Yes the 16 A/R is stamped on the housing

 

But could that be 16cm2?

 

The housing is too big for it to be 16cm^2.

Unless that's 16cm^2 per port!

Using 26cm^2 and calculating radius to clear the turbine wheel it comes out as ~50% bigger turbine than a hx35-12. Which is about where I expect it to be.

 

It seems like holset typically stamp the housing in cm2?

 

Next paragraph from that supra. thread says the area ratio on the he451cw is 0.68


BUT wait theres MORE!
The Holset company has a bigger brother to the HE351CW, THE "HE451CW." Its measurements are as follows:
Compressor minor/major: 2.4645"(62.60mm)/3.6455"(92.59mm)
Turbine minor/major: 2.3630"(60.03mm)/2.7405"(69.61mm)

So this thing should be a monster. The exhaust housings on the HY35W turbo and the HE451CW/HE351Cw are about .68 A/Rs. Should spool just fine!

 

Yeah I read that, went "bollocks" and ignored it.

No way is that housing 0.68 A/R. As turbos get physically bigger the A/R does too. Small A/R is only possible on small turbos or with extremely large housings.

 

Ebay guy might have misidentified it I suppose.

HOLSET CUMMINS HE451 TURBOCHARGER 2837788

URL: http://pages.ebay.com/motors/link/?nav=item.view&id=321825607413&alt=web

 

But the part number from the tag is correct. The retail is 1250 usd but maybe I will lowball him.

 

Well I have it set at 150cc right now so maybe I will just try it at that level and see if it is drivable. One problem I see with tuning is that once you move the throttle stop off the calibrated bench position, you really don't know how much fuel you are burning at max.

I will need some new valve springs, new exhaust manifold with custom wastegate, and a bigger intercooler, so will have to figure that stuff out and how to fit it all in. It will probably get sent out to move things along.

I am fatalistic about auto box and motor. We have good resources here for rebuilding both to higher performance specs. The transmission I have can be made to handle those sorts of numbers by cranking the modulator pressure up and adding some clutches.

At least I know what boost numbers to shoot for now, and which turbos stand a chance of getting me there. Thanks again.

 

Edited inducer sizes

Does it make any difference whether I use the 46mm inducer compressor or the 44mm on the hx30? I guess it depends how close the 451 is to its limit at high rpm. Alcaid seems to think the regular hx30 is enough.

 

Does it make any difference whether I use the 46mm inducer compressor or the 44mm on the hx30? I guess it depends how close the 451 is to its limit at high rpm. Alcaid seems to think the regular hx30 is enough.

For 6000 rpm you'll need the 46mm. Otherwise the 44mm will do to 5000.

 

Seems smart to go for the extra capacity. Maybe a tad slower spool but my current limit is 5500. Thanks.

 

Yes I like the offset idea. I had the idea to actuate the bypass using difference between the emp and the boost pressure. I am sure if it was a good idea, someone would have already done it though. Maybe ole fejer was running his vgt controller like that.

 

Well it showed up today but it definitely has 16 stamped in the turbine inlet. I didn't have have a caliper handy but I am guessing each port in the flange is maybe 2.xcm x 4cm. So is it not possible that is to necks down to 16 cm at the end of the straight part of the scroll? I think that that is where these are measured. I think if it was from a 9L cummins genset it could have a small housing for limited rpm range. I will pull it apart this weekend and measure it, but a parts suing isttt isttt 16cm that would mean I need another housing, correct?

 

What matters is the A/R. So measure the area best you can and measure the radius to the same point you measured the area. Tell us what units you use.

 

Someone mentioned original application for he451:

PEGASUS L SERIES ISC8.3 - QSC8.3 - 6C - ISL9 Holset HE451

I have some part numbers now for the wheels and the turbine housing, but still need to measure it.

 

This is probably the turbo from the ISL G developed in conjunction with Westport for CNG use.

http://www.cumminswestport.com/models/isl-g

 

These guys think a 16cm housing is approx 1.13 a/r

http://turbolabofamerica.com/turbine-housings/

 

Ok I wedged some modeling clay down there and fired up a photo editor. One half of the inlet is 762 mm2. So approx 1524 mm2 total at the inner end of the ramp.

Turbine wheel is 64mm small and 74.87mm large diameter.

Will have to estimate a scroll radius later.

