Waste Gate

[clean32]

Waste Gate
I am looking for an external waste gate, Not a blow off valve. that will spill hot back in to the dump pipe. i need just over 3.50 cm2.
it will also need to be ajustable, but should be able to mod anything.

[discowhite]

yes and?:eek:

cheers phil

[harry]

Waste Gate
I am looking for an external waste gate, Not a blow off valve. that will spill hot back in to the dump pipe. i need just over 3.50 cm2.
it will also need to be ajustable, but should be able to mod anything.
which means what exactly?
hint -
inches would be nice

[catch-22]

you running a standard computer or aftermarket? What brand and model?

[Bush65]

These are good - google for ED wastegate.

[clean32]

which means what exactly?
hint -
inches would be nice

There is only 1 thing I have in inches, and I will not post that, because it will send you along the path of depression then Prozac.

[clean32]

These are good - google for ED wastegate.

yes but big ugly and vent, i realy need to bypass back into the dump pipe,

what you have posted looks like a over boost thingy.

[clean32]

you running a standard computer or aftermarket? What brand and model?


ha ha ha ha

[clean32]

Come on guys im being serious here. if I have a .32 AR sitting in front of a .65 AR, I need some way of getting the large volume of gas around the .32AR very important, more so if the .65 waste gate ever opens, I don’t want massive over run and a small shrapnel producing device under the bonnet, the ,32AR waste gate gives only 1.34 cm2 I need in total about 4.5 cm2

[catch-22]

I have never known a wastegate to be measured in A/R....:huh:

[Rosscoe68]

i have an external plumbed wastegate here somewhere from my days of toyota 4banger turbo's. will look this arvo at what it is and see if it comes close to what you are looking for.

[Dougal]

Come on guys im being serious here. if I have a .32 AR sitting in front of a .65 AR, I need some way of getting the large volume of gas around the .32AR very important, more so if the .65 waste gate ever opens, I don’t want massive over run and a small shrapnel producing device under the bonnet, the ,32AR waste gate gives only 1.34 cm2 I need in total about 4.5 cm2

0.32 is a tiny exhaust housing. I have a 0.36 around here somewhere, originally off a Nissan CD20T.
So you're running a compound turbo setup and want to bleed enough exhaust around the little one? Small turbos in a compound setup are often similar size to a single turbo on the same engine. So you're winding the snot out of a small diesel?

I don't think you'll need a particularly big wastegate (doesn't a turbo that small already have an interna?) as the volume flow through the little turbine will be much smaller due to the higher pressure. Wastegating the little one could be counter-productive unless you're also bypassing the small compressor on the other side.

Unless I'm barking up the completely wrong tree.

[clean32]

I have never known a wastegate to be measured in A/R....:huh:
suring waste gates in AR

sheesh, I am not measuring waste gates in AR, I am measuring turbos in AR cool end, I measuring waste gate in cm2 because that’s how much of a HOLE I have calculated that I need.

And as this was a bit of an oversight originally on my part, with the turbos ordered. Even the yank boards id it as a problem, but then they just push more in and under fuel to keep the pressure and EGT down.

[Blknight.aus]

now Im curious.....

you running your twin turbos in series or parallel?

[catch-22]

OK...I had to read your post a couple of times to kinda get it...

Can you explain your setup a little more please? Are you running twins?

[Bush65]

0.32 is a tiny exhaust housing. I have a 0.36 around here somewhere, originally off a Nissan CD20T.
So you're running a compound turbo setup and want to bleed enough exhaust around the little one? Small turbos in a compound setup are often similar size to a single turbo on the same engine. So you're winding the snot out of a small diesel?

I don't think you'll need a particularly big wastegate (doesn't a turbo that small already have an interna?) as the volume flow through the little turbine will be much smaller due to the higher pressure. Wastegating the little one could be counter-productive unless you're also bypassing the small compressor on the other side.

Unless I'm barking up the completely wrong tree.
My high pressure turbo (BorgWarner K16) is larger than the stock single turbo. It has a 5.35 cm^2 turbine housing.

I don't believe it should be significantly smaller than the stock single. And it should still provide higher boost at lower revs than the single turbo.

The low pressure turbo (BorgWarner K27.2) has a 12.5 cm^2 housing.

The wastegate on the high pressure turbine discharges into the inlet of the low pressure turbine (along with the exhaust from the HP turbine).

I was not intending to also bypass the HP compressor.

[Bush65]

yes but big ugly and vent, i realy need to bypass back into the dump pipe,

what you have posted looks like a over boost thingy.
That example is on a larger engine than I expect to see in most Land Rovers.

