Power on a Budget


For some time I have looked at the ins and outs of improving the performance / mpg of my Frontera 145 (2.2 Petrol).

I have spoken to many friends / contacts in the auto trade and formed several conclusions.



The Frontera as a vehicle is designed as a workhorse and as such little thought went into its performance and fuel return figures, apart from adhering to European emission restrictions.
There are substantial gains to be made without laying out huge wads of cash, if a little thought is applied.
There are longer dwell cams available at about £350 per kit plus fitting, or the other extreme is a blower at about £800, both I am sure you will agree, expensive options.


I started by looking at how air flowed through the induction system.

On a standard setup the air is taken from the void between the inner wheel arch and inner wing sections, it then has to change direction three times before reaching the air box. Once in the air box the air then flows through a cotton gauze filter (which flows quite well for a factory fitted item) then through the main induction tubes to the throttle body, along the way there are several air reservoirs or “resonators”, the largest of which is situated adjacent to the Throttle Body.

These resonators are necessary because the air is flowing relatively slowly in comparison to the demand by the engine at anything greater than ¼ throttle opening and also prevent stalling at low engine rpm.



Stage 1

To overcome the lack of airflow was obviously the first hurdle, I could have fitted an Eco-Tec device, but that will only provide a small improvement in air throughput.

I started by giving the air box a direct cold air flow from as close to the front grille as possible using 70mm bore expandable alloy tubing and a home-made stainless air collector.

I fed the pipe and collector through the gap between the right of the radiator and the chassis, by putting a couple of turns of gaffer tape around the pipe I ensured that there would be no electrolysis and rust development between the pipe and the chassis.



I use my Frontera mostly on the road, when I go off-road it is usually through farmland and small streams so the air collector is high enough off the ground to provide me with water free air.

Result – An improvement of about 4MPG across the range.



Stage 2

As I pondered my next move, another member of the group fitted a Hi-Clone into the main induction pipe on his 145 2.2 petrol but it made no difference!

After reviewing the install with him it was obvious why this had occurred

The induction system was still flowing air (or not as the case may be) in standard trim.
He had installed the Hi-Clone within 50mm of a resonator, so any turbulent air was pulsed into the resonator not the throttle body.
I told him about my experiences and that there was not enough air moving through the system to make a difference. He agreed and said he would make the same mod as I had in stage 1.



After his experiences and to make maximum usage of the air available I decided to develop a replacement for the main induction system and its distinct lack of flow and resonators, but include connections for both the air temperature sensor and gas recirculation from the rocker / cam box, thus ensuring that the vehicle will comply with the original manufacturers specification.



The finished kit in component form and assembled:

  




The assembled unit shows the temp. sensor and grommet installed for clarity.

 
Once fitted the kit proved my earlier theory, that you can only control airflow and induction if there is sufficient air flowing in the first place.


First road test - extremely positive with no Hi-Clone fitted. Power and engine pick up from low rpm were a definite improvement over stock, with a smoother feel to the acceleration curve and more power mid-range. An added bonus being the lack of induction noise from the main resonator attached to the inner wing.

Second road test – Hi-Clone fitted. Power and pick up from low rpm were a total surprise, the power surge from 2000rpm through 3500rpm are to be experienced to be believed.

Third road test – Two Hi-Clones fitted …………………………………………….watch this space!!!



I haven’t any MPG or power / torque figures yet as the rolling road is busy at the moment, I will release them ASAP.



All the above tests etc were conducted using the standard air box and filter.



Stage 3

I will make comparisons on the rolling road using a K&N type cone filter of the correct size, and a K&N replacement pad filter to fit the standard air box.