OEM brake calipers vs "race" calipers

[turbogrill]

Hi,

 

Is there really a significant performance benefit going to "race" calipers instead of OEMs?

 

With the OEMs we could still easily lockup the brakes. I assume that means that the OEM calipers has enough

stopping power?

 

This is true for both on our Datsun and NC Miata.

 

Maybe if we are running turbo and slicks it would be different.

 

I am just curious to why people are so excited about aftermarket calipers, I don't think wilwood improved our lap times significantly. 

 

(We switched to wilwood because OEM caliper got busted up in crash and wilwood is cheaper, also gave us a few pounds and switching pads is so easy.)

 

 

[wvumtnbkr]

I think it's more in the pad choice / cost if you already have enough braking capability.

 

Also, some cars calipers require a ton of maintenance to keep functioning in this environment.

 

Last thing is caliper availability.  I know my car is getting much more difficult to find calipers for.

[karman1970]

And weight.  You can shave something like 10 pounds of unsprung mass per corner off our Civic between aluminum calipers and now 2-piece rotors.

[enginerd]

41 minutes ago, turbogrill said:

Hi,

 

Is there really a significant performance benefit going to "race" calipers instead of OEMs?

 

With the OEMs we could still easily lockup the brakes. I assume that means that the OEM calipers has enough

stopping power?

 

This is true for both on our Datsun and NC Miata.

 

Maybe if we are running turbo and slicks it would be different.

 

I am just curious to why people are so excited about aftermarket calipers, I don't think wilwood improved our lap times significantly. 

 

(We switched to wilwood because OEM caliper got busted up in crash and wilwood is cheaper, also gave us a few pounds and switching pads is so easy.)

I said the same thing years back (I can lock up the tires with stock brakes, what’s the benefit of expensive ones?).

The answer I got dealt with pedal feel and modulation and predictability being superior on a higher piston caliper compared to my e30 single piston brakes. Basically “you think you can threshold brake and get on the limit of traction with your current brakes, but you can get closer to the threshold more consistently with racing calipers.”

(and weight savings... my calipers are cast iron)

I still use the stock brakes. Have yet to drive something with aftermarket equipment. 

Edited October 20, 2020 by enginerd

[Chris Huggins]

Consumables costs is the largest advantage that I can think of.  Without FCP euro I would have wanted to switch a long time ago.

 

Pads for my front are $186+shipping, with a volume of (49x95x16) 75,000 mm3

Pads for a wilwood superlite (7420) are $180+shipping, with a volume of (120x62x20) 149,000 mm3 

 

So, theoretically, braking should cost 1/2 as much all things equal (its not that simple but it serves for this discussion)

[turbogrill]

Based on what you all said it would be cheaper to run wilwoods in the long run  Should I get -5 pts?

 

Agree on the weight savings, we saved 2-3lbs per corner. But we use stock rotors, maybe the fancy 2 piece is much more. 

 

 

Edited October 20, 2020 by turbogrill

[thewheelerZ]

55 minutes ago, Huggy said:

Consumables costs is the largest advantage that I can think of.  Without FCP euro I would have wanted to switch a long time ago.

 

Pads for my front are $186+shipping, with a volume of (49x95x16) 75,000 mm3

Pads for a wilwood superlite (7420) are $180+shipping, with a volume of (120x62x20) 149,000 mm3 

 

So, theoretically, braking should cost 1/2 as much all things equal (its not that simple but it serves for this discussion)

 

Now imagine if your car is a family sedan instead of God's Chariot and custom cut pads is the only way to get something decent!  The costs you stated are even more exaggerated.  I calculated that Wilwood calipers would be paid off/offset in two races or so, certainly less than a full season.

 

Performance wise for a faster lap time, I think weight is the only thing adding to speed. Pedal feel as mentioned is marginal at best (though, never ran them back to back, so maybe im talking out my butt).

