Track brake pads for the 1988 Fiero

Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.

Moderators: The Dark Side of Will, Series8217

User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Track brake pads for the 1988 Fiero

Post by Series8217 »

I have been running Porterfield R4-S pads on my Fiero since 2005, for street use and driving in the canyons. I have stock calipers with 12" Corvette rotors. Last year I started autocrossing on these pads, and I was happy with their performance. I finally bought a set for the Apocalypse Wagon earlier this year because I won a gift certificate at a RallyCross event, and Porterfield is the title sponsor for the RallyCross series. They are great pads for street, autocross, and rallycross use.

I have also tracked the Fiero with R4-S pads at Buttonwillow and Auto Club Speedway. Probably 4 or 5 track days total. Braking was definitely a weak point on the track, but I had other issues to work out so I just replaced the pads when they wore down.

This last weekend I really picked up the pace and dropped 4 seconds off my previous fastest time.... and wore out an almost new set of pads, and a totally new set of pads, in less than six 20-minute sessions. The pads worse so fast I could probably have measured the difference with calipers after each braking zone.

After spinning off the track due to not braking enough at the end of the front straight, I came into pit lane with scraping/squealing brakes. No rocks in the calipers, just messed up pads. I figured I must have been overheating them, and the compound was coming apart. I also noticed a big crack in my rear rotor, so I parked it for the day and then limped the car home.

I talked to Tom at 7s Only Racing and he didn't think I was overheating the pads since the paint wasn't turning white. He offered to let me use some temperature indicating paint on my pads so I could see how hot they're getting. Unfortunately the rear rotor was cracked too badly to risk driving the car, so I wasn't able to do the test.

After I got home I did some research on the R4-S. It seems these pads fall apart at a particularly low temperature --- low enough that they don't turn white. They jut aren't a good track pad.

Apparently they crystallize and crumble when they overheat. Not my pic, but I found this in a Google search:
http://s498.photobucket.com/user/scmcin ... S.jpg.html

Some mention of it on the forums:
http://forums.pelicanparts.com/2658753-post13.html

So I will no longer recommend R4-S pads for mixed use. Autocross and RallyX and street use they are still great. They just don't hold up on the track.

I sent an email to Porterfield to see what they say, and if they think the R4 compound will not have this problem. I will update this thread with more info when I have it, as well as some pics of my pads when I pull them.
The Dark Side of Will
Peer Mediator
Posts: 15610
Joined: Wed Nov 24, 2004 11:13 pm
Location: In the darkness, where fear and knowing are one
Contact:

Re: Porterfield R4-S pads

Post by The Dark Side of Will »

I've seen strong recommendations for R4-S pads used on Fieros in AutoX before. Interesting info on using them on a track.
fieroguru
Posts: 258
Joined: Sun Jan 15, 2006 1:30 pm

Re: Porterfield R4-S pads

Post by fieroguru »

Bigfieroman mentioned/posted that he burned through a brand new set of porterfields at the track day at the 25th, but don't remember the part number.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Porterfield R4-S pads

Post by Series8217 »

From Wendy at Porterfield:
White crumbling edges are indicative of overheating. R4-S is not a track pad
by any means. I would recommend using at least an R-4.
So I will order some R-4 pads.

I need to find some good rotors. It looks like DBA discontinued their 4000-series offering for the front of the C4 Corvette (which is all 4 of my rotors). They were part numbers 4999SL (left) and 4999SR (right). These are slotted (not drilled), coated rotors, with temperature indicating paint. They are intended for track use.

Otherwise I'll get some undrilled/unslotted rotors, and set up some G code to slot them for me as well as drill for 5x100 while I have it in the fixture.
AkursedX
Turbo-boostin!
Posts: 1078
Joined: Wed Nov 17, 2004 2:14 pm
Location: Lackawanna, NY

Re: Porterfield R4-S pads

Post by AkursedX »

If you could afford it, you should buy some Baer Eradispeed 2-piece rotors. That's a lot of money though. Centric sells Cryo-treated rotors fairly cheap and I have read that cryo-treating really helps extend rotor life for track-day cars.

