90Hp injector nossel Change

[tdi power]

I have a 90 Hp B5 and I'm told the only difference between the 90 & 110 is the nozzels. Would you recommend changing the nozzels or are they other down sides. I do not want to lose significant mpg. I have a performance box fitted so I can adjust the set up slightly, this did not effect the mpg.

I've checked out a few web sites and they are advertising its possible, should I do it?

Cheers for your advice.

 

[icenutter]

Another very important difference is that the 110 bhp engine has a variable geometry turbo (a VT15). I think it they also have a proper oil cooler and different piston rings, but don't quote me on that.

If you simply change the nozzles for 110 bhp ones then the engine will smoke although this might be mitigated by adjusting the AGR fraction. You can get uprated nozzles that have the 'bigger hole' of the 110 nozzle, but an improved spray pattern which gives more power without much smoke. YMMV etc.

Diesel engines run at a much wider AFR than petrol engines, so in simple terms you only need to add the amount of fuel needed to produce the required power. So if you need 25bhp to maintain your speed then you need only add 25bhp worth of fuel. Hence tuning a diesel doesn't change fuel economy much (unless you drive like a lunatic in which case it will go down). This is a simplification by the way