Craig approached us with a request to transform his Toyota Supra JZA80 into a Single Turbo Charged Sleeper, of course what else could we do but accept the task!

Front Bumper Removed

We started of by looking at the various 'off the shelf kits' to see who was offering what and more importantly what was included within the kits, we settled with the 'Boost Logic' kit which is manufactured in the USA.

The Boost Logic Kit included:

• Turbo Charger
• Exhaust Manifold
• Down Pipe
• Decat Section
• Oil Suppy & Drain Pipes 'Braided'
• Front Mount Intercooler
• Polished Intercooler Pipes & Silicone Hose Joiners
• Hose Clips
• Walbro Uprated Fuel Pump
• Drain Pipe Flange
• Tial External Waste Gate & Screemer Pipe

 

Intercooler Fitment

Fitting the kit went well although there were a couple of minor issues mainly because the kit is designed for a LHD vehicle. The main issue was the turbocharger compressor exit pipe, this pipe runs over the top off the steering rack and then should run along and behind the front anti roll bar but because the steering rack would interfer with this route we had to the run the piping in front of the anti roll bar meaning an additional aluminium pipe would be required. The second issue is with the lambda sensors, the kit only allows for one lambda sensor to be used so to get around this we simply tagged the R/H lambda to the L/H lambda sensor signal.

Turbo Charger

During fitment of the kit more consumables will be required:

• Heat Protective Sleeves
• Exhaust Heat Wrap
• Cable Ties

Due to the temperatures that will exist after fitment it is very important that any plastics & cables are protected against the heat, you will be surprised how much extra 'under bonnet heat' will be generated! To reduce heat even further we would recommend heat wrapping the exhaust manifold and downpipe also a turbo charger turbine boot would be beneficial.

Once the turbo kit was fitted a oil and filter change should be carried out, flushing the engine prior to draining will help to remove sludgy oil deposits which occur in the engine, these sludgy deposits can lead to serious turbo failure and engine failure so as a general rule a 'engine oil flush' should be used on every oil/filter change. After fitting the turbo kit oil/filter change frequency should be increased and depending on types of use it should be at least every six months.

The next thing to consider is the fuel / ignition requirements, any increase in air will require an inrease in fuel requirements, although boost logic advertise the kit as 'every thing you need' it does not include any fuel or ignition control items. There are numerous ways to achieve the control required and these range from:

• Full Standalone Engine Control Unit
• Piggy Back Engine Control Unit

A standalone control unit is the most suitable but is also the most expensive method, a good standalone for example 'AEM PEMS' will cost you around £1100.00 plus vat and mapping, the second option is the 'Piggy Back' which is an additional computer that can intercept & manipulate various ecm signals. After much thought we decided to fit the newly released 'AEM F/IC-6' controller costing just £290.00

Fitting the F/IC is relativley straight forward and once fitted its time for mapping, during the 1st few map sessions its very important that loading and boost pressure is increased gradually to prevent any major issues such as lean running and excessive boost pressures, during the mapping it became obvious that the boost pressure was indeed excessive for the application! boost pressure is being limited by the included Tial external wastegate. To test the wastegate required removal from the vehicle, we tested the wastegate using compressed air and a pressure gauges. Unlike common internal wastegate actuators the tail external type are designed to bleed off air volume so operating the actuator with a mityvac will not operate the unit as there is insufficiant air volume. The test result showed us that the wastegate began to open at 10PSI which is 5PSI more than the target pressure, so the wastgate required stripping to insert a lower pressure spring, for anyone fitting the Tial external wastegate we would recommend that the pressure be checked before fitting, even if you are running an electronic boost controller (boost controllers cannot lower the boost below the actuator minimum).

"Peak Power 418BHP"

Once the tial spring had been fitted it was time for mapping again, the majority of mapping we do is normally carried out on the road, we find this method safer for the engine! Once happy with the drivability of the car it's time for a dynomometer session, the dyno we use is a Maha AWD. The dyno session went very well with the  exception of a slipping torque converter (auto supra), the slippage mainly caused a problem when it came to steady state tuning due to the fact that we can hold a specific RPM in any load condition. We carried out only 1 power run after the mapping due to the gearbox issue and peak power recorded was 418BHP/388 Ibft torque @ 6.8 PSI boost pressure.

We believe with a better condition gearbox or a manual box and a little more mapping time this kit should be capable of achieving approx 450BHP @ the flywheel without modifying engine internals, although a set of larger injectors would be required.

If you own a Supra JZA80 2JZ-GE and would like to convert yours to a turbo charged sleeper please call us on 01246 230 500 to discuss your options.