Feature: The Forging Of A Silhouette – An ISF Unrivaled

Despite it’s pivotal role in guiding Lexus towards an evolutionary trajectory of car design, the ISF was a project that was often forsaken in favor of it’s European competitors.  However, with over a decade since its initial release, many enthusiasts are finally realizing just how special this car really is.

With the bulk of its development taking place in the hallowed grounds of Japan’s Fuji Speedway, Lexus elected to class their new creation as the ‘F Series’; a designation that would soon come to be synonymous with the companies performance line of luxury cars.  Unveiled in 2008 alongside it’s super car companion the LF-A, the new offering created quite the buzz in the automotive world; that was, of course, until the reviews started rolling in.  Despite its boisterous, albeit commanding presence, and it being a blast to drive, critics unanimously decided the car had fallen flat when compared to BMW’s infamous M3 – it’s main market competition.  Over the next couple years, the ISF fell into its niche with a small group of believers who accepted its shortcomings in favor of Japanese reliability, but never truly caught on in the mainstream.

In 2011, Chief engineer Yukihiko Yaguchi, made some very noteworthy changes that resulted in bringing the chassis closer to its intended potential.  These updates, which arguably should have been considered for the initial platform launch, really breathed new life into the car.  The gap was suddenly closed significantly between the ISF and its rivals.  That isn’t to say, however, that the zenki version of the car was a complete loss.  With a few key changes, the early year platforms could be just as deadly, and nobody discovered this in a shorter time frame than our good friend, Willem Drees.

Some time last year, in a sort of haphazard, ‘why not’ fashion, Will entered a mutual friends raffle to win a stock 2008 Lexus ISF.  The odds weren’t the worst, but nevertheless he definitely wasn’t expecting to win.  Truth be told, the last thing Will needed was another project, already juggling a very in-depth, rather troublesome, CRX build alongside the brand new FK8 he had been tinkering with.  Be that as it may, in a lucky, but oddly not that strange (knowing Will) twist of fate, his number was called and he ended up taking delivery of the 2008 Lexus ISF the next day.  Not anticipating to have an unfamiliar chassis thrown his way, his initial reaction was to take it slow; drive it for a few days, do a little research, and decide how to approach this new guest in his driveway; and that’s exactly what he did:

When I brought mine home it was in pretty poor shape. Opaque clear-bra, Blown shocks, cracked headers and disintegrated mounts. As busted as it was I REALLY liked it the few days I drove it to work. This instantly meant that flipping it was off the table.  I decided to get it up in the air and go over it. After getting together a list of issues I decided to triage them and fix the easier stuff then re-evaluate. The more I fixed the better it got, and the better it got the more I wanted to fix. At that point I was choosing to drive a 200k mile 08 Lexus over the brand new modded FK8 that I had at the time.  Eventually, I brought it back to a stock baseline. The problems were fixed but i hadn’t started to mod anything yet.  Mechanically, I now felt it could handle a light track day and it was that day that was sort of the dam buster for me. It was SO different than anything that I had been tracking at the time, not only was it a perfectly comfortable driver- but on track all 3900lbs was sliding all over the place at 100mph to pretty respectable times. I was a total Dr Jekyll and Mr Hyde. Probably most surprisingly was the 8 speed paddle transmission. The same transmission that most unqualified people bemoan as ‘disgraceful’ was actually way more than adequate. That was the moment I realized the bones of a good circuit car were there, the cherry on top was if it could be built to be fast it would be a very unique car amongst its peers at the pointy end of a hot grid. This is when I really started to form a picture of what ultimately I wanted. “

This enjoyment of the car in its simplest form, and the realization that with a few key modifications the car could be extremely fun on track, served as the catalyst for Will to dive into full research mode.  Gathering information about the platform, growing accustom to its technicalities and studying every forum thread and article about the car, soon gave the assurance he needed to convince him he could turn this car into a formidable machine on track.  Drawing inspiration from the factory backed world of silhouette racers, he set out with the general idea of having a finished product that still maintained the resemblance and presence of the big bodied sedan, but performed fundamentally different when unleashed on circuit.  This was the car that he wanted to build.

Understanding that, while most silhouette builds have nearly unlimited budgets, he would most certainly be working with financial constraints and in doing so would be performing much of the work himself.  Embracing the contrast between the two resulted in the car having the aura of a silhouette car, with the added styling of Will’s signature aesthetic – drawing heavily upon the influence of Japanese time attack cars.  Aside from the car retaining the look and feel of an OE car, Will mandated that the car must look good as well.  If he was going to do this, he was going to do it right.

