Cord

Was just having a look and pricing up a re-circ dump valve, either MRT or Forge and came across a "MRT Hybrid Recirculating & Vent To Atmosphere Dump valve" So has anybody got any experience of them, why re-circ and VTA?

nom

Probably taken from the APS idea - recirc at low boost (to keep the meters & stuff happy, etc. as a normal re-circ does), then VTA from high boost, ie when the re-circ could potentially not be able to ditch the volume of air.
I think that's the plan, anyway

lucky_strike

Spot on - I nearly bought the MRT Hybrid valve for my 02 WRX but settled on the APS High Volume Twin Dump version eventually.

They recirc at low speeds and lower boost which maintains the airflow to the appropriate fuel/air sensors (so no lumpy idle) but at higher speeds/boost they will vent to atmosphere.

Very happy with mine, didn't want too much noise when it dumps the gases especially around town etc. but when I'm pushing hard I get the nice - brakes on the bus 'psshhhhht'.

I suspect it isn't as noisy as a pure VTA because even at full some will still be recirculated - but it is adjustable (the APS, I'm sure the MRT is as well?) so you can change the amount it VTA's and when.

Cord

Thanks for the info chaps, anybody else got one and gonna give me a review?