TrackSTer – Mountunes Out Of Molehills
In the last TrackSTer update that covered its exterior mods, we mentioned a certain visit to Ford Racing’s Dearborn HQ that took the TrackSTer build plan to a much more exciting proposition. Essentially, Ford asked us to go a little nuttier with the build and that included adding serious horsepower to the equation. Are those dudes cool or what? We didn’t need any arm-twisting and even before the meeting had ended we all knew we’d be immediately contacting a certain Ford Motorsports engineering firm that goes by the name of Mountune.
For those of you still unaware, Mountune is the leading authority in Europe on small displacement turbocharged engines and is the only source of Ford-approved performance upgrades. We’ll let them tell you the rest of the story: “Founded in 1980, Mountune Racing experienced great success on the race track, eventually becoming the builder/supplier of Ford’s WRC engines, covering Sierra, Escort and latterly the Focus. Mountune’s engines have powered some of the most talented drivers to hundreds of stage, race and championship victories throughout the world. More recently Mountune were enlisted to design and build Ford’s Global Race Engine (GRE), which subsequently powered the Ford Chinese Touring Car team to championship victory in 2012, and the RallyCross engine found in the Olsbergs MSE, which powered Tanner Foust and Ford to championship victory in the GRC for 2011 and 2012. Mountune’s performance division has offered factory-backed, market-leading power upgrades since 2009 and also helped engineer the powertrain uplift on the highly acclaimed Ford Focus RS500 special edition.”
In planning the new project strategies we realized we weren’t in a cost-no-object position, but we did have the ability to dictate exactly what we were looking for in the way of a Mountune engine build. Dreams of Ken Block horsepower levels quickly subsided into more realistic discussions based around one simple and incontrovertible fact – our Focus TrackSTer was not going to get an all-wheel-drive conversion. Nope. Sorry. And while we know some of you are actively cursing us right now, we’re going to take a moment to go on a little rant…
We know lots of people wish the Focus ST were AWD (we actually do read your Facebook comments). We know that these people think that since WRC cars have AWD, all performance cars need it. We also know those people are wrong. Of course, if some of them want AWD for better poor-weather performance, well, we’re kind enough to give them a pass on the whole being wrong thing. But those folks who think AWD would have made for an over all better ST, then, yeah – they’re the ones we’re singling out here.
The ST is not the fastest car on the market, nor does it lap the Nürburgring quicker than any number of other cars. What the Focus ST does best is provide driving entertainment of the very best kind, regardless of cost. What makes it so fun to drive? A willing 2.0l EcoBoost engine and close-ratio 6-speed manual trans certainly do their share, and no doubt that quick, variable-ratio steering is due for props, but in our opinion it’s the car’s ready-for-anything, hyper-playful personality that shines most brightly. Grab this thing by the scruff of its neck and toss it into the meanest off-camber, decreasing radius turn you can find and the Focus ST is completely un-phased.
There’s no understeer giving you that “you sure you really wanna do this?” whimper, and the rear end is totally unwilling to believe it’s not supposed to be part of every fast-driving conversation. Haldex-based AWD systems (which is your only realistic AWD option here) tend to understeer at the limit and are unable to divert more than 50% power to the rear wheels when the front wheels have adequate traction. We won’t even go into the negative effects adding 200lbs more hardware and electronics would have… Simply put, go and add a Haldex-based AWD system and say goodbye to most of the fun and general awesomeness. Argue all you want but it’s true; AWD would not make the Focus ST a better car.
So with our rant out of the way but its message always fresh in our minds, we knew we wanted a lot of power. Our version of a lot of power had a number attached to it – a number we felt that the ST’s FWD chassis would be able to handle while still retaining it’s overall ST-ness. Years ago automotive experts told us that 150hp was the limit for FWD cars. That figure rose to 200hp, and then more recently, Ford’s Mk2 Focus RS convinced the thick-headed that 300hp must be the max. Until Mountune gave the same car 350hp… You see, there are so many variables involved that it’s silly to try to decree anything so generalized as max power figures for FF (front engine, front-wheel-drive) chassis cars. We looked at our FF chassis, and all the mods we had planned, and came up with some of our own numbers. With our planned Quaife LSD swap, along with suspension and tire mods, we were confident an extra 50hp over the Mk2 RS500 would be damn close to perfect, so we told Mountune we thought somewhere around 400hp sounded good to us and they agreed to try to make it happen.
