Considering a Twin GT2256V setup on OM606

Considering a Twin GT2256V setup on OM606 - Printable Version

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Considering a Twin GT2256V setup on OM606 - JoeB - 06-07-2017

As we get closer to the actual build of the 606 for Project GelandeRover, and after messing around with some superpumps, HX35's and w116's among other things, some consideration was given to using the w163's GT2256V on the 606 destined for the RRC, but instead of using one turbo, why not use two?

Seems pretty obvious really, because the stock 606 rear housing is a choker. I'm sure it could be machined, new turbine etc... But there may be something in the twin setup worth exploring, and I do like the ability to use factory stock parts when looking for performance increases.

To be honest, I really don't need the added complexity of doubling everything up on one side of the engine bay in the Range Rovers engine bay - it's pretty cramped as it is, but nonetheless, this twin setup might have some advantages - the key thought behind using two, was the turbine housing seems more suitable for 1.5 litre displacement and in theory at least should not have as much lag as a big single.

With the design intent of the application being a broad spead of power and torque - as much as possible, and a conservative redline of 5.5-6Krpm (let's face it, it's not going to spend an eternity there while hauling 2.5T+ of 4x4) it would seem the factory OM612 turbo sizing is quite good.

The aim is not to use huge boost figures, or 170cc of fuel at max rack travel. The design contraints are fairly conservative - quick spool, medium boost performance - say 2.5 bar, low EGT's and low stress.
The engine is going into a 4x4, with 32" (235/85R16) tyres, 3.54 diffs and will have an altered LT230 transfer case with crawler gears down the track. For now though, it's a 1.2 ratio (for those who understand landroverspeak)

One other area which has been given much consideration was using the mercedes gearbox versus the landrover. I have a ZF4hp22/BWTC already in the car, and a spare R380/LT230 plus another LT230 which will be built for a divorced application, should I decide to use the 717.404 or a 722.6

the "easy" way out is naturally use an adaptor setup to mount the 606 to a LR box - be it the R380 or ZF auto. That allows the trans and transfer case to remain in situ and helps to keep it simple, but the longevity of the R380 and the ZF box behind a torquey 606 is not likely to be sufficient for my reliability requirements. So it'll probably end up being the 722.6 and a divorced LT230.

For those familiar with gearing changes etc, the 722.6 and the LT actually are not much different from the ZF and BWTC, with the added bonus of being much more reliable and proven behind a 606.

Back to the turbo setup though. I haven't seen many twin setups, certainly very few on diesels, more common on m104's though. I wonder if this is simply down to cost / maintenance, or if there are just too many issues to work around.

any ideas / feedback / experiences would be appreciated. We have time to get this right before the engine goes anywhere near the car, so it's crucial to make this a reliable setup. As I said, we're not chasing huge horsepower, just a stout combination with good response and pickup, low lag, and reasonable fuel consumption. 350bhp would be 'nice'

cheers

RE: Considering a Twin GT2256V setup on OM606 - starynovy - 06-07-2017

2,5bar with gt22v? Haha..no it will not last a week.

RE: Considering a Twin GT2256V setup on OM606 - 50harleyrider - 06-07-2017

A couple of vnt 17/22 would be awesome and quick spooling. A couple of GTB2056V would also be awesome and also quick spooling. As soon as I figure out my F150 tranny problem, that's my plan too.

RE: Considering a Twin GT2256V setup on OM606 - Tobulus - 06-07-2017

I have a GR2359V on a 605. with closed vanes this turbo pushes 0.5 bar at 2000rpm in Neutral without load!

But its quite some work to control it. But definately doable.

RE: Considering a Twin GT2256V setup on OM606 - Turbo - 06-07-2017

(06-07-2017, 01:52 PM)50harleyrider A couple of vnt 17/22 would be awesome and quick spooling. A couple of GTB2056V would also be awesome and also quick spooling. As soon as I figure out my F150 tranny problem, that's my plan too.

like starnovy said before comes to the GTB2056v too, they will not last long at pr 3 you start to leave the compressor map at that stage and is quite short range at that pressure ratio, I ones by accident charge 3,4bars with one of the GTB2056vl and it did hold but not the engine, no om606, but since exhaust in to VNT carriage is stupid dum build in my opinion, talk about pressure losses.

