screamer pipe

[S2central.net]

The farty noise at part throttle is not very nice and is what generally makes people put a silencer on - that and the complaints from neighbours, wildlife and 'da fuzz'.

[Audi-Porsche Avant RS2]

Hello, so N75 work also when for example from idle I accelerate with the car parked? Because I had hear mine work in this situation.
Thanks!
Alessio

[prj]

Oh yes, I am ordering one right now!!! Wait.... :-p

Dude, let the "how does Motronic work" manual and read carefully please. I said the wastegate opens not the n75.

And what do you think opens and closes the wastegate? N75. I recommend looking some at Paul's "Boost control essentials", it explains everything well.
Also, it's not about "how does Motronic work", it's more about "I don't like people talking out of their ***" sort of thing.

Actually Jamo said:

It will open anytime you boost over the spring pressure.

If it's a stock spring then 0.4 bar

And you replied:

Don't think so! It will open at 0.4 only if the n75 is disconnected. It will scream only when the ecu trust to controll boost.

And this is incorrect, it is as Jamo said, it will open and thus the pipe will make some noises any time you go over 0.4 bar. The area where the noise is at it's maximum depends on throttle position, current boost and target boost.

Have you ever considered the fact, that I might be speaking from experience?

[A80Avant]

i probably know less than both of you, but if read correctly Dmitri, you are saying on one instance that N75 controls the opening and closing of the wastegate, and then below that you are saying that the spring and exhaust gasses are controlling the opening and the closing of the wastegate. Now something does not add up.

If the N75 is disconnected, then has no effect over boost control AND the wastegate, then, yes it the spring is the only means of not allowing the gasses to open the wastegate. If the N75 is connected, then oscillates and allows more boost to be built by keeping the lower chamber of the wastegate pressurised. right?

[Billman]

And what do you think opens and closes the wastegate? N75. I recommend looking some at Paul's "Boost control essentials", it explains everything well.
Also, it's not about "how does Motronic work", it's more about "I don't like people talking out of their ***" sort of thing.

Man, i have read it a couple of years back when i was amazed about what Motronic can do.

N75 or not the WG valve lets the gases pass. That why we are talking about when WG opens and not what regulates it. It could be a simple bleed valve the result would be the same. The WG would not open at spring pressure but more.

pls do as all the favor and take your Motronic glasses off and think twice before you say your crap until puberty ends.

[[RPM]]

its getting a bit out of hand lol
i just wanted to know if anybody has one or how does it sound
the real question is:
if you run a screamer pipe can you have more power on the same diameter downpipe and exhaust system compared to a conventional wastegate pipe?
I hope you can understand me

[prj]

i probably know less than both of you, but if read correctly Dmitri, you are saying on one instance that N75 controls the opening and closing of the wastegate, and then below that you are saying that the spring and exhaust gasses are controlling the opening and the closing of the wastegate. Now something does not add up.

Exactly like it is...
Below spring pressure N75 has no effect, but as soon as you go over spring pressure it will start to bleed little amounts of air, whether you have reached target boost or not.
Doesn't matter which solenoid or engine management system you use. If it didn't do it, you would overshoot boost very hard. The closer you approach to target boost, the more it bleeds. With stock ECU management part-throttle boost target is a lot lower than WOT (to limit stress on the turbo), so just driving around at part throttle it will make lots of noise.

If the N75 is disconnected, then has no effect over boost control AND the wastegate, then, yes it the spring is the only means of not allowing the gasses to open the wastegate. If the N75 is connected, then oscillates and allows more boost to be built by keeping the lower chamber of the wastegate pressurised. right?

Correct, but due to the oscillation it makes a bit of noise all the time.

N75 or not the WG valve lets the gases pass. That why we are talking about when WG opens and not what regulates it. It could be a simple bleed valve the result would be the same. The WG would not open at spring pressure but more.

For the third time, you said that it will open at spring pressure only if N75 is disconnected, which is not true, as even with N75 connected it will bleed small amounts before it reaches target boost. Not noticeable in spool, but it is possible to hear it with a screamer pipe.

pls do as all the favor and take your Motronic glasses off and think twice before you say your crap until puberty ends.

Talking out of your ***, then resorting to personal insults once you have been proven wrong surely must be very mature. :corey:

its getting a bit out of hand lol
i just wanted to know if anybody has one or how does it sound

Sounds annoying. But it's a matter of preference, try it out and see (hear) for yourself. To me it sounds even more annoying than a BOV.

the real question is:
if you run a screamer pipe you can you more power on the same diameter downpipe and exhaust system compared to a conventional wastegate pipe?
I hope you can understand me

No.

[[RPM]]

why not?
the exhaust will be flowing less

[prj]

why not?
the exhaust will be flowing less

I honestly doubt there will be noticeable difference.
How much HP does your car have?

[[RPM]]

I honestly doubt there will be noticeable difference.
How much HP does your car have?

it has a mrc chip should be around 280 ( back in the day)
but that's not the point

I'm just trying to know the facts

[Bram]

If the exhaust system becomes a restriction in terms of flow, then yes a screamer pipe can bring extra performance, as not all exhaust gasses need to be pushed through the full exhaust system. However I don't think that your existing setup will benefit it. You most probably need a remap to take advantage of it.

[Billman]

Exactly like it is...
Below spring pressure N75 has no effect, but as soon as you go over spring pressure it will start to bleed little amounts of air, whether you have reached target boost or not.
Doesn't matter which solenoid or engine management system you use. If it didn't do it, you would overshoot boost very hard. The closer you approach to target boost, the more it bleeds. With stock ECU management part-throttle boost target is a lot lower than WOT (to limit stress on the turbo), so just driving around at part throttle it will make lots of noise.

Correct, but due to the oscillation it makes a bit of noise all the time.

For the third time, you said that it will open at spring pressure only if N75 is disconnected, which is not true, as even with N75 connected it will bleed small amounts before it reaches target boost. Not noticeable in spool, but it is possible to hear it with a screamer pipe.

Talking out of your ***, then resorting to personal insults once you have been proven wrong surely must be very mature. :corey:

You are right i apollogize! You are not personal when saying talking out your ***!

But tell me something master: Are you familiar with the term WG Creep?

[S2central.net]

Frig sake chaps - put a lid on it... can we keep this thread on topic and NON personal. Nobody has anything to prove here.

[Billman]

You are right, i stop here.

[[RPM]]

If the exhaust system becomes a restriction in terms of flow, then yes a screamer pipe can bring extra performance, as not all exhaust gasses need to be pushed through the full exhaust system. However I don't think that your existing setup will benefit it. You most probably need a remap to take advantage of it.

thank you Bram
that is what I though regarding the extra performance
on my setup of course I wont fell anything
when I will replace the downpipe and exhaust i will give it a go
I don't mind the noise