I believe it is an external waste gate.

[Dougal]

My high pressure turbo (BorgWarner K16) is larger than the stock single turbo. It has a 5.35 cm^2 turbine housing.

I don't believe it should be significantly smaller than the stock single. And it should still provide higher boost at lower revs than the single turbo.

The low pressure turbo (BorgWarner K27.2) has a 12.5 cm^2 housing.

The wastegate on the high pressure turbine discharges into the inlet of the low pressure turbine (along with the exhaust from the HP turbine).

I was not intending to also bypass the HP compressor.

Do you know the wheel sizes in your BW compound setup? The wheel radius and the housing A/R ratio gives you an equivalent area at the wheel tips which seems as close to a universal turbo sizing number as I've found.

Is the wastegate on the smaller turbo sensing total boost or the boost from the larger turbo?

There are some setups which start to bypass the small turbo as the larger one picks up. A wastegated little turbo gets part way there but they're bypassing the compressor too.
This one bears the same name (R2S) as yours, but the function varies.
https://www.aulro.com/afvb/.

[clean32]

Do you know the wheel sizes in your BW compound setup? The wheel radius and the housing A/R ratio gives you an equivalent area at the wheel tips which seems as close to a universal turbo sizing number as I've found.

Is the wastegate on the smaller turbo sensing total boost or the boost from the larger turbo?

There are some setups which start to bypass the small turbo as the larger one picks up. A wastegated little turbo gets part way there but they're bypassing the compressor too.
This one bears the same name (R2S) as yours, but the function varies.
https://www.aulro.com/afvb/.


I will try an explain it.

Think back over previous posts here, to get EGT down, you back of the fuel or push in more cold air. OR as EGT and EGP is caused by back pressure at the turbo housing, the easiest way is to just dump some of this gas, but once you start to do this it limits the air you can pump. OR you fit a bigger housing which we know will lift the RPM before there is boost. simple really


So small turbo working at max, second larger turbo spools up, but now the second larger turbo has a problem, it cant get rid of any more hot gas than the down the line small turbo can, this is the limiting factor. So as you said you need to start to bypass the smaller turbo.

Another thing to remember and is forgotten often, I will try to explain it another way. WW!! war movies, the spitfire is flying along, spots the Nazi, tally ho wing over into a dive. Cant do that in a jet though, no propeller. even if the prop is spinning at max revs it will act like a air brake if the plane is diving faster than the bite X rpm of the prop, a little different with a centafugal, but if the cool side spins to fast or the air gets to soft( hot) the flow will delaminate off the back face of the blades, interfering with the front of the next blade. LOL a bit like a Harvard at full tip RPM.

Any way at some point in the rev range I have calculated that I will need to dump hot gas, 2250rpm

[Dougal]

I will try an explain it.

Think back over previous posts here, to get EGT down, you back of the fuel or push in more cold air. OR as EGT and EGP is caused by back pressure at the turbo housing, the easiest way is to just dump some of this gas, but once you start to do this it limits the air you can pump. OR you fit a bigger housing which we know will lift the RPM before there is boost. simple really

Reducing exhaust backpressure has minimal effect on EGT's. I've fitted *tiny* turbines to my engine, backpressure went through the roof but EGT's only increased as much as you'd expect with the ideal gas law.



So small turbo working at max, second larger turbo spools up, but now the second larger turbo has a problem, it cant get rid of any more hot gas than the down the line small turbo can, this is the limiting factor. So as you said you need to start to bypass the smaller turbo.

You don't need to bypass the little turbo unless the big turbo is massively oversized or you're controlling boost levels.
The little turbo can flow a certain volume, but we can increase the mass flow through it easily by compressing the air and exhaust it processes.
The big turbo does this already, when it spools up it'll compress the air and exhaust through the little turbine, letting it flow a bigger amount of air than it could alone, but still only passing the same volume (because it's compressed).

Remember, your engine which sits in the middle faces exactly the same volume flow as always, just it's compressed more. Your little turbo faces exactly the same prospect.

It's like you've taken a standard single turbo engine and put it in a room with double the air pressure. It processes more air mass and it generates more power. But the volumes remain the same.
It's a b'stard to get your head around.

But anyway, 4BD1T or other engine?
There's a guy called "carcrafter" on 4btswaps.com who's plumbing up his 4BD1T for compounded holsets right now.
My original plan of being the first to fit a variable vane turbo, then compounds to a 4BD1T has evaporated through procrastination.:D

[clean32]

I don't think you'll need a particularly big wastegate (doesn't a turbo that small already have an interna?) as the volume flow through the little turbine will be much smaller due to the higher pressure. .

yes it has an internal, higher pressure that will hold up the biger turbo

3.9 /2X3000 @ 650, needs a big hole

[Dougal]

What is your expected drive pressure upstream of the bigger turbo's turbine?

