guys, i got an aluminium box on the bulkhead, under the intercooler and directly above the bellhousing.. its got one black pipe goin into the top, and three pipes coming out the n/s. one pipe goes to the n/s head, the one in the top goes above g/box, but isnt attached to anything.. what is this box? is it some kind of breather?

the car is a my98 uk 2000, cheers

andy

 

Aftermarket ally oil catchcan/breather hose system.

The 3 returns in the side are routed from all the parts of the engine where it used to breathe oil vapour through them. The one on top is just vented to atmosphere, so ISN'T a lossless system, and so the oil vapour gets jettisoned (therefore check oil levels on a more regular basis).

Catchcans are great - means you don't have oil vapour being reintroduced into the intake i.e. it would otherwise lower the octane rating of the fuel after mixing with it in the inlet manifold, etc.

So, assuming it has been mapped after the catchcan intstall, (no doubt in harness with other mods), then you should have gained a bit more power - everything else being equal. Even if it hasn't been remapped, then taking the oil vapour out of the intake will make the mixture 'safer' (due to the increased octane), and therefore less prone to any potential detonation.

 

joz8968, you are a star! thankyou for that reply... fantastic!