 

Short version:

Holset He451
Part numbers 2837788, 2837789
Original turbo on cummins ISL9 etc

Compressor Inducer 64mm
Compressor Exducer 93mm
Compressor blades: 7+7

Turbine Exducer 64mm
Turbine Inducer: 75mm
Turbine blades: 12

Turbine housing radius: 6.95cm
Turbine cross sectional area: 16cm2
Turbine A/R: 0.9 inches
Twin scroll


Long version:

From the above I assume the true area at the end of the tongue is actually 16cm, and that my modeling clay method is off a bit.

Compressor inducer was a bit more difficult to measure, as it has the odd number of blades at the inducer. Basically, I got a triangle from the tips of blades 1,3 and 5 of a seven blade config, with tip to tip measurements of 50,50 and 62.6. If anyone has an easy way of fitting a circle to those points please let me know, or I will do some math later today to figure out the diameter of the circumcircle (haven't found that online calculator yet). It is probably 64mm because if I put the sides at 5, 5, and 6.2 on this java thingy http://www.mathopenref.com/trianglecircumcircle.html it comes out at 6.38cm diameter, but the 6.2 side should really be 6.26, which makes the diameter a bit bigger than 6.38.

Compressor exducer I measured at 92.9. This seems dramatically larger than the inducer, which apparently moves lots of air, but less efficiently than lower trim wheels. It has 14 blades down low. It has machining marks on it, so I assume it is billet, unless the marks are transferred from the casting mold.

Area ratio A/R on the turbine seems to be 16cm2 divided by 7cm, or 2.28. I measured it at 6.95cm so it could be a bit larger than that actually. If we use my actual measurement of 1524mm2 and 69.5mm radius, we get 2.19 after converting to cm. I tend to trust the 16cm2 value stamped in the housing, so 2.3 is probably closer to the truth. Apparently this is equivalent to 0.9 inches, which is the conventional unit.

Turbine has twelve blades on it, if I didn't mention that already.

I take all this to mean that the turbine wheel is larger than the guy on the supra forum indicated, which should be good for backpressure. The turbine housing A/R seems medium-ish.

The compressor also appears high trim. But it should flow a bit more on the top end, where we were bumping into a flow limit at 6000rpm I believe.

I would put some photos in, but I cannot figure out how that works just now.

 

The A/R you've measured is in cm. Most use inches which is 0.9.

 

OK thanks Dougal. I've corrected it in the previous post.

 

Aha!

Found this gem: The diameter of the circumcircle can be computed as the length of any side of the triangle, divided by the sine of the opposite angle.

from here: http://math.wikia.com/wiki/Circumscribed_circle

Anyway, it requires solving for the angle opposite a side. So we have Vertices A, B and C, angles alpha, beta and gamma, sides a, b, c.

By law of cosines, alpha = acos (b^2 + c^2 - a^2) divided by 2bc.
= acos [2500+3918.76-2500 divided by 2*50*62.6]
=acos 3918.76/6260
= acos 0.63
= 51.24 degrees

so a=50, alpha =51.23
circumdiameter = 50/sin 51.23
= 50/ 0.7727
=64.127mm is the diameter of the compressor inducer from measuring distances between three of the seven blade tips of 50, 50 and 62.6mm

 

Turbine specs match an HX40-16cm pretty close, it's about 20% bigger (flow wise) than an HX35-12cm turbine.

So it's smaller than I initially thought (26cm became A/R 1.5 inches). That website with a list of cm-A/R conversions is only true for some MHI TD05 turbos. It's wrong for everything else as the radius differs from their assumptions.

I think what we're seeing with all these newer generation Holset turbos is bigger compressors and tighter turbines (compared to compressor size) to give a turbo that naturally leans out and cleans up a diesel engine. So you've basically got an HX55 compressor with a HX40 turbine attached.

 

I wonder if an 25cm hx40 hot side would bolt on. That would help backpressure and shift things toward the original 451 estimate by Dougal.

 

Apparently to get big exhaust housings like 28cm etc, the hx55 is best.

Hx52 is typically an hx50 turbine wheel with an hx55 compressor, so might be better turbine flow than 451, but housing is still 16cm usually.

Hx55 have the range of huge turbine housings.

Above info from here http://www.compressorracing.com/our-turbos.html

If I can find a core hx40 with a 25cm housing, I have a feeling it may bolt up to the 451. So that would probably be the cheapest way to improve exhaust flow.

