VERSION 5

Engine Control and Engine Safety Trips

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This is something we have already had working effectively in our version 4 maps. We had observed a number of issues on cars and developed these features to help protect the engine from damage.

The fuel pressure protection is interesting. It is quite scary to see how long the GTR will normally try to run flat out when there is a serious pressure drop. The most common cause is one of the fuel pumps failing causing a pressure drop at the worst possible time - when the engine is demanding maximum flow. This can also happen if the fuel temperature rises to high (often on a very low tank) and the fuel cavitates causing a dangerously low pressure drop.

Using the custom map inputs we are able to have the ECU monitor if any of the parameters start to drift away from the expected levels. The ECU can then apply a correction or significantly reduce performance to protect the engine. More serious problems will trigger the engine warning light to alert the driver.

Super R Mode Transmission Settings

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With Ecutek defining more of the Transmission maps we are now able to make changes to the settings allowing quicker gear changes and acceleration when in R-Mode. We have also changed the Automatic shift points to aid a smoother town driving experience. Previously the GTR would be very quick to change up into higher gears (for emissions reasons) which could make the engine feel laboured at low revs.

Revised upshift points

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With new understanding of the gearbox software we are able to modify when the Auto mode upshifts to the next gear. Previously this would have been around 6,800 rpm but on our higher power conversions it may require a different shift point to achieve the very best acceleration times when in Auto mode.

Ecutek Flex Fuel Control

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The ability to run Ethanol as a higher octane fuel has become increasingly popular. Some of our European customers are able to get E85 at the pumps and some of our higher power customers use Ethanol blends for competition.

Ethanol offers fantastic power increases and significantly drops the cylinder temperatures to aid overall engine performance. However the engine also requires a lot more fuel (around 30% extra) and you can’t always trust the percentage of Ethanol mixed with normal fuel.

Ecutek’s hard coded control means that with the installation of a Flex Fuel sensor the ECU is able to measure the percentage of Ethanol available and applies a number of tuned maps to give the best possible performance. Previously we needed to use a large number of custom map slots to control the Ethanol mixture detection and add extra power. This meant all the custom maps slots were being used by the time we added some of our other key features. By hard coding and improving the Ethanol control Ecutek have freed up these slots once again. Now when Ethanol is detected we can easily change fuelling, ignition timing and boost to suit the percentage of Ethanol in the tank.

Below is an example of Ecutek’s Flex Fuel Control working on two different setups. The higher power car on the left produced 1,056bhp on Vpower and a massive 1,164bhp with 55% Ethanol detected. The car on the right was from Switzerland and was running Stage 4 which produced around 640bhp on Vpower and 700bhp when we added Ethanol.

Litchfield Traction Control (LTC)

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The problem as we see it is the standard Nissan traction control just isn’t quick enough to control high powered GTRs. The standard traction control is quick to intervene but many powerful cars will trigger this too frequently when using the available performance even in normal dry conditions.

The basic Nissan model relies on a reduction of engine torque, achieved by closing the throttles. This instruction is both slow to issue the command but it is also hampered by the speed at which throttles can physically close and when the engine finishes consuming the available air it needs to make the power. When you do get the sudden drop in throttle angle it is very slow to reintroduce the power again.

Most drivers default to the Race mode which lifts the intervention thresholds however although the stability control is effective the traction control element is too slow to react and when it finally does it is often too harsh, unsettles the balance and is generally clumsy as well.

Race mode still incorporates stability control which is very effective however the driver that wants to push hard around the limit of grip will find the Nissan Stability System continually clamping brakes. This can be intrusive to drivers that are happy to push through a degree of understeer/oversteer as they try to balance the car through a bend and at the very least it is hard on the car’s brakes. Our Traction Control system can reduce some of the unexpected power deliveries that unsettle the balance, without completely shutting down the engine performance.

We are pleased to offer our own Litchfield Traction Control (LTC) which fully utilises the power of Ecutek’s custom maps. Using Ecutek’s version 4 custom maps we were able to provide a successful and popular solution. Our version 5 software enables us to improve this further with additional inputs to make the LTC more powerful in both Launch conditions and when driving hard on track.

Below is a simple example of a GTR with larger turbos accelerating with the standard Nissan traction control switched on versus our LTC. You can see how the standard setting cutting throttle which the LTC doesn’t need to.

LTC Development

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What started out as a simple attempt to reduce wheel spin after the car is launched grew into a more complete traction control solution, designed to work both with the standard Nissan system and as a standalone support to the driver. This took a number of months to refine as finding places to safe push the traction limits is difficult. Initial testing was completed on tracking including the Nurburgring.

In late summer 2013 we managed to secure access to a local private airfield used by the Police and Special Forces for vehicle training. So while they were doing serious looking work we found a nice few corners which allowed us to do our “crucial” development testing.

It is also a good time to thank Michelin for their continual support in fresh rubber! In October 2013 we returned to the track and hired Castle Combe (officially the UK’s most accident prone circuit) to shake down a number of new parts and access the changes made to the traction system.

We also used some of the very best professional drivers (and fellow Litchfield GTR customers) in World Touring Car Champion driver Rob Huff and Touring car ace Tom Chilton to help us improve the setup. As well as our demonstrators, Rob’s own LM700 GTR at the time featured the latest evolution of the LTC.