23/10/2023
The REAL REASON why the Supra used 4cyl at the beginning of the JGTC
It’s well-known and the story is often romanticized, but do you know the REAL REASON behind the fact of why the Toyota Supra A80, base model for Toyota’s factory acts in the GT500 class during the first years of JGTC, used a 4cyl (or inline-4) bespoke racing engine (3S-GT) instead of the original road going’s 2JZ?
You’re not totally wrong if you say it was because they wanted to save on weight and all, but that wasn’t the main reason.
The main reason was because they already had a 4cyl engine in the catalog for that purpose.
“What purpose?”
To race an extreme modified racing car.
During the early days of Group C, Toyota’s race cars were powered by the TRD 3S-GT, also known internally as 503E - a 2.1L 4cyl turbo active until the arrival of the first V8-powered Toyota’s Group C car in 1988: the 88C-V. But the 503E was later used in the IMSA GTP, powering the AAR-built race cars.
And then we have the JGTC, a championship that, despite the “GT” on it, several modifications to the models were wide open - including engine swaps, as per regulation stats.
And this is where it all started…
Generally speaking, it doesn’t really make any sense of Toyota developing a standard 2JZ for racing purposes if they already have a developed engine for proper endurance racing purposes.
Having the 3S-GT 503E previously seen on the AAR Eagle MkIII GTP, after the demise of IMSA GTP rules in the early 90s, the engine went on the hood of the very first Supra JGTC [factory] iteration in 1994. More three chassis were built for the 1995 season and the all-new 1996-spec chassis debuted the ‘171F’, which is technically a variation of the 661E found on the Celica WRC of the same time. The 171F is 20kg lighter than the 503E and it’s down to 2.0L instead of 2.1L. Although they’re all named 3S-GT/GTE, this (171F) was the engine that powered the first Supra champion of the series, the #36 Castrol TOM’S Supra from 1997.
Curiously, though, the first Supra from the JGTC had the 2JZ (BLITZ Supra), but then with the factory intervention, this car also received an engine swap in favor of the 503E at the time.
