First HPDE - Tire Pressure and Brakes Questions

[mu22stang]

Thanks to brkntrxn for the link on my initial thread. I will be entering The Drivers Edge HPDE on Oct. 3-4 at TWS, running CCW. I have a few questions about my race prep as this is my first event.

My questions have to do with brake pad and fluid choice, and tire pressure. As of now, I'm going with Carbotech XP10s for the front and XP8s on the back, utilizing stock Brembo blanks. The brake fluid I plan on using is Wilwood 570 fluid, but I have yet to order this and am curious if another cheaper and/or better alternative fluid is available that still provides the necessary performance and boiling resistance. Finally, tire pressures. I plan on running 38psi on all four Nitto NT555 ZRs (275/285). Does anyone see anything overwhelming wrong with these decisions, specifically the tire pressure?

My 2004 Cobra has the following modifications:

MM FLSFC
MM aluminum steering rack bushings
MM K-member brace
Midcontinent Mustangs front brake cooling

:beer:
Trent

 

[David Hester]

looks like a good place to start.
I do like to start with a couple of extra lb in the front. Sweet spot you don't have push. 38-36, 36-34, etc.

 

[Force4.6]

You will like the XP10s and XP8s on the Cobra, that is what I use at the track and they provide great feedback and stopping power. It will take you a little bit to get use to them on the track since you have to get some heat into them. Another alternative is Motul RBF 600 for brake fluid, been using it for years now and I thinks its $15 a bottle. Looks good overall, the tire pressure maybe a little high. I think I started out around 35 or so then altered depended on the track temp with tire pressures. Get use to the car first then make small changes to adjust, be prepared to learn, be careful, and have fun.

 

[brkntrxn]

No problem, glad you found a track event.

I will probably switch to Motul 600 when my current batch of brake fluid runs out. Motul is good and about 90% of my friends use it, so it just makes sense to run the same as them in case I run out and need more.

36 front and 34 rear is about where I would start on those tires (per David's suggestion). Have your instructor or some of the other experienced drivers read your tires and give you advice during the event.


-Kevin

 

[sonic cobra]

38# on the front has worked well for me. I set 32# cold at the rear. this with nitto 555 RII's which work well. I also use the Motul RBF 600. Carbotech pads are great. I ran xp10/8's for a couple years and just went up to xp12/10 when I got the nitto nt01's. Really happy with that combo. But haven't figured out best TP for the NT01's yet. I also use the bobcats for the street. No noise and average dusting .

 

[gmsux]

Having just completed my first HPDE my .02, everything looks good. I used synthetic valvoline fluid (not sold anymore) and had no issues with braking. I did install a brake cooling kit I think probably helped a lot. Might look into that too.

http://www.svtperformance.com/forums/new-edge-cobras-51/626620-cobra-brake-mod.html

 

[mu22stang]

Glad to get some great responses on the pressure and fluid, I appreciate the advice. gmsux, I installed my front brake cooling kit this weekend along with my MM K-brace.

 

[mu22stang]

How much fluid is in the system? I'm trying to determine how many bottles of brake fluid I need to completely flush the system, while having some on standby at the event.

 

[ac427cobra]

How much fluid is in the system? I'm trying to determine how many bottles of brake fluid I need to completely flush the system, while having some on standby at the event.

Be sure to never let your master cylinder reservoir even get close to empty to suck air!

A liter of fluid should be sufficient to flush your system. Then take another fresh liter with you to the track!

Have fun!
:thumbsup::coolman::beer:

 

[BlackBolt9]

What we have been using in our race cars, a bit overkill for open track but it's good stuff, but of course the price reflects that accordingly.

ENDLESS RF 650 BRAKE FLUID - REHAGEN RACING PRODUCTS

 

[mu22stang]

Be sure to never let your master cylinder reservoir even get close to empty to suck air!

A liter of fluid should be sufficient to flush your system. Then take another fresh liter with you to the track!

Have fun!

10-4. I've read countless threads on the bleeding procedure, and that was one tip I came across a lot. I could never seem to find a capacity number though, so thanks Bruce. :beer:

What we have been using in our race cars, a bit overkill for open track but it's good stuff, but of course the price reflects that accordingly.

ENDLESS RF 650 BRAKE FLUID - REHAGEN RACING PRODUCTS

Looks like some serious stuff, and probably a bit out of my league and price range as a novice. Duly noted though, and bookmarked. :thumbsup:

 

[LargeOrangeFont]

I've had good luck with ATE Superblue, and TYP200. It is the same fluid, just different colors. Alternating colors makes it really easy to flush as well.

 

[mu22stang]

I changed back to my street pads on Saturday and noticed a couple of things. First, I melted one of the dust boots on the front passenger side piston (PBR). The caliper overhaul kit is $21.11 from Tousley Ford, but I'm curious if there is a way to just get a replacement boot.

Also, when removing the caliper to change the boot, what is the best way to remove and plug the brake line to avoid brake fluid spillage? If I don't have compressed air, can I still work the pistons out by hand?

On the rears, I noticed the brake pad nipple was not seated in the piston groove, but resting (and melting) into the boot. The grooves were aligned properly. Any ideas as to why this happened?

 

[Greensix]

I changed back to my street pads on Saturday and noticed a couple of things. First, I melted one of the dust boots on the front passenger side piston (PBR). The caliper overhaul kit is $21.11 from Tousley Ford, but I'm curious if there is a way to just get a replacement boot.

Also, when removing the caliper to change the boot, what is the best way to remove and plug the brake line to avoid brake fluid spillage? If I don't have compressed air, can I still work the pistons out by hand?

On the rears, I noticed the brake pad nipple was not seated in the piston groove, but resting (and melting) into the boot. The grooves were aligned properly. Any ideas as to why this happened?

Melting off the boots is just part of the game. Everybody has done it. Don't worry about replacing them. Just do a caliper rebuild every couple years or so and you will be fine.

 

[brkntrxn]

I changed back to my street pads on Saturday and noticed a couple of things. First, I melted one of the dust boots on the front passenger side piston (PBR). The caliper overhaul kit is $21.11 from Tousley Ford, but I'm curious if there is a way to just get a replacement boot.

Also, when removing the caliper to change the boot, what is the best way to remove and plug the brake line to avoid brake fluid spillage? If I don't have compressed air, can I still work the pistons out by hand?

On the rears, I noticed the brake pad nipple was not seated in the piston groove, but resting (and melting) into the boot. The grooves were aligned properly. Any ideas as to why this happened?

1) Do you drive the car in bad weather? IE rain, snow, dust?
2) Are you going to do more open track events?

You can replace the dust boot, but in the end it will melt when you do another track event. I would just leave it alone unless you plan on driving the car in bad conditions.

On the rears, the pad could have shifted when you installed it or when you bedded them. Hard to say.


-Kevin

 

[mu22stang]

The car is my daily driver for at least another 6 months, so it will see its fair share of water, dust, and dirt. I live in Houston. I am changing my oil this week, so I will pull of the calipers again and check their integrity. Do the dust boots provide the sole boundary between brake fluid and the environment? I've watched a few videos on the rebuid and it seems like if the seal is compromised, brake fluid can escape.

Edit: Yes, I plan on doing more track events.

 

[gmsux]

How about replacing the boot and using titanium backing plate to reduce heat transfer?