need serous stopping power

[jedhead]

Autozone too.

Bob

 

[AREA 91]

Bob, I'm taking your brakes.

 

[chknhwk]

I think you need to learn how to use your brakes better. Next, I've heard several people say that there's a big difference between the PBRs on a 13" rotor and on a 11.6" rotor. Step up to the 13". I doubt that you'll be outdriving them.

It doesn't matter what size tires you chose if you buy crappy tires. Some of the fastest SHOs out there only run a 225 section width tire.

Get better pads and learn how to use your brakes better. The Cobra PBR calipers are awesome for the money. I used to have a lot of brake fade at the track in my Cobra (3434 pounds) until I learned how to use the brakes. Then I only had brake fade towards the ends of my sessions with street pads. After upgrading the pad compound I NEVER had any brake issues.
My recommendation would be to try the PBR pads and bed in the rotors really good and practic braking. Stay off the brakes until you need to slow down then quickly and firmly apply the brakes, slowly trailing off as you rotate the car.
Good luck!

 

[NJSHO]

Also re: above, i would NOT run 13" brakes on a track under those 16x7" PR2

Why not?

 

[Ishodu]

Although they do fit under I wouldn't think there would be enough air flow with the tight clearance for "track" use.

 

[yamahaSHO]

I know 13" cobras fit but i'm not a big fan of them because of their small swept area.

Cobra's actually have a very large, wide swept area. The pad isn't tall, but a wider pad is much better than a taller pad, especially since most of the force should be focused where you're going to get the most leverage (the outer edge). MANY companies, like Wilwood, have long (wide) skinny pads because of this. The problem you have is the 11.6" x 1" rotor. It doesn't handle much heat and there's not as much leverage as a 13" x 1.1" rotor.

honestly I don't think the 11.6 cobras are much more powerfull then my stock calapers (had motorcraft pads). + I warped the living crap out of my rotors and they only have 5K on them.

I've never warped a rotor, not even a stock '92. That's more of driver error than anything.

 

[yamahaSHO]

That's because Hawk pads SUCK ASS. I don't know how many times I've said that, but I've seen Hawk pads spark like **** on a stock SHO with stock brakes...the suck and can't even stop a SHO from 140.

Want some good pads? Go with PFC and get the Z-rated ones, those guys make some bad ass brake kits and their pads are great!

My HP+ pads have done very well for me. The only time I had a problem is when I had a crappy rotor. With good rotors, I tracked these pads without any problems.

With the old rotors, I would throw sparks, but sparks aren't a bad thing. You're grinding metals together.

 

[TYSHO]

With the old rotors, I would throw sparks, but sparks aren't a bad thing. You're grinding metals together.

When they sparked, they didn't help in stopping the car. Maybe it was the rotors. I can't remember if they were new or not and if they were still completely smooth without grooves. Anyhow, it left me with a bad taste for the Hawks.

 

[nc89sho]

They are FREAKIN' AWESOME!!!!!!!!!!!

I won't be autocrossing them until the season resumes in January, but so far the grip is phenomenal in the dry. Pretty good in the wet. Very stiff sidewalls makes the steering ULTRA-responsive. It is very easy to see why they have a reputation for being the #1 street-class autocross tire. Definitely give them a try.

They blow away the Goodyear Eagle F1 GS-D3's I used to run on the street.

i second that comment

 

[somedude_001]

The only time I had a problem is when I had a crappy rotor. With good rotors, I tracked these pads without any problems.

With the old rotors, I would throw sparks, but sparks aren't a bad thing. You're grinding metals together.

well that may be part of my problem. when I have my stock calapers with motorcraft rotors and pads I loved them, but now i'm running cobras on cheap rotors. i'll try upgrading the rotors to something stronger and see if that helps the situation any. I never did warp my old rotors but the cracking was starting to make the brakes click and pop under hard braking so I tossed them. the pads were also chipped, cracked, and separated to a dangerous level so they were tossed with the rotors.

i'll try different rotors and/or I will upgrade to 13" at the same time. I really apreciate the input.

 

[Dylan]

Alex if you wanna be different and try something new. WHy not try the Roush 4piston 14" rotor kit they make for the mustangs. Other than the fact they cost more than most of our cars. Just gotta get the rotor redrilled. I'm only "assuming" this will work. Other than that, 4 or 6 piston from TCE or Willwood with a nice 2 piece rotor. And don't forget the SSbraided lines, if you don't have those already.
But my Cobras with 13" rotors and the gen1 vented dics in the back, work pretty damn good.
Keep up the good work Alex

 

[yamahaSHO]

well that may be part of my problem. when I have my stock calapers with motorcraft rotors and pads I loved them, but now i'm running cobras on cheap rotors. i'll try upgrading the rotors to something stronger and see if that helps the situation any. I never did warp my old rotors but the cracking was starting to make the brakes click and pop under hard braking so I tossed them. the pads were also chipped, cracked, and separated to a dangerous level so they were tossed with the rotors.

i'll try different rotors and/or I will upgrade to 13" at the same time. I really apreciate the input.

