“It is amazing how many drivers, even at the formula one level, think that the brakes are for slowing the car down.” -Mario Andretti
This month I would like to make a couple of observations that mean you might all like to hear about the latest modifications to the Black Sun Racing Mustang (www.blacksunracing.co.uk). American cars are generally pretty heavy and therefore need powerful brakes in order to dissipate a lot of energy. The readers of American Car Magazine tend in the majority to modify their cars for performance which would suggest they like to drive them hard – then you need really good brakes. Although this story is about my Mustang it equally well applies to any heavy American car (so probably not a Corvair then….).
This is the story of all the lessons I learned while trying to get decent brakes on my Mustang, the most important lesson being that it is the middle pedal that makes you go faster (was it Mario Andretti who said that?). I hope this helps some other readers of ACM make their cars truly great!
From the moment I did my first track day in my completely stock 2007 Ford Mustang GT (with the Mustang Owners Club at Mallory Park in 2009), I found that the brakes were the weak point of the car; after just two laps they filled the car with clouds of smoke as they overheated. Their instant loss of performance terrified me and I switched to the “slow class” for the rest of the track day so that I could take it easy.
My first upgrade was to a set of EBC discs front and rear with Yellow Stuff pads. At a track day on the full Silverstone F1 circuit in 2010 I learned my next lesson – use high temperature race brake fluid. After just one lap the fluid boiled and the pedal went right to the floor. This was mildly terrifying, however, I found that by braking much more gently I could let the fluid recover and carry on.
The next time out at a Lydden Hill track day with the race fluid, in just three fifteen-minute sessions on track I reduced the almost new rear EBC brake pads to the consistency of a crumbly digestive biscuit. They really couldn’t handle the temperature resulting form the huge energy dissipation form the heavy Mustang. A lot of people use EBC and think they are OK. Maybe for street use, but I think for track use or even spirited street driving they are woefully inadequate.
Next I decide to throw a load of money at the problem and buy a set of Roush brakes with 4-piston calipers and braided brake lines. They were much better than EBC but still gave me no confidence during a track day at Brands Hatch, they never gave any great feeling of deceleration and the discs warped really quickly, so they were still pretty rubbish. I changed to set of Hawk brake pads (HT14 compound front, HT10 rear) and a set of AP discs custom made to fit the Roush calipers and bell housing. This did make an improvement and I now found my next problem was cooling I would come into the pits at barnds and people would scream hysterically “your brakes are on fire!” as clouds of smoke filled the pit garage. To help with this, Trevor Kitney of Surrey Mustang fabricated a set of cooling ducts from the front spoiler and side air intakes to cool the rear brakes which did help matters. However, it wasn’t until Mike Thompson and Kevin See of Redline American Muscle improved the design with better airflow around the discs centres and added inline electric fans in the ducts to move sufficient air that the problem was really bought under control.
I was so desperately disappointed with the Roush brakes that would struggle to provide enough brake force to activate the ABS on a dry road, I decided to throw a load more money at the problem in the form of a set of Wilwood 6-piston caliper big brakes. These looked like the biggest discs and calipers you could buy for the Mustang off the shelf, I was sure that they would give me the performance I was hoping for – wrong again! Although they were significantly better than Roush they still had a load of problems, again without producing a significant feeling of deceleration even when you were standing on the pedal. I tried changing to a set of full race pads (Wilwood polymatrix-E) which ate through the discs in just two track days, without giving much performance testing. With new discs and fast street pads (Polymatrix-B) I did further testing and concentrated on a few of the other brake problems I had suffered for a while. I fitted large Wilwood rear 4-piston discs which did make a significant improvement to brake performance, the car lowed more effectively under control and heat dissipation at the rear was no longer an issue with the much large brake mass.
I had always had a very soft pedal. Redline American Muscle investigated and fitted a Mustang GT500 master cylinder which has 30% less power assistance than the GT version, so this helped and boosted my confidence under braking. They also noticed that there was significant flex in the Wilwood caliper, meaning that above a certain pedal pressure you get no more braking. This was the last straw for the Wilwood setup and meant that I still had to find another answer.
I approached Hispec, a local brake manufacturer in Dartford to ask if they could design some custom brakes for the Mustang. I Spoke to Geoff Bedding, the managing Director and engineering mastermind behind Hispec, who was himself a racing driver and was able to advise on my needs form a point of view of great experience. He was extremely helpful and together we specified a 400mm disc (16 inches) that would entirely fill the space in my 20 inch Steeda race wheels for swept maximum friction area. We agreed on an 8 piston caliper that uses two brake pads end to end, again to create a massive effective area (larger than the equivalent sized brakes in a Nissan GTR). Finally we chose a floating disc to give maximum resistance to warping from asymmetric heat build up. This is generally not recommended for a street application due to the chatter noise from the disc mountings, however I cant hear it over my V8 so cant see what the fuss is about!
The results were astounding, as I drove the car away from the fitting workshop the brakes felt much more effective with easy control and much greater deceleration. The caliper flex issues due to the massively stiffer design which includes cross bracing, so now I could stand on the pedal and actually get greater brake force. As I thrashed down country lanes I could feel the brakes bedding in at every turn, with the pad to disc contact are increasing. I was very pleased to find that the ABS was now coming on regularly meaning that the limit was now tyre grip rather than the brakes. Two days later I took the car the car to my first sprint event of the 2016 season at Hullavington (see last months ACM) and I am pleased to say that I scared myself witless! Being able to carry much more speed close to the apex of a corner with massively later and sharper braking meant that I had to relearn how to drive the Mustang, it really was like having a whole new car!
Some ACM readers who may have had dealings with Hispec in the past or come across Internet forum stories may have heard about Hispec customer service issues. I can be completely open about this – when I first contact Hispec I experienced the problems others described with a disinterested and dismissive attitude to my questions. However, I am very pleased to say that they have responded to customer comments with a completely new set of staff to deal with customers, chosen for their public facing relationship skills. Furthermore, these staff are receiving continuous training and monitoring to ensure that they are responding effectively to customer needs. If you have problems with Hispec in this area in the past, give them a call you will be amazed at the change!
Hispec are continuing to provide support and are currently investigating different pad compounds to further improve performance. I just wish I had approached Hispec at the beginning rather than thinking that an off the shelf design for Mustang brakes would be better. The most amazing thing is that these awesome brakes are only around half the cost of the Roush or Wilwood brakes! Give them a call and see what they can do for your American car on 01322 286 850 or http://www.hispecmotorsport.co.uk/