Nissan R34 Gtr Vs Gtt

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  • Big Shout out to the Team Nismo Elite for allowing me to shoot 2 more of the members out the camp. This time we did the R34 and R35 which was a great experi.
  • R34 GT-R compared to my R34 GT-T. They are a little different anyway!

Basic tuning

Bugatti Chiron race vs R35 Nissan GTR drag race at the driving force club airstrip Buy our Gear Like and S.

Below is a quick breakdown for the RB25DET motor which lists at what point you need to upgrade various componants.

  • when the ecu needs upgrading > around 300bhp (go for a Rising Sun ECU/Map)
  • when the turbo needs upgrading > when you want to run 330bhp or 0.85bar
  • when the clutch needs upgrading > 340bhp
  • when the head gasket needs upgrading > when you want to run more than 1.2bar
  • when the injectors needs upgrading > over 330bhp or 0.85bar
  • when the airflow meter needs upgrading > same as injectors
  • when the cams need upgrading > no set time, just always a good power mod once you finished with everything else.
  • when the pistons need upgrading > over 500bhp

Thanks to Bruce from skyline owners

If you have the R34 tiptronic box they will take up to around 400BHP with no problems but after that it can start to become a bit much for them and you might want to think about a manual conversion (see the how-to section).

Tuning Stages

Stage 1

Exhaust (around 160rwkw)
The RB25DET NEO is a sweet sounding engine but very quiet in standard form and as with most factory turbo cars the exhaust causes a huge restriction. A good free flowing exhaust will have the RB sounding great, turbo lag will be reduced, and power gained throughout the rev range. The new exhaust should start from the turbo with a dump pipe either a 3″ open bell mouth or better still a split dump to separate the gases from the turbine and wastegate. From here a high quality 3″ high flow cat should be used, then 3″ all the way to the back of the car with high flow mufflers.

Intake (160 to 170rwkw)
Now we have the exhaust side of the engine breathing the next step is to get more air into the engine. Either use a high performance air filter, or replace the air box with a POD style air filter. If you choose to go the POD filter route I recommend you fabricate some type of shield to keep hot air from the engine bay away from your intake. A cold air intake to the filter from the front of your Skyline will also give you a performance advantage. 5-10 rwkw is achievable with this mod.

Boost increase (175 to 185rwkw)
In standard form the R34 runs a two stage boost control system 5psi to 4500 rpm then 7psi to red line 7000 rpm. As mentioned before the turbo’s exhaust wheel is ceramic and they tend to fail if to much heat is generated. The amount of boost you can run with the stock turbo is debatable but I don’t recommend running more than 10 psi. You have a few options when choosing to increase the boost either a manual boost controller, electronic boost controller, or a new wastegate actuator.

A manual controller is very basic in its operation it bleeds off air causing the wastegate actuator to open later. The amount of boost run depends on the amount of air bled form the system. It is critical to install an after market boost gauge before carrying out this modification as the stock gauge is not accurate enough and is measured in mmg not psi or bar. Manual boost controllers are cheep and easy to install but they do have there disadvantages some can cause boost spikes and boost creep I have also found boost tends to tail off high in the rev range.

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Electronic boost controllers on the other hand use stepper motors and monitor boost about every 10th of a second because of this boost spikes and boost creep are kept to a minimum, and the desired boost level is held to redline. Electronic boost controllers are expensive and for this level of modification a manual controller will probably be good enough.

A 3rd option is to install a different wastgate actuator and the good news is the R32GTST item is exactly the same as the R34 except the spring inside is set for 10psi. R32 actuators can be hard to find but I think it’s the best option for this level of modification as boost spikes and boost creep are eliminated.

Nissan R34 Gtr Vs Gtt

Nissan R34 Gtr Vs Gtt Lexus

No mater which system you choose the 2 stage boost control system should be disconnected. After this mod is carried out many people notice flat spots throughout the rev range this is due to the ECU seeing an increase in airflow and as a safety precaution it richens the air fuel mixtures. Many people find re-gaping the spark plugs from 1.1mm to 0.8mm fixes this problem but if it does not you need to consider the next upgrade.

Clutch and Fuel Pump At this level of modification it’s likely that your clutch and or fuel pump will need upgrading to handing the extra power.

Conclusion
This completes stage 1 engine tuning for the Nissan Skyline R34GTT. Basically at this stage we are at the limits of the standard turbo and fuel systems but in terms of car modification this level of tuning offers great value for money. Many people with these modifications along with well sorted suspension and tyre packages have 12 run second quarter mile passes.

STAGE 2

An uprated or rebuilt/strengthend Turbo can be supplied to your specification by Rising Sun Performance.
Intercooler Upgrade
The standard R34 Nissan Skyline intercooler runs out of its efficiency range at power levels above 200rwkw and needs to be replaced by a larger front mounted intercooler. GTR intercoolers are a popular choice but custom piping will be needed in order for it to fit. Many aftermarket bolt on kits are available for the GTT these days starting at around AU$500 but as with most things you get what you pay for. Be aware a small decrease in throttle response may be noticeable due to the extra piping and larger core size. You may notice a small increase in power with this mod before upgrading your turbo as airflow will increase and the air will be denser.

Fuel system
If you haven’t done so already the fuel pump will need to be upgraded. Second hand GTR pumps are a popular option as are new pumps from bosch, walbro, and tomei. The GTR and Tomei pumps are a direct fit. You may also install a fuel pressure regulator to increase fuel pressure.

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Standard injectors will also need to be upgraded at this stage. You can either have your standard injectors high-flowed, or buy after market ones from Nismo or Performance company’s. I recommend you use injectors that are a direct replacement and don’t require any modifications s to fit.

Airflow meter
To improve the tunability of the engine its a good idea to upgrade your airflow meter this allows for finer tuning which will result in smoother power delivery and make it easier for the tuner to produce a higher peak power output . Popular upgrade choices include the Z32 and the Q45. The Z32 is cheaper of the 2 but the Q45 will allow more airflow

ECU (185 to 200+rwkw)
As mentioned before many people have problems with flat spots and rich air fuel ratios. Even if you don’t have these dreaded flat spots an aftermarket ECU will give good power gains and improve drivability. While piggy back style ECUs/fuel controllers are available, the most sensible thing to do at this stage is contact a skylien specialist tuner who can provide the right ECU for your car and remap it to get the most out of your mods.

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Rising Sun Performance can provide a custom ECU for your GTT, they are also able to map this on their dyno to get the best performance from your car.

Head Gasket
Running boost levels above 1.2 may require a new metal head gasket to lower compression and improve reliability. Opinions differ on this subject so I think its best to ask you tuner.

Clutch and flywheel
The stock clutch will certainly fail quickly at this power level the hardest part is finding a clutch that will handle the power yet not make your car a pig to drive. Exeedy seem to be popular and reliable choice and while you are upgrading your clutch a lightened flywheel is well worth considering. This will help the car rev quicker but the trade off is your car will loose momentum quicker to.

Nissan R34 Gtr Vs Gtt

Cams or Cam gears
At this stage the skyline will benefit from a set new cams, cam gears, or both. The outright power will be increased but the main reason for installing cams is for a fatter torque and power curve. Upgraded cams can help reduce lag, improve mid and top end power. Popular choice is tomei pon cams as they fit without modification and are proven to give good results.