As for the pads, I'm not all too surprised that the R4S has finally given up doing what you do. It's much more of a street pad and with the track experience you have, dedicated track-pads are definitely what you need. I have done one HPDE with my RX8 which has R4S's and I didn't have any issues although wear was noticeable, but it was my 1st time on that track so I certainly wasn't pushing my braking as hard as you are now. I do hope the R4's work well for you as options for 88's are limited. I wonder if EBC makes Bluestuff or orangestuff.
'88 Fiero GT- 3800 Turbo Best E.T. 11.36 Best MPH 121.50 (Sold and gone)
2021 Hyundai Veloster-N (SCCA Solo D-Street)
2004 Mazda RX-8 (SCCA Solo STX)
WNY SCCA-Region Auto-X Program Chair
The Dark Side of Will
Peer Mediator
Posts: 15610
Joined: Wed Nov 24, 2004 11:13 pm
Location: In the darkness, where fear and knowing are one
Contact:

Re: Porterfield R4-S pads

Post by The Dark Side of Will »

fieroguru wrote:Bigfieroman mentioned/posted that he burned through a brand new set of porterfields at the track day at the 25th, but don't remember the part number.
I emailed him. He had this to say:
bigfieroman wrote: I put brand new sets of Porterfield R4S pads front and rear on my 88GT with 12" corvette rotors before the track day at the 25th. The car is engine swapped to a massaged 3800 S2 supercharged with close to 400 hp. In about 25 laps of Waterford Hills, the front pads were on the wear indicators. Bystanders reported sparks shooting out from between the pads and the rotors. Braking remained strong for those laps, but the fact remains that the pads were completely ruined in about 25 laps. There was so much dust down the side of the car, you could write your name in it.

That being said, they offered good bite, and would probably be a fine autocross pad, but the sustained high heat of a track day obliterates them.
AkursedX wrote:If you could afford it, you should buy some Baer Eradispeed 2-piece rotors. That's a lot of money though. Centric sells Cryo-treated rotors fairly cheap and I have read that cryo-treating really helps extend rotor life for track-day cars.
Cryo treatment really helps wear and fatigue resistance, from what I've read.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Porterfield R4-S pads

Post by Series8217 »

AkursedX wrote:If you could afford it, you should buy some Baer Eradispeed 2-piece rotors. That's a lot of money though. Centric sells Cryo-treated rotors fairly cheap and I have read that cryo-treating really helps extend rotor life for track-day cars.
The Eradispeed rotors are affordable and light but they are not track rotors, they're for show. Crossdrilled rotors just crack under the constant heating and cooling of road course use. Porsche gets away with holes in their rotors because they arent crossdrillrd. They cast in the holes, so the grain structure is uninterrupted by a drill.

I ended up ordering the Centric high carbon non-cryo treated rotors. A little over $200 for all 4.

My R4 pads should be here Thursday.

If the rotors come in before next weekend i'll test the brakes out at the autocross practice in Fontana on the 23rd.
AkursedX
Turbo-boostin!
Posts: 1078
Joined: Wed Nov 17, 2004 2:14 pm
Location: Lackawanna, NY

Re: Porterfield R4-S pads

Post by AkursedX »

Series8217 wrote: The Eradispeed rotors are affordable and light but they are not track rotors, they're for show. Crossdrilled rotors just crack under the constant heating and cooling of road course use. Porsche gets away with holes in their rotors because they arent crossdrillrd. They cast in the holes, so the grain structure is uninterrupted by a drill.

I ended up ordering the Centric high carbon non-cryo treated rotors. A little over $200 for all 4.

My R4 pads should be here Thursday.

If the rotors come in before next weekend i'll test the brakes out at the autocross practice in Fontana on the 23rd.

For some reason I thought the Baer rotors were cast with the holes as well. Oh well. I wonder if they sell a solid disc for their 2-piece rotors. I do remember that they were a fair bit lighter that the rotors I took off and the rotor was far beefier.

I'm looking forward to the review on the R4's. I have wondered if they are streetable. I have heard they squeal a lot.
'88 Fiero GT- 3800 Turbo Best E.T. 11.36 Best MPH 121.50 (Sold and gone)
2021 Hyundai Veloster-N (SCCA Solo D-Street)
2004 Mazda RX-8 (SCCA Solo STX)
WNY SCCA-Region Auto-X Program Chair
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

