hi all,

I heard today that if you put on an aftermarket dumpvalve (like a bailey or forge) it actually prolongs the life of your turbo cos it gets rid of the unused gases better?????????????????????

is this true or was he ****ting me??????????????

sedge

 

vta dumpvalves can cause irratic idle, flat spots and poor fuel consumption.. as for extending turbo life, i dont think so!

 

ok thanks,

sedge

 

In theory, it is meant to keep turbo spinning so less lag etc.

Depends on your application.

 

How could I tell if my forge dv is VTA or recirc? Was on the car when I bought it and thinking it may be something to look at when trying to resolve my faulty idle

 

If it makes a whooosh, Psshhttt, shhhiiitttt noise its a VTA,lol. If if makes no noise when you let off the throttle its a re-circ,

 

+1. it dont matter wether its a vta or recirc they both dump the excess air pressure when you release the throttle, this is so that the turbo doesent stall which can cause a few probs and damage the turbo or at least thats the theory i was taught at college.

 

Gay. I love my chav whistle.

Think I'll try cleaning the iacv an maf first tho before I go Recirc again

 

i have never had any probs with vta dv's they do the same job as a recirc but instead of dumping the air back into the inlet tract they just vta, but a cheap crappy dv can cause probs as they tend to leak. Good quality dv's can and often do extend turbo life be it a recirc or vta because they reduce the risk of turbo stall which can stress and blow the turbo thats why most petrol turbo'd cars have a dv of some description fitted from manufacture.

 

The problem is, venting the air to the atmosphere rather than recirculating it as it confuses the maf reading as there is not as much air passed through the system as it thinks, hence over fuelling, Poor fuel consumption, Bad idle, etc.... The maf and the ecu know how much air has entered but not how much was VTA.

 

so i guess a recirc one is better

sedge

 

[quote=rogos;9712786]i have never had any probs with vta dv's they do the same job as a recirc but instead of dumping the air back into the inlet tract they just vta, quote]

I have fitted the following 5 vta dump valves to my cars over the last 2 years: baileys,forge,turbosmart,gfb,& blitz,and none of them perform better than the std recirculating valve. The problem you have is with a maf based car is the ecu monitors the air through the maf and takes into account this air for fuelling.When the excess air is vta the ecu compensates for this leading to overfuelling(popping & banging from the exhaust).
Where as a recirc valve feeds it back into the input of the turbo thus keeping the system pressurised. When you get back on the accelerator the vented system then needs to momentarily build up pressure again whilst the recirculating system doesn't, which explains why although my cars never felt any quicker with a vta/recirc valve fitted,it did feel a lot smoother through the gear changes with the std recirc valve fitted opposed to the vta valves.

 

+1

 

Yes mate.

 

Ditto for me. And to be honest i hate the sound of my forge VTA. It looks like a no brainer, recirc for me.

Are these simple to pipe back in and are there any makes worth avoiding.

Sorry to derail slightly.

 

Should be simple enough to do. The standard ones are as good as any unless you are running a huge turbo.......

 

[QUOTE=midnight;9712977]+1

I`ve had GFB, HKS, Perrin & Forge and still think that the car responds a lot better with the standard recirc, you live and learn thats why i went back to standard valve and airbox with a decent panel filter, tried HKS, Blitz & APS induction kits, Car feels much smoother to drive with the standard set up.

 

i am running a bailey dv + hks ind kit etc and have or have had no probs at all i have had the car on the rollers and everything is running spot bollock, fuel is spot on @ 10.1, idle is spot on 855 rpm smooth, very smooth to drive and very responsive, i dont know wether its luck or just the way i built my car? but i dont understand why everyone else has probs running with them cause i dont get any at all.

 

The last dv i had on my car was a blitz and as i said in my previous post it never gave me any running issues with exception to a slight overfuelling , so no not everyone does have a problem with them ,the issue is subaru fitted a recirc valve for a reason and the baileys dv's are prone to weak springs(especially the top one).How long have you had it fitted on your car? ,as some people have had them fitted for years before they start to play up,unlike a std recirc valve,which depending which o/e model you had was prone to splits/cracks after many years of abuse.

 

had my dv on the car for just over three years i also had one on my old car for five years and both have been good never had a failure yet but then again as with any component no doubt they do fail coz everything wears after time.