Dump valve with FMIC question.
 

Car is a v3 STI with an SC42 twin scroll conversion.
Currently running with dump valve delete,I was told the turbo was strong enough to run without a dump/recirc valve but I'm not to keen on the sound it makes,i know it stalls the turbo to get this noise but I very much doubt it improves on performance(probably the opposite tbh?)
Don't really like dump valves either,although I do have a bailys one knocking around somewhere which I might fit for now.
My question is,what boost levels will the standard recirc valve be good for? Car is approx 400bhp. Running 1.6bar

Cheers
Rich

Forget the horrible Baileys dump valve mate, stop torturing your turbo and get a Forge recirc valve or similar.

I know what you're saying Paben,the baileys came off my old car,hated the sound and the car ran terrible. I was just thinking of sticking it on for now until I get a recirc sorted.
Maybe the DV delete isn't going to damage the turbo but I don't want to take the risk for the sake of a noise that sounds like it belongs on the starship enterprise.

Also forgot to mention I'm running mafless set up.

Done a bit of research and looks like the oem recirc is only good for around 1.4bar.
Looks like the baileys will be going on for now.
Is anyone using one of these?... http://www.ebay.co.uk/itm/2013706310...072%26_rdc%3D1

Hi there

As above have look on Forge recirc or their DV,we've run Forge for several months without the issue.

If you running SC42 then you should be OK to run DVless,as on most Garrett ball bearing based turbo,we're run MDX321T without for several m9nths without the single issue,you shouldn't be concerned about this

Stock recirc should be OK too for beyond 1.4bar,I know few guys who run stock recirc at 1.65bar for sevral months without the single issue,you can have sligt issue if you wil be running higher boost,but this can be sorted by running stiffer spring,which should helps.

Personally we always running on Garrett based turbos dvless,noise is not what people love or like,but we like just induction noise

Hope this helps

Thanks,Jura

Cheers Jura This puts my mind at ease knowing I won't be damaging the turbo :)
I may just keep it as it is,the noise is kind of growing on me.
Does the fact that this stalls the turbo not lose any performance?
Car was hitting 1bar at 5000RPM and 1.6bar at 6200RPM,I've made some small changes to the map and now hitting 1bar at 4200RPM but would like to get it spooling a bit faster if possible?

Cheers
Rich

Hi Rich

What I know about the Garrett turbo or ball bearing turbos they should be OK running DVless,what can kill turbo is aggressive ALS or when you are using something like is foam air filter like is HKS,I've got few pictures of Precission turbo which has run HKS filter for 6 months and with no DV,turbine has been been damaged,CHRA has been OK,just friend replaced the turbine and now he using RCM filter and after 8 months,turbine is like new

Agree that noise is very nice and can grow on you.

If you will loose performance with running dvless,not sure,nobody that tested or tried to compare,in my view you can loose a bit,but nothing as 500-1000rpm,I would suspect you can loose,but hard to say,on mafless setup you shouldn't see any difference as on MAF based ECU where DV can cause overfueling and yours performance can suffer.

What I read and know about the Bailey DV they have weak spring and they can leak,if you want to use Bailey DV then please check seals,gasket and spring and I would fit stiffer spring.

Yours earlier attempt,hitting 1bar at 5000rpm I would say its late and I would say its bit poor,yours later attempt 4200rpm is OK,when you are hitting full boost(1.4bar)?

Here is good link,please have look on this
http://forums.nasioc.com/forums/showthread.php?t=2033940

Hope this helps

Thanks,Jura

I ran an MD321T for a couple of months dvless. but never really liked the noise it made. When the turbo impeller disintegrated it was sucked into the engine in a flash, certainly before I realised what was happening. By the time I'd declutched and coasted to a stop it was end of engine.

It might not have been caused by running dvless but I'd never risk it again.

Thank you Jura the lean spool link you sent is a good read :)
I'm hitting My full boost(1.6bar) at 5500RPM so I'm defiantly heading in the right direction.
I don't want to make too many changes as my last AFR gauge got stolen so need to get another before I look at leaning out the fuel map. And need to set up my detcans.
The main reason for me making changes to the map was that I was logging loads of knock events(12 in a 2 miles trip) the IAM did stay at 16 so not too worried but FLIC was pulling the timing,I've taken out a few degrees timing in the knock areas and now not getting any knock(want to keep thing pretty safe)
Car is running a 2 port BCS and I have a scoobyworx 3 port to fit so this should help boost contol a bit better.
@Paben,,that's a nightmare and not surprised you don't want to run DV delete after that experience :(

Cheers
Rich