Hi guys n gals, what would be the pro's and cons of removing the dump valve completly. I have read on a few other car specs that they have been removed iv got an RB 5 version 6 running standard map just got a full decat with bell mouth. Cheers Paul.

 

Depending on turbo really. Newer VF's are stronger, TD's are good and strong.
Pros, sounds good.
Cons, turbines are forced the other way and stall. Turbo life is shortened. And as it stalls slightly, might take a little bit longer to pick up again.

Up to you really.

 

Ive just done this to mine (vf34). Sounds great and if you change gear quick you dont have to wait for tubo to pick up cos its already there.

 

im not sure about this but i read on he web that it is a misconception that it spins the blades backwards as there is too much anertia in the blades but it does slow them down and cause that flutter sounds as the air goes back in this is not a forced oppinion im just sharing what i have read and would be happy if someone could verify or give reason to another theory thanks

on another note my97 catalunya does the flutter noise but i have some sort of dump valve sitting just under my intercooler on the righ hand side any ideas? maybe needs wd40'd or slackened maybe?????

 

mine chatters on low boost n half throttle sort of thing then dumps on full boost n hard on throttle. ive got a HKS SSQV dump valve.

 

so what sort of pressure is being generated between throttle flap and turbo if you don't have a dump valve?

 

Basically whatever pressure is in the system when you back off will be felt directly back on the compressor wheel. So if you back off @ 1.5 Bar most of the 1.5 Bar will push back against the compressor as this is the only way for it to go.

Cheers Iain

 

Its mad, as I have chatter, as put in stronger spring, but when reading what people have put etc, it starts me thinking, and get worried.

 

I have set my Forge DV up so that it opens @ around 0.3 bar, this means that under light boost I get a chatter and on boost above 0.3 bar I get the dump from the DV and the chatter from the compressor. By having the DV set like this seems to get the best of both worlds you get better boost hold due to the aid of the stonger spring, you are not dumping a huge volume of air under pressure back through the compressor and most interesting of all it seems to reduce/stop the rich state popping and banging that you would normally get with a DV that dumps all the air to atmosphere.


Cheers Iain

 

Think il get an original put on then getting a bit tired of the hks noise but dont want to cause problems long term

 

I have a TD05 18G and as prev mentioned, the TD series are strong turbos which can put up with the compression coming back thru the blades. I've also heard that with the earlier VF series turbos its not adviseable to remove the dump valve.

The noise you get without the dump valve is amazing - I love it!!!