Supra Turbo comparison tests
Which Turbo should I chose for my Supra?
Tests done on Stock twins, GT30/40, GT35/40, TO4E, TO4Z, T88/33D, T51SPL.
Back to back Dyno tests will help you decide.
Chassis dyno testing has been performed on seven different vehicles fitted with Turbochargers commonly used on the popular 2JZGTE engine.
The main objective was to measure the differences of spool time so you can see the "Dreaded Lag" time of each Turbocharger.
This testing was not performed to show what potential power each turbo could produce, it merely shows the responsiveness of each Turbocharger to help you decide and make the correct choice that suits your personal needs.
Vehicles tested were all 6 speed manuals, using 98 pump fuel.
Vehicle (1) Non modified 1998 Supra with all original equipment even still retaining the factory exhaust and air box. Boost on 10psi.
Vehicle (2) Supra fitted with a Garrett GT 30/40 single turbocharger, 3" exhaust system, large Blitz front mount, Power FC, High flow fuel pump and currently stock fuel injectors with increased fuel pressure. Boost on 15psi .
Vehicle (3) Supra fitted with a Garrett TO4Z BB single turbocharger, 3.5" exhaust system, large front mount, high flow fuel pump, currently stock engine management system and stock fuel injectors with increased fuel pressure. Boost on 17psi.
Vehicle (4) Supra fitted with a Garrett TO4E Std bearing turbocharger, 3.5" exhaust system, 600 X 300 X 75 Hybrid (relatively small) front mount, 2 x High flow fuel pumps in tank, high flow fuel injectors, after market engine management system and tuned to the safest reliable power on 21psi.
Vehicle (5) Supra fitted with a Garrett GT 35/40 BB single turbocharger, 3.5" exhaust system, large front mount, high flow fuel pump, high flow injectors, after market engine management system and tuned to the most safe reliable power on 23psi.
Vehicle (6) Supra fitted with a HKS T51SPL BB single turbocharger kit including front mount intercooler, turbo manifold and accessories. HKS cams, fresh engine re-build, high flow fuel pump and injectors, after market engine management system and CDI ignition system, tuned to the safest reliable power on 18psi.
Vehicle (7) Supra fitted with a Greddy T88/33D single turbocharger kit including Greddy intercooler, turbo manifold and accessories. HKS cams, high flow fuel pump and injectors, after market engine management system and CDI ignition system, tuned to the safest reliable power on 24psi.
Respectively the vehicles are very different in many ways. Vehicles 4, 5, 6 & 7 are completed and tuned to safely on 98 pump fuel. Vehicles 2 & 3 limited fuel systems and are de-tuned presently. Never the less, the spool time would hardly be different.
From the Dyno graph shown you can see substantial differences in low end to mid range power and what to expect if you were to use one of these Turbochargers. The top end gain in power doesn't justify a major loss in lower end power. It's evident that you can over Turbo charge an engine.
The T51SPL is simply far too large for its intended purpose making the vehicle terribly unbearable with large amounts of lag taking far too long to deliver the goods. When the Turbo eventually comes on the acceleration is not that fantastic because you're pulling the next gear before the rev limiter only to find that dreaded lag again waiting….. for boost. The rev limit on this engine was increased to give the vehicle owner some enjoyment. This turbo is best suited with a serious built race engine on C16 and maybe even the aid of nitrous.
The T88/33D combo is far better in respects to lag time, however the vehicle must be driven hard in order for it to perform. It still lacks low end to mid range power, but is nowhere near laggy as the T51SPL. T88/33D Turbocharger on this set-up is delivering the best possible safe power it can, but the Turbo is limited to the stock engine and 98 pump fuel. Obviously this set-up tuned on C16 race fuel would produce more power.
Vehicles 4 (TO4E) & 5 (GT35/40) Draw a simular power graph this because the TO4E Stand bearing specs are very much the same as the ball bearing GT35/40. These Turbochargers are a good match for the 2JZGTE engine delivering good response and power through out the entire rev range. Both vehicles accelerate rapidly with no lag on gear changes and pull hard all the way trough to the rev limit. Both of these Garrett Turbochargers are well suited for street driving for vehicle owners who hate Turbo lag.
Vehicle 3 (TO4Z BB) an excellent choice for the street/drag-race enthusiast with low end power slightly compromised the TO4Z comes alive making awesome mid range power that pulls all the way to the rev limit. As you can see the on the dyno graph shown the TO4Z comes to life quicker than the T88/33D, both these Turbochargers are rated around 800Hp. As a Dyno tuner I can see the potential this vehicle has when an adequate fuel system and a tuned engine management is fitted.
Vehicle 2 (GT30/40) This Turbocharger is all you need to make around the 400Hp at the wheels. The GT30/40 is a good choice if you don't want to break the budget. You can get around 370Hp at the wheels with the factory engine management system on only 15psi. This is a great replacement for the factory twins, you need not worry about lag. When this vehicle is completed I would expect this set-up to produce on more than 410 wheel Hp.
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