Increasing rear brake bias on track only Gen3...

[Magnus_]

So I was talking to one of the Viper Cup teams at the past NARRA event and he suggested putting a set of front calipers on the rear to help increase the rear brake bias of the car.

That got me thinking..

Currently I run brakeman 3 pads front and rear on ACR rotors on 295/345 Hoosier R6's.

I noticed I do a LOT of engine braking coming into the turns to really help me brake very late.

I tried to go into the turn without the engine braking and holy crap, no way, not enough stopping power.

I'm going to bigger front tires and am considering switching to the ACR-X rotors up front so I can run a bigger pad, but am also thinking I might as well visit the rear braking setup as well.

What do you track rats think?

- Keith

 

[bluesrt]

the front calipers are not the same as the rear on a gen 3?= definatly do the acrx rotors and pads on the front,more pad surface- also there are differant grip compunds of pad for stopping power

 

[Allan]

the front calipers are not the same as the rear on a gen 3?= definatly do the acrx rotors and pads on the front,more pad surface- also there are differant grip compunds of pad for stopping power

the calipers look identical, but the rear have smaller pistons.

 

[Allan]

So I was talking to one of the Viper Cup teams at the past NARRA event and he suggested putting a set of front calipers on the rear to help increase the rear brake bias of the car.

That got me thinking..

Currently I run brakeman 3 pads front and rear on ACR rotors on 295/345 Hoosier R6's.

I noticed I do a LOT of engine braking coming into the turns to really help me brake very late.

I tried to go into the turn without the engine braking and holy crap, no way, not enough stopping power.

I'm going to bigger front tires and am considering switching to the ACR-X rotors up front so I can run a bigger pad, but am also thinking I might as well visit the rear braking setup as well.

What do you track rats think?

- Keith

Step up to the Mintex pads. I used to run the Brakeman #3 also. Night and day difference.

 

[Magnus_]

Allan, I'm stepping up pads for sure, either mintex or carbotechs but even so, right now running the same pads front/rear, I'm not getting enough rear bias.

I'm curious how many have put front calipers on the rear to help.

 

[Allan]

Before you change rear calipers, Try the Mintex front and rear first. I did that once and ended up spinning the car because of too much rear brake. -for fair comparison, my car is stock suspension, Pilot sport cups, slotted rotors, steel braided lines, stock calipers, aggressive driver that brakes late. Now I run the proven combo of Mintex front / Brakeman #3 rear. The brakes are not lame by any means. FYI- another thing I noticed with alot of rear bias, is the rear tires will wheel hop -the shifter flops around ugly while braking hard.

 

[Boxer12]

Personally, I would go with more aggressive pads before making this swap but I have never tracked a Gen 3. What did Tommy think about your brakes at RA?

 

[steve911]

Here is my setup. I have an '06 coupe w/Gen 4 aero on it. I have Motons w/1200 rears and 700 fronts. 1st Gen comp coupe sway bars and hoosiers.
I have Mintex front pads with Brakeman 3's in the rear.

I was at Road America w/NARRA and had no problems with my brakes all weekend. They were able to take everything I was handing out w/o a problem.

I am still running OEM 1 piece rotors that were slotted. ( I bought many take off sets for pennies when everyone was buying ACR 2 piece rotors when they first came out). They may be heavy but they are like a Timex watch. It takes a licking and keeps on ticking.

 

[Leslie]

My GenII has always done better with more brakes up front, 80% of braking happening from the front.

When I had the GenIII calipers I ran a more aggressive pad up front....Mintex pads....B3's in rear, had lots of brake.


Is it feeling like your back end is too lose? ....or brakes just not responding like you want? Every braking zone or just on the straights?

I am jealous you got to run a NARRA event, hoping to go to VIR next month!

 

[gb66gth]

Hey steve911, can you slot the OEM rotors?
Please tell me about that. I bought a few sets as well. The price was too good to pass up and for the price of the 2-piece set up I can go through multiple sets of these.

 

[steve911]

Hey steve911, can you slot the OEM rotors?
Please tell me about that. I bought a few sets as well. The price was too good to pass up and for the price of the 2-piece set up I can go through multiple sets of these.

The short answer is yes. We can discuss this more off line. PM me your contact info

Steve A.

 

[Magnus_]

Hey guys.. been busy working on our lemons car.

My brakes work good.. BUT, I notice that I'm able to get even more stopping power by using engine braking, which means, if I could increase the brakes in the back, I could use less engine braking.

The car is very good in the braking zone when using engine braking. I have no issues with the back end wanting to move out, but I also brake in very straight lines as well.

Boxer, it was the other Keith's car that Tommy drove.