I could have 1bar boost at idle but that does not mean flow is good, when the vnt is close to close turbine efficiency is very poor so it need a lot of drive pressure and that really hurt volumetric efficiency, if you add two of these it get even worse, I ones did a long time ago on a om606, though it would really needed a second turbo in series to come to full advantage in that kind of build.... I guess two GTD1752VRK would be a better choice for drive ability but small turbo normally had bad isenentropic efficiency on turbine, and turbine is special on that turbo properly for the worse though efficiency in gtb2056vl compressor i mazing good if used right

RE: Considering a Twin GT2256V setup on OM606 - starynovy - 06-08-2017

Had 2260V on 525tds controled by PID regulator, good low end torque but top end sucked.. they are too smal for prechamber engine.

The thing is, twin VNT engines were a fashion long time ago when there were no better options. Good example is Alpina 530d biturbo which mounted two 1544V for 180kW, since then they never used technology like this simply because there is no need. Todays GTD VNT turbos can outperform these old gen biturbos easily. If you insist on biturbo I would go with two top WG turbos, for example GTD17 used on 3.0BiTDI they will get you just to 400PS with perfect spool.

One last note.. if it is not obvious from my saying I will say again.. dump the idea of mounitg 20 year old GT V turbos, I know they are cheap but they suck dick today. Big Grin

Just second gen GTB1756V (OM629) can give you in twin over 300kW and that is considerably smaller turbo than mentioned GT2256V which will lag on 1,5L engine considerably.

RE: Considering a Twin GT2256V setup on OM606 - CRD4x4 - 06-08-2017

Ignore all the naysayers! The turbos you mentioned are plentiful and inexpensive and that's exactly why you should use them. Experiment with twin variable turbos and enjoy the experience! That's what I'll be doing down the road. Keep the updates coming!

RE: Considering a Twin GT2256V setup on OM606 - barrote - 06-08-2017

Fella starynovy is not beeing polite, wich in this forum is not common....apart.....
But not all he said is nonsense, actually IDI engines produce too much exaust in high idle and with too litle inertia in low idle rendering a GTV series turbo less efective than a modern WG .
Too small for high speed and too big for low idle, they were meant for DI engines wich suffer less with low idle back pressure (drive pressure) and in high idle they ingest as much as 60% exaust due to EGR system.
Another fact is that the model 22 is too big for 1.5 liter it will lag. But a 17 will not lag that much and is seldom availave cause they were sold thousands in the vw/audi TDI engines.
And i'm fond of gtv crap...
Wich u good luck with the project.

RE: Considering a Twin GT2256V setup on OM606 - Turbo - 06-09-2017

Sorry Barrote, but can you please explain more I can not understand why a IDI not can have a VNT turbo as I understand it from you
what do you mean with do much exhaust on high idle? There are
two VNT22 to big? it is not determine how you want the turbo to work? ok a IDI have bigger range since normally it rev higher then a DI so it need wider compressor map, that what you mean?

if someone wants some cheep GTB2056vl I have some lying around and collect dust, I think even one is just 750km

