15 replies to this topic

[dannynewport]

Thorney say...

Why no dump valves? 


Simple again, the VX220 Turbo's Turbocharger has an internal re-circulation valve. Replacing this with an External Dump Valve or VTA Dump Valve drops power and can cause irregular engine firing. If you want to sound like a WRC car then buy a Subaru.

Regal list them for a VX so just a simple curiosity question...Why do they sell them for VX220 Turbo? Or is it simply as the recent poll says...Regal are crap?
Is it worth getting one or not?

Edited by dannynewport, 28 June 2009 - 08:54 PM.

[VIX]

I can't see it listed for the VX220T. Link?

[danger7]

Hi, The KKK does have a recirc, so a dump valve is not required and would reduce power. I fitted a blowoff valve which is more efficient but I changed turbocharger to a Garrett G2871RS, which needs a stand alone unit, no recirc system. Cheers Ian

[dannynewport]

I can't see it listed for the VX220T. Link?

Read again!! My mistake...sorry!

[Duncan VXR]

I have an external recirc fitted Keep meaning to do some back to back tests between this and the std recirc and also the new forge recirc on the turbo DG Not sure I have lost any power, dumps better than std setup but possibly a tiny bit more lag between gear change. This could also be the extra porting and flowing of the turbo though?

[slindborg]

a DV shouldnt lose you power.... the only time it "could" is if the diaphragm/spring is fcuked and it leaks. it only dumps when you lift off, ie when you are off the power. On some newer (and I mean NEW, not 20 year old LET stuff) ecu's they wont behave right if you dump to atmosphere compared to using a recirc.

[Duncan VXR]

Will 2nd that Different dv setups can effect gear change tmes though. Which in turn does effect performance but it is not much, certainly nothing to worry about I would rather get rid of the air when needed and not dump it in all directions back to the turbo blades (oe) Dg

[slindborg]

recirc helps spool times though... just recircs dont tend to be high flowers to prevent stalling. bit like a lighter flywheel, wont add power but changes the way the engine behaves.

[Duncan VXR]

A recent test on a nissan gtir with no dv, atos dv, recirc and std did back to back tests with racelogic and results were interesting. Was slower on the recirc, but on VAG setup was quicker, really does seem to be effected by turbo setup Keep meaning to do some back to back test with std, forge piston recirc, ext recirc and none If only I had time

[siztenboots]

A recent test on a nissan gtir with no dv, atos dv, recirc and std did back to back tests with racelogic and results were interesting.

Was slower on the recirc, but on VAG setup was quicker, really does seem to be effected by turbo setup

Keep meaning to do some back to back test with std, forge piston recirc, ext recirc and none

If only I had time

any further ideas about the recirc valve , I am thinking about replacing mine with Forge Motorsport , even though OE is only a few months old

[Steve B]

A recent test on a nissan gtir with no dv, atos dv, recirc and std did back to back tests with racelogic and results were interesting.

Was slower on the recirc, but on VAG setup was quicker, really does seem to be effected by turbo setup

Keep meaning to do some back to back test with std, forge piston recirc, ext recirc and none

If only I had time

I had a Mistu EVO stock re-circ on my MX5 and changed it to a Forge filtered piston VTA to simplify pipework, I noticed absolutely no change to performance or the way the car drives, but then its on a standalone ECU and the AFM's long been ditched for a MAP sensor. I've always read never to use a VTA with any air metering setup as you loose the metered air and so you end up with a differetn amount of air entering your engine than the ECU thinks there is.

[Nev]

Danny, I am not sure it's really worth installing a dump or bypass valve in your car, as the turbo surge issue is fairly negligable at your state of tune. I suspect that the integral bypass valve on the turbo is sufficient for 285 BHP and 14 PSI.

However, if you want to get one for the future mods, it probably best to get a bypass valve and return the pressurised air to the inlet pipe (post MAF). Forge motorsport do one:

LINK

BTW, dumping the air back into the inlet pipe will also have the added benefit of being a lot quieter than venting to atmosphere.

Edited by Nev, 27 October 2009 - 03:18 PM.

[Duncan VXR]

http://www.forgemoto...product=FMDVVXR

As per fitted to Cheeky car - an improvement over std but you could argue about cost - 1 thing is clear refurbing / changing etc is 100 times easier as you do not need to remove the 3 bolts as per normal setup

I found uprating the spring with oe recirc setup gave a similar improvement - the forge one runs a slightly stronger spring also

Using a lot larger ext recirc in mine and does a similar job but seems to vent the boost better when fully open (much larger piston)

It is not a single fix to the chatter though guys on stg 4 but does help

Was going to offer a group buy on the recircs at forge but not sure how much interest there would be?

DG

[cnrandall]

I use a recirc valve from an evo 8... great OEM quality and loads available second hand for cheap money :-)

[dannynewport]

Danny, I am not sure it's really worth installing a dump or bypass valve in your car, as the turbo surge issue is fairly negligable at your state of tune. I suspect that the integral bypass valve on the turbo is sufficient for 285 BHP and 14 PSI.

However, if you want to get one for the future mods, it probably best to get a bypass valve and return the pressurised air to the inlet pipe (post MAF). Forge motorsport do one:

LINK

BTW, dumping the air back into the inlet pipe will also have the added benefit of being a lot quieter than venting to atmosphere.

I know Nev,this was an old post of mine that has been brought back up. I only had the car a few weeks when I posted the original post & knew absoloutely fcuk all about VX's,my car was a totally std example back then.

Edited by dannynewport, 27 October 2009 - 04:26 PM.

[Steve B]

I use a recirc valve from an evo 8... great OEM quality and loads available second hand for cheap money :-)

I've an EVO one sat in my garage, not sure off which generation EVO. Came as part of my BEGi turbo kit for my MX5.