The first iteration of this Lexus had a supercharger kit added on which you can read the review here. More than a year on and thousands of dollars later, the owner decided that it wasn’t enough power so he changed the beating heart of this IS300.
Performance – Powering this sedan is now a 2JZ-GTE motor from the Mk. 4 Toyota Supra. Normally this inline-6 engine produces around 320hp but the one in this IS300 has been upgraded to produce in the vicinity of 500hp. This impressive power figure was achieved through the use of a massive single Greddy T-78 turbocharger. Unfortunately there is a price to pay with having such a large turbo (apart from the dollar price) and that is massive turbo lag. The turbo begins to spool at 3500rpms with full boost coming in at around 4500rpms. When the turbo delivers full boost to the engine, the best way I can describe how it feels is that it’s like you’re on a roller coaster as it’s beginning to go from the first and tallest hill to the bottom. The G forces push your body into the seats and no matter how hard you try to lift your back off them, you can’t. The only other car that I’ve driven and has accelerated this violently was the Corvette Z06 and in some ways when the engine in this IS300 reaches and stays in its “sweet spot”, it feels somewhat like a big V8 muscle car.
Feeding the explosive juice to this hungry engine, are 2 in tank Walbro 255 LPH fuel pumps along with massive 850cc fuel injectors. Helping the turbo breathe is a custom 3” downpipe and exhaust with a straight-to-atmosphere Greddy wastegate. Below the turbo’s “sweet spot”, the car is actually surprisingly quiet but when the wastegate opens, the raw, unfiltered, deafening engine noise can be heard from blocks away in every direction. The actual engine itself has not been modified much, just a rebalance of the internal moving parts (crankshaft, rods, pistons, etc.), and that’s because a stock 2JZ-GTE engine can support up to 1000hp. So at 500hp, it is well within the capabilities of the stock engine components.
Comfort – Like in part 1, it has none because race car. No interior trim, no sound dampening materials, and super stiff suspension that will rattle your teeth.
Odds and Ends – The handling characteristics of the car has not changed by much. It is easier now to get the back end to swing out of line with the extra power but in terms of suspension upgrades, it is the same as before. TRD yellow coilovers, TRD yellow sway bars, solid bushings everywhere, and 4 piston brakes from the Toyota Supra.
The difference between the old supercharged engine and the new turbocharged engine is night and day. Before, power delivery was smooth and predictable whereas now it comes in a giant lump through the middle of the rev range and it keeps pulling until the rev-limiter decides to “end the fun”. To be honest when the owner told me years ago that he wanted to switch to a turbocharged engine, I had my doubts about needing more power in a city car. Now those doubts are gone and I can definitely see the appeal and joy to be had with more power. Oh, and I’ll let you in on a little secret, the owner is now considering swapping this engine with an LS3 V8. So, Part 3 coming soon???
Thank you to the owner for the opportunity to test drive the vehicle and if you have an interesting car or motorcycle that you’d like to be reviewed, contact me through the Contact page.