Toyota Supra NA-TT Conversion – Final Thoughts – Part 6

Summary                                        Part 1  

Removal of stock parts         Part 2  

Wiring                                              Part 3  

Aristo engine differences    Part 4    

Installation                                    Part 5   

Final thoughts                             Part 6   – You are here

Well I figured this final thoughts page can be used for me to come back to and update if required and also be used to add any further information that may fall outside the scope of the conversion directly.

Dyno figures

I went from a 2JZGE NA with K&N panel filter with 2.5 inch custom exhaust at 135rwkw (181rwhp) to a 2JZGTE TT with HKS intake, 2.75” exhaust/3” dump pipe/stock mid pipe and cat, 3 row FMIC and electronic boost controller at 16psi for 261rwkw (350rwhp) which is almost double the power and relatively low boost, this was daily driven without any issues.

NA dyno

TT dyno

Costs

Unlike some I’m going to be open and honest here, I was very lucky with some of the parts I purchased but I also had a fairly bad exchange rate with Japan and USA at the time for other parts and obviously I saved on the labour component.

Cost breakdown as follows;
*All figures are in Australian (AUD) dollars.

• Engine, Loom, Injectors, Radiator: $3400
• OEM new and 2^nd hand parts: $1100
• Aftermarket clutch and flywheel: $2000
• Aftermarket FMIC, Intake, boost controller and timing gear: $2600
• Misc (Not including beer): $300

Total costs:                                                                                                                         $9400

Minus Sold items:                                                                                                            $1600

Total project cost:                                                                                                            $7800

Troubleshooting

There are so many steps to troubleshooting and there can be lots of things that go wrong, here are the top items I encountered and others have contacted me about over the years;

• Wiring (Usually 12v+ or sensor related)
• More wiring…….
• Something related to wiring!!!
• Cross ECU compatibility (i.e – Aristo ECU/Supra body loom)
• Electronic throttle body issues/limp mode for ETCS-i
• Transmission/gearbox speed sensor issues/differences (i.e – Using R154 on 2jzgte)

Links to all of the resources that cover these topics are within Page 1 and also throughout this guide.

Tuning / Cams / Aftermarket Support

One thing some people were very afraid of (because they knew nothing about it) was tuning of the VVTi system and cam timing. When the car is stock or running the stock ECU then tuning is not required, you do have the option of running a piggy back and making some basic AFR changes or running an aftermarket VVTi cam control kit. There then becomes a point where the piggy back system won’t cut it, that’s when you move to a standalone ECU setup, which I’d highly recommend.

If you upgraded the cams then there were also options around aftermarket VVTi cam control (Such as the HKS Valcon system), but I think a standalone ECU with VVTi support is a much better value for money option these days. I’m not going to say which ECU or brand to go with, you need to find a tuner you are comfortable with, explain what functionality you want out of the ECU and then what they recommend based on your budget and their tuning experience/recommendations. I’ve personally ran the ViPEC V88 ECU for 4+ years without any issues with VVTi cam control and trigger wheel setup with my local tuner providing the ECU recommendation at the time of purchase.

Cam choices are limited compared to the non-vvti but there are some nice gains to be had retaining the VVTi and using larger cams and turbo setups, the stock 2JZ GE VVTi cams are 248 degrees duration and there isn’t much more peak power over 6500rpm with stock cams and tuning.

To modify the cam timing you will need an adjustable exhaust cam gear to get the required setting on the exhaust cam position. As for the intake cam this is variable from full retard to 30 degrees advance in stock form, with an aftermarket ECU you can adjust the cam timing to different values based on rpm/load.

I leave the VVTi settings and tuning up to my tuner, since I’ve upgraded my VVTi cams to Titan 272 items then the below settings have changed again. But to give you an ideal of the tuning method for a stock cam single turbo setup with VVTi the following was complete;

1500-4500rpm – 25 degrees advance working down to 8 degrees, then VVTi back to fully retard (0) after 5000rpm. Also this is adjusted for throttle percentage, an example would be at 3000rpm and 50% throttle you may retard it another few degrees compared to 100% throttle. You will not see a lot of benefit advancing the stock cams past 6000rpm. My 272’s are now advanced all the way to redline due to their design.

I don’t have any write ups or steps on locking the VVTi system, it’s not something I would recommend doing, most aftermarket ECU’s usually have VVTi support these days and I would highly recommend this as the route as a first option. If you were to lock the system you would need to do 2 things, one would be to remove the VVTi solenoid or not supply power to it, if the solenoid was removed you would need to block the oil passage. Also finally you would need to find a way to lock the intake cam in position as it would default to the full retard position. If you are not going to use VVTi then I’d go down the non-vvti path as it will be much easier than disabling VVTi.

I have a link here which goes through some of the ECU and VVTi Aftermarket support options – http://www.2jzgarage.com/2012/02/2jzgte-vvti-aftermarket-support

Keep in mind with the VVTi there are wiring difference, cam differences and also that the AFM is used, rather than the MAP sensor, you can find more VVTi information here – http://www.2jzgarage.com/2012/02/2jzgte-vvti-information

I may plan on having a single turbo upgrade guide at some stage in the future that I’d cover some of these options more in-depth.

Videos / Pictures

I have a video which goes through the build on YouTube;

I have a complete picture library here of the conversion;

http://www.2jzgarage.com/image-gallery/nggallery/supra/szr-to-rz-conversion