Member - Alan replied:

I think the only way you'll get any better than that Jack is to push it!
I've got a 2003 Defender Td5 and get approx. the same as you and am well satisfied.
From what I've read these things are more of a gimmick than anything else, the sort of thing Range Rover owners like my son (and big petrol Nissan/Toyota owners) buy in desperation!

Member - Ross replied:

Alan & Jack

I'm almost getting that from mine, but not quite. Only done 8000 Km so expect better when it loosens up some more.

How many K's for you blokes before you felt it was loose .... 10 - 12 K Km ??

CheersRosco

Aston replied:

Jack,

As a manufacturer of carburettor parts I doubt the effectiveness of some of these gadgets as I have seen them all come and go.

I thought that you would be interested in that I just filled the Td5 up at the local ampol and put in 76.92litres for 697.8kms mixed H'way running and a small amount around town 11litres/100kms (25.6mpg in the old language).

I also give it a dose of "chemtech" diesel power every 3rd tank.

Rosco try and keep the engine revs under 2,700 and let it work and see if the economy improves.

Cheers Aston

Hughesy replied:

Jack I've tried the Hiclones in my cruiser diesel and found it did SFA (still left them in though). When you think about it - for a diesel, the air is drawn into the cylinder (past the hiclones) and then compressed anything up to 22:1 before the diesel is injected. Now I'm pretty sure the bit of swirl that the hiclones put into the air before it enters the cylinder is all but gone by the time the diesel is injected at the top of the compression stroke. Therefore doing SFA for the motor - if anything it gives a higher resistance for the intake air.....???? I could see it possibly working in a carbouretted petrol because the fuel is mixed with the air before being compressed.

But some people swear by them so who knows....

I'd be happy with 10l/100km. Happy motoring.

Cheers,
Hughesy

Andrew replied:

The principle behind these things ( and the squillion widgets that have gone before) is that they increase the turbulence in the inlet tract.

The simplest one I have seen was a piece of flywire mounted underneath the carburettor, but I digresse.

Increasing the turbulence may (but not necesarily) improve fuel atomisation so that the air/petrol mix is more consistent which can improve torque and reduce petrol consumption. Great idea if it works for low to medium throttle openings.

However as it is a restriction most devices will hurt maximum power because they hurt the airflow at higher revs.

Now all this assumes that your basic carburettor and manifold setup is not good at mixing fuel and air and keeping it mixed. Hard to see how this applies to modern engine designs.

Should make damn all difference to fuel injected engines and may actually hurt the effectiveness of the injectors if you stuff up the air flow past them.

Creating turbulence in diesel engines is pretty pointless as the fuel is injected inside the cylinders, not in the manifold where the device is fitted. Probably still acts as a restrictor though.

regards

Member - Bob replied:

Jack, there are various chips available for the TD5 which can boost power, torque and economy. The cheapest is about $850 from Bruce Davis. I think it lifts power from 101 kW to about 136, and torque goes up similarly. There are extreme chips which will lift power to 200 kW (hehehehe) but that would be silly wouldn't it? If you are going to fiddle and spend money that's where I'd start.Bob

David N. replied:

I reckon the Hicyclones work very well.
Very well at lightening your wallet!!!
Do you seriously think the manufacturers would ignore them if they worked.... fuel economy is a big selling point.
Save your dough and if you want to improve your economy
1. Drive (and accelerate) slower.
2. Raise your tyre pressure.
3. Remove excess weight from your vehicle
4. Remove roof racks etc when not absolutely needed.

All of the above cost zip and DO save fuel!

ross replied:

My FJ73 had a hiclone fitted when I bought it.Just to confirm what I always thought they are nothing but a con.The advertising blurb is just mumbo jumbo and has no practical basis what so ever.They have been tested by the EPA and found not to improve economy/efficiency at all.I personally would not deal with any mechanical workshop that pushes these onto their customers.

Member - Bradley replied:

My jackaroo had one of these fitted but i have since changed the induction system and gave it the arse, they may work if your induction system and filter are standard. If the disco has a round inlet pipe about 4 inch diameter - then you can have mine for nix, and buy us a beer if it works LOL.... cost me nothin, willing to pass it forward .. Cheers Brad. Life is short- but there's always time for a yarda.

ToyMotor replied:

I have these installed, they are guaranteed to repel lions and crocodiles, and in over 300,000 km of outback motoring, I've NEVER hit either one! They work really well. (I'll sell you a set for $200.00)

Cheers

ps Bugger! Sorry, wrong thread.....