A good, cheap route is Napa Gold for about $30/rotor. I've used these and they held up great on track. A more expensive route is Eradispeed. I've done both, but I haven't tested out the 2-piece rotors yet.

 

[shomesomesho]

A good, cheap route is Napa Gold for about $30/rotor. I've used these and they held up great on track. A more expensive route is Eradispeed. I've done both, but I haven't tested out the 2-piece rotors yet.

What part number is the Napa Gold rotor? On their website they have UP 86844 for $53.99. Is that the same one?

 

[somedude_001]

i'll do ford rotors, i've had good luck with them in the past. and dylan the new ford calapers (all models) use a much wider bolt spacing and I would have to make a custom bracket for them. + 14" brakes are HUGE.

 

[yamahaSHO]

What part number is the Napa Gold rotor? On their website they have UP 86844 for $53.99. Is that the same one?

Maybe they have raised their prices over the last year. IIRC, I paid around $35 a rotor. I've tracked them once and now Scott (w/ the remote-turbo SHO) has them.

 

[SHO Dude]

Cobra's actually have a very large, wide swept area. The pad isn't tall, but a wider pad is much better than a taller pad, especially since most of the force should be focused where you're going to get the most leverage (the outer edge). MANY companies, like Wilwood, have long (wide) skinny pads because of this. The problem you have is the 11.6" x 1" rotor. It doesn't handle much heat and there's not as much leverage as a 13" x 1.1" rotor.

Ish...

Remember that every brake's job is to generate negative torque. The engine and powertrain makes positive torque to push the car along, but the brakes generate negative torque to pull you back and slow you down.

Swept area is a major factor in the braking system and is the amount of surface area of the rotor that actually touches the pad. But swept area is far less significant that Torque Arm. Torque arm is the distance from the center of the axle to the center of the pad. The longer the torque arm, the more negative torque the brake can develop. For example, lets take our ORIGINAL 12" BRAKE UPGRADE and compare it to the 13" Cobra conversion. The 12" brake has a comparable swept area to the 13" setup (I don't know what the numbers are but they are comparable for this exercise). The 12" brake has wide, tall pads while the cobra pads are shorter. The difference being the Cobra brake is much larger in dia., so the torque arm is much longer. This makes the 13" brake much better.

The rule of thumb is that 75% of the braking is done with the outer most 10% of the braking surface.

So a bigger rotor is much more desirable than a smaller rotor. The rest of the brake composition is pad compound, swept area per ton, rotor mass and rotational weight, each with it's benefits to the system as a whole.

 

[yamahaSHO]

Ish...

Remember that every brake's job is to generate negative torque. The engine and powertrain makes positive torque to push the car along, but the brakes generate negative torque to pull you back and slow you down.

Swept area is a major factor in the braking system and is the amount of surface area of the rotor that actually touches the pad. But swept area is far less significant that Torque Arm. Torque arm is the distance from the center of the axle to the center of the pad. The longer the torque arm, the more negative torque the brake can develop. For example, lets take our ORIGINAL 12" BRAKE UPGRADE and compare it to the 13" Cobra conversion. The 12" brake has a comparable swept area to the 13" setup (I don't know what the numbers are but they are comparable for this exercise). The 12" brake has wide, tall pads while the cobra pads are shorter. The difference being the Cobra brake is much larger in dia., so the torque arm is much longer. This makes the 13" brake much better.

The rule of thumb is that 75% of the braking is done with the outer most 10% of the braking surface.

So a bigger rotor is much more desirable than a smaller rotor. The rest of the brake composition is pad compound, swept area per ton, rotor mass and rotational weight, each with it's benefits to the system as a whole.

Ummm.... Okay... You pretty much described what I said in a much longer statement. Although, I don't think Todd agreed with you last time on the "The rule of thumb is that 75% of the braking is done with the outer most 10% of the braking surface."

 

[SinisterSHO]

The rule of thumb is that 75% of the braking is done with the outer most 10% of the braking surface.

78% percent of stats are made up on the spot, and 38% of people know that.

 

[SHO Dude]

Todd would be the resident expert and did question my figures. But he never refuted them.

 

[somedude_001]

ok here is the big issue. i'm bringing the turbo SHO to the convention.

the striaght is 3200ft and i imagine i'll have a 40-50mph entrance speed. by my guessing i'll be going well over 100mph probably closer to 140 or higher and have to slow to probably 45-50 for turn 1. i contacted a local performance shop. I asked for a full track pad for the front and something sticky for the rear. does anyone have expierence with what he reccomended for me?

Hawk DTC-70 race pads for the front cobra calipers - 205

Porterfiel R4 pads for rear sho calipers - 119

again i'm on 11.6 rotors but i really fear that i might run into serous problems with these brakes. where can i get the 12.5" brakes because i'm still running slicers.

edit:i'm also strongly considering lowering the boost to 6psi for a roadcourse.