screamer pipe

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jambo_gtir

Member
mine sounds ok, not too bad when driving, i can rev it and cup my hand over screamer pipe and cant feel anything coming out. Its very loud tho at full chat. I had problems with fitment tho, had to make a few alterations to air con setup :(
 
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youngsyp

New Member
steve963 said:
I know what you mean I`ll have to see if he makes single hole elbows to join up the the rest of the system, but think they may be difficult to make from steel tube, wouldnt it need to be cast due to the unusual shape of the turbo?
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You won't be able to make it from just 1 piece of pipe. My one is made from stainless sheet to form the elbow and then smoothly attached to a 3" pipe.

Paul
 
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steve963

Active Member
i couldnt swap it for one like that, as AM elbow is only 2.5" and increases to 3" in the "J" pipe, will have to see if AM can make a "hollow" elbow

whats the smoothness like on the inside of elbow? the AM one isnt 100% curved!
 
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youngsyp

New Member
steve963 said:
i couldnt swap it for one like that, as AM elbow is only 2.5" and increases to 3" in the "J" pipe, will have to see if AM can make a "hollow" elbow
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This is aimed at you bud as, I know you didn't design the thing but, could they possibly make the design any worse ?! First the restrictive and leaking partition 'seal' and then a 2.5" design into a 3" pipe !

I still don't understand how a company can make a 'performance' exhaust system in that way ?! "I know, let's have the most restrictive part of the exhaust at the very start of the pipe run and then make the pipe larger in diameter after that !" That's a completely backwards way of doing things and will actually slow the gas speed as, it allows the gas to expand after the elbow.

steve963 said:
whats the smoothness like on the inside of elbow? the AM one isnt 100% curved!
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From what I can remember (it's been on the car for 5 years and I only briefly saw it internally) the smoothness is great. Exactly what you'd expect from a hand shaped fabrication.

Paul
 
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steve963

Active Member
i thought, that as the gas was moving fast it only needed a small diameter, then as it slows the diameter needs to be bigger,

f**k it, ill put the std front pipe back on:doh:
 
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youngsyp

New Member
steve963 said:
i thought, that as the gas was moving fast it only needed a small diameter, then as it slows the diameter needs to be bigger,
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With a turbo charged engine, you want to get as much gas out, as quickly as possible. So, you'll put a large bore elbow on the turbo, along with a large bore downpipe.

As the gas get's further away from the head/turbo, it will lose heat so, expand and slow down. To counter act this, you'll narrow the pipe diameter slightly. This will keep the gas speed up until it exits the tail pipe. This may build back pressure slightly though. So, for max power on a turbo charged engine, it's probably advisable to have the same diameter pipe for the whole system, in the GTiR's case (and most 2.0l turbo engines) 3" pipe work seems to work well.

My system consists of a 3" elbow and downpipe that narrows to 2.5" just after the flexi section. It works very well at my current power/torque/boost level but, I'd be interested to see how well it would work on a more powerful engine !

Another good way to keep the heat in the exhaust gas, and therefore keep gas speed up is to lag the manifold, elbow and downpipe, which will also give you the obvious reduction in under bonnet temps !
steve963 said:
f**k it, ill put the std front pipe back on:doh:
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I wouldn't go that far mate ! :lol:

Paul
 
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youngsyp

New Member
steve963 said:
gunmetalgtir, thanks for adding what I was thinking

no ones gonna buy it whos read this thread though?
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Personally, I'd get it to an exhaust fabricator, get them to remove the internal 'partition', cut the current 'screamer' pipe off and weld a smaller pipe from the screamer outlet, back into the main pipe at its base. Just like the non VTA option you had with these.

That should be a fairly cheap way of (much) improving your current pipe. ;-)

Paul
 
W

webba23

Member
youngsyp said:
It's supposed to reduce turbulence around the turbo outlet and so, improve gas speed. That's great in theory but, the T28 doesn't have a partition between the wastegate outlet and the exhaust turbine outlet. So basically, this design is a complete waste of effort on the T28 or any turbo with a (G)T28 style internal wastegated turbo housing.

I've not had any issues with Hayward & Scott 3" single pipe elbow and downpipe. It's made quite good power actually.

Paul
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Hi I'm after a turbo elbow at the moment and can't seem to find one anywhere. Live quite near Hayward & Scott and have heard good things about them. If you don't mind me asking how much did the downpipe and elbow set you back?Matt
 
J

Jamaala1

New Member
Damn, after reading youngsyp response i looked at my non screamer version of the pipe. You can see the increase from the 2.5 to 3 inch in the pipe work. I am now contemplating whether I should put this piece on the car:doh:.
 
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steve963

Active Member
Jamaala1 said:
Damn, after reading youngsyp response i looked at my non screamer version of the pipe. You can see the increase from the 2.5 to 3 inch in the pipe work. I am now contemplating whether I should put this piece on the car:doh:.
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ive been thinking about this and im not sure i agree with paul

as the turbo outlet is only about 1"-2" wide, having a 3" pipe connected directly to this will leave areas of vaccume, and hence turbulence, I think an outlet the same size as the turbo outlet then increasing in size it the correct way, this way there is no sharp steps in the air flow

look at the turbo outlet pipe to the intercooler, this is small then expands rapidly..

i ran 326bhp and 325ft lb using this pipe at 1.2bar... even considering, as paul said, the turbo outlet is reduced by the thickness of the pipe (and the gap around from which its blowing:doh: bet the edge facing the turbo outlet gets a bit hot:doh: )

surely the perfect design would be to blend into the turbo outlet smooth and increase in size by a certain rate up to ?"
 
E

EssexAaron

Member
to use a screamer properly you need and external waste, the car sounds terrible in that vid.

my pals skyline has a properly built screamer and it sounds the nut! doesnt sound like a blow in the exhaust and doesnt sound any different on normall driving.
 
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steve963

Active Member
youngsyp said:
What were your other mods mate ? Just for comparison...

Paul
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walbro, decat pipe at 2.5" and 2.75" (IIRC) fujitsubo cat back, so not the smoothest exhaust run! still got std top mount, and metal air filter by the looks of it it dosent filter very well

this was running less than 10 AFR also, gauge only goes down to 10
 
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youngsyp

New Member
steve963 said:
walbro, decat pipe at 2.5" and 2.75" (IIRC) fujitsubo cat back, so not the smoothest exhaust run! still got std top mount, and metal air filter by the looks of it it dosent filter very well

this was running less than 10 AFR also, gauge only goes down to 10
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So your power figures are comparable to what mine ran at 1.1 bar, with My H&S exhaust and Blitz SUS filter, stock everything else including TMIC and turbo. Although, your torque figure is quite a bit higher (32 lbs/ft).

Paul
 
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steve963

Active Member
youngsyp said:
So your power figures are comparable to what mine ran at 1.1 bar, with My H&S exhaust and Blitz SUS filter, stock everything else including TMIC and turbo. Although, your torque figure is quite a bit higher (32 lbs/ft).

Paul
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maybe this design is better for torque??

what we really need is an external wastegate turbo with a 3" outlet and the elbow bolted straight to that:thumbsup:
 
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youngsyp

New Member
steve963 said:
maybe this design is better for torque??

what we really need is an external wastegate turbo with a 3" outlet and the elbow bolted straight to that:thumbsup:
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The higher boost level would increase torque, not sure about the exhaust but, I'd expect it's more than possible. But, I won't pretend to understand how the exhaust design effects torque levels.

But yes, a turbo with external wastegate would be nice. Along with the 3" outlet on the turbo with 'V' band elbow ! GT3071 it is then ! ;-)

Paul
 
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