MBC fuel economy improvement= Total Rumour!

[andydckent]

Well I just want to quash the rumour thats been going about that fitting a MBC and upping the boost on the auto's actually improves fuel consumption as this is clearly not the case!

After fitting one to my VR-4 and setting the boost to 0.9 Bar I have had consistently lower mpg than before.

Mind you, my foot seems to have become planted to the floor at all times!

[Davezj]

In theory, upping the boost should not make any difference to you mpg, if you only use the same amount of boost as before (e.g. 0.55bar), all you are doing is adding the potential of more boost, if you don't use it, it will not affect fuel economy.

but this is never the case in the real world. As whats the point in adding the potential of extra boost and not using it, it would be foolish. and with extra boost comes extra fuel, (you don't get out for nout in this world) but it also adds more smiles per mile and i know that is what everyone wants.

if you have the potential of more boost there is now way on earth that yoou are going to be able to control the max boost used to 0.55bar, it is just not going to happen. So you will end up using more fuel.

you could fit a solenoid valve to switch in the extra boost when you want it. connected to a swith on the dash. this is what i am going to anyway.

[bradc]

What he said ^

[rees]

would a ebc automatically do that ?

[aboo]

Adding more boost & not useing it all the time is just crazy talk IMO

[Nick Mann]

PMSL!

Always the case!

I do have to point out with my serious head on that upping boost will never help fuel consumption - you need fuel control to do that, not extra air!

[elnevio]

Extra boost?

Use it! Don't lose it!!

[Turbo_Steve]

It can improve your economy dependant on how you use the vehicle: heavy acceleration to cruise will mean consistently less acceleration to reach the same target speed. As long as the ECU isn't doing mental compensation fuelling (which in a VR4 it probably is) you WILL use less fuel overall. This is why lorries keep getting more and more powerful: they have a fixed target speed, and the more power they have, the less time the engine spends at full throttle, and consequently the less fuel is used.