[clean32]

Reducing exhaust backpressure has minimal effect on EGT's. I've fitted *tiny* turbines to my engine, backpressure went through the roof but EGT's only increased as much as you'd expect with the ideal gas law.



You don't need to bypass the little turbo unless the big turbo is massively oversized or you're controlling boost levels.
The little turbo can flow a certain volume, but we can increase the mass flow through it easily by compressing the air and exhaust it processes.
The big turbo does this already, when it spools up it'll compress the air and exhaust through the little turbine, letting it flow a bigger amount of air than it could alone, but still only passing the same volume (because it's compressed).

Remember, your engine which sits in the middle faces exactly the same volume flow as always, just it's compressed more. Your little turbo faces exactly the same prospect.

It's like you've taken a standard single turbo engine and put it in a room with double the air pressure. It processes more air mass and it generates more power. But the volumes remain the same.
It's a b'stard to get your head around.

But anyway, 4BD1T or other engine?
There's a guy called "carcrafter" on 4btswaps.com who's plumbing up his 4BD1T for compounded holsets right now.
My original plan of being the first to fit a variable vane turbo, then compounds to a 4BD1T has evaporated through procrastination.:D

Mate we are both thumping keybords at the same time. posts missed and a bit out of order.

we are on the same wave length but i will add incresse pressur is to incresse temp ( same volume of energy)

as pressure is the difrence between inside and out. or the big turbo the difrence is beween the manifold and the inlett of the small turbo. as it is for the small turbo the difrence being the diffrence between the outlet of the big turbo and the tail pipe BP

you are correct but look at the energy wasted buy the gas fighting past the small turbo, and we doint need to completly bypass, just bleed of a bit. but more than the std waste gate will handle.

any way i think we are trying to teach eac`h othere to suck eggs, but all good, its good to be questiond makes you re think things

[clean32]

What is your expected drive pressure upstream of the bigger turbo's turbine?

ill email my spread sheat though, cast your eyes over it and let me know what you think

[Bush65]

Do you know the wheel sizes in your BW compound setup? The wheel radius and the housing A/R ratio gives you an equivalent area at the wheel tips which seems as close to a universal turbo sizing number as I've found.

Is the wastegate on the smaller turbo sensing total boost or the boost from the larger turbo?

There are some setups which start to bypass the small turbo as the larger one picks up. A wastegated little turbo gets part way there but they're bypassing the compressor too.
This one bears the same name (R2S) as yours, but the function varies.
http://www.whnet.com/4x4/pix/R2S.jpg.
The only dimensions I can easily check are the compressor inducer and turbine exducer for the LP turbo. Below is some info I have found. My measurement agree for the LP turbine exducer, but I make the LP compressor inducer approx 52mm vs 53mm given.

K16
Compressor wheel OD 2.39" (60.7mm), inducer 1.60" (40.64mm)
Turbine wheel OD 2.17" (55.12mm), exducer 1.81" (45.97mm)
Turbine A/R 1.1
Mass flow 0.19 kg/s

K27
Compressor wheel OD 3.19" (81.03mm), inducer 2.09" (53.09mm)
Turbine wheel OD 2.16" (must be a typo), exducer 2.47" (62.74mm)
Turbine A/R 1.1
Mass flow 0.38 kg/s

From a BorgWarner article on this particular turbo and its original application;

The high pressure turbine has a bypass valve which is opened by a pneumatic actuator. The engine management system commands the bypass to maintain valve closure up to approximately 2,000 rpm for maximum use of the small turbo’s low inertia and quick response. As the rpm increases, it then opens the valve to regulate system boost pressure and to keep exhaust manifold pressures within limits.

My intention is to use boost pressure to regulate the wastegate. It will involve some trial and error.

[Dougal]

ill email my spread sheat though, cast your eyes over it and let me know what you think

Look forward to it.:)

[Rosscoe68]

here's my spare wastegate and bypass plumbing with flex pipe
http://lh4.ggpht.com/_cvwP9OwkabE/SWmq1WtlKJI/AAAAAAAACVk/cVzVqsZekcA/s640/P1111204.JPG


http://lh5.ggpht.com/_cvwP9OwkabE/SWmqeA_v7vI/AAAAAAAACVc/D_8Aej4vdbI/s640/P1111203.JPG