Looks like there may be some more compounds available with some slight modifications. From user mcguiver3 on Old Europe in this thread: http://www.fiero.com/forum/Forum2/HTML/126408.html
I found a great alternative for the 88's because there is not much out there for performance pads.
The Wilwood Dynalite caliper uses a HP100 pad and it's easy to modify for 88 Fieros.
If you grind a bit off the width of the backing plate and enlarge the 2 holes they fit.
It also gives you a choice of compounds to run.
I have modified the calipers to eliminate the plate modifications on future pad swaps.
I run Hawk HP plus pads for AX & Track days and they are perfect.
Good initial bite and no fade with elevated heat. They are kind on the rotors too.
I get them from Pegasus Racing.
AkursedX wrote: For some reason I thought the Baer rotors were cast with the holes as well. Oh well. I wonder if they sell a solid disc for their 2-piece rotors. I do remember that they were a fair bit lighter that the rotors I took off and the rotor was far beefier.
From the Baer web site:
Each gas relief hole drilled in an EradiSpeed rotor is located directly behind an internal vane and chamfered appropriately.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

I got the HB100N.480 HP Plus pads since my Porterfield order hasn't shipped yet.

They fit the stock 88 Fiero brakes after lightly filing the edges of the backing pads, and drilling out the holes to 6.8mm. However, the pads don't have the nubs/pins for the rear e-brake piston. The backing plates are also pretty thin so it may be hard to add the pins.

In addition, the inboard pads interfere with my WCF 12" rotor caliper brackets. I had to file the brackets and backing plates quite as bit to make them fit. Not a huge deal, just didn't expect to have interference there.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

I added the rear brake piston anti-rotation pins to the Hawk HB100 pads by drilling and tapping the backing plates for M3 and installing a button head socket cap screw. The screw head was just the right side to fit into the square cutouts in the piston... but then my Porterfield order came in so I switched over to those pads. I'll keep the HB100 pads as track spares, or maybe swap them on for street use.

The Porterfield R4 pads felt great at the autoX on Saturday, but the rotors still need to be seasoned and the pads need to be fully bedded.

I really need more rear brake bias... the fronts lock up quick. I ordered one of aaron88's prop valve adjusters, so hopefully that will be enough.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

I found the temperature rating for the Hawk HP Plus pads here. They're only supposed to be used up to 600*F with a max temp of 800*F. So I don't think they're going to be all that useful for me. I just bought them because it's what Amazon had available with fast shipping.

The "480" style pads are available in all of Hawk's compounds. The part number is HB100x.480 where x is one of the following:

Code: Select all

U    DTC-70
G    DTC-60
W    DTC-30
H    DTC-05
V    HT-14
S    HT-10
L    MT-4
E    Blue 9012
M    Black
J    DR-97
N    HP Plus
It's definitely a good idea to adapt these pads, as it more than doubles the number of viable compounds that can be used with the '88 Fiero calipers.

One thing I noticed about the 480 pads is they don't have a slot down the middle. They're also designed for a 4-piston caliper (2 pistons per pad). Could that slot be import for single-piston applications?
Red3800SC
Posts: 33
Joined: Fri Nov 19, 2004 3:15 am

Re: Track brake pads for the 1988 Fiero

Post by Red3800SC »

I have had really good luck with EBC Yellow Stuff Pads. They work awesome with my Stock 88 Calipers which are front on front and back of the car. I also have the 12" C4 Vette Rotors and a Big Brake Booster from Old Europe. The EBC's work amazing at the drag strip and on the street. They really help over the stock style calipers from the parts store, etc. Not sure what how they compare from the Porterfield's, etc. I suggest you give them a try. They are around $100 per set for front or back. They don't really need to warm up at all and work well in the cold too.
1988 Pontiac Fiero Formula
2000 L67
4t65e-HD Tranny
Best 1/4: 11.77 @ 114.62mph.
60 ft: 1.60

Formerly known as Rare87GT.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

Red3800SC wrote:I have had really good luck with EBC Yellow Stuff Pads. They work awesome with my Stock 88 Calipers which are front on front and back of the car. I also have the 12" C4 Vette Rotors and a Big Brake Booster from Old Europe. The EBC's work amazing at the drag strip and on the street. They really help over the stock style calipers from the parts store, etc. Not sure what how they compare from the Porterfield's, etc. I suggest you give them a try. They are around $100 per set for front or back. They don't really need to warm up at all and work well in the cold too.
Thanks, I'll put those on the list. At $100 per axle they're $50 cheaper than Porterfield R-4 pads. It would be nice to hear from someone who has used them at the track though.
Unsafe At Any Speed
Posts: 975
Joined: Wed Nov 17, 2004 11:29 pm
Location: Washington, DC / Kabul, Afghanistan

Re: Track brake pads for the 1988 Fiero

Post by Unsafe At Any Speed »

Series8217 wrote:I got the HB100N.480 HP Plus pads since my Porterfield order hasn't shipped yet.

