The Basic 2jz-gte Non-vvti Tuning Guide

[Aristopheles]

Alongside Nissan's RB26DETT, the 2JZ-GTE - in my opinion - is one of the best performance engines to have come out of Japan. While its standard outputs are impressive, one of the characteristics that makes the GTE so appealing is the ease with which it can be tuned. No doubt many of you will have heard the terms 'Stage 1', 'Stage 2' and so on bandied about, and while they may well apply to various cars and engines, if you're tuning the GTE properly, there's only really one main stage of tune above standard. A car at this stage of performance tuning is referred to as being a BPU car or one having had BPU modifications. The term BPU - which stands for basic performance upgrades - was coined by an American company which specialises in the modification of the MkIV Supra. While the term only tends to be used on Supra forums, it can readily be applied to the 2JZ-GTE engine in general.

In order to get the most from the GTE in terms of performance upgrades, everything that constitutes BPU should be performed at once, for both reasons of performance gain and engine longevity. The three main componenets of BPU are the exhaust, air filter and de-cat, with everything else being linked to these in one way or another. This trio is essentially what gives a BPU car its extra power, but you have to take precautions to make sure that the rest of the engine can cope with the extra power it is now being asked to produce.

In all honesty, an exposed after market air filter is somewhat unnecessary, though most people will fit one anyway, so I thought I'd include it in the list of BPU requirements. It is widely accepted that the standard GTE airbox is in fact far more efficient at supplying the turbos with plenty of cool air as it isn't affected by heat-soak, so rather than shelling out for an exposed filter, it would be far more worthwhile - and cheaper - to simply slot a free-flow panel filter into the standard airbox. It might not give you any extra power as such, but it won't do any harm and it's not expensive at around £30.

In the JDM GTE, the cats act as boost controllers, so removing these will allow the boost to increase, resulting in more power. The trouble is that without cats, the boost levels will reach dangerously high levels, which is where the restrictor ring comes in. This is essentially a washer that is fitted between the de-cat pipe -or pipes - and the exhaust, and when the correct diameter is chosen, it will prevent boost levels from going beyond 1.2bar. Beyond this point, you will significantly shorten the lifespan of the ceramic turbos, and they will be operating outside of their efficiency range. Due to the fact that you can control boost levels on the JDM engine with nothing more than a restrictor ring, this negates the need for expensive boost controllers, at least at this stage. In order for the turbos to be able to actually reach 1.2bar, you must first overcome the ECU's built in safety system. The standard ECU is designed to cut fuel to the engine if it detects boost levels over 1bar. You must therefore fit an FCD (Fuel Cut Defencer), which over-rides this safety cut, allowing you to up the boost freely. Once you have removed the cats and are limiting boost with a restrictor ring, it is essential to get a boost gauge, regardless of how cheap or expensive a gauge you choose, in order to monitor boost levels and to make sure that everything is running as it should

The final performance modification is the exhaust - there aren't many available for the Mk1 Aristo, but try and choose a fully stainless system with a nice pipe diameter all the way through the exhaust - 70-80mm or thereabouts.

The final two must-haves on the BPU list are a set of colder plugs and an uprated pump. The plugs that come with the highest recommendation are the Denso iridium IK24s, which run cooler than normal, but don't cause any problems with everyday driving. You may be tempted by HKS plugs, but they are in fact Densos with HKS logos and a higher price tag. As for the pump, the standard item will struggle in trying to supply the engine with the extra fuel it will now need - probably the the best choice is the Walbro 255lph pump.

You may also want to fit a blow-off valve - the HKS SSQV is easily the best available, mainly because it pretty much won't leak under any circumstances, as it is designed to be held closed by the pressure of the air running from the turbos to the engine, instead of using a spring to hold the valve closed.

This covers the basics to reach the first main stage in tuning the GTE. I will edit and ammend this to add any additional information, such as details on BPU+ etc. but the basics have at least been covered here. Happy tuning.

[chips229]

Good Info fella.

Cheers Chips.

[skeet94]

Didn't know about the Restrictor Ring up till now. Thanks,

Mitul.

[norkep]

Well impressed, given me a few things to think about and possibliy having ago this week end. Have printed this out for future ref.

Excellent Info

Thank You

[Aristopheles]

Thanks for the feedback guys - glad you found it useful.

[skeet94]

Also look into EGR Block Off Plates, heard alot of people in the US losing compression in cylinders 5 & 6 due to VERY high heat build up and burning the valves.