If the twin turbo supra is just too much - check out these sweet naturally aspirated supra's.
Non-Turbo Supra's
As popular as the turbocharged supra is the normal naturally aspirated (NA) non turbo varient is in fact just as available - not only is the insurance a group (or two) less its also still damn fast!
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Supra Non turbo MKIV
There is a bunch of years the Naturally-aspirated supra was made - every year they made a twin turbo and turbo version of the supra they also made a nonturbo supra, so whatever bodyshape supra you want there will be one about
The uk is a hot house for non turbo automatic supra imports...
The Most common uk non turbo model is the aerotop or the automatic standard top - you can usually catch a bunch of these at reasonable price here - there was a lot of them imported and a fair few naturaly aspirated models sold in the uk - making it an easy catch - you should be able to get these at a very reasonable price - bang for buck they are quality too.
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Modified NonTurbo Supra's
As far as engine modifying for a non turbo supra goes theres tons of stuff you can do - from adding a turbo (lol) to Nitrous oxide (nos) fast and furious style to boring out the engine, uprating fuel pumps etc. etc.
Screw turbos the naturally aspirated non turbo supra is fast as it is!