Thread: Has anyone compound turbocharged a TD5?

The Borg Warner R2S have evolved a lot since the beginning. The first application I was aware of was the BMW 3.0 tdi which was pushing 600Nm and about 42psi boost.
Here is the early one from 2004:

BorgWarner to Supply Regulated Two-Stage Turbocharging Technology to BMW

Here is the boost curve from it. John this is conveniently from your Photobucket account. The BMW system above follows the curve at the bottom. At higher rpm the small turbo is bypassed and only the big one is working:


In 2010 I visited the BMW factory museum in Munich and took these photos of the evolved system:

Originally Posted by Bush65

At best adiabatic efficiency of 0.75 a Garrett GT2052 turbo (52 mm exducer) compressor wheel typically would at best have a pressure ratio of approximately 2.2 (17.5 psi) with a 52 trim wheel or less than 2 (less than 14.5 psi) with a 48 or 50 trim. These wheels are off the map by approximately 2.5 PR

By comparison a Garrett compressor wheel with 71 or 76 mm exducer and largish trim can have better efficiency beyond a PR of 3.0 (over 30 psi).

It's also worth noting that the compressor blade design affects the exit angle and boost capacity greatly.
The MHI TD04-19T compressor wheel is 58mm and runs a PR of 3.
The Holset HE221 compressor wheel is 60mm and runs to a PR of 4.

The difference is the 19T wheel has a significant rearward exit angle which gives it better surge resistance and better efficiency.
But it can't produce the boost and the compressor speeds are much higher. 170k rpm for the top of the map.
The HE221 is turning 147k at similar boost pressures.

But all is not roses. The HE221 has significantly lower efficiency across the range than the 19T.
Trade-off efficiency for operating range.

Originally Posted by Bush65

When compounded the adiabatic efficiencies also compound, and for example if both were 0.75, the overall would be 0.56 (0.75 x 0.75).

That I don't agree with. I have worked examples.
Two 60% efficient compressors working in series (PR 2.1 each) with no heat loss produce a temperature of ~569k from 293k intake.
That is equivalent to a single stage of 55% efficiency

Two 75% efficient compressors would produce 506k final temp for the same PR which is equivalent to a single stage efficiency of 71%

Inter-stage cooling is also difficult to predict. I get two cooling stages of 60% heat removal giving a similar temp reduction to a final stage cooling of 75%.

I think we should try the triturbo from the 550 bmw

How easy is this going to be to bolt to a td5



you could put a fake (hollow) spare wheel on your bonnet to hide the lump.

BorgWarner compound turbo setup from Iveco Daily, the small turbo is a wasategate job about the same size as the Td5 turbo, the big mother runs all the time

Originally Posted by goingbush

How easy is this going to be to bolt to a td5



you could put a fake (hollow) spare wheel on your bonnet to hide the lump.

BorgWarner compound turbo setup from Iveco Daily, the small turbo is a wasategate job about the same size as the Td5 turbo, the big mother runs all the time

Which was is up? Or rather down with the direction of the drain on each turbo. Can the centres be reclocked (rotated) if new location is on a different angle to the original?

Some guy in the US was selling a set of these (from a Fuso, same engine) for about $US200. Thankfully someone else bought them.

$200 -

they normally sit this way

Dougal, way off topic, but being a Diesel man , Im wondering if you had any thoughts as to why the Canter Fuso 4P10 (same engine as you already know) has an exhaust brake as standard equipment, but Iveco , absolutely no way , not ever will fit an exhaust brake to the F1C , and will blow the warranty if I do , ( the downhill braking is crap- and dangerous if your towing) . Iveco give some excuse as it will damage the EGR , But the 4P10 uses exactly the same VDO supplied EGR , The only difference is Iveco use regen DPF and Fuso use AdBlue. Ivecos answer is to ask you to fit a $20,000 Telma retarder , which is very heavy and not easy to retrofit to the 4x4 anyway.

that complete pile of garbage across the top of the engine (above the top turbo) is the EGR and EGR cooler (with shiny pipe coming out the back on the way to the inlet manifold)

Here is the same Fuso/Iveco compound set fitted to that 2.4td Volvo in a disco from the video on post #2.



It's interesting just how small a turbo needs to be to deliver significant boost right off idle. Compound is the only way to do this.

Another video here: [ame]http://www.youtube.com/watch?v=uq0OH4EGYd8&feature=youtu.be[/ame]

Regarding EGR and exhaust brakes.
If the Fuso is running Ad-blue aftertreatment then it suggests it's not running as much EGR. The EGR system is likely programmed to be shut more often, particularly when the exhaust brake is being used.
The Ad-blue afterwards will keep the NOx down in these situations.

Of course if you map the EGR out there is nothing stopping you from running an exhaust brake. You likely wouldn't do this within warranty though. With EGR mapped out (literally switching two bits in the ECU file) I like to leave it in place as the hardware can also peform some hidden functions on some vehicles. Like venting intake to exhaust on rapid release of throttle to stop the turbos barking.