Focus ST Trackday Weapon: 2017 & 2018 Build

A lot has changed with our Focus ST shop car since we first wrote about its initial track outing (in case you missed it, read It here).  Countless more track days, modifications, and plenty of fuel have all gone into the ST since it’s been in our hands.  What started as a new platform for us to develop and test products has quickly become a fun little FWD track weapon.  We live by our slogan Track Tested, Driver Trusted, and we find no better way to test our products than by pushing them to the limit on the track—so this little FoST has been seeing plenty of laps.  While the Focus ST is a potent street car in stock form, it does need a little help to get it to perform well on a track. 

On our first track day, we noticed that the factory brakes and much of the cooling system struggle to make the grade.  The factory brake fluid boiled, the pads couldn’t keep up with the high temperatures of repeated hard braking so they glazed over, and engine was on the brink of overheating.  While the car does make great power to keep you entertained on public roads, more power can add some excitement on track, and is relatively easy to obtain with this platform.  The suspension is tuned nicely for aggressive street driving, with its high rebound dampening and lively back end, making it fun to drive day-to-day.  However, on the track there is a lot of body roll and nose dive under braking, and the rear-end can be quite unpredictable.  Our goal is to show you what was done to the car in 2017 and 2018, to have it perform well and consistently on a road course, and to give you a sneak peak of what is to come in the future from Damond Motorsports.

First on the list were brake upgrades.  With the RS recently being released, we just dove into the Ford parts bin and got front RS 4-piston Brembo calipers, rotors, and lines, and flushed some RBF600 in the mix.  The wheels that came equipped on our ST were replaced with 18” Konig Hypergrams, not only to fit the larger brakes but shed some weight as well (about 9lbs per corner).  To help balance the brake bias, larger RS rotors, Mazda5 caliper brackets (to accommodate the larger rotors), and our brake bushings were added to the rear.  Because swapping pads is a quick easy task on the front fixed calipers, we opted for G-LOC GS-1 street pads for daily use and R12 compound for track use.  For the rears we run R10’s for street/track and we just deal with the noise and dust. Brake ducts, fed from the main grille opening, were also added up front to lower brake temperatures.

With all the brake upgrades and modifications, we are able to really push the car hard under braking on the track. It inspires confidence to threshold brake and get consistent feel and feedback with linear modulation from the high-temp G-LOC pads.  Due to the more fixed Brembo calipers and solid caliper bushings, pedal feel is quite firm and predictable.  

 
EVERYTHING IS SO HOT!  From constant lapping we noticed right away how inefficient the factory intercooler is.  Under fairly continuous boost it would heat soak and the air exiting the intercooler would be +160F.  Hot air isn’t good for power or durability so a more efficient FMIC was installed.  For better engine cooling an upgraded Mountune radiator was installed and some front ducting was fab’d.  The factory antifreeze was drained and replaced with distilled water and Water Wetter.  Water itself has better cooling properties vs antifreeze and mixtures.  We didn’t stop there, though.  Seeing as there was a little dent in the hood (that probably could’ve been fixed), we deemed it worthless and decided to cut some holes and add vents to help scavenge the heat from the engine bay and improve flow through the radiator.  Lastly, we began development on an oil cooler set-up specific to the ST.  More info on this soon to come.

With the upgraded cooling efforts, fluid temperatures are finally manageable and we’re now able to fairly continuously hot lap the car.  On very hot days, we’re still seeing coolant temps creep up, but since the modifications we have yet to get the car into limp mode 250F+ coolant temps.  Most of this heat source is suspected to be due to the factory turbo and higher engine revs, where the turbo is also operating out of its efficiency range. 

With heat management under control, we added a few go-fast bits.  Mainly just a free-flowing full turbo back exhaust.  A Green Filter air filter and our larger throttle body kit were installed to free up some intake restrictions.  Nothing too crazy, but enough to free up some trapped ponies.  To keep the ponies planted, we’re rocking some sweet Damond motor mounts, and to keep it all managed we began work with JSTuning on custom 93 and E30 tunes. 

 
 
To add in grip, we swapped the previous season’s Firehawk Indy 500’s to some sticky 120 treadwear Nankang NS-2R tires on the Konig Hypergrams.  While the Firehawks were a pretty decent all-around tire, especially for the price, they lacked a stiff sidewall and overall grip of a more track focused compound.  Then came the suspension tuning. Bilstein B14 coilovers were sourced from the UK, due to being on backorder in the US for months.  The springs that came with the B14 kit were set aside for different rated Eibach springs.  To adapt the springs to fit the car, we ran Vorshlag Camber plates up front with helper springs, and we used the lower spring seats from a secondhand Ground Control coilover kit. Doing this allowed us to run whatever rates we choose and have the spring ID be the same for both front and rear, which comes in handy when playing with and changing the rates.  A Hotchkis rear sway bar tied in the rear nicely and reduced some weight due to being hollow, and a front traction bar was added to connect the lower control arm mounting points.  

Suspension and grip tuning have had the biggest impact on how the car performs.  The LSD is by far one of the best things you can do to the Focus ST, especially if you do any spirited or track driving.  Keeping the power planted gives you, the driver, another whole level of control.  It’s also fun just mashing the go-pedal in the lower gears and getting more traction among the wheel spin.  Even with the higher spring rates, 7k front 9k rear to start, the ride even on the street isn’t harsh.  The shock dampening of the “Nurburging tuned” Bilsteins very much keeps the chassis stable, and over crests the car settles quickly and without drama.  The rear sway bar has allowed the rear of the car to be much more controllable, as it is round, unlike the factory bar which is flattened in the bushing mounts, only allowing restricted movement.  This removes the darty, uncontrollable feel, and replaces it with a nice, linear, easy-to-manage rear end.  And the tires, albeit not many have heard of them, are fantastic once warmed up.  They fall more towards a race compound, providing excellent dry grip on track without getting too greasy after constant hot lapping.  They’re not the greatest tire we’ve driven on, but for the cost, they get the job done very well for just trackday tires.

Where we have the car at now, it would be hard to improve on it much . While we can always go a bit crazier with it, the current set-up feels very ideal.  Instead of messing with it, it’s best to get that seat time in and work on what really matters... #drivermod

We hope to see you on track!