebay. Cheap cross drilled, slotted rotors and ceramic pads from China for like $159. Man what a difference. I used this setup on both the street and track (mostly autocross) and never needed more for these light cars. I could lock them up all day long if needed. I've also used this setup on my daily drivers. For my other cars, meh, they lost a bit of braking but still worked. I put them on the 818 and it solved my braking problem instantly.

My theory is that for these pads, they are softer and with the crossdrilling and venting you get more bite unless weight overcomes the pad. They wear out quickly on heavy cars but I doubt I'll ever wear them out with the limited mileage we do in our FFRs. I would really like to put them on the cobra but you can see the discs through the wheels and I prefer the vintage look. So for now it's the kit rotors with the cheapest Napa Semi Met pads which work fairly well.

But for under $200 for rotors and pads front and rear, you might consider brakemotiv on ebay. The only problem is you have to find the exact model to reference which can be tricky on these cars. Just my experience!

++1 I have just replace all 4 rotors and pads on my daily driver and love them.

[Dodgeman]

Eric,
What was the rotor and pad numbers that you used from the eBay website for the 33. In my 33 you don't want to do any panic stops. any help would be appreciated.