Lexus IS 350 Build Lead

Relax and let out a giant sigh of relief. That is exactly what we did upon finishing the Lexus IS 350 SEMA project two days before transport to SEMA. This left us a day to get video and still shots in the studio for this build and the IS 500 build that was also featured at SEMA. The DSPORT build of this Lexus IS 350 for the 2021 SEMA Show would have induced a good amount of panic for the less experienced builder. One-off custom parts getting made and shipped overseas just in time to make a deadline, wheel and tire sizes spec’d on a best guess and using every spare minute available to address every detail. It was definitely one of our most nerve-racking builds so it is a good thing we’ve never been short on nerves.

By Michael Ferrara // Photos by Michael Ferrara and Joe Singleton

DSPORT Issue #240

Body in Art

The majority of our project cars over the past 20 years haven’t included any type of wide-body or over-fender treatment. Lip spoilers, side skirts, rear diffusers and a hood and trunk here and there are what we are familiar with. However, when Artisan Spirits provided us an opportunity to use the SEMA IS 350 build to showcase the world-premiere of its over-fender body kit, we jumped on board. We worked with 3D models provided to us before real parts arrived to get an idea of what would be needed for the install and what could be accomplished with the graphic schemes. The kit arrived just three weeks before the SEMA Show and we immediately delivered the IS 350 and kit to Freedom Auto Body for the install. The team did a fantastic job to install an incredibly well made kit in four days. Even though this was a pre-production kit, fitment was still exceptional.

The matte gloss applied to all of the carbon-fiber elements provided a more race look as opposed to the show look of high-gloss carbon fiber. Mods were made to the lower mount of the rear dampers to allow fitment.

While we had submitted over 30 different designs for the graphics for the vehicle wrap, the final design selected was actually penned by Troy Lee Designs working with legendary race car drive Scott Pruett. Using graphic elements inspired from artwork on Pruett’s helmets done by Troy Lee throughout Pruett’s racing career, a design was created that would ensure this IS 350 would be remembered from the show. The complexity of the design and the desire to avoid printed vinyl required some skilled installation that was ultimately completed by the team at Boss Graphics. In this exercise, we got to learn a great deal about the ins and outs of vinyl wraps.

The A’PEX Integration axle-back exhaust was an extremely easy install. Fitment and sound were excellent which the tips tied in well with the  color scheme of the graphics.

Suspension

Mike Kojima and the crew at MotoIQ worked with KW Suspension for a Variant 3 coil-over solution. Since there wasn’t enough time to make a custom damper at the KW Suspension factory in Germany, Mike worked with KW Suspension to fabricate a solution from off-the-shelf components. Another Lexus application damper was selected and a custom lower mount was made to fit the IS350. The suspension and brake upgrades will be evaluated and compared to the OEM setup that MotoIQ already tested at the track.

Brake Upgrade

The RC-F track-edition CCM brake upgrade that we installed on the Lexus IS 350 was one of my favorites. The system features massive two-piece, full-floating carbon-ceramic-matrix rotors; 6-piston front calipers; 4-piston rear calipers and massive motorsports brake pads. I particularly liked that it was Lexus branded to highlight the fact that the Lexus brand is tied to motorsports. While the system was touted as potentially being a bolt-on system (it hadn’t been done before but enough parts seemed to possibly be interchangeable), we have been in the game long enough to expect the unexpected. We ordered up a mass of OEM Lexus parts including the RC-F hubs, knuckles, brake lines and some other hardware only to find out it wasn’t going to work as intended.

At the rear, the RC-F knuckles, hubs and dust shields worked as expected to get the rear rotors and calipers in place. What was unexpected was the parking brake dilemma. On the IS 350, the rear brake caliper has an integrated motor that applies the brakes when the “parking brake” is selected. On the RC-F, a conventional drum brake system is built into the rear rotor hub. To make it in time for the SEMA show, we had to forgo a parking brake temporarily. Ultimately, we will solve this with an aftermarket electric parking brake caliper from Wilwood and we will opt to machine a new hat for the rear rotor out of aluminum to save some weight as we do not require a brake drum in the rear rotor hat. While we had ordered the RC-F brake lines, the IS 350 lines fit without modification.

