is it benificial to run no dump valve all opinions appreciated cheers

 

In my opinion there is a reason why the manufacurers fit a dump valve. If they did nothing they wouldn't fit them, so personally I would always have a dump valve.

 

All Scoobs have a DV as standard, a recirc one which doesn't make a silly noise. The whole intake and turbo system is set up to work perfectly with it, giving a smooth power delivery along with reliability. Fitting a VTA DV instead can ruin that smooth running, risk reliability and make the engine run like a dog, whilst giving no performance benefit whatsoever. Many people perceive the sudden shut off of boost and the resultant surge of boost these create as attaining more power, but this is not what is happening and your car is much better running smoothly with the OE items unless you modify to a boost level which could split the diaphragm, although the later new-age recirc DV's were much stronger making this no issue. If you change to a MAF-less intake with suitable ECU, possibly with a FMIC, you can run without a DV at all, but otherwise, stick with the OE item and spunk the cash on suspension and chassis mods which will make your car both faster and safer, although they won't give you any power gains to brag about.

 

The other option you have is a dual vent dump valve. These recirculate the gases at low revs and vent to atmosphere at high revs. Personally I use an APS one and it's awesome.

 

When I bought my car it had a VTA on it, and was rough as a raccoon. I then blanked it off, and ran DV-less, and it was a lot smoother. (I've never experienced a recirc to be honest).

Now I'm running bigger power, and am still DV-less and think it's great.

 

And the noise is better with no DV.

 

cheers guys any1 else?

 

removed today and like the noise also seems to have cured my overboosting/fuel cut problem well chuffed

 

I'll get rid of mine but best mapped for optimum performance

 

It is indeed

Run with a DV if on MAF based system else it will run very jerky.

On a proper ecu it is fine and dandy