Turbo Elbow

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gunmetalgtir

New Member
Everyone knows how restrictive the standard turbo elbow is, so I'm sure someone must have an aftermarket one! How much did it cost to get made up? I went to the local exhaust place near me and they wanted around £400 as they said before VAT for an elbow and a downpipe. Thought that was a bit expensive??

Grant
 
Mr GTiR

Mr GTiR

New Member
gunmetalgtir said:
Everyone knows how restrictive the standard turbo elbow is, so I'm sure someone must have an aftermarket one! How much did it cost to get made up? I went to the local exhaust place near me and they wanted around £400 as they said before VAT for an elbow and a downpipe. Thought that was a bit expensive??

Grant
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I'm having one made for £250. A new company called Pipeworx.
 
Lionel

Lionel

Member
:doh: how many times:der:

this will fit BUT it will not fit your down pipe

get the company that andy has said about to make you one as this one will not fit unless u want to do lots of work to make it.

Lionel.
 
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pulsarboby

Guest
but someone told me that they were bendy metal, and they would fit, now im really cccconfused and dont know what to do, HELP ME PLEEEASE!
 
fubar andy

fubar andy

Moderator & N/W Rep
Staff member
I’m going to pay Pipeworx a visit in a month or so for a 3” elbow and downpipe. What I’m interested to know is, would it really be beneficial to go for a whole 3” system or will be as efficient with just a 3” elbow and 3" downpipe.

At the moment mine isn’t hard tuned, but I do want to increase the efficiency of the system and also help it to be more responsive.

I’ve had a read about 2.5” and 3” systems before, but one area seems to crop up is that the 3” system on a mildly tuned GTiR will perhaps make it “out of puff” around the redline area. Also with the expansion and compression of the hot gasses I was thinking that for something say with stage one modifications would benefit more from a 3” elbow and downpipe, but could retain the rest of the system (2.5”) as being 3” to the end wouldn’t really be necessary?

Your thoughts would be appreciated!


(Apologies for hijacking the thread!)
 
GTiR_Mic

GTiR_Mic

New Member
pulsarboby said:
but someone told me that they were bendy metal, and they would fit, now im really cccconfused and dont know what to do, HELP ME PLEEEASE!
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Why don't you do what I done.

Ditch the elbow and use a V-Band straight from the turbo. A lot easier to work on the car then ;)

Even Rob will agree there and he has taken it off so many times now :lol:

Mic
 
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pulsarboby

Guest
someone who finally agrees with me, hooray!
cars must retain a minimal back pressure, even turbo'd cars, and i believe that all these people, throwing money at straight through exhaust systems, will see minimal increases in power, and in a lot of cases will drop power by having these systems fitted!

unless your running a very big turbo, bigger than a 3071r then i would not waste my money!
i know all the arithmatic boys are gonna slate this post with theory, figures and so forth, but i will still not be convinced. show me a car which is faster with a setup like this, like for like! (on the road or track)then i may change my mind, but untill then, im afraid not.
 
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gunmetalgtir

New Member
pulsarboby said:
someone who finally agrees with me, hooray!
cars must retain a minimal back pressure, even turbo'd cars, and i believe that all these people, throwing money at straight through exhaust systems, will see minimal increases in power, and in a lot of cases will drop power by having these systems fitted!

unless your running a very big turbo, bigger than a 3071r then i would not waste my money!
i know all the arithmatic boys are gonna slate this post with theory, figures and so forth, but i will still not be convinced. show me a car which is faster with a setup like this, like for like! (on the road or track)then i may change my mind, but untill then, im afraid not.
Click to expand...

I'm running the mighty standard T28 at the moment :wuss: so do you think think there wouldn't be much point in changing the standard elbow and downpipe to meet up with the mongoose exhaust?
 
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pulsarboby

Guest
imo no there isnt!
i can understand people changing the downpipe for a stainless aftermarket one, as the o/e one will rot anyway!
but it is a rather expensive job to get the turbo elbow aswell, and you will gain precisely nothing in fitting this, all you will succeed in doing is losing all back pressure and make the engine run out of puff quicker.
everyone seems to think that big straight through exhaust with no restrictions=more power, well there wrong.
you need to have a BIG turbo running high boost for that sort of system to work correctly, (ie like the one thunderpants is flogging) as the big tubby will obviously need a bigger breathing ex system, and the standard one will restrict it!

i firmly believe that all this exhaust thing is a falacy on behalf of the aftermarket manufacturers, who make wild claims of big bhp improvements just by fitting there system to your car! the full engine spec should be taken into consideration when purchasing an exhaust system, but they dont tell you that! as all they want to do is make a sale! the only real restrictive item i would get rid of on a standard system, is the catalytic convertor, but other than that, leave it be!

it is good to have a nice breathable exhaust with FEW restrictions, but straight through with no restrictions on a standard engine setup is a bad thing, it WILL NOT be good for your engine, and you WILL be down on power.
 
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gunmetalgtir

New Member
Cheers boby! :thumbsup: I've got a full stainless with a de-cat (mongoose) would there be any point in changing the downpipe to an HKS one as its mild steel or should I just get a stainless one made up?

