I have a reasonable understanding of how the turbo engine of the Impreza works. I know that it has a re-cerc valve and that the general consensus is that dump or blow off valves give no improvement in performance.

But if this is the case, why do the WRC team use them? Is it due to large differences in the construction of the engine or are we missing something?

P.S. Lewis, feel free to drop in your usual dump valve crap valve comments blar blar blar

 

I didn't think wrc teams used them?

 

yes they make your car run rich,ruin your maf and 02 sensor

 

I think most add them for effect rather than purpose these days.

Lewis is banned at the mo

Had an HKS SSQ on my bugeye, and got to admit I did like the sound.

 

They help you blow your turbo quicker (friend with S3 has).
I wouldn't fit one, it's just for noise!

 

https://www.scoobynet.com/scoobynet-...mp-valves.html

Ian,

Here's some sensible replies. Do a trawl in Search and you'll see what I mean. I had one on my old Classic, OK for a few weeks but got bored of old grans filling their bags as you drive around town..............eeeewwww!

 

Yes.......they go psstttttt!!!!!

 

A vent to atmosphere dumpvalve ruins the drivability of the impreza.
I have tried one on an sti4 and my99 uk turbo. Both cars became very 'jumpy', when applying any throttle.

You just can't beat a good recirculating dv.

 

Fit a Turbosmart dual port if you want a dump valve, it recircs while pottering round but also vents to atmosphere when pushing it a bit. No issues with the ecu and fuelling. Nice noise at full chat but can be silent when pottering around. No turbo probs either.
If dump valves are as bad as everyone says, how come nearly all the subaru specialists sell them
I think its more down to personal preference, I have had one on all my turbo cars, going all the way back to R5s in the early 90s, cant say any of them had major probs caused by vta dump valves.
I think most people who recommend not having them think they are chavy, but really Subarus arent really discreet in anyway are they

 

mine gives me an extra 200bhp

 

agree with scoobystiv8 - i have a forge which recircs driving normally and only vta's when booting it. I love the sound and it's had no bad effects like some people mention

 

Another in agreement - I have a Scoobyclinic WRX Hybrid and love the Pshhhhtttttttt sound! Hasn't ruined drivability of the car but has ruined my ability as a driver - I always drive like a bus driver now to max out on the whooshes - at my age I should know better

 

dump valves dont ruin your car if you get one just make sure its the correct one for car,i have i bailey motorsport one fitted the trumpet one,and no problems,supposed to take the pressure off the turbo and make it last longer,also rally teams dont use them the sound what you here from the rally cars is the turbo boost pressure is changed so there is more pressure but there could be damage done like this but makes them faster.

 

R5's and old Escorts may indeed perform admirably with a VTA dumb valve,alas the humble Impreza equipped with it's mass airflow sensor as it is,will not and cannot

 

its good for getting people in convertibles out the way on dual carriageways!!!

 

What they do do is protect the blades in the turbo. Giving a standard turbo a much longer life.

 

I think you will find that a dual port or hybrid as most are recommending does overcome the MAF issue as it does both recircs and vta.

 

If you want one,get one

 

Noted on this post someone mentioned the Rally Boys.


Out of interest, any one know for sure what the SRT use dump valve wise??

Think this should be an inerstinf question.


Kind regards


Alan MaC

 

HELLO ALAN EH

 

Dump valves work if ur under say 30 years old lol

 

[QUOTE=mozzaITA;7217334]Dump valves work if ur under say 30 years old lol

mine works and its great,i am 31,and love it,blow my trumpet blow

 

for the records I also called a tuner before buying mine who mentioned even on an unmapped car fitting a model specific vta dump valve will not effect performance in a negative way - these tuners build and tune rally cars

 

....they also make money selling them

 

I am over 30 and so are most of the other owners near me, most of us have dump valves.




Your point is????????????????????????????????????

 

they don't sale them mate - they only tune cars. I am sure that VTA dump valves causing all sorts of problems is a myth. I think a few people have bought cheap ebay or non model specific units and have had bad experiences and put a lot of people off. If you like it, buy it - if you don't, don't buy one. Speak from experience I say and not what you read

 

OK, I will rephrase my question.

DUMP VALVE WISE,does anyone know what Solberg & the other Scooby Rally Team Members have on their SUBARU RALLY CARS??#

Regards.
Alan MaC

 

standard dump its due to the boost pressure upped

 

Subaru WRC cars have no dump valve.

Little point, when they have antilag



I think the point in question is why mess with the original recirc valve; ain't broke don't fix. It's sole purpose is to stop the chattering noise and relive excess pressure when the throttle is shut. Performance wise it does nothing, the only thing it will do is reduce the sudden changes in thrust loading on the turbo - beneficial if you have a VF series turbo. Changing the orginal valve won't improve it, although if you fit the wrong one (like a vent to atmosphere type) you can introduce other problems - especially if its adjusted incorrectly (or not at all), which most aftermarket ones are. Hesitation and backfiring being the main known issues....although some people like to have popping and banging accaompanied by the odd flame spitting out the exhaust (depending on the system fitted), so to them its a good thing.

 

At the end of the day fitting a dump valve is the same as fitting bigger wheels, different exhausts, turbos, air filters, lights, spoilers etc.............
The phrase in the above post "if it aint broke dont fix it" is rubish, anything done to the cars as upgrades(mods) is basically away from the manufacturers spec and acording to the above post should be left standard.
Wouldnt life be boring