Calipers

[dukeyyyyy]

Big calipers in the back and smalls in the front, or vice versa? Or does it really make a difference?

[TheJet-09]

I assume you're talking actual body size but should technically be looking at piston size. I don't think it's wise to mix caliper size front to rear, but maybe it's not unheard of.

[dukeyyyyy]

it's not unheard of when you're balling on a budget lol. the 2 rears went out and i have spares to replace them but not the same ones that came off. The fronts now have bigger pistons than the rears. Didnt know which way is better

[TheJet-09]

Completely understood, I'm in the same boat...wrecked in qualifying once and ran a 100 lap feature with only the LF and LR calipers. Didn't stop well but had an interesting effect! The bigger piston calipers "should" generate more clamping force which would typically be warranted on the rear of a dirt car, not the front. You might be able to compensate with the balance bar (adjuster) but it's just that...compensating. I've thought of running a smaller caliper on the RF.

[collateralDamage]

dukeyyyy, i would say it definitely does make a difference (piston size) being different front to rear.

years ago, you tighten the hell out of the car all the time for forward drive and put the big calipers on the rear so when you stomp the pedal the car pitches and turns.

the trend over the last couple of years seems to be like jet said: running 1.75 piston calipers on 3 corners with a 1.375 piston on the RF. you get a "throttled" 3 wheel brake effect, leading the front end into the corner as you massage the brake and gas pedals.

Recently, since front end traction is getting the most attention and we now don't need as much roll-steer, etc. to turn the car (actually use the steering wheel to drive the car), I'm not so sure big calipers on the front aren't the way to go. ????

just thinking out loud.....

[Matt49]

Nothing wrong with thinking out loud...
Here's me thinking out loud: If your car won't turn by using that big round thing in front of you, it is too tight. Now I know what somebody is going to say/think, "in some track conditions, you need all rear brake or RF shut off to turn the car." Again, I say your car is too tight and you're using the brakes as a crutch. The fact is, it doesn't make much sense to have a setup for hot laps so we just use these crutches because it's a quick fix for a track condition we're not going to see much of. But if you were going to race in those conditions you should be doing something to fix corner entry that doesn't involve donkey-kicking the brakes.

[hucktyson]

Matt as usual your talking crate racing, when you have 400 hp you can make a car free enough for it to rotate by casually turning the wheel and still have plenty of drive coming off. Watch the top guys they throw the dog fuk out of that car !!! They throw it that hard because if they don't the car won't turn and if they don't have that kind of side bite and drive in the car it won't come off the corner . I having being jacing off spiders for years thinking I could get a car to drive like a Cadillac on the way to get grocerys and still be fast but it's just not reality . The top guys are UP ON THE FUKING WHEEL !!! Watching the heats and features at eldora finally woke me up to what my problem is ..... Driving like a bitc h !! A car that has enough drive coming off isn't rotating unless you rotate the dam thing ... I guarantee if I don't run well at PRP it will not be because I didn't run hard enough.

[Matt49]

Matt as usual your talking crate racing, when you have 400 hp you can make a car free enough for it to rotate by casually turning the wheel and still have plenty of drive coming off. Watch the top guys they throw the dog fuk out of that car !!! They throw it that hard because if they don't the car won't turn and if they don't have that kind of side bite and drive in the car it won't come off the corner . I having being jacing off spiders for years thinking I could get a car to drive like a Cadillac on the way to get grocerys and still be fast but it's just not reality . The top guys are UP ON THE FUKING WHEEL !!! Watching the heats and features at eldora finally woke me up to what my problem is ..... Driving like a bitc h !! A car that has enough drive coming off isn't rotating unless you rotate the dam thing ... I guarantee if I don't run well at PRP it will not be because I didn't run hard enough.

https://www.youtube.com/watch?v=jTa2oJfV26Y
Here is a video of Jimmy Owens going around Eldora. Qualifying, heat race, and feature. Throughout the entire thing, I don't see anything that resembles "throwing" the car into the corner. Sometimes he doesn't even turn the wheel to the left at all. And if I had to describe his entry when he does turn the wheel to the left I would describe it as "casually turning the wheel". Eldora is a momentum race track so if you're in search of forward bite there it is because you're killing your momentum somewhere before corner exit.
I also fail to see any correlation between a car that doesn't want to rotate and car that has a ton of drive. You can easily have one without the other and vice versa. In fact, I would say that if you are having to FORCE the car to rotate because it won't do it easily, you've consequently killed any chance at having forward drive. This is the classic tight in/loose off condition that people fight so often and I would venture to say you may be fighting it yourself.

