Mr.M

I have a forge VTA DV fitted to my MY01. I noticed tonight that the DV is leaking pressure quite alot during normal driving conditions.

Anybody else suffered this problem?

Bob Rawle

You should not use the VTA, use the recirc version.

Mr.M

Why?

Dark Blue Mark

Bob,

Interested on your views on this (MY99) as I would like one but am aware of the fuelling issues. Is there a good D/V to get? I notice the APS one connects back to the air box, while some is vented. Does the Forge recirc make any noises?

Ta,

MB

Turbo_Steve

VTA dumpvalve causes ECU's meaused air intake to be innaccurate, as charge is vented under bonnet rather than back into the air intake (after the fuel meter). This can cause rough idle, rich running and (rarely) stalling after hard driving.

Saying all that, VTA's sound cool, and you can get your ECU remapped to allow for one being fitted.

Bob Rawle

As said, VTA's confuse the maf big tme, the APS combo bov is not a good option but that's my experiences with several of them ... basically all the ones I've come across leak past the piston and restrict turbo spool. The Forge recirc is the best option especially if you are using your maf (std ecu). (IMHO of course but thats what I keep going back to)

Remapping the std ecu will not cure the problems that a VTA gives, I've seen enough of em to be able to say that. If the maf is not used and an aftermarket map based ecu used instead then yes it can be mapped to take account of it but thats an expensive bov if you end up having to replace or remap your ecu just to get "woosh". (not that I would complain of course)

cheers

bob

Dark Blue Mark

Thanks both,

Bob, does your re-circ give any mild whoosh? If not, why fit one aprt from capacity? Does anyone know what volume / pressure the standard one is good for?

MB

Turbo_Steve

Not arguing with you Bob, cos I know jack fish about anything, but as I understood it, the ECU could be persuaded to 'forget' about the re-circulated charge, and run purely from the MAF? I am probably wrong about this, but I had assumed it was how the WRC car worked (JECs ECU, No dump valve at all?) but just looking at that statement, I can see that doesn't make sense as with no BOV at all, the charge still remains within the system. Hmm.

On less shaky ground () and with a good deal less theory, I have recently invested in a new dumpvalve (Forge Re-Circ, now you should mention it!!!) and have a modified airbox to get a better soundtrack. Does this mean I will hear a nice "Shhhtftftftftft" on a hard throttled lift-off?

I don't want it loud enough to draw any attention, just so that it annoys R5 GT Turbos.

Dark Blue Mark

Come on, someone must be able to tell me what it sounds like!

MB

TBMeech

DBM,

I have a Forge re-circ on my MY99 STI-V (Supplied by Bob), It does make wooooshing noises, the woosh is not in your face like VTA's which is fine for me, its plenty loud enough imho, it also chatters on a trailing throttle from 1/2 bar of boost....

Dark Blue Mark

Thanks for that,

For many months I have been asking this question! I will get one as the VTA was a little tasty for my liking...

MB