'91 Celica GT...you shouldn't have any problems beating it.
That Celica is powered by the 5S-FE, the same engine found in the Camry and the U.S.-spec MkII MR2. Honestly, that is a POS engine...very lethargic (130 hp @ 5400 rpm, 140 lb-ft @ 4400 rpm) and not suited for anything sporty. It probably feels faster because it's a lot lighter than the IS300 (~2600 lbs. vs. ~3200 lbs).