[hucktyson]

Your right davensnort and pierce never once turned their wheel to the right .... The right rear stays outside the right front as viewed top down . Please come to prp and demonstrate to me this asphalt driving style you think these guys use .... The front ends have improved but they are still no where near capable of rotating the center without having the rr outside the rf I'm not talking 1980's sideways ...

[hucktyson]

Come to think of it Boggs , pierce , davensnort and those guys know for charging hard all drive like ms Daisey is in the car with them ....

[Matt49]

I never said anything about an asphalt driving style which would be just turning the wheel to the left all the way around the corner.
You said that the car must be "thrown hard" into the corner and cannot be setup in such a way that allows it to be turned with a casual turn of the wheel or it won't get off the corner.
I showed a very clear video that contradicts that and demonstrates a top driver (I'm assuming you would include Owens in that category) that has his car so free for corner entry that he sometimes doesn't even have to turn left to get it rotated. The only time he EVER turned the wheel more than 5 degrees left was when he plowed the RR into the cushion.
Your argument seems to be that the only way you can get a car to have drive off the corner is to set it up so tight on entry that it needs be just to be man-handled to get it to turn. That simply isn't true. It is just the opposite. A car that is tight on entry will almost always be free on exit and not have any forward bite.

And I stand by my statement that a properly balanced car for the track conditions will always be faster than one that needs to use a ton of unbalanced braking to get it to turn (that's what the topic of this thread is about: brakes).

[hucktyson]

Throwing a car in doesn't necessarily mean stomping on the brake pedal ...

[billetbirdcage]

Billet says: WOW

[Matt49]

Throwing a car in doesn't necessarily mean stomping on the brake pedal ...

I give up...

[swartzman]

Boggs is driving prp about as close to asphalt as your going to get this year.

[swartzman]

Jet09 the only reason at all your car would have been driving funny was because you have never driven a car with just 3 wheel brakes on it before.. I can assure you just having one brake caliper on the left rear did not have one thing to do with it unless you have a unlocking rearend..

[kaij15]

I guess I need to get tickets to the Dream. Apparently observing heat/features at Eldora speedway has turned this mans life around. I just hope attending in June isn't to late for me. Way to kill a topic hucktyson.... On the flip side of moronic.... Anyone run there brakes Left/Right versus Front/Rear?

[Matt49]

Jet09 the only reason at all your car would have been driving funny was because you have never driven a car with just 3 wheel brakes on it before.. I can assure you just having one brake caliper on the left rear did not have one thing to do with it unless you have a unlocking rearend..

Assuming both rear calipers are clamped to the axle tube. If one or both were on the birdcage, this could definitely cause some strange things besides the obvious 50% reduction in rear brake.

[fastford]

I guess I need to get tickets to the Dream. Apparently observing heat/features at Eldora speedway has turned this mans life around. I just hope attending in June isn't to late for me. Way to kill a topic hucktyson.... On the flip side of moronic.... Anyone run there brakes Left/Right versus Front/Rear?

I don't have a onboard adjuster per say to adjust left to right, but when im on the left rear brake floater, I use a big piston caliper and very aggressive pads on left side, which could be called adjusting left to right, just cant change it on track.

[swartzman]

Your not going to find anybody who has a adjustable left to right brake system. What you will find is people do have a adjustable right front brake. I'm not saying someone may have something like that but no one I am aware of.

[TheJet-09]

Swartzman - To further explain my "left side only" brake scenario, I'd start by admitting I am of the driving style where I dump the throttle and jab the brake on corner entry (at least when the track is heavy). I unfortunately still drive that way today, but back to my story....when qualifying that night (this had to have been around 1998), I heard a clunk come from the rear as I came off of four, but didn't think too much about it...heading into one on the second lap, I realized what the clunk was - the RR caliper mount broke, which allowed the caliper to spin along with the rotor, which in turn broke the brake hose (= no more rear brakes). Hitting the brakes going into one then locked up the fronts, which sent me into the wall, which tore up the RF. Due to time and lack of parts, we just plugged the RF and RR brake hoses and ran the feature with just left side brakes. I have driven with the RF shut off but have never liked it...seems to "jerk" the front end to the left and I've just never liked that feel...also had concerns of what it would do if I was in traffic and had to get on the brakes hard - might end up in the infield! With just the left side brakes I felt like the car had a subtle "pull" to the bottom on entry, but possibly due to the significant reduction in overall braking ability. One last thing I'd point out is that the rear end was locked (spool). Despite that, you most certainly can tell when only one rear wheel has brakes. I'd ask this...we can alter the drive/influence of our rear wheels (left vs. right) under power by changing the difference in weight/force on each tire (LR heavy vs. RR heavy), even though the two wheels are "locked together." Wouldn't the same hold true under braking as well?

