Project Pathfinder Part 2, Making it Stop
When we last left off on Project Pathfinders brakes over a year ago in our first installment of the project, our simple upgrades to our brake pads and fluid brought our brakes performance up from the pathetic, unable to lock the wheels level to something a bit safer.
Safer still leaves a bit more to be desired. We would really prefer something like being able to uses the descriptive “good” when talking about our brakes. You can never have too much brake, especially when towing a decently sized trailer and with our racecar trailer weighing about 4000 lbs or 1000 lbs over our rated tow capacity, we need all the help we can get to make sure we are safe.
Even with our prior upgrades to Project Pathfinder, our brakes still had much room for improvement. Although we could now lock our wheels on clean dry pavement (amazingly the stock brakes could not lock our big sticky Yokohama tires!) it took pushing with all of our might and several revolutions of the wheels to get the pads hot enough so they could get enough bite to lock the wheels. This sort of braking added precious feet to our stopping distance and made pedal modulation difficult, critical for limit braking performance.
No more was this apparent when an idiot driver cut across 4 lanes of freeway in an attempt to make an offramp, suddenly slamming on the brakes and coming to nearly a complete stop in front of Project Pathfinder towing the Dog Car in the number two lane! The brakes were slammed hard and the trailer brakes jammed into emergency override to avoid punting the idiot into the next county. It seemed like death coming in slow motion and only a combination of threshold braking, manual and automatic trailer brake application and swerving avoided disaster.
If you tow much, then you know that a trailer with a race car on it is an idiot magnet and somehow people often either fail to see the trailer when changing lanes, want to drive close to stare at the pretty racecar only to nearly hit it or crash due to the distraction, road ragers who become furious that your big and slow rig is on the road or the most idiotic, ricers who try to race or cut off the rig on purpose for no reason other than being idiot ricers. Infuriatingly after such retardedness, ricers often flash their hazard lights as if to further add insult to injury. In heavily urban Southern California nearly every road trip has at least one encounter with idiots. Having good brakes is important when dealing with idiots safely.
Help for our brakes came from the folks at Automotive Customizes or AC for short. AC is a company devoted to Nissan trucks and SUV’s and should be one of the first places you go to when looking for upgrades. It’s refreshing to speak to people who actually know about and care about Nissan trucks. AC’s customer service is also terrific. Due to a miscommunication, AC accidentally shipped up the wrong parts and jumped through hoops to get Project Pathfinder back on the road quickly, important when its your daily driver.
We started off with AC’s drilled rotors. Drilled rotors are probably not the greatest thing for race cars where their tendency to crack under racings brutal repeated hard use that drives temps up over 900 degrees F for long periods of time is an issue.
For trailer towing, the likelihood is that you will use the brakes extremely hard for short periods of time. In this case the drilled rotors really shine.
When brakes are used hard, a thin layer of the brake pads surface actually vaporizes. Its possible for the pads to hydroplane on this layer of vaporized material and not grab the rotors. The holes in the drilled rotor give the vaporized gas a place to vent to assuring that the pads can grab. The holes also give a mild cheese grater effect which helps prevent the pads from glazing over and losing effectiveness at a slight penalty in wear. The holes also give water a place to go, helping wet performance. The holes help cooling reducing the time it takes a rotor to cool down from heavy use by up to 25%.
AC’s rotors are high quality replacements made by Brembo, a well-known manufacturer of racing brakes in case you have never heard of them. The holes are chamfered and cast into the surface, reducing their likelihood of cracking. The Pathfinder SE has its parking brake drum as a part of the rear rotor. This makes finding upgraded rear rotors a difficult proposition and AC is the only company to have an upgrade for Pathfinders with rear disc brakes that we are aware of.
We also installed AC’s braided steel brake line kit. Pathfinders have long rubber brake lines. When the brakes are pushed hard, the rubber swells and the brake pedal gets mushy. This mush also makes the brakes hard to modulate. Braided steel lines do not swell so every bit of brake pedal travel gets transferred to the calipers. The only disadvantage to AC’s kit is that it’s designed for both drum and disc brake Pathfinders. On a 4 wheel disc SE Pathfinder, two short rubber lines to the rear calipers remain. Hopefully AC will be able to make braided steel lines for these soon. What’s good is that all of the longer rubber hoses on the vehicle are replaced with the braided steel parts.
|Braided Steel Line|
We replaced our metal master brake pads with AC’s metal matrix pads. AC sources these pads from Stillen and they are an excellent choice having better cold and hot properties than the metal master pads they replaced. I would say that these pads should be mandatory replacements for any Pathfinder in need of pads, they are practically essential for safely stopping the car which is woefully underbraked whenever lager wheels and tires are fitted.
Of course we bled our system with Motuls excellent RBF 600 brakefluid, which our race testing has shown to be nearly fade proof.
When completed and after a short drive to bed in our new pads and rotors, we were absolutely amazed at the difference in braking prowness. The Pathfinder could be stopped with fully half the previous pedal effort. The pedal travel was greatly reduced and the pedal was much firmer and easy to modulate. We were skeptical that a simple upgrade as this would make such a huge difference but the difference is amazing. We now don’t even think about the brakes and our paranoia while towing is greatly reduced. We are now totally confident in our ability to stop. AC’s brake system feels like brake upgrades involving 4 piston calipers and much bigger rotors costing thousands more.
We are well on the way in making Project Pathfinder a good half-ton V-8 truck replacement. In fact we think our Pathfinder tows more easily with better handling stopping and power with more confidence than our friend’s prior generation V-8 4.6 liter F150 and another friends V-8 Dodge Dakota.
Stay tuned, in later installments of Project Pathfinder, we experiment with fine tuning our ECU program and other minor tweeks to really dial in our tow machine. We would also like to test Project Pathfinder offroad where our suspension should prove to work really well in rough conditions.