B58 Reliability

[bemax]

?

„Combusted air back into the intake…. Hot, combusted air back into the intake…. I’m thinking ‘No’. Don’t crap where you eat…“

But you know that there is a system called „exhaust gas recirculation“, don’t you?
There is no connection to the turbo but the engine gets a certain amount of „used“ air to lower the emissions.

 

[Disco Dave]

Yes, the dirty diesel version, the B57, has one of those.

 

[emax]

Modern turbocharged engines are equipped with a VGT. This means they do not have a wastegate at all.

Every "non-carbureted" engine has an airflow sensor in the intake tract. This sensor responds to airflow, air temperature, and air pressure. Each of these values is an absolute value. Since all of these values are known at all times, I would be very surprised if the VGT is not controlled by the ECU in question.

While it is only a guess, I therefore do not believe that the boost pressure is dependent on a fixed setting. I rather believe that it is optimally adapted to the given conditions at any time.

As things stand, the B57 is a VGT loaded engine ("VTG" in German):

 

[Disco Dave]

I researched it a couple of hours ago. The B58 has an electronically actuated waste gate, to vary the amount of exhaust gas powering the turbo. Excess exhaust gas is dumped into the exhaust pipe. See video from 2:55. The B58TU, which I believe the IG is getting, has has a different manifold arrangement, but the turbo is the same.

 

[emax]

From the "B57 Engine" brochure, page 71:

 

[DaveB]

I researched it a couple of hours ago. The B58 has an electronically actuated waste gate, to vary the amount of exhaust gas powering the turbo. Excess exhaust gas is dumped into the exhaust pipe. See video from 2:55. The B58TU, which I believe the IG is getting, has has a different manifold arrangement, but the turbo is the same.

Yes, as I rather badly tried to explain

 

[emax]

I researched it a couple of hours ago. The B58 has an electronically actuated waste gate, to vary the amount of exhaust gas powering the turbo. Excess exhaust gas is dumped into the exhaust pipe. See video from 2:55. The B58TU, which I believe the IG is getting, has has a different manifold arrangement, but the turbo is the same.

I first thought that the wastegate part in that video is outdated. But according to the engine brochures it indeed seems that the B58 still has a wastegate system as opposed to the B57 which is VGT controlled.

 

[Disco Dave]

emax, you brought a B57 to a B58 fight

 

[emax]

As far as I'm concerned, there is no reason to fight: I'll get a B57.

 

[globalgregors]

Isn't an modern turbo motor controlled so that power is maintained automatically according to the current altitude? (i.e. air pressure, to be correct)

In that case, there shouldn't be too significant a difference.

High altitude performance was a real issue for us in the Pamir Mountains in particular, and I’ve been prowling the B57 literature to establish what one might expect with the IG… field testing being difficult in Oz.

With the Disco, I gather a couple of systems contribute to performance issues at altitude;
- Turbocharging makes a positive contribution, as discussed already;
- Exhaust Gas Recirculation makes a detractive contribution (I stress, this in the LR SD4) as it further dilutes the oxygenation of the input charge;
- The DS gearbox is never truly ’manual’ in the sense that it cannot be forced to hold 1st gear, which can be necessary to spool the turbo up enough to give one somethimg to work with.

Protracted high altitude use can for some vehicles delay DPF regeneration and reduce engine cooling efficiency, I didn’t see these symptoms in the LR.

Point being it’s helpful to know what to expect (and compensate if necesary) rather than stumbling across the issue on some goat track at 4,000m, with the weather blasting in.

 

[Shaky]

Gents, this most certainly is an area where I have very little experience. I have ordered the petrol version and whilst others would most likely be looking for more power I would be looking for more MPG.

Is this going to be harder to achieve than getting more power with a ECU update or a box fitted ?

I see these company’s offering performance chips but I am more suspicious with the fuel economy versions.

 

[MileHigh]

While, everyone concentrates on the amount of oxygen in the charge of air, going into the cylinder, which is obviously very important for combustion, the amount of inert gases that absorb energy and act more energetically is important also. That’s why a water injection system for airplanes, and sometimes cars, will increase power. You’re increasing the amount of participant molecules to absorb the combustion energy and move the cylinder. For some reason, I remember an experiment where they tried a combustion engine on pure oxygen, and it just burns up.

 

[DCPU]

I thought I would ask Mr Garrett as it is Garrett turbo's in both the petrol (Single turbo)and Diesel

Just read an article saying they were potentially up for sale and were bankrupt back in 2020 before being bought out of Chapter 11 in 2021.

 

[burtmacklinfbi]

Turbo's can compensate to a degree (as pointed out in the data from Garrett Turbos). At 10k feet you will still see a fair amount less power due to the efficiency range, not to mention a considerably slower spool up time. Turbos spool up faster and can hit the targeted PSI (whatever that is adjusted to) at lower elevations. For example, I did a test roughly 10 years ago with an Evo 8. Up at SLC (just over 4k ft), the car ran a 13.5 s 1/4 mile at 107mph. Then drove the car down to Texas, using the same setup at lower elevation (just above sea level), the car ran a 12.6 at 115 mph. Driving around town it was a noticeable difference in spool time, about 500 rpm sooner. I drove this same car from Utah to Colorado, and around 8k RPMs, the turbo was taking another 1k RPMs to start going into boost.

 

[DaveB]

Turbo's can compensate to a degree (as pointed out in the data from Garrett Turbos). At 10k feet you will still see a fair amount less power due to the efficiency range, not to mention a considerably slower spool up time. Turbos spool up faster and can hit the targeted PSI (whatever that is adjusted to) at lower elevations. For example, I did a test roughly 10 years ago with an Evo 8. Up at SLC (just over 4k ft), the car ran a 13.5 s 1/4 mile at 107mph. Then drove the car down to Texas, using the same setup at lower elevation (just above sea level), the car ran a 12.6 at 115 mph. Driving around town it was a noticeable difference in spool time, about 500 rpm sooner. I drove this same car from Utah to Colorado, and around 8k RPMs, the turbo was taking another 1k RPMs to start going into boost.

That is why the diesel with the twin compound turbo setup would be better for high altitude and quicker spooling up.
Unfortunately not going to the US

 

[Krabby]

Pumped-up straight 6.

 

[DCPU]

Is that engine related to the Grenadier ones?

 

[Krabby]

Is that engine related to the Grenadier ones?

Don’t know. It’s a BMW straight 6 so maybe. But it must have different internals regardless.

 

[emax]

I think this just shows what is possible.

BMW can handle power at will. Their engines are exceptionally well designed and seem to have no limits.

What kills them, though, is all the stuff to keep exhaust emissions below those of the Alpine forests.

 

[ChasingOurTrunks]

I am nervous about turbos; recognizing they do improve power and emissions-per-HP, they also introduce additional mechanical complexity to the unit. But, it's one of the compromises we have to make. The fact is everything breaks eventually, my main concern is how devastating the break is to continuing a journey.

So a scenario, based on what I understand is a common issue with Turbocharged Ford motors for a spell - they were regularly failing at 100k kms because of failed turbos:

I'm cruising up through Alaska at a steady 100 KPH, turbo screaming the whole way. I put in a 12 hour day, pull into camp and kill the motor, and since my vehicle has been "rode hard and put away wet", that's the day the turbo really needed help cooling down gently but because I didn't do that, I wake up the next morning to an awful sound of a siezed turbo and a motor that won't mote.

What's my solution, assuming I've got a robust set of handtools?