[turbogrill]

No difference in pedal feel for us, both OEM and Wilwood pedal feel suck on the NC. (I blame the electric computer ABS)

 

[karman1970]

1 minute ago, turbogrill said:

No difference in pedal feel for us, both OEM and Wilwood pedal feel suck on the NC. (I blame the electric computer ABS)

 

Your Miata sounds like a headache.  You ought to sell it and bring the Z back out

[enginerd]

8 minutes ago, turbogrill said:

No difference in pedal feel for us, both OEM and Wilwood pedal feel suck on the NC. (I blame the electric computer ABS)

Real race cars don’t have ABS. Just cut the wire. 

[hotrod]

Our 02 Focus has big front calipers with a large pad surface area. Some Wilwood caliper do flex a little. The car works so good under braking I'm afraid to mess with it. Might have to do a comparison with an aftermarket caliper to save weight & maybe be able to but cheaper pads. 

 

[turbogrill]

1 hour ago, enginerd said:

Real race cars don’t have ABS. Just cut the wire. 

 

Well funny you ask. We had an wheelspeed sensor go out, that disables the ABS gadget that also controls the brake bias.

 

The rear wheels locked up instantly and caused our new expensive RE71 to flatspot really bad.

 

Another NC team removed the ABS module, apparently they are quite heavy. But my drivers are now used to ABS so don't want to mess with it, flat spotted tires sucks. (

 

Edited October 20, 2020 by turbogrill

[turbogrill]

1 hour ago, karman1970 said:

Your Miata sounds like a headache.  You ought to sell it and bring the Z back out

 

The Z is sitting in the parking lot next to the race track, it sees the Miata race every race at Harris Hill. It is very depressing for it, especially since it has a huge cam and lots of go fast parts that really never got used in a race....

 

I need to loose my job so I have time for all these cars...

[MR2 Biohazard]

12 hours ago, Huggy said:

Consumables costs is the largest advantage that I can think of.  Without FCP euro I would have wanted to switch a long time ago.

 

Pads for my front are $186+shipping, with a volume of (49x95x16) 75,000 mm3

Pads for a wilwood superlite (7420) are $180+shipping, with a volume of (120x62x20) 149,000 mm3 

 

So, theoretically, braking should cost 1/2 as much all things equal (its not that simple but it serves for this discussion)

You might get 3X the life as when the pads get low they wear exponentially faster. I went Wilwood for long term pad cost and having the same front and rear calipers I can use my half used fronts in the rear until I can use them all up. The cost benefit only takes about a year to save enough to basically get the calipers for free.

[Cam Benty]

With ABS their is not much of a learning curve. Just get to your braking point and mash the brakes.

 

 

Without ABS  my experience is the more pad that is on the disks and disk size make modulation easier if the Master cylinder, booster and bias is set up properly. Just throwing big brakes at a car without MS, Booster and bias to accompany the big brakes is a waste and can be problematic.
 

I have driven 2 piston  PBR’s with race pads in a 2500lbs car that are fantastic. The 1969 Aluminum Kelsey Hayes Lincoln Calipers on 14 inch Boss disks on a 3375lbs Coyote Cougar at Road America Let me brake with anybody. Bigger brakes and pads will reduce costs. As Nat  stated reduction in car weight makes your standard brakes better with proper pads. 

[Ian]

8 hours ago, MR2 Biohazard said:

You might get 3X the life as when the pads get low they wear exponentially faster. I went Wilwood for long term pad cost and having the same front and rear calipers I can use my half used fronts in the rear until I can use them all up. The cost benefit only takes about a year to save enough to basically get the calipers for free.

 

Most of us don't have enough junk in the trunk to run matching front/rear brake calipers.

[wvumtnbkr]

2 hours ago, SonsOfIrony said:

 

Most of us don't have enough junk in the trunk to run matching front/rear brake calipers.

I'm not sure what you mean?

 

In Troys case it makes sense since mid engine.  However, you could use a different rear compound if it's too aggressive.

 

I do agree that most cars don't need brakes as big on the rear.

[turbogrill]

2 hours ago, SonsOfIrony said:

 

Most of us don't have enough junk in the trunk to run matching front/rear brake calipers.

 

 spare wheel, tools, empty modello can, etc

[Ian]

8 minutes ago, wvumtnbkr said:

I'm not sure what you mean?

 

In Troys case it makes sense since mid engine.  However, you could use a different rear compound if it's too aggressive.