Mountune’s expertise was invaluable to us in making this all happen over such a brief period of time. To us in the US, at the time the 2.0 EcoBoost was pretty much a new engine, and there was much to learn regarding piston and rod strength, exhaust manifold flow, fueling capacities (direct-injection, remember), and of course, ECU recalibration. The fact that Mountune had already addressed all these issues meant that when they told us we’d need to swap out rods and pistons, upgrade the valvetrain, address the fueling system, and employ a trick turbo-to-manifold adapter, along with a host of other mods, we just nodded along and said, “yeah, sounds good to us.”
When it came to the need for extra fuel, Mountune delivered some very rare pieces: high-flow DI injectors. Direct injection has been a major tech advancement in the automotive industry; the nature of the technology allows for a much more efficient air and fuel ratio, while in forced induction applications the by-product of injecting fuel directly into the combustion chamber is a cooler and more stable burn. To us in the power-making business, that means higher compression ratios and more boost are now more reasonable propositions. The issue is that DI injectors are built to such extreme tolerances that there simply aren’t many aftermarket options. Unless you’re Mountune, of course. Providing more fuel and pressure for the larger injectors is a Mountune high pressure in-tank fuel pump. For now the mechanical rail pump remains standard, as Mountune does not see a requirement for a change at this power level.
Just a couple days before shipping the car off to Chicago, from the UK we received a wooden palette with a giant plastic bag strapped to the top. In that bag was our freshly-built (hopefully) 350whp (approx. 400bhp) Mountune-built 2.0 EcoBoost (FreakoBoost?). Of course we had already removed the TrackSTer’s stock engine so that the engine bay was ready to receive the new motor right away.
While we were waiting for the new engine we also took the opportunity to install the new Quaife limited-slip differential. No doubt many of our readers are well aware of the huge benefit an LSD can make in any high-hp car – especially the front-wheel-drive variety – but for those who may not be aware what a magical piece of equipment our Quaife diffy is, we don’t mind filling you in. While Ford’s electronic LSD-style differential is very effective on the street, since it uses active braking strategies to reduce wheel-spin it’s not the ideal situation on a racetrack due to the fact that the front brakes of any FWD performance car are already close to falling into the over-worked category. We were planning to add over 100hp to the TrackSTer, so even on the street we knew that a mechanical LSD was the way to go. Quaife uses a torque-biasing design, and what that basically means is that the gear sets within the differential are designed to distribute torque back and forth between the two driven wheels as traction opportunities permit. When one wheel begins to spin faster than the other wheel, the differential sends power to the other wheel. While very effective, it’s not a completely seamless operation, and in fact many people confuse the diff’s actions as being simple torque-steer. Regardless, the net effect is that you still very much need to keep both hands on the wheel.
While we succeeded in installing the new engine in two day’s time and getting the car to CAS, there simply wasn’t time to sort a few wiring incompatibilities or confirm engine output on a dyno. When the car returned from Chicago the plan was to do all of the above. However, it wasn’t long after the car had returned that Mountune informed us they were going with a new piston supplier and that the new parts and spec were large enough improvements for us to consider retro-fitting them to our engine. We saw this as an opportunity to keep pace with Mountune’s R&D process, so the minor setback involved with removing the engine again didn’t phase us in the least. And when Ken Anderson (head of Mountune’s forthcoming US operations) offered to perform the piston retrofit at the new SoCal facility, we were very much good to go.
With the retrofit completed it was time for installing the engine a second time. We took this opportunity to add a high-capacity Mocal oil cooler supplied to us by our good friends down the road at FSWerks. Our previous trips to the track didn’t exactly have us worried about oil temps, but the old-school portion of our brain that remembers serious heat problems with various VAG cars over the years wouldn’t let us overlook the potential. And when Mountune suggested a larger cooler was excellent insurance, we knew we were doing the right thing.