Conceptually I have trouble understanding how turbine exducer size and housing sizes each contribute to backpressure.

 

I can always put an external gate on the LP turbo also, to keep the pressure ratios split more evenly. I don't really want to mess around with trying to bypass the HP compressor. I guess it just depends what the map looks like on an he451/hx55 compressor, e.g. what pressure ratio it likes at the target flow rate. And also what it looks like from a backpressure standpoint.

The 120cc Calc above for hx50 and he451 assumed a smaller turbine wheel, but a much larger turbine housing, than I actually have. So now there is a big 16cm fixed obstruction limiting what can go thru the LP turbine, but a larger wheel. I assume this will be a net increase in backpressure.

Either I waste gate the 451, or I look for an hx50 with a larger turbine wheel and housing to lower backpressure.

 

hx52 16cm at 160cc om606

https://www.dropbox.com/s/cel7evzvpkwps1p/2016-03-03 08.57.30.jpg?dl=0

 

https://www.dropbox.com/s/cel7evzvpkwps1p/2016-03-03 08.57.30.jpg?dl=0

So what was used on that engine? Looks peaky!


I haven't had any time to run more calcs.

 

So I've got a few spare minutes to run some calcs. So is the intent to run the 16cm 451 ungated or with an external gate?

I'll do a run with the 451-16cm ungated at 120cc and see how it looks.

*edit*
So I've run some ungated calcs and this is looking surprisingly good. You'll need a huge wastegate to bypass the HX30 pretty much completely from 4000rpm to 6000rpm.
Power should be around 350kw (crank).
Drive pressure is below boost from 4000-6000rpm.
The 451 runs straight up the middle of the compressor map.

You may or may not find the HX30 compressor to be a restriction at higher rpm. It's too close to call A flap valve to bypass it (with a wastegate actuator set to ~35psi triggered off the HE451) would cure that.

 

Thanks Dougal. I have been going back and forth on the big turbo selection question.

Eventually I decided to just bolt it up and see how it goes. A guy stamsas in Norway has hx35/hx52 compound on a 606 and there is a dyno run on facebook which has both of them spooling quite late. Another guy Hans Persson in Sweden run straight hx52 but very late spool. All hx52 have 16cm housing, but larger turbine wheel than he451. So I think the smaller wheel on mine with similar housing cm should be about right.

I had not considered the flap compressor bypass until seeing blacksmoke racing on facebook with he221w under hx50 sequential. It has a gizmo like that. Somehow. Does the hx30 super contribute anything at 4000-6000? It is still presumably cranking away at 40psi or whatever. I did get the super so that should help.

Anyway now just have to either build the manifold or get someone working on it.

Cheers,
Karl

 

Would a passive check valve work for the compressor bypass? I guess it would never open until the wastegate opens, because it would have to open against compounded boost on the back side before the wastegate opens and takes drive away from small turbo. After wastegate opens, all drive goes to the 451 and it's boost should rapidly exceed the boost from the small turbo, which is unspooling. Could be a valley of death before big one gets up to full speed, but it should already be spooled...

 

A passive check valve will always be a pretty good restriction or risk sticking open if it doesn't have a spring closing it. Where an actuated valve can be fully open as it's needed.

I think the compressor bypass needs to open a fraction after the small turbo wastegate is fully open. This should be pretty easy to acheive with only a small boost window where you are still blowing through the small turbo.

 

A passive check valve will always be a pretty good restriction or risk sticking open if it doesn't have a spring closing it. Where an actuated valve can be fully open as it's needed.

I think the compressor bypass needs to open a fraction after the small turbo wastegate is fully open. This should be pretty easy to acheive with only a small boost window where you are still blowing through the small turbo.

Audi has a nice passive check valve on their 3.0 tdi motor that looks pretty slick. about $150 usd. it Should open shortly after the wastegate opens I would think.

actuated butterfly valves are not as easy to find. Retrofitting throttle bodies sounds like a pain and they are not designed to work under any real pressure. Maybe turbo smart makes one. not sure.

I would like to be able to turn up the fuel at some point. I suppose either passive or actuated compressor bypass could work at a higher boost level.

 

Hx35/hx52 coal smoke racing is 517whp at 3 bar on 210cc