RE: Considering a Twin GT2256V setup on OM606 - barrote - 06-10-2017

IDI can be fitted with any turbo....
I stated VNT/VGT tech start to show up with CR engines, if i'm not mistaken MB was launch OEM for the GTV series, it might well not be complete true, but remember MB is also about trucks.
The needs/abilities of the very high direct injection engine are a lot diff from our IDI engines. One thing is the drive pressure for turbo, it does not afect as much as in a IDI, the other is the combustion speed, this process hapens very fast and the engine seems to rev faster and deliver much more tq in low to mid range.
This turbos were meant to control exaust ingestion in a diff way, cause after year 2000 euro4 rules stay that nox got to be reduced then averybody decide by full EGR systems even the trucks.
I have been using a gtv23 since i turboed my 605.910 and some 50k ago , something i did not expect happen never the rods bent or pistons melted, neither the turbo quit with a lot of pushing 2.5 bar and lately was updated with a 64mm compressor and is still roling.
When i stated vgt is too big or too small i had 2 things in mind that i learned with my experiences over the years:
1 is that the vnt crap need gas to wake, the size of the turbine determines were in the rpm range it will wake like any other. Setting the vanes give us room to play a litle with the load in the turbine/boost level / wake rpm, no matter how u control it .
2 once the turbine is producing power we can alter the a/r by opening the vanes in function of many needs like egp/boost control/ engine brake ... whatever but the housing and turbine is smaller than a camparable wg turbo so chokes pretty pretty fast. In OEM aplication the egp can be reduced by opening the EGR. In our aplications since we dont like egr systems we have to balance a way of bleeding that gas cause they will not cross the turbine . I usually use the Egr valve with some mod to balance that. Others may have theyr one system but as far as a have seen is still the cheapest and easyer solution.

And u know better than i that the 2.7 OM612 uses a gtv22 and comparing by this don't u think it will take some time to wake in 1.5 liter 3 cylinder half 606?
That was the discussion i belive. But other arrangements can be done to use 2 gtv 22 with success in the 606. Nevertheless can't be in 3 plus 3 arrangement.
Regards

RE: Considering a Twin GT2256V setup on OM606 - Turbo - 06-10-2017

Well I get and see you point but I want to ad some things

If it is a IDI or DI engine, turbo only "think" about the pressure and temperature it receive, more temperature and pressure give more energy to drive turbine, the opposite is real for the compressor, the higher temperature reflects on more energy needed to compress air, and density lowers so mass flow by it self, and Reynolds numbers lower since higher temperature increase viscocity of gas that can lead to that flow less want to follow shape of the blade with is essential for building pressure. turbo machinery is all about relinking flow, key part of Eulers equations for machinery

If you take away egr function, for egr function to work exhaust back pressure need to be higher then boost pressure in the first place, if the flow of the egr is 60% you need to have turbo that can handle the increase of the flow to turbine and compressor in that point if you want to take advantage of that the engine can breath more. oem manufactures what’s higher back pressure in the way to increase higher egr flow to extreme sometime, look at this turbo
https://turbo.honeywell.com/whats-new-in-turbo/story/worlds-first-dual-compressor-turbo/
it was created for very high egr flow, and guess they wanted lower inertia on the turbine wheel as well, it actually has a waste gate as well since it was so easy to over spin them, they had ball bearing cartridge. So you can understand turbocharger did not like it so much when some shut of egr function and tune them up, many exploded, I have not seen that turbo construction on any newer diesel application.

if you have higher back pressure valve in engine need to shut to handle bigger exhaust pressure, if you want to spin a VNT/VGT turbo at low flow at little open the vanes it is going to have high back pressure since turbine efficiency go way down, and that really too hurt volumetric efficiency of the engine and by that bad flow, so it is not strange that if you take away egr function that turbo can have problem, and yes old IDI engine I can not remember they had VNT/VGT turbos at that time or did use them, can not remember, have not seen it anyway.
A good DI engine can take good combustion efficiency at lower a/F ratio as fare as I have seen then a IDI engine and only that produce more torque.

a VNT/VGT turbo have nice efficiency in some range but at higher open it start to chocke quite alot, typical of people say a VNT work bad since it choke a easy, at top efficiency a waste gated turbo have less back pressure, vnt wane give more friction losses since they are in the way of the flow, but if you treat a VNT like a waste gated one you are doing wrong in use of them in the first place, you can not drag a bold man in the hair, and look what turbie is on, turbines can choke quite early on some models, and full opening do not mean best efficiency

and often there is a not optimal turbine wheel watch to the compressor in reason to have response and not top efficiency, read
http://www.pcaeng.co.uk/library/Publications/WhitePapers/Turbocharging_seminar_2015_Cox_2_final.pdf
simply higher efficiency on the turbine mean it will hurt inertia for the turbine.

like I wrote before just look at the cartridge of the VNT of GTB2056VL and in the suspension of the VNT mechanism it going to choke quite bad on the turbine and not uniform flow by it shape if you trying to out run it ie out flow it, garret newer GTD serie and specially the duty drive VNT serie for medium diesels more optimal flow passes to VNT, and duty drive have support on both side of the vane so less back pressure just by that.

