Thread: Tuning options - Puma

Gavster, I have just got a BAS re-tune from the UK. I have found it has improved power and fuel economy, can't comment on Torque. The quoted figures can be found on the website, Diesel performance and economy remap chip tuning for Landrover Defender Discovery TD5 Puma TDV6 TDV8 The tune interface will also read any OBD fault codes. Overall I would recommend it.

I have just replaced the factory ducting from the vent in the drivers side guard/snorkel to the air box on my 08 PUMA, with 65mm ID marine exhaust tubing.

The factory ducting is various shapes and quite squashed in places and obviously restrictive to a smooth air flow.

The marine exhaust tubing provides an inside diameter of 65mm that is uninterrupted.

I wasn't really expecting a lot of change in performance, but I have surprised with the gains, particularly in the upper gears.

Cruising speeds of about 110km/h are achieved with a lot less throttle and maintained up hill much easier.

Cheap and simple project.

Originally Posted by Drover

I have just replaced the factory ducting from the vent in the drivers side guard/snorkel to the air box on my 08 PUMA, with 65mm ID marine exhaust tubing.

The factory ducting is various shapes and quite squashed in places and obviously restrictive to a smooth air flow.

The marine exhaust tubing provides an inside diameter of 65mm that is uninterrupted.

I wasn't really expecting a lot of change in performance, but I have surprised with the gains, particularly in the upper gears.

Cruising speeds of about 110km/h are achieved with a lot less throttle

and maintained up hill much easier.



Cheap and simple project.

so what RPM?

RPM's have not changed, it is about 2250rpm @ 110km/h.

I am not an expert by any means, but the higher the gear, the higher the speed, the more fuel air mixture is needed to maintain a certain RPM.

With the new ducting it allows air to be drawn in to the air box without any restrictions, making it easier for the engine to maintain a required speed without choking it.

In the lower gears the gains are not as obvious as the motor does not need to work as hard and the demand for fuel/air mix is not as great.

The difference when driving is noticeable, not huge.

Gavster, I believe Tombie2 is offering the BAS unit for the Puma now, he posted up something the other week.

Originally Posted by dm_td5

Gavster, I believe Tombie2 is offering the BAS unit for the Puma now, he posted up something the other week.

Thanks mate - will PM him

Originally Posted by Drover

RPM's have not changed, it is about 2250rpm @ 110km/h.

I am not an expert by any means, but the higher the gear, the higher the speed, the more fuel air mixture is needed to maintain a certain RPM.

With the new ducting it allows air to be drawn in to the air box without any restrictions, making it easier for the engine to maintain a required speed without choking it.

In the lower gears the gains are not as obvious as the motor does not need to work as hard and the demand for fuel/air mix is not as great.

The difference when driving is noticeable, not huge.

sorry should of wrote a bit more than what I did, was just curious at what RPM you were at at 110... never actually asked anyone before just wanted to see if it was the same which it is....

I have an engine light at the moment, its my turn for a failed EGR

The compressor on the turbo produces boost pressure which is a ratio of the inlet pressure.

At sea level standard atmospheric pressure is approximately 14.7 psia (absolute, not gauge pressure). The pressure will drop as the air flows from the inlet, through the ducts, air filter, etc. to the compressor inlet.

Comparing 2 hypothetical installation where the standard system has a pressure loss in the intake/filter of (for sake of example) 2 psi, and a modified system where the losses in the intake/filter are reduced to 1.5 psi - an improvement of 0.5 psi.

Then the absolute pressures at the compressor inlet would be 12.7 psia (14.7 - 2) and 13.2 psia (14.7 - 1.5) respectively.

For this example, assume the compressor is operating at a pressure ratio of 2.4 (for some particular engine rpm and turbo rpm).

Then the absolute pressure at the compressor outlet is 30.48 psia (12.7 x 2.4) and 31.6 psia (13.2 x 2.4) respectively.

Then to find the boost pressure the absolute pressure is converted to gauge pressure by subtracting the atmospheric pressure (14.7 psia in this example). i.e. 15.78 psi (30.48 - 14.7) and 16.98 psi (31.6 - 14.7) respectively.

So by reducing loss in the inlet system by 0.5 psi (2 - 1.5), we achieve a useful gain of 1.2 psi (16.98 - 15.78) boost at the compressor outlet.

The above gain in boost pressure could have been determined simply by just multiplying the inlet pressure difference by the pressure ratio i.e. 0.5 psi x 2.4 = 1.2 psi.

I hope the above discussion helps to understand what Drover has experienced.