What DV to buy? - RS2

[s2-1.5bar]

I got 007 Forge with Red spring-and mine stil does whoosh and shatering. I think u still better have a DV fitted-healther for your turbo.

[Jay]

It won't destroy the engine. Can't remeber where I read about vent-to-atmosphere DVs and MAFs but I am sure someone here can comment. Vent to atmos will be no more improvement than a standard recirculating one in terms of response at gearchange. Tom (Audiman) had a vent to atmos on his S2 but then changed for a recirculating type. What were the issues you had Tom?

I'm running a non recirc dump valve and my car performs better with that than a recirc type (both bailey sport items) but I am considering running 2 as one is not dumping down quick enough on full boost in the high gears, I'll put the second by the throttle body (this is the correct place for them any way)

There is no prob with non recirc type on a maf type car, its the old K/KE-jetronic where you lose metered air and the car stalls all the time. eg Ur quattros and escort turbos (did I just mention those? )

Piston type are best as they are more robust.

Jay

[bcdesigns]

I know that mine have 2piston, and the tuner tell me that its great, but after a read this infos, i think 007 its better, because put the air into the intake again, but in the rigth order!

[DAVIDP20V]

I am confused ! When you dump that air to atmosphere, you get your tschhh noise. yep ?
But will this not make the car run rich ? as your maf is expecting this load of air back into the intake system ? so unless you have a remap to tell the car its not getting the air, it would run rich with a lack of oxygen.

Is that very wrong ? Please tell me as I dont know much about engines.

[audiman]

Will, your turbo wont last very long as it isnt actually wastegate chatter, its the air rushing backwards through the turbo making it stall, in severe cases the blades just shatter.

[jogi730]

Will, your turbo wont last very long as it isnt actually wastegate chatter, its the air rushing backwards through the turbo making it stall, in severe cases the blades just shatter.

Tom, I had this chat with Mark at the London meet. I have no DV at all! Guy who built my engine said there is no need. Mark explained as you say above, but all seems to work. All so confusing.... will try and find out his reasoning.
Chris

[WabTheKing]

Will, your turbo wont last very long as it isnt actually wastegate chatter, its the air rushing backwards through the turbo making it stall, in severe cases the blades just shatter.

new turbo so best put it back on! only reason i took my old one off was beacuse the T piece split on the rubber hose, so chopped the middle bit out and replaced it with a steel T piece which was a larger diameter than my DV hence why i pluged it but never got round to sorting anything permanet for it, MOT up on the 28th so can sort it which the rest of the jobs on the list!

[Jamo]

Tom, I had this chat with Mark at the London meet. I have no DV at all! Guy who built my engine said there is no need. Mark explained as you say above, but all seems to work. All so confusing.... will try and find out his reasoning.
Chris

You can run without a dump valve, it's not a necessity, Cosworth and Renault 5 run like this BUT it is there to protect the turbo from back pressure and damaging the blades. Personally for the price of a turbo vs price of a dump valve i know which i'd prefer.

[Jay]

Will, your turbo wont last very long as it isnt actually wastegate chatter, its the air rushing backwards through the turbo making it stall, in severe cases the blades just shatter.

Rushing air backwards?? I know on mine its high pressure air going out! confirmed with pressure guage thats why i know it requires 2.

Dumping air in after the MAF causes reversal and the MAF will read this so neither are great for mixture but dont effect it as much as to cause a prob.

Dont run without, on a standard turbo not to much of a prob but on some of our dustbin sized things- snap-clatter you also get a slight MPG increase/ save the hoses and get a nice noise to scare grannies with

Jay

[WabTheKing]

Rushing air backwards?? I know on mine its high pressure air going out! confirmed with pressure guage thats why i know it requires 2.

Dumping air in after the MAF causes reversal and the MAF will read this so neither are great for mixture but dont effect it as much as to cause a prob.

Dont run without, on a standard turbo not to much of a prob but on some of our dustbin sized things- snap-clatter you also get a slight MPG increase/ save the hoses and get a nice noise to scare grannies with

Jay

what if you have your MAF on the pressure side?

[Jay]

what if you have your MAF on the pressure side?

Not a problem if anything better as it will see no reversion or loss from the DV

Jay