Why can't you get performance cams for diesels?

obi_waynne

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They are not tuned as much as petrol engines so there is less of a market for them but there are also technical reasons why you can't get diesel performance cams.

Diesel engines are quite low revving, so a performance cam will not provide as much lift as it would on a petrol.

On petrol engines the gains tend to come in at 4000-8000 rpm, and most diesel engines just don't hit this level or are just about to redline.

The principles behind a compression ignition engine, as apposed to a spark ignition engine are very different when it comes to tuning them, so things that work well on a petrol do not always work on a diesel.

Interestingly a remap on a diesel nearly always gives better fuel economy, whereas on a petrol engine this is very unlikely to happen.

That's not to say there is no benefit from a slightly longer intake/exhaust duration, but most performance diesel engines out there are designed to a pretty high standard.
 
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