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DrmCtchr said:
OK damnit quit guessing:
Ice mode is when the brake booster is not preloaded with vaccuum to assist the braking .. its similar to not having the car running and ending up with manual brakes. This is due to going from WOT or at least +psi boost to brakes too quickly. The engine hasn't had time to develop vacuum by the time you are asking the braking system to use the vacuum.. that hasnt yet built to a value that actually assists the brakes.
well ok one more driving style fix ... press really freaking hard on the brake pedal the brakes are still there and will work as if the car isnt started they will still work you just have to really press em.

David Jackson
I think we may be talking two separate things. "Ice Mode" as it's known to autocrossers, is when are trying to get maximum braking while cornering, and the inside rear tire is unloaded. This will cause inside rear to lock, and thus the brakes to back off, and then all of the sudden you loose braking ability. This is what pretty much all of us autocrossers run into.

When this happens, the pedal goes to the floor. The ABS is working, but in autocross, it's often hard to feel/hear it working. You can try to push the pedal harder, but you don't get any additional brake application (again, because the ABS is cycling).

If Ken is having problems straight line braking, it might be what you are talking about. Another thing he should double check is his brake fluid level. I found my fluid level getting low this year, and it caused a bit of a soft pedal, and occasionally it took a split second before the brake apply I asked for actually started.

As for pumping the brakes, there really isn't time to do something like that in autocross. Your brake applies are typically so short in duration, they'd be the total equivalent of at most 2-3 pumps of the pedal.

Usually what I feel when I'm left foot braking (and using gas and brake at the same time) is just the loss of assist, and results in a nice, firm pedal. That's not the case once the ABS starts cycling. Once ABS starts, the pedal will drop significantly closer to the floor.

That's just my $0.02, for what it's worth.
 

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rallyfreak said:
DrmCtchr said:
OK damnit quit guessing:
Ice mode is when the brake booster is not preloaded with vaccuum to assist the braking .. its similar to not having the car running and ending up with manual brakes. This is due to going from WOT or at least +psi boost to brakes too quickly. The engine hasn't had time to develop vacuum by the time you are asking the braking system to use the vacuum.. that hasnt yet built to a value that actually assists the brakes.
well ok one more driving style fix ... press really freaking hard on the brake pedal the brakes are still there and will work as if the car isnt started they will still work you just have to really press em.

David Jackson
I think we may be talking two separate things. "Ice Mode" as it's known to autocrossers, is when are trying to get maximum braking while cornering, and the inside rear tire is unloaded. This will cause inside rear to lock, and thus the brakes to back off, and then all of the sudden you loose braking ability. This is what pretty much all of us autocrossers run into.

When this happens, the pedal goes to the floor. The ABS is working, but in autocross, it's often hard to feel/hear it working. You can try to push the pedal harder, but you don't get any additional brake application (again, because the ABS is cycling).

If Ken is having problems straight line braking, it might be what you are talking about. Another thing he should double check is his brake fluid level. I found my fluid level getting low this year, and it caused a bit of a soft pedal, and occasionally it took a split second before the brake apply I asked for actually started.

As for pumping the brakes, there really isn't time to do something like that in autocross. Your brake applies are typically so short in duration, they'd be the total equivalent of at most 2-3 pumps of the pedal.

Usually what I feel when I'm left foot braking (and using gas and brake at the same time) is just the loss of assist, and results in a nice, firm pedal. That's not the case once the ABS starts cycling. Once ABS starts, the pedal will drop significantly closer to the floor.

That's just my $0.02, for what it's worth.



Thats what i feel. The peddle goes very soft.
 

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I have the same problem, most of the time it is at the finish where i push hard and then come to the brakes hard and the pedal is like a rock. I was thinking all along that there is too much boost and not enough vac., but i do run 205 in the rear with 51 pounds of air but i never thought about how that might affect it or abs. I wish the was a very good solution to this?
 

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I replaced the cheap 'lil green check valve before the master cylinder with a heavy-duty brass check valve.
Now I have brakes again! :thumbsup:

The brake booster line comes right off the bottom of the intake manifold so if that plastic check valve leaks then you have boost pressure getting back there instead of the helpful vacuum.

I have an AutoX this Sat, I'll report on how the braking feels & post pics of my setup.
 

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I don't think the ice mode (too sudden abs activation due to rear wheel lift) is something you'd get on a road course. It seems that autocrossing with the slower speed and sudden change in direction make it show up more.
 

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stowaway said:
I don't think the ice mode (too sudden abs activation due to rear wheel lift) is something you'd get on a road course. It seems that autocrossing with the slower speed and sudden change in direction make it show up more.
ah ok gotcha
 

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Discussion Starter #29
I don't think it's lack of vacuum assist because in one run I pulled the abs fuse and didn't seem to have a problem. Fuse back in and problem was back.
 

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Old, old topic. IIRC, the "official" solution was to pull the plug on an ABS wheel sensor. If you pull the fuse you lose EVBP (electronic variable brake proportioning) as well. I want to say it was recomended to pull the sensor on the side of the car the would have the fewest turns (ie if the track has more left turns, bull the right sensor) but don't quote me on that.
 

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Sudden inside rear lift caused by soft springs and stiff swaybar and too much pitching diagonally. The fix is less swaybar in the rear, better roll resistance in the front, and/or disabling abs.
 

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Discussion Starter #33
Anyone have any experience with the new Hawk Street 5.0 pads?

High Performance Street 5.0 | Hawk Performance

NEW Brake Pad Compound!

Hitting the Rev Limiter just took on a whole new meaning with Hawk Performance’s High Performance Street 5.0. For years engine builders have been pushing motors to the limits of their ability, and at Hawk Performance we continue to get one step closer to the ABS Rev Limiter. High Performance Street 5.0 is one step closer to giving you the greatest stopping power and pedal feel for your vehicle without compromising your ABS. Too much Brake Torque and your ABS goes into ICE mode, too little and there is no improvement to the product. Pedal feedback, Noise, Brake Torque and Dust control was our goal with High Performance Street 5.0. Not a replacement for our current HPS product, but a change that allows the driver to challenge themselves and their car with a new and unique driving feel.
High Performance Street 5.0 disc brake pads are designed to be the premium replacement pad for your American Muscle sports car, German or Italian Touring Sedan, Tuner Market, Light Truck and SUV with over 1900 vehicle applications offered.

The new High Performance Street 5.0 Pads are a Ferro-Carbon compound brake pads that provide advanced braking characteristics to enhance the driving experience. This new compound combines the safety and quality of aerospace design partnered with the braking technology of motorsports, the results are shorter stopping distances, improved performance under heavy braking conditions and street car friendly characteristics.
 

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So hawk is trying to come out with a more progressive pad compound? Only a few years late to the game on that. The on/off nature of hawk pads is why I've pulled them off of cars before.
 
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