 

I do agree that most cars don't need brakes as big on the rear.

 

Troy's car being mid engine requires significantly more rear brake that a traditional car.  I'm not sure changes in compound would be enough on most, and would negate the ability to burn up old front pads on the rear.

 

For most cars in this series the suspensions are too soft and the weight transfer too great to make the rear brakes share near as much of the load as the front brakes.

[wvumtnbkr]

2 hours ago, SonsOfIrony said:

 

Troy's car being mid engine requires significantly more rear brake that a traditional car.  I'm not sure changes in compound would be enough on most, and would negate the ability to burn up old front pads on the rear.

 

For most cars in this series the suspensions are too soft and the weight transfer too great to make the rear brakes share near as much of the load as the front brakes.

Gotcha.  That's what I thought you meant.  Just wanted to make sure.

 

 

[MR2 Biohazard]

I am at 61-63% front bias. I would think most front engine rwd cars are in the 70% front bias and fwd cars might be 80%.

 

I did choose smaller rear pistons with the same calipers, but I basically had to max out to the smallest size rear piston size and fairly large front pistons to balance it out.

 

A way to do it also would be a dual master pedal box and adjust the masters to the correct size for the calipers if to similar.

[Ian]

2 hours ago, MR2 Biohazard said:

I am at 61-63% front bias. I would think most front engine rwd cars are in the 70% front bias and fwd cars might be 80%.

 

I did choose smaller rear pistons with the same calipers, but I basically had to max out to the smallest size rear piston size and fairly large front pistons to balance it out.

 

A way to do it also would be a dual master pedal box and adjust the masters to the correct size for the calipers if to similar.

 

I suppose with differing piston sizes and different rotor diameters you could make it work on just about anything.  I didn't realize there was that much piston variety in the race calipers.  Never taken the time to really price stuff out.

[MR2 Biohazard]

39 minutes ago, SonsOfIrony said:

 

I suppose with differing piston sizes and different rotor diameters you could make it work on just about anything.  I didn't realize there was that much piston variety in the race calipers.  Never taken the time to really price stuff out.

The wilwoods have a nice range in their models. I also went onto rock auto and spent hours looking up rotors and making a spreadsheet of diameter, center, offset to see what would work best. The excel calculator is key. When we are off by more an 1-2% bias our rears will lock up early, you see the devil and death happens.

[Darth Turbo]

Just changed to the wilwoods on our car, 1991 mr2. So far we are happy and have realised that there are several benefits. The main one being cost. Our stock callipers were getting hard to find,  New ones had been discontinued or were out of stock, and people were asking $500 to $1000 for a used set. Also we were having to get custom pads made in order to get anything good, so it took a long time to get them and we were having to spend $240 for a set.  Pads and rotors on our old set up costs around $1150 but would last us 3 to 4 races. But now the rotors we use now from wilwood are around a $100 a piece,  And ST43s are now a $160 a set.  We are set up to use the stock style master cylinder, but we oversized the rear pistons so that we could take advantage of an adjustable proportioning valve.  So far we have only run the new set up at Barber.  We were quite pleased with the performance, Modulation seems to be a marginal improvement over the old setup. And I can't even tell that the pads have worn at all!  However Barber seems easy on brakes. We also saved about 30 pounds of unsprung mass overall!  My 2 main complaints are, I feel like the pedal feel in my car could be better,  Mainly they are a bit touchy and they require almost no pedal effort might have something to do with the pad compound and/or master cylinder bore size. And holy crap the squealing noise is outrageous when they are cold!  Otherwise I am very happy with the setup so far, I was able to get the callipers and rotors directly from wilwood.  With our champ car discount the calipers were less than a $140 apiece.  In my case the cost savings in the long run will definitely benefit my team. I think it fits the spirit of the series for everybody to have access to a affordable and reliable braking system. 

[TimS]

If you are using boost assisted master cylinder that is likely the touchyness.  You could change the bore diameter of tbe MC or convert to a manual brake setup to improve the feel.  Noise is just a function of pad type and the fact race cailipers don't have any anti rattle function built in.  Experiment with pads and cooling to improve pad temps.  Sounds like a good setup.