[kaij15]

I understand. I know it is used in different applications. It has it's advantages and disadvantages. More of a Driver preference thing. Maybe L/R would work better with a RF shutoff? Since your pressure gain would be to the RR and not lock up the LF (usually going to mostly if not ALL rear brake with RF shutoff in a F/R system). Just a thought. Maybe Billet or Matt49 has an opinion on this?

[billetbirdcage]

I'd ask this...we can alter the drive/influence of our rear wheels (left vs. right) under power by changing the difference in weight/force on each tire (LR heavy vs. RR heavy), even though the two wheels are "locked together." Wouldn't the same hold true under braking as well?

It does, but:

You have to have a change in tire loading from the brakes to make that work. If you have a brake floater or caliper mounted to birdcage, it is loading the tire through that devise and adding load to the tire which will effect the traction of the tire and therefor may pull car one way or the other.

Now granted even with a clamped to the axle brake bracket as you brake it tries to unload the rear end through the torque arm. But I'm not sure there is enough force there to unload the LR more enough then the RR to notice a difference, I could be wrong but I'd agree with swartzman I don't think you'd see a difference on a locked axle with clamped brakes.

Seeing it was that long ago for JET, it's possible that he had both calipers on the birdcage as it was still reasonably common back then but going away at that time. If both were on the birdcage, I'd expect that you could see a difference if you unhooked the right. 50% less braking power but the LR would get the loading from the caliper pushing down on the cage thru the bars and by unhooking the RR you removed that on that side. So theoretically the LR would have gained more load then the RR (just from braking) and should cause the car to be looser (LR has more traction to slow car from engine braking and regular braking) just from a rear brake standpoint. How noticeable is going to depend on bar angles and how much it's loading the LR.

To answer the OP's question, it's not uncommon to use different size calipers front to rear. If you a heavy trail braker you may like smalls on the front and big on the back. I'd personally prefer to stay with big all the way around unless your running a sanction that you having trouble making weight and need to shave weight. It's not so much you going small on the front, but just bigger on the back some like or are fine with small brakes. I generally just don't like them as once you've had big brakes it's hard to go backwards, IMO.

Keep in mind also just cause they are large brakes doesn't mean they stop better. As a generalization:

1. Small cast calipers don't stop as good as big cast calipers
2. Small billet calipers seem about the same as big cast calipers
3. Small billet calipers don't stop as good as billet big calipers

Obviously it varies among brands, but gives you a basic idea.

[TheJet-09]

^^^ Billet - As always, great information! I didn't even consider the difference in B/cage mounted versus axle mounted. I can't recall which it was but would have to believe they were mounted on the birdcages. It wasn't my car although I ended up buying it later on, and I'm certain we weren't even on the LR behind stuff yet. Because of my antiquated driving style, I've considered going to a floater on the LR to keep it up on the bars on entry. I just haven't made the investment $/time wise out of fear I'd be no better off than I currently am.

[Matt49]

This is what I was eluding to in post #18 but a great explanation as usual from billet.

The place where I felt the biggest difference in floating versus not was on a big flat track where you were really on the brakes for longer durations.

I believe Lazer chassis have frame mounting options to run a separate brake floater rather than floating the caliper on the birdcage.

[swartzman]

Matt I think your right, I think Lazer does have them..

[hucktyson]

Spike Logue from wildwood swears testing has proven that large calipers do not produce more force than small calipers .... The only difference is that the pads last longer .... That isn't my option it's wilwoods ...

[Matt49]

Correct. Caliper and pad size don't matter (much).
Piston size certainly does though.

[hucktyson]

Yes since the line pressure is constant the force exerted on the pad is greater when you have a larger piston .

[25drtrkr]

Your not going to find anybody who has a adjustable left to right brake system. What you will find is people do have a adjustable right front brake. I'm not saying someone may have something like that but no one I am aware of.
A friend of mine who is a crewchief on an asphalt team, told me awhile back, they have been running this with good success. They run Port City cars so Im sure it came from them. I have looked into doing this on a dlm and believe have found an easy way to try it. I believe you could install a small ball valve into the brake lines going to the lf and lr calipers. Then adjust as necessary. Of course, this would be for testing only. If it shows any gains, then you could modify your brake line system to make it permanent.

[swartzman]

One of the things that upsets a car and gives drivers more fits is being able to regulate how much pressure your hitting the right front with.. wilwood makes something for that. They make a lever style proportioning valve, simple to use, simple to install, click it forward or pull it back. Depending on how much rf brake ur actually needing.