braking question: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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July 8, 2010 1:33 a.m. 240TrackX None

Hey everyone, I'm new here so forgive me if I posted this in the wrong place! I have a question about braking that I'm sure you guys can help me with. I have a 92 240sx with stock calipers and rotors, but hawk hp+ pads, ss lines, and rbf600 fluid. I've done a couple hpde's at Sebring and I was wondering if when I start to lose my brakes, is it better to continue to get on them hard to slow the car down quick, or go lighter on them for less intense friction and less heat.

Hard will obviously heat them up faster, but if I go softer on the pedal it will be for a longer period of time, so I'm trying to figure out which will be better for the cooling to reduce fade. Switching to HP+ from HPS and RBF600 from normal dot4 made a big difference, but obviously it's still a problem. Thanks for any advice!
July 8, 2010 1:58 a.m. 2002maniac Reader

HP+ pads are not track pads! They are auto-x pads meant to have great initial bite, but they are not high temp pads! Try a real track pad like HT10 etc and your fade will disappear..
July 8, 2010 12:35 p.m. 240TrackX New Reader

I know, but I daily drive the car and autox more than I do DE's, so the HP+'s are the best I can use on the street until im some day able to afford to build a full track car! So back to the fading question... does it really matter which way I brake or will the same amount of heat basically build up either way...?
July 8, 2010 12:57 p.m. 2002maniac Reader

It shouldn't make much difference either way. But seriously, get better pads. Even hps can handle higher temps than hp+. Get track pads and swap them out on the track. Won't affect your daily drive at all.
July 8, 2010 1:15 p.m. robertcope New Reader

I think ya'll make have things backwards. HPS are billed as "high performance street" tires, while HP+ are "ideal for Autocross and Track Day drivers looking for a high performance race compound that can take the heat of the track and get you home safely without having to change the pads."

I run HP+ at the track all the time and haven't had issues. Maybe I'm not braking hard enough.

robert
July 8, 2010 1:40 p.m. nickel_dime Dork

Get track only pads and use them only on the track. If your over cooking your pad material then your shortening the life of them anyway. Plus if you keep using lesser grade pads on track sooner or later they won't be there when you need them the most. Use the proper tool for the proper job.

The way braking was explained to me is, brakes turn motion into heat. It takes the same amount of heat to slow a car whether it's done in 200 feet or 600 feet. By braking harder for a shorter amount of time the heat is quickly generated then quickly starts the cooling cycle. By braking lighter for longer the heat builds up and heat soaks all the brake components and takes longer for them to cool.

Just my 2 cent
July 8, 2010 2:10 p.m. 2002maniac Reader

In reply to robertcope:

In my experience HP+ is just fine on the track for cars that are light, low horsepower, on street tires, or driven at 9/10

Change any one of those factors and you'll fade them.

The HP+ is a great auto-x pad because it bites INSTANTLY at low temperatures. Because the optimal temperature range is shifted down, they fade pretty easily when you get some heat in them.

Track pads on the other hand do not bite well at all when cold. They need a lap to get up to their operating temp, but you'll boil your brake fluid before fading the pad material.

On my old E30 318is, i even went to a BBK so I could use HP+ for street and track and they still faded running street tires!

I like to be well within the limits of my cars brakes.
July 8, 2010 3:52 p.m. robertcope New Reader

2002maniac wrote:

In my experience HP+ is just fine on the track for cars that are light, low horsepower, on street tires, or driven at 9/10

So, what you're saying is I have a slow car and can't drive, I get it. :)

Actually, you're obviously dead on, at least in my opinion. Part of performance driving is managing your car. I can drive in a manner that fades the brakes, but normally I dial it down a bit. I prefer that over swapping pads constantly. Ah, to have a dedicated track car.

robert
July 8, 2010 6:17 p.m. iceracer Dork

I ran a lot of track days with my ZX2SR with HP+ pads, never had any fade and I drive 10/10 when I can. A short time on the brakes seems to work for me.
July 8, 2010 6:30 p.m. BoxheadTim Dork

Just to throw this into the mix, but what about looking into improving the brake cooling?
July 8, 2010 7:12 p.m. wbjones Dork

and really... changing out pads isn't all that hard..
July 8, 2010 7:56 p.m. StevenFV19 New Reader

To help out,and not bash you about your pads...pump the brakes before the brake zone to build up pressure and get the pad closer to the rotor. Also, brake earlier and lighter, it will be easier on the brakes, and you have a longer distance until you get to the turn. If you were to brake hard and normal, your brakes would get really soft quickly, and fade away, also youll be braking later, thus when they fade, you will have less time to react.

hope this helps, Steven PS Get Hawk HT10s or Hawk Blue's