They fit the stock 88 Fiero brakes after lightly filing the edges of the backing pads, and drilling out the holes to 6.8mm. However, the pads don't have the nubs/pins for the rear e-brake piston. The backing plates are also pretty thin so it may be hard to add the pins.

In addition, the inboard pads interfere with my WCF 12" rotor caliper brackets. I had to file the brackets and backing plates quite as bit to make them fit. Not a huge deal, just didn't expect to have interference there.
If there's a HP+ pad that works with modifications, what about the DTC-70? I have no experience with the Fiero on track, but the HP+ won't last with an experienced driver and sticky tires. I've liked the DTCs on my CTS-V though.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

Unsafe At Any Speed wrote:
Series8217 wrote:I got the HB100N.480 HP Plus pads since my Porterfield order hasn't shipped yet.

They fit the stock 88 Fiero brakes after lightly filing the edges of the backing pads, and drilling out the holes to 6.8mm. However, the pads don't have the nubs/pins for the rear e-brake piston. The backing plates are also pretty thin so it may be hard to add the pins.

In addition, the inboard pads interfere with my WCF 12" rotor caliper brackets. I had to file the brackets and backing plates quite as bit to make them fit. Not a huge deal, just didn't expect to have interference there.
If there's a HP+ pad that works with modifications, what about the DTC-70? I have no experience with the Fiero on track, but the HP+ won't last with an experienced driver and sticky tires. I've liked the DTCs on my CTS-V though.
See this post.
FieroWanaBe1
Posts: 427
Joined: Sun Mar 11, 2007 11:26 pm

Re: Track brake pads for the 1988 Fiero

Post by FieroWanaBe1 »

I can assure you that HPS+ pads do not take well to track use. I suffered sever fade on my '04 GTO during and HPDE at Road America.
car.
User avatar
Series8217
1988 Fiero Track Car
Posts: 5971
Joined: Thu Jun 02, 2005 9:47 pm
Location: Los Angeles, CA

Re: Track brake pads for the 1988 Fiero

Post by Series8217 »

My friend has HP+ pads on his S2000, which weighs the same and has about the same power as my car. No brake ducts. He runs slightly faster lap times than me and likes them. Might just be the tracks we run.

Since I have them already I'll probably just keep them as spares (or to drive to and from the track). Once the R4 pads wear out, the DTC-70 looks like a nice choice.
Unsafe At Any Speed
Posts: 975
Joined: Wed Nov 17, 2004 11:29 pm
Location: Washington, DC / Kabul, Afghanistan

Re: Track brake pads for the 1988 Fiero

Post by Unsafe At Any Speed »

Series8217 wrote:
Unsafe At Any Speed wrote:
Series8217 wrote:I got the HB100N.480 HP Plus pads since my Porterfield order hasn't shipped yet.

They fit the stock 88 Fiero brakes after lightly filing the edges of the backing pads, and drilling out the holes to 6.8mm. However, the pads don't have the nubs/pins for the rear e-brake piston. The backing plates are also pretty thin so it may be hard to add the pins.

In addition, the inboard pads interfere with my WCF 12" rotor caliper brackets. I had to file the brackets and backing plates quite as bit to make them fit. Not a huge deal, just didn't expect to have interference there.
If there's a HP+ pad that works with modifications, what about the DTC-70? I have no experience with the Fiero on track, but the HP+ won't last with an experienced driver and sticky tires. I've liked the DTCs on my CTS-V though.
See this post.
:roll: I don't know how I missed that. I read that post, I don't think that the colored text was showing for me though... Anyway, yeah.
fierobill
Posts: 1
Joined: Sun Mar 29, 2015 6:44 am

Re: Track brake pads for the 1988 Fiero

Post by fierobill »

I have run EBC Yellows pretty hard on my 3800SC Fiero at Barbers Motorsport Park and took them down to almost nothing after 8, 20 minute sessions. No complaints on their performance and essentially zero rotor wear. I need something harder and I need more rear brake bias. I had more than 1/2 life left in the rear pads. I'm looking seriously at the Hawk HP100x.480 pad "conversion". I think the Hawk W compound (DTC-30) might be a good choice (100-800 F optimal range). The DTC-70 compounds wants a minimum of 800 degrees for optimal performance according the the Hawk compound chart. That's a bit high IMO. I'm using front OEM calipers on all 4 wheels .... much easier to service between events.
Post Reply