Holset Hx35

[peter 20]

Can anyone decipher this compressor map?

 

HX35 Compressor map

 

Thanks!!

Edited July 1, 2010 by peter

[jimistdt 1]

Depends on the application, have a look at this site http://www.squirrelpf.com/turbocalc/ it allows you to input your engine specs and plots the map to deem suitability.

 

Like so;

 

http://www.squirrelpf.com/turbocalc/graph....;product_id=113

 

Won't allow me to post as a picture, but change all the variables in the box above.

 

Hope this helps.

[wracing 19]

what do you want to know, its not much use as its missing the efficiency contours and speed lines. but you will at least be able to tell if your engines operating pass the surge line and see the the turbo is capable of making the power you require.

 

James

[peter 20]

I dont quite understand whats going on there, plus i cant quite read the graph due to my computer screen not being very clear.

 

I have a holset hx35 the one that i have the graph for, its going to be fitted to a 3.0 m3 engine that revs to 7500rpm.

 

Will the turbo be in its efficency window, what hp could it produce, I dont realy want the answer but if you could point me in the direction of how to work it out...

 

edit:wracing how can i tell if the engine is operating past the surge line and see if the turbo is capable of making the power i want?

 

Also noticed this is in the wrong section! sorry!

 

thank you!

Edited July 1, 2010 by peter

[jimistdt 1]

I've plotted roughly the data you've given on the graph, and I'm by no means as familiar with all this as James is, but I have looked into it.

 

If the turbo operates past the surge lines then the plots of the graph will be way off to the right, this means the turbo has hit a wall and is unable to keep up with the engine output, if it were way to the left then this is beyond the stall line and it means the turbo is well below peak efficiency.

 

Ideally the plot lines would remain close to the centremost efficiency contour on the map, whilst spooling up and also when operating at peak RPM. If it isn't then you need to look at another turbo.

 

I'm sure James (Wracing) will be along to fill in the gaps in my rudimentry understanding of the subject.

 

 

 

I've had to guess a lot of data, (such as a BHP figure of 350bhp) but from what i can deduce this is how the turbo would match the engine. IE Not very well at all.

 

If I'm very wrong I apologise, but the maps are interesting to sit down and have a play with.

 

EDIT; Unless you were chasing 800bhp then that would be lovely!!!

 

 

Edited July 1, 2010 by jimistdt

[peter 20]

Just been trying different figures there,

 

It doesnt seem to make sense to me, lets say i want a random horsepower say 600 which puts the turbo out of its range you can adjust the boost pressure (12psi) so it stays in the centre of the graph.

 

you can see what i mean here.. http://www.squirrelpf.com/turbocalc/graph....;product_id=113

 

So is the turbo too small as the plot line is off to the right?

 

 

 

edit; just seen the your second graph! So the turbo is large enough to support 800hp?! but that must be dependant on what the boost pressure is, for example if the variables you put in were a boost pressure of 15psi at 800hp surely the engine wouldnt make that at 15psi, or is this turbo just HUGE?

 

Im even more confused!

Edited July 1, 2010 by peter

[jimistdt 1]

I don't think thats the boost pressure your chaning, rather it's the air pressure at sea level, atmospheric pressure, that would normally remain unchanged unless you were doing something like Pikes Peak where you would be 1000's of feet above sea level then you would need to lower that figure.

 

The boost pressure is in the data area below where you change all the details and above the graph picture, it gives a breakdown of how much boost you would be producing at various RPM's.

[peter 20]

Ahh i see now, i just saw pressure drop I/C above it so assumed wrongly it was boost pressure.

 

for a laugh i put in 1000hp

 

http://www.squirrelpf.com/turbocalc/graph....;product_id=113

 

That cant be right the turbo realy isn't that big, ive seen plenty of these (some even bigger) used on the old 12 valve bmw engines which work quite well, the one from ppc for instance.

 

So, if i wanted a huge amount of power this would be fine?

but surley it depends on how much boost its set too if its limited to 10psi it wont be flowing as much so it should be at full boost at the same time but only flow enough for lower amount of power.

 

To make 800hp the turbo is at 35psi at 450hp its only at 14.5 psi but the plot lines plato in the centre of the graph does this not mean that it doesnt need to spool up any more, not that its unable to keep up with the out put as it can output alot more?

 

to be honest im lost and think ive missed a vital point!

Thank you for trying to explain this to me though!

Edited July 1, 2010 by peter

[peter 20]

http://www.squirrelpf.com/turbocalc/graph....;product_id=113

 

What am i doing wrong, 1800hp would be right in it efficiency window?!!

all be it at 82psi

[jimistdt 1]

The pressure drop I/C would be pressure drop on either side of the intercooler, some are more efficient than others, thats what I mean about the guesswork element, really you'd need guages fore and aft the intercooler to see what was happening there, so to some extents it is just theorectical at this stage.

 

 

Yes, you'd be limiting the amount of boost available either by management or a wastegate.

 

Where the graph plataeus is more the engines limits I think than the turbos. I think anyway.

 

Like I say, I'm not that much up on it all, but I'm glad I've cleared the muddy water a bit

 

Hopefully someone with a bit more experience will come along and fill in the gaps and not rip me to pieces!!

[peter 20]

It cant be the engines limit though if it can produce more hp, i think we have both missed somthing!

[jimistdt 1]

Looking at the last graph, you are going back out of the efficient zones, the compressor wheel is rotating at 135,000+ RPM there, that in turn would give a massive increase in temps, you would be needing an intercooler the size of a fridge, I think you are right we are both missing something fundamental.

 

From what I have read from searching on the net, these are very capable turbo's, and they're bloody massive!

 

The turbo on the left is from a 3000GT the one on the right is the one you have!

 

 

 

I think they are from diesel trucks, do you know what your came from?

 

What other modifications would you be looking to run alongside the turbo?

[peter 20]

The turbo i have is from a dennis eagle cummins diesel engine

 

part no. 3597179 which is an HX35W. ive removed the internal waste gate (W)

 

Holset turbocharger turbine housings are usually identified by their 'critical area' - in this case 12sq.cm. Some other turbo manufacturers use A/R and in this case, the housing in question is 1.9sq.cm/cm.

 

The other modifications will be either a totaly standard engine standard CR, with tial waste gate large intercooler and 550cc injectors and stand alone management omex 710 hopefuly! 3.5" exhaust system. This has been done before with a different turbo and management, megasquirt! and worked well producing around 420hp

 

Then will be upgrading to low CR pistons and forged H beam rods.

[welshpug 1,661]

you think a turbo from a 6 litre + diesel engine will work on a 1.9 petrol pug engine??

[jimistdt 1]

Have another read , Mei!

[B1ack_Mi16 67]

you think a turbo from a 6 litre + diesel engine will work on a 1.9 petrol pug engine??

 

Possibly quite ok

 

My mate ran a HX40 that's even a tiny bit bigger afaik.

That was on a 2.0 4 cylinder VAG engine and it produced 600bhp with some lairy camshafts at 1.7 bar boost.

 

Due to exhaust cam tweaking (opening it quite early to get more energy in the exhaust gases) it spooled up at 3000-3500rpm and pulled hard to 8000rpm.

 

It will work but if it is suited or not is really down to what you'll be using the car for.

[wracing 19]

I'm running a GT42r off a volvo d12 engine that 12 litres, that spools fine!

 

When i get home ill post some info try and help you out

 

James

[peter 20]

After hours of searching im still not sure wether this turbo is best suited to my 2.1 t16 build or for my 3.0L m3.

 

if anyone could confirm how i can use the spec or compressor map to work this out i would be very appreciative!