classic Subaru Si

If they are good enough for Andy F, then that will do me!!

scoobyhoobydoo

Not seen fuelling changes on a UK 2002 WRX between the OEM and V.T.A. This is using a laptop connected to ECU and driving over a distance of 25 miles at different speeds with the OEM and then with a V.T.A. same temps and roads, then checked again 1 & 4 weeks later.

But if you want "improved" reliability go for the standard recalculating valve as this is what the car was designed around, but that can be same warning for changing any part on a car away from standard.

Mikkel

You get a nice sound from the Forge recirc dump valve without sounding like the number 10 bus... give it a whirl.

Aaron1978

iTrader: (12)

he probably has it mapped in. tsl put a turbosmart vta on my gaffers old hawkeye sti because they said it would be better because of the high bhp around 530bhp at the time ,don't know how true it was but my gaffer didn't like the noise and would rather not have had it.

also prodrive don't use a dumpvalve/bov on their rally cars doesn't mean its good for your car, allthough some people on here have blanked it off!

Aaron

CHUNKY.MONKEY.

anyone

subaruturbo_18

If it was mapped in then it would not overfuel as the ECU would know the dump valve is their.

I personally don't think they cause to much damage when bolted on. Its the same or worse to fit a cone filter or decat etcetc without mapping.


Correct me if im wrong but the fuel differences with and without a VTA valve will be very minimal?

rbaz

iTrader: (1)

I have removed my VTA today and put a std valve on. WOW its a different car
Better tick over and as its more stable the oil pressure is higher at tick over, no exhaust banging and popping on over run gear changes are so much smoother the power is not like a switch I bet I can drive it much faster now without the wife kicking off
Will keep an eye out on the economy.
I would remove it
Oh and it doesn't sound like a bus now

RS_Matt

If it's not stalling or Shooting oil out keep the DV! Prevents lag, turbo blade damage and doesn't throw hot dirty expanding air back into the engine.

rbaz

iTrader: (1)

If anything mine is more responsive with the VTA off
Probably feels faster with the VTA because of the snatchy on off throttle response you get but its really not a nice feeling gives passengers whip lash unless you haven’t driven anything else quick before doesn't feel good.

wiley

iTrader: (63)

i really like my hks bov, hope it doesnt eff up my engine in any way. but i know quite a few ppl has it so i should be okay
wiley

Aaron1978

iTrader: (12)

thats the one i had car is much better without it tbh matey.

Aaron

masterbates1

I will take mine off and post out come.

Scoobyslammed

Spend your money on a decent roller bearing turbo and ditch the dump valve. . . Dump valves sound poo

masterbates1

Takin off will let know of MPG and any response in the right foot.

WRX Blues

That's a shame then

masterbates1

My car was mapped to 1.3 bar, takin dump valve off car boostin 1 bar. Will be swopin back tom.

rbaz

iTrader: (1)

Did you replace it with an OE valve or just take it off altogether?
Have just been out in mine again and the difference really is unbelievable its so smooth between gear changes and better throttle response the boost levels are exactly the same.

adam6900

iTrader: (4)

Sounds like some people are forgeting they need a TWIN piston Dumpvalve not a Diafram or single piston one! if its not a twin piston d/v it Will screw the tickover up totaly as the AFM does not see all the air going in the engine!

masterbates1

Replaced with standard OE, the car is as you state more smooth between gear changes. Throttle response was seemed the same, will leave on till full tank as gone.
Do you guys have any links to these twin OE valve thingi mi bobs, its my00
cheers

masterbates1

Been out in car again, full boost 1.3 bar. Must have been cos standard OE as been sat there borded and forgot how to work. But all is good nice and smooth

cos-ram

Hi all,

i myself run an atmospheric dump valve on my blobeye although they do seem to run quicker without them, i also ran one on an rs500 cosworth which again ran quicker without, but saying that in the mid 90's toyota were disqualified from numerous rallys for running atmospheric dump valves as it gave the cars an unfair advantage when it came to lag, in other words they help your turbo to spool up quicker meaning less lag. i think personally to benefit you'd have to run flat out gear changes to notice any difference either way...

run what you think's best imho

cheers

cos-ram

sorry forgot to mention that the idea of a dump valve is to stop compressor stall in the turbo, but either way it would make no oddds to a scooby as they have one fitted as std albeit a recirculating one.

rbaz

iTrader: (1)

Most of us know what a dump valve does. The recirc one does just that reusing the air so when you fit a VTA and dump it to the atmosphere the fuelling is all wrong as it would have been mapped to be recirculated. Makes a huge difference.

Toyota where banned from rallying for using a device that opened the restrictor on the turbo inlet allowing much more power not for using a VTA dump valve

cos-ram

we must be talking differnent rallies here because it was definatley for using dump valves, to mention one was the car of miki biasion on a celica with the lift up lights (dont know model) ,

anyway what does it matter............people will run them and some wont

cheers