The Mustang Forum for Track Enthusiasts

Track Mustangs Online was built specifically for those who track their Mustangs!

Register Log in

S197 2014 Mustang GT Premium - 6R80

Mad Hatter

Gotta go Faster
Messages
2,976
Reaction score
1,412
Location
Santiago, Chile
Cos, was wondering if you have any problems with the brake pedal getting stone hard at the track. We have about 3 club members with the 6R80 and they all have the same problem after upgrading to Brembos from stock.
 

Eric62

TMO Intermediate
Messages
65
Reaction score
82
Location
Fort Myers, FL
Cos, was wondering if you have any problems with the brake pedal getting stone hard at the track. We have about 3 club members with the 6R80 and they all have the same problem after upgrading to Brembos from stock.
My car is very similar to Coz's from a chassis development perspective. My engine is just running a tune but otherwise stock. I have 4 piston Brembo 14 inch fronts (2 piece Wilwood rotors) and the 13.8 rears with the single piston caliper. I am running Hawk DTC 30's on the front and Hawk HPS or Street/Race rears with Wilwood 570 fluid. I have no issues with hard pedal at all. The pedal effort is actually a bit lighter than I'd like. I use the unmodified ABS and tickle it a bit on track at times.

Since I have stock cams, I am not affecting the vacuum signal to the brake booster so there is plenty of boost. A hard pedal seems to indicate a booster issue. I track at sea level. Altitude could have some effect. I'd data-log manifold pressure (vacuum) to try an identify what the heck's going on when the pedal goes hard.
 

Mad Hatter

Gotta go Faster
Messages
2,976
Reaction score
1,412
Location
Santiago, Chile
My car is very similar to Coz's from a chassis development perspective. My engine is just running a tune but otherwise stock. I have 4 piston Brembo 14 inch fronts (2 piece Wilwood rotors) and the 13.8 rears with the single piston caliper. I am running Hawk DTC 30's on the front and Hawk HPS or Street/Race rears with Wilwood 570 fluid. I have no issues with hard pedal at all. The pedal effort is actually a bit lighter than I'd like. I use the unmodified ABS and tickle it a bit on track at times.

Since I have stock cams, I am not affecting the vacuum signal to the brake booster so there is plenty of boost. A hard pedal seems to indicate a booster issue. I track at sea level. Altitude could have some effect. I'd data-log manifold pressure (vacuum) to try an identify what the heck's going on when the pedal goes hard.
I wonder if the base GT cars they sent down here have a different setup. All the S197 cars that got upgraded brakes from the stock Ford setup have this problem at the track... One has a set of Stoptech trophy calipers and his problem went away with a change to a manula setup, make one think its to do with the vacuum.
 

Eric62

TMO Intermediate
Messages
65
Reaction score
82
Location
Fort Myers, FL
I wonder if the base GT cars they sent down here have a different setup. All the S197 cars that got upgraded brakes from the stock Ford setup have this problem at the track... One has a set of Stoptech trophy calipers and his problem went away with a change to a manula setup, make one think its to do with the vacuum.
My car is the second S197 I've owned upgraded to Brembos on the front. That earlier car was a 4.6 liter 5 speed. No issues with hard pedal on that one either. If switching to manual brakes solves it, then the vacuum booster and how much vacuum the engine creates would be under where I'd look. Maybe compare booster part numbers in Chile vs US domestic market.
 

Mad Hatter

Gotta go Faster
Messages
2,976
Reaction score
1,412
Location
Santiago, Chile
My car is the second S197 I've owned upgraded to Brembos on the front. That earlier car was a 4.6 liter 5 speed. No issues with hard pedal on that one either. If switching to manual brakes solves it, then the vacuum booster and how much vacuum the engine creates would be under where I'd look. Maybe compare booster part numbers in Chile vs US domestic market.
Sorry, I ment to say switching to manual transmission. Will double check the part numbers, thanks.
 

Coz

TMO Addict
Messages
731
Reaction score
548
Location
Philly Metro Area
Since I have stock cams, I am not affecting the vacuum signal to the brake booster so there is plenty of boost.
I have the L&M intake cams but my pedal feel was unchanged after the cams were installed.

The only other thing I can think of is if they also changed their brake lines to a version with a thinner profile banjo fitting. I hear that some Russell lines are like this. If you use the standard length banjo bolt with the thinner banjo fitting it may affect the flow of brake fluid through it?

But if its an intermintent problem, I doubt that would be the case. Unless either the caliper body or the banjo bolt expand in a certain direction just enough when hot to restrict flow of the fluid?

Just a wild ass guess...
 

TMO Supporting Vendors

Top