As mentioned we had a couple problems sorting various wiring incompatibilities between our US-spec harness and the new UK-spec engine, but once we got past them it was time for break-in. Not much in this world is more difficult than taking it easy on your new Mountune-built monster engine, but we used a long-ish drive up the coast to Santa Barbara as a solid opportunity to knock out much of the break-in process in one shot. Long highway trips aren’t ideal break-in strategies, but we’re talking LA here, so not many steady-state RPM situations to worry about.
Once broken-in, the engine has proved to be almost everything we’d hoped for. The power is there, no doubt, and the delivery is very close to perfect. Spool is a little delayed compared to stock, but that says more about the amazing zero-lag nature of the stock EcoBoost than it does about our Mountune engine being laggy. Our torque curve is still very meaty from as early as 2500rpm, and unlike the stock turbo that runs out of breath well before redline, our GTX2863 makes power all the way up to fuel-cut rpm levels. Max power occurs at around 6,000rpm and never dips below 310hp before the rev-limiter kicks in. On the street the car is very easy to drive and while freeway acceleration might mean a single downshift in some situations, we still consider this to be an extremely flexible engine. But dang, the power… Our TrackSTer now goes just as mean as its menacing exterior suggests.
While away on business we gave the car back to Ken Anderson from Mountune USA and asked him to try it out, see what he thought, and hopefully strap the car to their dyno. Gotta say it was pretty freaking cool when we got the text from Ken showing that TrackSTer had made 340whp at 6020rpm, and 327ft-lb of torque at a low 3600rpm.
Keep in mind this is power measured at the wheels. Due to a huge assortment of dyno/vehicle/environmental variables it’s not reasonable to suggest a universal correction factor, but even conservative factoring puts us pretty damn close to 400hp at the crank. Just as we ordered. Even better than receiving the dyno numbers was hearing Ken suggest there’s still a fair amount of headroom (on 91 and 100-octane programs), as well as further calibrating that should yield more available power in the earlier parts of the powerband. Needless to say, TrackSTer is looking forward to another visit to Ken and his Dynojet.
On the track the extra power and Quaife LSD have completely transformed the car. Just as before we’re able to dive deep into corners, trail-brake to plant the nose and lighten the tail, and as soon as the nose begins to dive toward the corner apex it’s time to get back on the throttle. Whereas before we needed to wait for full throttle opportunities due to the inside wheel spinning, even with an extra +100hp the Quaife allows almost full throttle even before the front wheels are pointing straight again. Sure, there’s some power-on understeer at times, but even with both wheels spinning (vs. just one), the opportunity to carry way more corner exit speed is always there. We should mention that currently we know of no suitable clutch and flywheel upgrade for the Focus ST, so we are currently running the stock parts. We’ve avoided hard launches, but our track time hasn’t exactly been considered shy and reserved, and we’re rather impressed that so far the OE pieces are holding up to our abuse. We still have to dial-in the suspension settings a bit more (and add that stronger clutch we alluded to), but the TrackSTer is finally living up to the first part of its name.
Besides the engine build, Mountune hooked us up with some of their other Mk3 Focus ST parts, including their intake kit and short-shift assembly. And to show their true versatility, they were also able to build us a 3-inch downpipe-back (with high-flow cat) exhaust system that incorporated their Mk2 Focus RS rear muffler with twin pipes to fit our custom Mk2-based rear bumper and diffuser.
Without a doubt our Mountune engine is the highlight of the TrackSTer build. It gives the project undeniable OE feel and credibility, and definitely raises the entire build well above typical tuner level work. We couldn’t be more proud of the partnership we’ve established with such a talented group of engineers. Further, the new engine has gotten us almost to what we feel are the limitations of our FWD chassis, while still offering a truly streetable package. Further, with Mountune’s engineering prowess and attention to detail, we expect a long and healthy life for our new FreakoBoost engine.