If you recall, back in 2011 at Tokyo Auto Salon, Lexus unveiled their own ‘silhouette’ version of the IS-F dubbed the CCS-R.  While the development objective of the CCS-R may have been a little cloudy at first, the track-ready adaptation of the ISF became, without a doubt, a contender on circuit at venues like Pikes Peak, the 25h of Thunderhill, and the 24h at Nurburgring.  Its success in endurance races proved that Lexus was able to produce a formidable race car without sacrificing the reliability the company has become synonymous with.  What’s even more interesting, is that the CCS-R’s engine and drive-train remained the same units as the production model ISF.  Where the Circuit Club Sport Racer model truly was different, was in the chassis prep and reduced weight.

“Anyone who has ever built a car they intend to use hard knows that is a sentiment easier said than done. Like a factory car, I wanted things to be thought out and professionally executed- but at same time have a sense of purposeful ‘wabi-sabi’; Do what works, leave the soul.  This is to say I built MY car with more of an eye towards the factory Ethos in lieu of just using the CCS-R as a road map. Weight, CG and traction improvements were the big goals.”

Working from the top down, Will stayed close to the recipe he knew would work from experience.  Maintain the reliability of the already hearty motor, and do whatever he could to strip the car of some of its bulk.  The first steps began fairly simply, a carbon fiber hood, carbon fiber trunk, remove the rear seats, replace the heavy front seats with fixed back alternatives.  But that’s about where the simplicity of this build stops.  It wasn’t long before Will was commissioning John from Alpheyga to produce a one-off set of carbon rear doors and a carbon kevlar roof.

Once the parts were made, Chris at Wisecraft Fabrications took the ideas from Wills head and made them realities.  The carbon doors were mounted in a quick release fashion that allowed the removal and installation of the pair in just seconds.  The roof was installed, but not until the custom gusseted roll bar was fabricated and installed, so the main hoop fit snug against the new roofline.  The new roof not only shed a multitude of weight, but also effectively lowered the cars center of gravity; a sometimes overlooked concept of vehicle behavior.  A reduction in weight transfer and propensity to roll are the two prominent features of having a lower center of gravity.

Taking advantage of the time in the fabrication shop, a custom front ducting system was made along with a quick release splitter mount – both adding to the concept of OE quality work with motor sport in mind.  If you’ve ever transported a race car to and from the track by yourself, you’d understand how important it is to have a convenient system in place that minimizes the work getting the car on and off the trailer.  The system that Chris and Will came up with does this extremely efficiently without compromising utility or aesthetic.

The rear doors were mounted with a simple pin hinge system and 3 Aerocatch latches.

 

When removed, Will has easy access to the rear seat area to work around – considering this is where the bulk of the electronics are housed it worked out quite well.

Another feature of this build which brings it to the summit of what would be a silhouette emulation, is the amount of data capture utilized.  Will consulted Amir at RS Future when it came time to purchase sensors and tools from AIM for dash display and data logging on track.  An entire array of sensors were employed including shock potentiometers at all four corners, steering angle, throttle position, brake pressure, GPS speed, rev speed, accelerometer, as well as the standard trans temp, oil temp, oil pressure and water temp sensors.  Everything is routed to the AIM Dash that has warnings set for each sensor in case the safety parameters are exceeded.  Off track, the data can be downloaded and compiled using software to find time at every position on track.  The amount of technology used on this car is just one of the many facets that set it apart for your typical ‘build’.

The main unit is housed on the drivers side rear gusset of the cage and the cables are routed appropriately to each sensor.

The AIM GPS antennae is mounted atop the carbon roof.

A HANS Recaro and 6-point harness hold Will in place while on track, while the OEM 3-point belt remains in tact, rerouted to provide him road legal safety for drives home.  The OEM steering wheel is retained however it has been sent out to be wrapped in grey suede.  And yes, this car is still registered for street use.  Once again staying true to the theme of the build.

Judging from the car’s exterior, you may not have expected to see the full OE-spec dash still in place.  However, as stock as it may look (including the retention of the OE back up camera and monitor), you’d be fooled in thinking it was left untouched.  Every airbag, bracket, clip, plug, hard drive, entertainment component, and all the sound tar were pulled from the interior in the name of cutting back on weight.  Akin to that of a Porsche GT3, or newer high-end sports car, the facade of a comfortable daily driver remains.

The final weight of the car is 3,310 pounds with a half tank of gas.  Compared to the OEM curb weight of 3,965 pounds, that’s a 655 pound reduction in weight; keep in mind that’s after adding extra aero, new jack points, and a roll cage.  Impressive to say the least.