At the front, the RC-F knuckles were a no go as the tie rod and other suspension mounting points differed. The RC-F knuckles and dust shields were also not compatible. Fortunately, the calipers and rotors did mount up in place of the IS 350 rotor and caliper once the IS 350 dust shield was removed. We modified the IS 350 hubs for the ARP extended wheel studs by reaming the holes to the proper size for the knurled-shoulder wheel studs. Again, the IS 350 brake lines were a surprise as the lines fit the RC-F calipers without modification. While we were able to make the system functional for SEMA duty, we plan on finding a solution for the dust shield. If attempting to do this conversion yourself, be sure to have access to the Toyota/Lexus vehicle interface that allows you to run the brake bleeding program through the factory ECU. Failure to do so may result in trapped air not getting bled from the hydraulic brake system.

Wheels & Tire Upgrade

Since we were tasked with ordering wheels for an over-fender vehicle with a widened track without being able to rely upon actual measurements, we had to rely upon math calculations. One of our personal pet peeves with wheel and tire upgrades is when the resulting upgrade makes more than a ½-inch change in total tire height. Ideally, an upgraded wheel and tire combination should have a tire height within ¼-inch of the combination it replaces. The OEM wheel and tire combination features a staggered setup with 235/40R19 tires up front and 265/35R19 tires in the rear. These tires have heights of 670.6 and 668.1mm respectively. The height difference front to rear is less than 0.37 percent. Knowing that we had an addition +50mm of width from the over-fender being added, we knew a rear tire with 40-to-60mm of additional section width should fit without issue. Looking at the 305 and 315 options in 19-inch resulted in a 305/30R19 for the rear pairing with a 275/35R19 in the front. This combination also had an average tire height of 670mm. For a 20-inch setup, we opted for a 325/35R20 to pair with a 275/30R20. After getting the kit installed and knowing what we now know, it would definitely be possible to go with a 285/35R19 front and 345/30R19 rear with 19-inch wheels. The problem is finding the rear wheels with enough width and proper offset.

We had the opportunity to fit both a 19-inch and 20-inch wheel and tire combination on the IS 350 in its stage-1 configuration. Yokohama Advan GT Beyond Hyper Black Machine were our choice for the 19-inch selection while Scott Pruett selected the 20-inch KPS Rotiform wheels in Matte Monaco Copper to tie in with his Troy Lee Designs graphics package.

Interior

Gary Castillo of Design Craft Fabrication came in to make the custom motorized seat mounts and 4-point roll/harness bar. While the motorized seat bracket was simple for our Project R35, the IS 350 OEM seats were a bit more complex. Once Gary was able to cannibalize the necessary components from the OEM seat, the SPARCO QRT-K Carbon-Kevlar seats could be properly mounted. The SPARCO 5-point racing harness was tied into the custom 4-point roll bar.

One of the lightest and best-fitting seats on the market is the SPARCO QRT-K. The “K” version features a Carbon Kevlar shell.

Coming Soon

A special thanks goes out to Artisan Sprits, Yokohama Wheel (Mackin), Michelin Tire, KW Suspension, SPARCO, MotoIQ, Design Craft Fabrications, Freedom Auto Body, Troy Lee Designs, Scott Pruett, Boss Graphics and all the hard workers on Team Lexus for the support on stage one. Our apologies to those that we forgot to mention. With stage two, we will be jumping into engine development of the Lexus V35A-FTS powerplant. This will again require calling in favors from several the leading aftermarket parts producers around the world. We’ve already recruited a few key players to the team and we will be drafting the rest during our visit to the 2021 PRI Show. While part one was fun, we can’t wait to be the first to develop big power on the V35A engine platform. Stay tuned.

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