If you’re not familiar with the Lexus IS-F, it is the first platform that was really a performance breakout for Toyota’s luxury brand. Packing a 5.0L V8 churning out 416 horsepower at the crank, coupled to a direct-shift 8-speed automatic transmission, and a 0-60 MPH time of 4.6 seconds, this Lexus doesn’t mess around.
Brett Epstein out of West Palm Beach, Florida, was given a hydro-locked long block LS1 out of a 2001 Chevrolet Camaro SS. He wanted to do a budget rebuild with the motor, but soon ended up involved a year long, multi-thousand dollar rebuild. When Epstein first got the engine, he was dead-set on dropping it into a Lexus IS300, but over the year of rebuilding the LS1 he noticed that the 2nd generation IS models were dropping in price. Epstein did what any enthusiast would do – he pulled the trigger and bought a 2006 Glacier Frost Mica IS250, which still ran great, by the way.
Having bought a perfectly good car, Epstein felt a little wary tearing it apart. But he bought the car for that sole purpose, so he let the teardown commence. On his second night working on the car, Epstein ripped out the dash and center console because he knew that he would need access to all of the wiring. On day four of the teardown, Epstein had a buddy of his come help him with disconnecting everything from the 4GR-FSE motor that came in the car. Day five was the day that the motor was finally ready to be pulled. They removed the intake manifold for some extra clearance to the cowl, and with a few little shakes, the motor lifted right out.
Impatient, as any car enthusiast working on their pride and joy, Epstein dropped his LS1 mated to a T-56 transmission into his IS250 to see how it would all fit. It turns out that the LS1 is about five inches narrower than the 4GR-FSE that he yanked out, which leaves a nice amount of room to play with. One problem he ran into was the front crossmember; the oil pan was hitting and needed to be clearanced. Epstein bought an LS2 rear-sump oil pan and immediately cut into it, making it a mid-sump oil pan with just the right amount of clearance he needed.
Because this car was an automatic to begin with, Epstein needed space for his master cylinder placement. He took out the brake controller and installed a small proportioning valve so he could fit the master cylinder in there. Epstein received his Wilwood master cylinder and cut the hole for it in the firewall, but he still needed to modify the clutch pedal to fit. While doing that, he also cut a hole in the center console for the shifter that he would later install.
Planning on not spending a lot of money on the suspension, Epstein came upon a set of BC Racing coilovers from a local Lexus enthusiast. This build was really starting to come together as Epstein received his custom motor mounts, transmission mount, and modified oil pan that he sent out to be fully TIG welded at a shop called TIG Vision in Riviera Beach, Florida.
After cleaning the engine bay, it was time to start bolting some parts onto the motor and getting some of the pre-wiring out of the way. Finally, it was time to set the motor into its final destination. Epstein went with Holley’s HP EFI programmable fuel injection on this build. With all of the capabilities of the HP EFI system, the car should make great power and run really smooth.
With the motor and radiator in place, it was time to solve the ongoing steering rack issue that Epstein had encountered throughout the whole build. After all was said and done, he went with an AGR Performance Mustang steering rack and fabricated a custom adapter plate, which allowed it fit like a glove with no interference. The only problem he had with clearance issues was with the Hooker cast iron exhaust manifolds. Epstein needed about one inch of clearance for the steering joint, so he pulled the motor again and cut a hole in the frame and welded in a pocket so the steering joint wouldn’t hit.
This is the hole and welded-in pocket that allowed accommodation of the steering joint.
Right after the motor and transmission went back in the car for its final finishing touches, Epstein installed an MGW shifter and the BC Racing coilovers that he had purchased. With all work being done besides the dashboard customization, Epstein took his car to Real World Horsepower in Riviera Beach, Florida to get it tuned on a dyno.
Seeing all of the work that Epstein has put into his Lexus IS250, we can’t really do anything but admire it. This is in no way an easy task and swaps like this take time and money in generous proportions. We applaud Epstein for his effort and overall cleanliness of the build, not to mention his awesomely detailed build thread on the Club Lexus forums, which would be a great help for anyone looking to tackle an LS swap into an IS chassis. Also, check out his YouTube channel for a few more videos. And to anyone looking to take on a project like this, just remember, patience is a virtue!The completed swap looks as if it was there from the factory.