I think I'll switch to carbotechs which should give me more pad options for front and back, then I'll just have to reassess.

 

[REDSLED]

Engine braking = FAIL. You need to visit racing pad compounds and the condition of your tires. Running a bigger tire up front will help with braking as there will be more tire for the track to adhere to. Engine should be used to accelerate not decelerate. You don't want to put unnecessary stress on the motor, trans and rear diff by using them to slow the car down. Even when doing that the limiting factor will be tire adhesion. Good luck.

 

[JoelW]

Engine braking = FAIL. You need to visit racing pad compounds and the condition of your tires. Running a bigger tire up front will help with braking as there will be more tire for the track to adhere to. Engine should be used to accelerate not decelerate. You don't want to put unnecessary stress on the motor, trans and rear diff by using them to slow the car down. Even when doing that the limiting factor will be tire adhesion. Good luck.

Curious about your logic here. Seems that using engine braking judiciously (I don't mean long term engine braking but in concert with brakes) would help load the car for a corner as well as braking. Deceleration would seem to be less stress on the powertrain than acceleration as the loads would be based on chassis weight not engine power and torque. I realize those loads can be high but engine braking and partial throttle to control speed in a corner seems to serve to "set" the car up while braking alone will transfer weight - sometimes to places you don't need it. But I could be wrong as I am just starting to track my car.

 

[345s-bspinnin]

I always thought engine deceleration also helps to cool the engine. At least that most Exhaust Gas Temp sensors will read.

 

[Allan]

Engine braking = FAIL. You need to visit racing pad compounds and the condition of your tires. Running a bigger tire up front will help with braking as there will be more tire for the track to adhere to. Engine should be used to accelerate not decelerate. You don't want to put unnecessary stress on the motor, trans and rear diff by using them to slow the car down. Even when doing that the limiting factor will be tire adhesion. Good luck.

This somewhat harsh, ugly comment is totally correct. You need to mod the driver, not the brake bias. Any instructor from Skip Barber, Bondurant, and the like, will tell you that the 'brakes only' are for decelerating the car. The reason for a downshift before a corner is to set up the powertrain for accelerating out of the corner. Proper technique is a 'rev-matched' heel/toe downshift that does not upset the car when the clutch comes out. If the car is at the limit, there is a possibility of 'trailing throttle oversteer' occuring. -even going straight. (don't ask how I know) When I first started tracking, I used to try to engine brake also. Then I learned what an idiot 'street driving' technique that is. (got schooled and learned from people that can actually drive fast on a roadcourse) I am not the most proficient driver by any means, but with an open mind and lots of seat time, I am learning. Not trying to slam on your driving, but you will end up in the wall if you get faster and keep the bad habit of engine braking the car.

 

[Magnus_]

Allan,

I have 5,000+ miles on Road America alone...

As I said in my original post, I don't have enough rear brake bias. If I brake has hard as possible into the turn without engine braking, I must use an earlier brake marker. With the addition of engine braking, I am able to go in deeper.

The solution is to increase my rear brake bias.

Simply ditching the engine braking and using an earlier brake marker is not a solution to me. Any solution that slows me down is unacceptable.

 

[Allan]

Wow. There is something different with our cars, I wonder whats up with that. I have to use a less aggressive pad on the rear to avoid rear wheel lock up and spinning the car. I drive with a similar attitude as you. I brake late and hard, other people think I'm crazy, but I think that if the car is capable then why not. I wish you the best in getting your car sorted out the way you want it, hope you get there safe.

 

[ACR steve]

Magnus- you need more aggressive front pad. A pad that will take a quicker initial bite into the rotor. Not more rearbrake bias. Our cars do 75% of the braking upfront . By increasing the rearbias as a novice track driver you will create a very loose rear end under braking.Compound that with any trail braking and you will be backwards before you canblink your eye. Are you in ABS when you are braking? If you never get into youABS you aren’t using the brakes enough. The key is to get a feel of how muchbraking you can do just before ABS kicks in that your most efficient brakeforce.

I run full race pads on my street ACR and the brakes are insane. Probably thebest feature of the car.

 

[Magnus_]

Steve,

I've been thinking about this a bit recently and I'm sure you're right.

The only time I kick on the ABS is coming up the hill of turn 6 at road america.

I'm going to be putting a carbotech XP8 in the rear and haven't decided which one to run in the front yet.. But given that + the addition of wider front tires, I'll see how the car feels and reassess the setup. Depending on what front pad I go with, I could always go with an XP10 in the rear if the car felt it could pick up with a little more rear bias... but, won't know until I put some miles on the new setup.

