Driver question: 3 wheel vs 4 wheel brake

[7uptruckracer]

Thanks Mike for taking time out to personally give us info on here. Its always good to have something new to think about, as a driver and chassis guy you have to absorb everything. Time to get yall a premium house car driver! Cough Get Fergy Back Cough

7uptruckracer Sorry for leaving that out. Yes he went full rear bias so the trail braking would turn the car and less wheel input would be needed and that would make the guy less likely to sheer tire contact on very very slick track

Matt49 most def. have to tweek the thinking of how traction is applied to the tires now vs 20 years ago. Most of the time its hard for a older driver to adapt to the way we run Late Models with 3wheel being used a lot and car on RF vs RR in the corner


Mike Nuchols @ Warrior Race Cars

[parocket]

My point as already discussed is by running 3 wheel brake the car is too tight and there maybe more entry speed if running 4 wheel and braking differently. The driver insist 4 wheel has not worked for him. He already drives in like he is out of his mind, trying to make entry a smooth as possible to set up for the rest of the turn.

[Punisher88]

What about running a (not a nice word)(not a nice word)(not a nice word)(not a nice word) off on the rr? I broke a caliper bracket at the Bama bash a few years ago in qualifying when it was at green valley. Still qualified 4th with no brakes and no rr caliper. Ran the whole heat with the line clamped and won it by a straightaway. Wasn't as much stopping power but it sure kept the car straight in the slick. Basically both right front and right rear was off.

[Matt49]

Shutting off the RR just means you're getting half the braking power to the rear (assuming same piston size in both rear calipers). So it really wouldn't matter if you shut off the RR or the LR...UNLESS one of the calipers was on the birdcage or on a dedicated floater. Then it's a different ball game. But most folks are clamping calipers to the axle tube on both sides these days. Most but certainly not all.
Anyway, assuming you're most, you should be able to accomplish the same thing by just cranking the bias adjuster completely to the front. Unless you need even LESS rear brake. Then there's an argument for smaller rear master cylinder or smaller piston rear calipers.
But if you've got one or both calipers floated, you may have stumbled across something.
If both calipers are clamped and you cut rear braking power in half, not only will that tighten the car because of less tire traction loss due to braking itself, but it will also cut down on the de-wrapping affect and make the 6th coil not work as hard. = more rear traction on entry.

[TheJet-09]

We touched on the LF/LR brake scenario in a different thread a while back (I can't recall exactly), but I experienced the same issue as Punisher88 (left with only LF/LR) after wrecking in hot laps once, and it had an interesting feel to it. I described it as the car pulling slightly to the bottom of the track under braking. I rely way too much on my brakes for entry though, so maybe that influenced what I felt as well.

[AmickRacing]

Seems like there's a lot of talk about the RF being on or off.
What about the proportioning valves that allow you to shut the RF off in steps?
The one i have I think shuts off about 57% percent (according to the instructions).

[RacerX10]

Seems like there's a lot of talk about the RF being on or off.
What about the proportioning valves that allow you to shut the RF off in steps?
The one i have I think shuts off about 57% percent (according to the instructions).

Had one one my last car, never used it. My opinion is that a combination of the f/r adjust with 3 wheel switch you can get the brakes where you need them.

[warriorracerg9]

Was at a test session the other day an a DLM driver who teaches schools and is very well looked up to for his driving skill had my guy running 3 wheel to the brake bias full rear in a very slick slick condition so it would not lock up the left front an cause the front end to scoot across the center while braking on entry.... so it's all in when to use it. Think on this the way we run these cars now if the RF tire stops turning it causes the car to push so why not keep the RF that has most of the cars load on entry an center rolling along with the car.. Mike @Warrior Race Cars

mike do you think that anyone wa actually on 3 wheel brake this weekend at boyds? I would find that hard to believe but anything is possible. I guess its driver preference. I rarely run mine on 3 wheel as I like to keep the car free enough to turn without having to run it on 3 wheel.

[3wheelinphotos]

I will call some guys and even the guy who ran 2nd and find out! I do believe so especially is the car has a great amount of side bite then why not.

Mike @ Warrior Race Cars

[PushinTheLimit]

I ran 3 wheel the entire time at Boyd's last year for both of the UCRA races. I dialed in some LF brake, but still on 3 wheel brake.

[Chris Steele]

My opinion on the RF proportioning valve...if it slows the fluid down going to the caliper, it will be slow coming back out of the caliper. After the pedal is released it will cause the RF to hold pressure for a little after, but thats just my way of thinking, never had a car with one that actually worked.

[TheJet-09]

Just food for thought...I believe Ray Cook said he starts the night on 3 wheel and four turns off of full rear. Throughout the night he puts more front in until he's at 50/50. He then turns the RF on and goes back to four turns off of full rear. I believe he was also referring to a SLM. I'm sure Crates are a different story.

[RCJ]

I like the ideal of reduced braking on the r/f but on more than one occasion I've had the shut off bleed by and start binding the r/f.On the car now I have a small piston caliper on the r/f, then a prop. valve, then a shut off.