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therieldeal
therieldeal Reader
7/14/21 11:14 a.m.
ProDarwin said:
irish44j (Forum Supporter) said:

I run Hawk HP+ for stage rally, but find that when i rallycross the first several braking zones on course I have no bite to speak of until they warm up. I usually will drag the brakes from grid to start to try to get some heat in them, but even that doesn't work well. Now I switch back to HPS for rallycross. 

Interesting.  According to Hawk, the HP+ has more friction than HPS at all temperatures:

My comment on this comment is... that this data appears to actually begin at 100F.  Starting line temps at a rallycross could easily be significantly colder, and that's likely the issue.

 

wspohn
wspohn SuperDork
7/14/21 11:51 a.m.

My Solo days are a long time ago, but slaloms are just races in miniature, so....

There are two things to seek/worry about - how quickly do the pads grip, and will you generate enough heat in a solo event to have to worry about fade.

The answers are - yes, the initial grip of some pads sucks. That was the case with the stock GM pads on my Solstice.  If you lose 1/3 of a second every time you apply the brakes in a solo event, I think you just lost to someone with better pads.  I switched that car to some EBC Red Stuff that gave pretty much instant grip.  On the fade, I do believe that it is a concern especially for higher speed open courses with heavier cars. While obviously not as demanding as being on a race track, you want something that not only gives instant grip, but also a compound that doesn't fade on you in the last run of the day.  A full race compound will be overkill but a steer performance compound should work well.

I have some Porterfield R4S that do a good on on another car.

GameboyRMH
GameboyRMH MegaDork
1/17/22 8:28 a.m.
ojannen said:

I bought my last dedicatd autocross car from a hard parker.  The owner managed to find a set of brake pads that faded after three autocross 55-25mph brake zones.  As I got faster, I started getting random soft pedals that I couldn't figure out.  I spent a bunch of time chasing down bubbles and brake fluid compounds.  Someone finally suggested a different pad and it solved all my problems.

He probably put on some ultra-low-dust pads so he wouldn't need to wipe the wheels off again when he arrived at the car show.

spitfirebill
spitfirebill MegaDork
1/17/22 12:02 p.m.

Who moves TO Cleveland willingly?  

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) PowerDork
1/17/22 12:38 p.m.

Following up on my previous post. Fresh fluid helped with the modulation on my ES Miata. Not great, but improved, and the balance front to rear seems better also. 

I never liked the brakes on my 04 Ralliart wagon until I put some Stoptech Sports on the front. It would stop okay with regular parts store ceramics, but the modulation really wasn't good. I know the Stoptech is not a highly regarded pad, but they really transformed the car. They stop better and the modulation is great. 


One factor with the Ralliart is that there's not a lot of options if you want to have the same pads on both front and rear. It's a bigger concern than when it was when only a commuter car. I found out that it's a competent autocross car, so I'm going to occasionally compete with it instead of the Miata.

I want to do new pads all around, but there's not a lot of choices for the street and autocross category available for both axles. 

Mustang50
Mustang50 Reader
1/17/22 1:06 p.m.

In reply to spitfirebill :

Because Northeast Ohio is a great place to raise a family and with all the garbage we have going on now we have some of the best healthcare facilities in the world.  You should check things out before you open mouth and insert foot!

spitfirebill
spitfirebill MegaDork
1/17/22 4:10 p.m.

In reply to Mustang50 :

I did.  It didn't change my mind.  

GameboyRMH
GameboyRMH MegaDork
1/17/22 4:15 p.m.

So as expected, the pads made approximately no difference to overall performance. People often upgrade brake pads and discs and calipers for the wrong reasons - they want a pedal that feels sharper or is more sensitive, which is a more of a MC/caliper bore matching issue (and in the big picture, a comfort issue that you can work around with changes to driving technique), when there are really only two good reasons to change these things:

1: You're having trouble generating enough braking force to lock up the wheels/activate ABS

2: You're having brake fade or maintenance issues due to heat.

In autocross we can nearly disregard the possibility of #2 due to the length of an autocross run, you'd need a massive-but-powerful car on bargain-bin pads to have heat issues. #1 is a very uncommon issue especially with stock wheel setups, but might happen with wheel & tire upgrades.

So generally, you can't address a real braking problem in autocross by changing pads, but you can sure give yourself some pads that are harder to control due to very high friction compounds and being below a decent operating temp most of the time, and will eat your rotors a lot faster as a bonus!

Mustang50
Mustang50 Reader
1/18/22 1:02 p.m.

In reply to spitfirebill :

Your loss, chew vigorously!

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) PowerDork
4/25/22 8:04 a.m.

This rolled back through again on the forum, and since I have another car since I last read it, I thought I would refresh myself. Reading the comments, I found that I had also replied a couple of times.

Here's the update on my Miata. As I had commented in January, fresh fluid did help a bit.
 

What made a bigger difference is that I'm now re-bedding the brakes on my way to the events. I do three or four hard stops from 50 to 60 mph down to about 10 mph, then drive normally to the event. Pedal feel and modulation is much better since I started doing that.

The new car, a 2008 civic coupe with a 1.8/5 speed will be my daily driver and bad weather/backup auto cross car. It will get a set of Hawk HPS pads and some plain Centric or Brembo rotors soon. 

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