What are the benefits/problems of running without a dump valve on an MY97 UK turbo. Also what size are the pipes to the dumpvalve in order to get bungs for them

 

No Dump Valve?= No boost
block hole= knackered turbo

 

thats not what i`ve been told on other forums, I know of people that have run without them for a while but i`m trying to get more information.

Besides early cossies and RS turbo`s didn`t have them fitted as standard

 

Well you need to think about what it does, its my understanding that under boost you create a pressure between the turbo and where the air is entering into the engine therefore compressing more air into the same space before it goes into the cylinder. When you take your foot off the gas the turbo stops compressing the air so you have positive pressure engine side and atomospheric pressure on the other side of the turbo. The dump valve releases this pressure. Without the dump vavle the pressurised air would flow back the wrong way through the turbo potentially putting a lot of stress on the blades and shafts. With a hole where the dump valve is the turbo would just be spinning up to blow air out of the hole. From this I'd have to agree with:
"No Dump Valve?= No boost
block hole= knackered turbo"

Don't know about the fords as I've never really been interested in them.

 

this is what i`ve been told so far:

You can run without a dumpvalve if you are running a bigger turbo ie one of the TD05 range as they have much stronger blades than the chocolate VF range.It does stall the turbo a lot more and will put added pressure on the compressor wheel but saying that ive had no problems at all with my 20G and ive been running with no dumpvalve for 5 or so months,but then again i only do about 3k miles a year.I wouldnt recommend it on a daily driver but if its a weekend toy then there will be no ill effects.Makes a nice chatter too also my mapper ran his with no dv for almost 2 years with no problems whatsoever,most of the big power imprezas dont run with a dumpvalve

 

you can get away with no dump valve if it is the TD series of turbo's ie TD04, TD05 etc but the IHI VF**'s are prone to going boom with no dump valve.

Stuart

 

thanks coulty, has an MY97 uk turbo got a td series turbo though?

 

The dump valve is a device to increase the life of the turbo through preventing turbo stall ( i.e slows very quick due to the throttle butterfly being closed ) and help reduce spool up time of the turbo in between gear changes ( excess boost pressure vented through dump valve to atmos or recirculation ) . Blocking off may give you that ' turbo chirp ' if running enought boost but will shorten the life of your turbo .

 

What a load of ****e?

Tiny,look here.

https://www.scoobynet.com/6291060-post23.html

Also a good example for no DV.

Chatter - Google Video

As for wear on certain turbos that summant thats never been looked into on here.

I'd like to see some proof as it would be interesting.

 

cheers mate

 

No worries.

 

A negative would be that the standard puts air back into the system to keep air/fuel ratio level or what ever the ratio is and a DV increases the fuel to make it run richer (useful for flamer kits :naughty: ) What would no DV do? Would you block off all pipes?

 

from what I understand yes i`d need to block off all the pipes that run through the dump valve

 

remind me not to buy any cars that you have modded

 

why dont you get the best of both worlds. get a tighter spring in your DV then at low boost you get your chatter and at high boost (where the damage happens) you get a psssssssssss noise??
just a thought

 

Remind me never to listen to you.

There is one that does that a Turbosmart IIRC.

TURBOSMART: MODEL-SPECIFIC BLOW-OFF VALVES

That only recircs or VTA,which is strange as I thought it done like you said.

Would be good tho if I could find it.

 

is that the adjustable one you mean? twist top to tighten the spring or something like that??

 

Yeah think so mate.

I remember now someone told me that recirc at low boost then VTA at higher IIRC.

 

ah that does sound right. not sure where iv seen it though. im looking for something around the same thing. ATM i have a forge VTA but i have uprated the spring so it only vents at high boost. wouldnt mind a complete Recirc though.

 

Re: that google vid... how do I get that noise?????? I want, I want!!!!!

 

just to get this back on topic ....are there any benefits to running no dump valve? Apart from the chatter......

i.e. does it have less lag?

 

Yes Tuts it does have less lag especially when using a FMIC. BOB'5 on here runs his TD05-16g with no dump valve and has managed some great times on the 1/4 mile. Yes it does put more wear on the turbo but the rebuild kit is cheap enough and easy enough to do if you are mechanically minded and really doesn't need to be done that often. Just think how much of your driving you are actually on boost!

 

so thats how the rally cars have that noise

is there any problems when day to day driving or mainly when driven hard. how would u do this when the dump valve bolts to the intercooler

steve

 

They also have Antilag mate.

 

http://www.ashlyn.plus.com/video/fuzzathaynes2.wmv

Mine hasn't had a dump valve since I modified it 3 years ago.
However it is an aftermarket turbo.


Andy

 

That is what it's all about.

 

I also run with no dumpvalve and have done for the last 4 or 5 months.Seems to drive much smoother than it did before but maybe thats just a psycological thing ive certainly had no problems with the car since it was relegated to the boot

 

BUT.. how easy is it for me to do to a MY03 wrx??? remap??, crap driveabilty??do i have to drive like miss daisy so not to damage the turbo(TD04)

steve.

p.s cant afford the anti-lag and the subsequent replace,ment of exhaust parts!!!!!

 

anyone???

steve

 

nobody want to help poor little old me!!!!!! ;-)

so do i put a blanking plate onto the intercooler, bung the 25mm hose(already done as have VTA) and bung the small hose?????

any help answer will be appriciated(sp)
and if this is done is it been when i upgrade the turbo to stay away from ihi and get either a hybrid or a TD05

thanks

steve