 

[Allan]

Magnus- you need more aggressive front pad. A pad that will take a quicker initial bite into the rotor. Not more rearbrake bias. Our cars do 75% of the braking upfront . By increasing the rearbias as a novice track driver you will create a very loose rear end under braking.Compound that with any trail braking and you will be backwards before you canblink your eye. Are you in ABS when you are braking? If you never get into youABS you aren’t using the brakes enough. The key is to get a feel of how muchbraking you can do just before ABS kicks in that your most efficient brakeforce.

I run full race pads on my street ACR and the brakes are insane. Probably thebest feature of the car.

I totally agree with this dude on all points. I have spun the car with to much rear brake bias (Mintex front and rear) -sucked. I had the same idea as the OP, and it didn't work out well at all. Have been trying to get that point across, but my advice seems to have been falling on deaf ears, or I am thought of as a poser I guess -whatever.

 

[Magnus_]

lol Allan, relax. You're not falling on deaf ears. All the posts of this thread have answered my question and cleared up my confusion.

The bottom line is I have to get the car on track with the new setup to see what it needs, and just adjust it from there.

I figure I'll start off with the 16's or 14's in front, and order up a set of 8's and 10's for the rear and adjust per track.

I'd like to go with a track-proven setup. I forgot to ask around though at the last NARRA event. With the new ACR-X rotors, I'm not sure if carbotech pad choices have changed much.

 

[Allan]

Don't know anything about the Carbotechs, but from what I am told, the genIII competition coupe set up is the Mintex front / Brakeman #3 rear. I have tried several other brands and combinations, finally settled on the comp coupe choice. My brakes are killer. Only other non-oem brake parts I have are Stop-tech steel braided lines and DBA4000 slotted rotors. -stock calipers. ....Please post if you end up with a great Carbotech setup......

 

[Viper X]

Changing to 315 front tires will help with braking and turning.

Many of us started with Brakeman 3's up front and "outgrew" them. They work well for the casual track guy. When you start to go faster and get more serious, they just aren't up to it UP FRONT.

As above, upgrade to better front pads, Mintex is OK, PFC's are OK but after trying these I went to the Raybestos race pads and have never looked back for front pads. I'm now running the ACRX Brembo rotors up front with the most aggressive Raybestos pad and the Porterfield R4's in the rear. This is the best set up I've found for Gen III / IV cars, i.e. same calipers, master, booster, etc.

Porterfield Brakes in So Cal can supply you with whatever you need and they ship anywhere. http://www.porterfield-brakes.com/ Ask for Tim. Tell him I sent you.

Whatever you do, DON'T increase the aggressiveness of the pads on the rear of the car without upgrading the pads on the front of the car first. If you do, the rear of the car will become VERY unstable under heavy braking and as a side benefit, you will overheat your pads and rear calipers. They will turn a burnt magenta color. You will also overheat your rear tires and the car will become loose. I know, I tried this one day during a "test and tune" event at Spring Mountain.

IMHO, there is no reason to upgrage the rear calipers.....and the engine is for accelerating, not braking. Likely, you have just become faster and failed to upgrade your front brakes as soon as you should have. Now is the time.

One thing is for sure, as you get faster, you will continue to have to make adjustments to the car to be able to go faster comfortably and safely.

Good luck,

Dan

 

[Hirkophoto]

Changing to 315 front tires will help with braking and turning.

Many of us started with Brakeman 3's up front and "outgrew" them. They work well for the casual track guy. When you start to go faster and get more serious, they just aren't up to it UP FRONT.

As above, upgrade to better front pads, Mintex is OK, PFC's are OK but after trying these I went to the Raybestos race pads and have never looked back for front pads. I'm now running the ACRX Brembo rotors up front with the most aggressive Raybestos pad and the Porterfield R4's in the rear. This is the best set up I've found for Gen III / IV cars, i.e. same calipers, master, booster, etc.

Porterfield Brakes in So Cal can supply you with whatever you need and they ship anywhere. http://www.porterfield-brakes.com/ Ask for Tim. Tell him I sent you.

Whatever you do, DON'T increase the aggressiveness of the pads on the rear of the car without upgrading the pads on the front of the car first. If you do, the rear of the car will become VERY unstable under heavy braking and as a side benefit, you will overheat your pads and rear calipers. They will turn a burnt magenta color. You will also overheat your rear tires and the car will become loose. I know, I tried this one day during a "test and tune" event at Spring Mountain.

IMHO, there is no reason to upgrage the rear calipers.....and the engine is for accelerating, not braking. Likely, you have just become faster and failed to upgrade your front brakes as soon as you should have. Now is the time.

One thing is for sure, as you get faster, you will continue to have to make adjustments to the car to be able to go faster comfortably and safely.

Good luck,

Dan

great advice for sure