Nomad you have chose a very suitable nickname, as you have a very Nomadic approach to understanding concepts of the physics of a turbo.

Can any one elaborate on what I have said.

For years I have read articles by people who tune cars for a living so their hard earned experience and knowledge can be applied by myself.

Maybe you should read up .

The statement: -
"1. When you lift of the throttle the inlet butterfly closes, meaning the compressed air from the turbo charger is trapped and this causes the compressor wheel of the turbo to stall (or significantly slow down)

If the air is trapped it will slow the compressor wheel which will increase turbo lag

Its no the other way round

When you lift of throttle you are no longer on boost yes , where do you think the compressed air from the turbo goes????

Why do you think your Subaru has a dump valve in the first place???? Why do you think it vents the precious turbo boost????

Do you understand what a Butterfly is?? You seem to think it Flutters!!!
It’s not a real butterfly its a round piece of metal that opens and closing allowing compressed air either in the Inlet manifold or keeps it out.


"2. In the instance above the turbo bearings come under a lot of stress and over a period of time can wear causing turbo to seize”

There are a number of factors that can cause the turbo to seize e.g.
not leaving the car to run after a hard session.
Leaving a turbo timer on helps dissipate the heat from the turbo to the oil and prevents the hot oil turning to sludge and blocking the oil ways.

The turbo can also blow if you run to high boost,

If material comes in from the induction and hits the Thrust wheels blades the turbo bladed can shatter.

And yes you’re very intelligent comment about lack of oil causing the turbo to seize is also true, very intelligent of you

"If you want the sound of a dump valve, and still want to use the original Subaru set up.
Do the following, as I am going to do

fit an MRT inlet plenum pipe and a Blitz metal sus induction kit

1. The mrt inlet plenum pipe gives an increase in induction noise (so the Subaru dump valve can be heard better)
It also increases low end torque and significantly improves high RPM throttle response

2. The blitz dry sus metal induction kit, in my opinion is the best one on the market for the following reasons

1. Its free flow metal mesh design allows a unique induction ROAR to be heard as well as the Subaru dump valve.

2. Many filters on the market have oil on them or need oil,
this oil can go on the MAF sensor and burn. The result of this is the car will run very badly and if you’re running higher boost your going to be in trouble a few miles down the road."

The standard induction box on Subaru’s silences the induction roar and dump valve.
That’s one of its design requirements I suppose.

Have you ever heard a Blitz induction kit in action???

As for losing the perfectly good air box Subaru spent thousand on

Subaru have totally different criteria to that of a performance tuner company.
Just by changing the air box for a Blitz item you can add between 6-10 BHP and improve responsiveness .due to its flow rating and increased surface area

Performance air filters do have a hold air feed, so they DO get cold air from out side the car


As for the Inlet Plenum pipe and its advantages check out
www.jap-innovations.co.uk/ then products, then go to engine and ľ down the page is an article on the MRT inlet plenum pipe, and below that the Blitz sus induction kit.

Hope this has cleared things up, cant wait for your humble reply

Nomad
(Sees things through his ignorant eyes with a disrespectful Arrogance)

 

i asked HOW the pipe can significally improve throttle response and low down torque ? i am still asking that question, i am not saying it doesnt do what it says on the tin, perhaps someone has done a before and after test on a dyno ? cheers nomad

 

hatstand!!

 

""If you want the sound of a dump valve, and still want to use the original Subaru set up.
Do the following, as I am going to do

fit an MRT inlet plenum pipe and a Blitz metal sus induction kit"
you still havent mentioned about this ? do you vent the dumpvalve to air to produce the noise ? cheers nomad

 

Placebo effect.

 

Replace the airbox with any induction kit and you will hear the recirc DV in action Nomad, the airbox and resonator prior to it muffle the sound you would otherwise hear.
Regards
Chuck

 

This month's self importance award goes to............

 

Just added to say that on some cars a dump valve can increase lag and make the car slower. I take it as nomad you are nomad racing? A cosworth specialist yes? Well most cossies run faster without a dump valve and i think thats where hes coming from. I read this on this site on a post from AndyF aka cossie convert. If you think im wrong then ask him, surely he'll know more about it.

 

thanks for the posts, it may sound like im being very negative but i am seriously thinking about getting a scooby, so need to know the ins and outs of the performance mods, still not sure about certain things, like how would you hear the dump valve above the induction roar when you fit an induction kit ? currently we are working on a wolf whistle dump valve, its proving to be very difficult to do. i wonder if it would sell once we have sorted it, we did do a police whistle dumpvalve once, cheers nomad