16T vs 19T

[doorman]

O-K then, where did I go wrong?

[roy chu1]

Hi Alastair,

I am considering a new turbo.

Do they do a hybrid 16t? I will make some calles and find out.

Roy

[Al115]

Do you have an 850 or V70?

If an 850 - Yes - if a V70 - not as far as I am aware, unless you have one custom-made.


Alastair
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http://www.volvoclub.org.uk/photopos...357v70-sig.jpg

[sholtby]

Does fuel economy fall significantly with a bigger turbo?

Simon

Yes and No!!! You see, for the same level of boost, a larger turbo tends to be more efficient, which means that the air it compresses is slightly cooler and therefore more dense. The result is slightly more fuel required during closed loop operation in order to maintain the AFR at part throttle. However, at full throttle the fueling doesn't change since you are running open loop from the fuel mapping, so the result is simply a slightly leaner burn, and no effect on fuel economy.

The flip side is that an less efficient turbo can result in the ECU overfueling more often, for safety, since the intake temps will rise faster with the smaller less efficient turbo.

But this also depends on how the MAF readings change with the different turbo, so the difference in fuel consumption will probably be negligable.

Now I've probably confused the issue completely!!!! :)

Adam.

[sholtby]

Thanks Adam. I was thinking that with a larger turbo and increased lag you would be spending more time higher up the rev range and ecomomy would suffer because of this. I take on board your comments though.

Simon