Cheers!

Grant
 
S

Swampy

New Member
Do you think the side exit exhaust will have a detrimental effect power wise on a fairly standard set up aswell?
 
campbellju

campbellju

Moderators
Staff member
fubar andy said:
Your thoughts would be appreciated!


(Apologies for hijacking the thread!)
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Andy, Are you coming this Sunday? I'll be there in my shi**er and Stu(mo) might be in his too. As you know I've just had my full pipewerx system fitted, Stu should be getting his done today. We were chatiing about exhausts briefly on Sunday.

When talking in the 350-450 hp range, there is a resonable argument that a 3 " front section and a 2.5" back section will out perform a full 3" system off boost. However, now with my 3" front section its almost accademic anyway as my compressor is generating positive boost above 2K, 0.7 Bar by 2.5K and 1.8Bar at 3.5K. This is around 0.5-1K sooner.

After my RR result, I just went for the low risk (lazy) option in the end of a full 3" system. My guess is the map can have more of affect anyway but unfortunately, I'm doing the re-map :doh: :der: :lol: :lol:

You could always do your front section first and your back section later? Pipewerx are pretty local

Can talk ideas on Sunday if you want.
 
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K

Keira

New Member
pulsarboby said:
someone who finally agrees with me, hooray!
cars must retain a minimal back pressure, even turbo'd cars, and i believe that all these people, throwing money at straight through exhaust systems, will see minimal increases in power, and in a lot of cases will drop power by having these systems fitted!
Click to expand...
bob your a nice bloke but i really dont know what planet you are on. :lol:

please explain how backpressure is beneficial to getting exhaust gas through a horribly restrictive turbine wheel ?

turbos do not like back pressure, i recommend you do a run with a standard exhaust and then one with no other changes other than a full, turbo back including elbow exhaust system.

some snippets from various sources :

Reduced backpressure on the engine exhaust
Back pressure on the engine can reduce its power. Any way of improving the overall flow of air through the engine increases the engine's efficiency. Improving the turbine wheel and housing design, reducing bearing friction or improving the overall efficiency of the turbocharger will reduce engine exhaust back pressure.
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Turbo manifold back pressure is another area we should consider also, as it can contribute to many problems and low power output as well. If we have increased the boost and are now forcing in much more air and fuel than normal, it figures that it has to escape in much larger volumes now especially as it has vastly increased in volume through the combustion process. All this gas is trying to escape through the same small hole in the turbo snail with that same small exhaust exducer wheel in the way.

Needless to say the forces acting on the wheel turn it faster and make more boost which is good, but can be bad if the gas cannot escape quickly enough. The pressure in the exhaust manifold can be more than the intake manifold!
This is DOES NOT lead to efficient operation
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With a well matched turbo / engine combo, boost pressure should be higher than exhaust gas pressure at the low side of the power band (near peak torque). As the engine nears peak hp, the pressure differential will get nearer 1:1. At some point the pressures in the intake and exhaust will be equal then crossover making the exhaust a higher pressure than the intake. At peak hp there will usually be more exhaust gas pressure than boost pressure. The ultimate goal is to have as little exhaust backpressure possible for the desired boost.

easiest way to think of it is like a water wheel thats closed in a housing with a large pipe feeding the water in and a smaller pipe taking the water out the bottom, if the amount of water flowing from the top pipe is greater than the amount the smaller pipe at the bottom can flow, the housing with the wheel will fill up, restriciting the wheels movement as the water begins to back up.

if it was round the other way so the small pipe is feeding the wheel, the bigger pipe could easily take the water away from the wheel and nothing can back up into the housing

very simplified and theres more to it but you get the idea
 
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K

Keira

New Member
fubar andy said:
I’ve had a read about 2.5” and 3” systems before, but one area seems to crop up is that the 3” system on a mildly tuned GTiR will perhaps make it “out of puff” around the redline area. Also with the expansion and compression of the hot gasses I was thinking that for something say with stage one modifications would benefit more from a 3” elbow and downpipe, but could retain the rest of the system (2.5”) as being 3” to the end wouldn’t really be necessary?
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this is whats confused bob

the aim of removing exhaust gas on a turbo is to do so as quickly and effeciently as possible, gas velocity drops as it cools, the larger diametre exhaust allows the exhaust to expand and cool quicker than the 2.5", as its cools, velocity slows, it creates back backpressure causing problems with the efficiency of the exhaust system/turbo/engine.

by having a larger front section that tapers down alot of gas can flow directly from the turbo exhaust side without restriction and as it cools, velocity is maintained as the area that gas is filling decreases in size.

my old car had a 3inch frontpipe/elbow and tapered down to 2.5 to meet the decat, the torque curve was very good and although cars with standard elbows get similar peak torque theres would drop where as mine stayed nice and flat for 2500-3000rpm.

by just removing the standard turbo elbow and replacing it with something better flowing and then running a 2.5" system (goose) would be good enough for most cars on here, and you would see gains from that alone, the standard elbow is hideous

pick holes if you want ;)
 
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