The exterior of the car enlists several new additions to both gain additional downforce and command even more presence.  A RS Future rear GT wing and end plates mounted with custom, swept back, swan neck uprights finds its home at the rear of the car.  Because of the wing dimensions, estimated downforce created is far too much for a simple trunk mount, so the wing is chassis mounted to the frame to ensure both efficiency and rigidity.  The carbon trunk was fashioned similarly to the rear doors and can be removed within seconds.  Will even took into account the legalities of driving at night, and fashioned the rear taillights and license plate lights on a quick disconnect.

 

The OE side skirts have been replaced with carbon C-West units with the addition of carbon strakes.  Will has a collection of random carbon parts acquired over the years and often uses them to add small but unique aerodynamic modifications to the car; such as the small winglets along the back of the ISF fenders.

Seeing the car in an underexposed, dimly lit setting brings out an almost unholy appearance – a car that once requested attention, now demands it.

The front carbon splitter and winglets balances out the rear downforce and helps keep the heavy front end planted.

A single Hanshin Tigers decal (NPB Central League team based out of Hyōgo) but it’s a cool one.

The back of Will’s seat also sports an old Tsukuba Circuit decal that pays homage to the inspiration for many of Will’s builds.

 

Upon his initial tests after getting the car back from fabrication the first time, Will realized that the new ducting worked so well that the air was having trouble finding it’s way out of the vented carbon hood.  As a remedy, Will took a stock ISF hood and added a massive center drop vent as well as two, much larger side vents, produced by RS Future, to allow plenty of space for the incoming air to escape from.  Fender vents were added on each side as well to help vent the turbulent air pocketed by the front tires.

The new setup seems to be working great now and has ended the buffeting that his hood was doing previously.

The sedans low (but may I point out appropriately low) ride height is made possible by a set of 7500DA Penske Racing coilovers, which along with an entire catalog of FIGS Engineering suspension arms, contributes to the cars amazing grip on track.

 

Truth be told, the 2UR-GSE probably could have been left untouched and this car would be difficult to pass on track, but wanting that little extra bit of power, Will opted to improve the airflow with a carbon intake, a pair of headers, a GReddy titanium exhaust, and a tuned ECU.  The end result is a sizable increase in power without a sacrifice in reliability.

An OS Giken TCD clutch type Limited Slip was added almost as a necessity to improve mid-corner grip on track.  It was then mated to a new, carbon driveshaft that helped dropped weight and make power transfer more efficient.

Already equipped with Brembo Racing calilpers, and since the cars weight has been shed by over 650 pounds, the only thing needing upgraded in the braking department were rotors and pads.

A square 18×10 Desmond Regamaster EVO wheel setup with 295/35/18 Nankang AR1’s give the car the perfect mix of looks and performance.

I’ve attended several events with Will in the ISF leading up to the initial test of the ‘finished’ build.  As you can imagine there were small issues that arose, as do in most shakedowns, but the data was not lying. Piecing together the fastest parts of the track from each session would put the car capable of a theoretical 1’39 at Buttonwillow Raceway Park (CW13); which seems unbelievable, as theoretical laps typically are, but it does give an indication of what is capable.  From point to point, the car has ran a 54 flat – one second off his goal time of 1’53.  Being it was only on his second outing at BRP (first without issue) I’d say without a doubt he’ll hit that mark and then some.  With some time behind the wheel, I wouldn’t be surprised if Will can pilot the car to very low 50’s, perhaps knocking on the door of a sub 50 lap.

At Chuckwalla Valley Raceway, one of his favorite venues, a 1’56 is the target.  One I hope he’ll get close to during the NDF Attack Challenge on October 11th.  Having been friends with Will for some years now, I know first hand that once he puts his mind to something, it’s only a matter of time before it is achieved.  I have a feeling that the target times for this car are no exception to that fact.

“There’s something subtly different about a factory approach to R&D on a chassis they’re intending to race; you can tell that there has been a great effort to leave as much mother chassis DNA as possible. This approach, to me, is what differentiates factory cars from your standard ‘shop built’ race car. It’s an effort a-kin to honing a dull kitchen knife into a fighting weapon vs forging a new one. I respect that- and in my case I’d never  undertaken a build where a goal was to leave as much of the original ‘soul’ of the car as I could. It so happens that the ISF is a fantastic starting point, it has an unmistakably commanding presence, but is also vaguely familiar. It reminds me of the ‘silhouette racers’ of the past. The lineage to the pedestrian version is clear but the special version has a sharper feel.  I see ISF’s as a factory ‘silhouette racer’ and wanted to piggy back on this idea.   The goal of factory racers and indeed my goal here was to start out with a coherence of ideas in what i wanted to ultimately create.”

To read more in-depth information about this build, and Will’s other cars, check out his personal blog.