For a small turbo pushing 2,5 bar means pr ratio of 3,5 look at for the GT2056, 24-27lbs/min you are in the compressor map at pr 3,5 and 190000rpm, outside means the compressor efficiency go way down and turbine efficiency too, back pressure needs to go way up to spin it like that...

RE: Considering a Twin GT2256V setup on OM606 - barrote - 06-10-2017

Yep u're right in a way...
Anyhow plug and play is yet to be replaced by any theoretical aproach. ?

RE: Considering a Twin GT2256V setup on OM606 - Turbo - 06-11-2017

Good theoretical knowledge will make things so much easier most of the time, but the final is always to test, and no matter of how good you think you have calculate something in the end a stupid intake valve that do not close or oil in the intercooler can get catastrophic proportions and then you feel quite small but alive.

RE: Considering a Twin GT2256V setup on OM606 - JoeB - 08-04-2017

Yep, we're no closer than where we were before.
No interest in going compound for this application although I've seen it done - it's way too much pipework in the engine bay.

Then I thought what the heck.. back to a single T3 flange -

TB-58 spec:
0,60 A/R
Inducer 58 mm
Exducer 70mm
TRIM 68
Inlet 2,5"
Outlet 2"
360 lager

Turbine:
0,63 A/R
T3 single flange
Exducer (ut) 55 mm
Inducer 65 mm
TRIM 71
Outlet 2,5" V-band

Anyone familiar with these specs? They are from turbobandit and the promise is a quick spool.

RE: Considering a Twin GT2256V setup on OM606 - barrote - 08-05-2017

Have u taken a look at the kkk efr series?
Holset crap 30W? 35 is a good match for 606. But in a 4×4 i belive it will take time to wake?

Despite that one (seize) looks promissing.

RE: Considering a Twin GT2256V setup on OM606 - 50harleyrider - 08-06-2017

What about a single HX35W with a small (10CM) turbine housing? Should be quick spooling enough. Barrote Have you tried one?

RE: Considering a Twin GT2256V setup on OM606 - barrote - 08-06-2017

I had one in my 605 with nr 12 housing... and a friend wich i helped to build one 606 has one and it takes quite some time to wake, wich in my opinion does not suit a 4x4. Thing is the hx35 rotating core is too heavy is 4/5 times as heavy as a gt23v for comparisson, it takes time to wake. Even with a smaller turbine housing the rotating mass is the same.
So forguet the fast spool.
Hx 30 might be a good option...
My opinion , but if u want a 4x4 for long runs and sand cruizer well it may suit with the nr 10...

RE: Considering a Twin GT2256V setup on OM606 - JoeB - 09-07-2019

Well,
the 4x4 project has been terminated, due to finding significant rust in the vehicle which makes it not cost-effective (needs a new body firewall/a-pillar section) to continue. Sad

So a w124 300TE donor may be on the cards. I am in the process of securing one from a friend. If so, it will be out with the 3.0m103 and in with OM606/722.6
Just sorting out the costing, and parts needed for the swap. things like ign stop and other w124 diesel-specific bits.

Bit of a shame really, the RRC has hidden this rust issue for 5 years, and literally where the issue was discovered, had been inspected more than a dozen times in the period.
The rest of the vehicle is immaculate, but cost of body repair makes the entire project a no-go.
If it was a gelandewagen, the repair cost to do the exact same repair would have been insignificant by comparison.

So now the second OM606 with it's EDC pump is being considered for use in w124, although I'd like to put the original build with 6mm mech pump in.

A completely different set of reference points and information is now required to be understood.

Feel free to dispense advice/experience with your w124 setup (no I am not doing 8mm superpumps and hx35's this will be a daily)