I have seen in a few MR2 engine bays, a small breather, looks like a small air filter. I bought one, a Ripspeed one and although I mainly bought it for cosmetic reasons (being totally honest) I am not exactly sure of where it goes. I believe there is little to no performance gains, just allows some better breathing, so marginally functional.

Can anybody tell me more about these, what they do, don't do, where exactly they need to be fitted etc?

Example pic below, PiperCross brand:

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They're pretty much for anywhere air goes in or out. Mostly on our engines that is the PCV breather or the idle speed control valve (ISCV). As far as I know, they're not really a noteable performance upgrade per say, rather they are a way to clean up unnecessary piping in the engine bay.

Cheers Quandry. I was thinking they are more aesthetic than functional but that is fine by me, I think they look cool and any visual improvement / tidying is good.

I was thinking of putting those on my crankcase breather on the V6, but decided against it as the will catch the oil coming out the breather, eventually get sodden and drop oil beneath them. I did use one on the ISCV on the air intake on the V6 though.

If your looking for something funky and functional, search ebay for oil catch cans and pipe it up using braided hoses. They will catch the blown off oil, and you can drain the unit as well.

slipsliderg wrote:
I was thinking of putting those on my crankcase breather on the V6, but decided against it as the will catch the oil coming out the breather, eventually get sodden and drop oil beneath them. I did use one on the ISCV on the air intake on the V6 though.

If your looking for something funky and functional, search ebay for oil catch cans and pipe it up using braided hoses. They will catch the blown off oil, and you can drain the unit as well.

I've seen breathers on top of oil catch cans. I guess the theory is that the can will catch the oil and the breather will then let the crankcase gases out to atmosphere.

But in practice, I'd say the catch can will catch oil but eventually, so too, will the breather.

Spidey is right I missed that in my post.

Thanks guys, ill fit it to the idle speed CV. I was thinking of fitting an oil catch can in the future too, don't think id bother fitting a breather to that though, as you say, would just get destroyed in oil eventually.

You have a stock oil catch can already. Although, I take it you're after a nicer one for dressing up the engine bay.

Which reminds me - I might replace all my vacuum hoses.

Berk Technology do a gen3 "set".

But I'd say you could buy a generic pack and you'd get most / if not all the hoses sizes you need.

Yeah you are right Spidey, I have seen some nice aftermarket ones which would look great.

Was thinking of vacuum hoses too. Before doing any of this though, it needs a good clean up. Would love to paint the head cover too!