New twin-compressor Garrett

[93forestpearl]

The new 6.7 L FoMoCo built Powerstroke has an interesting turbo, reverse flow heads, and a bunch of interesting stuff going on.


Discuss...



http://www.dieselpowermag.com/features/ ... to_07.html

[fishbone79]

Nice!

Some honest innovation out of Detroit?? There must be a mistake!

[93forestpearl]

If Detroit wants to, they can engineer some phenomenal machines. They just have to want it...

[fishbone79]

Oh, I totally agree... Seems they have rarely wanted it as of late.

Unfortunately this motor is being manufactured in Mexico - I suspect we all agree on what that must surely mean...

[93forestpearl]

That doesn't necessarily mean anything. Quality starts at the top, so management practices have more to do with it than anything else.

[fishbone79]

Well, that's a mantra touted by VW corporate... and we see how well that worked out. There's a good reason they make the R32 in Germany and the beetle in Mexico. Even with the best intentions, precise manufacturing and strict QC sometimes just aren't possible.

[93forestpearl]

That's a mantra that is sweeping the whole manufacturing industry. 6σ, lean, sqc, TPM, etc.


You don't know what machinery they are using, what training is required of the employees, what practices are in place, etc. There are too many factors to simply say that a manufacturing plant in X location cannot maintain a certain level of quality. American quality wasn't the best for a long time, but has come a long ways as of late.

[fishbone79]

I prefer to stick with the numbers, which suggest poorer QC, etc. I'll believe better when I see better, but I have yet to see any indication of a drastic turnaround in quality. Hence, the R32 is made in Germany, for example.

The main point is, even given equal potential quality from both possibilities, they should be manufacturing here and not there

[evolutionmovement]

Other models than the New Beetle and Jetta (the ones built in Mexico) have way more problems than I'd tolerate from anything without old Lucas electrics and some of their problems were down to just plain old bad engineering (like 1.8T oil pickups) or improperly specced parts (like almost circuit board-sized wires for lights). Don't get me wrong, the New Beetle is almost in a class of its own as a complete POS, but it's not an exclusive club and some of that is still an issue of design (swapping a frequently-blown taillight out is enough to get an idea of just how terrible the company is). In fact, they're so bad that I'm convinced it's intentionally done by sadists and not merely ineptitude.

[206er]

i like the exhaust side. basically the same increased velocity of a devided scroll ala holset HX35 but with convenience of not having to join the cylinder banks into one pipe. seperating the two exhaust streams probably lets them aim it at the turbine wheel in the best way possible which might be compromised with a twin scroll. also maybe it decreases turbulence to have the two exhaust streams seperated from one another by however many degrees that is.

does it have VGT/VNT technology? I cant really tell. I am looking at a HE341VE or GT2256V with a mechanical vgt control for my next turbo.

[fishbone79]

I don't know how they are getting away with calling it a twin on the cold side. The two compressors are mirror images of each other mounted on the same shaft, which is not independent. It's a single turbo with a 2-stage compressor wheel... not a "twin." I understand they're producing independent streams, but they spool simultaneously.

Kinda funny, the left exhaust manifold looks so similar to the 1930's flathead manifolds (coincidence, I know, but weird):


1935:

[Aerotech]

Not a VNT, I think... looking at the CAD drawing the turbine housing looks like a standard-issue wastegated unit, aside from the twin inlets. VNT would have the actuator linked closer to the center of the turbo, pre-turbine.
VNT DEMO

I'm playing around with finding a VNT for my van 1.9TD project right now... looking at Garrett VNT-15 or-17 from the TDI motors, a few people have designed really clever mechanical vane controls to run them on cars without electronics; a direct cable link to the throttle arm, to open the vanes, buffered by a spring relief activated by boost pressure that backs the vanes off when boost builds up to correct levels.

VNT VIDEO LINK

I have to agree on the Mexican build quality question, our '98 Jetta Wolfsburg was plagued with Mexican-built Bosch parts that failed. Once I got the entire ignition system replaced with German-built replacement parts, she runs fine. VW reliability numbers have been in the shitter for years now.

[206er]

see if you can find a gt2056V or a gt2256v. sprinter vans and jeep liberty crd's. people are putting a wastegate actuator on the vnt actuator so it is open at whatever the actuators pressure is.

[Aerotech]

see if you can find a gt2056V or a gt2256v. sprinter vans and jeep liberty crd's. people are putting a wastegate actuator on the vnt actuator so it is open at whatever the actuators pressure is.

Those may be a bit too large for my rig... it's only a 1.9, and in a heavy van, set up for off-roading. I need instant spooling. There's a Mitsu unit on Ebay from Germany, it's for a VW Crafter, which is a Sprinter with VWs own 5-cyl TDI engine in it; the thing is huge. It's a shame, 'cause that would almost be a bolt-on for my exhaust manifold.... everything else I see is set up for inverted mounting, mine is a top-mount.

[93forestpearl]

It is a VNT, guys. You can see it in the exhaust housing right by the wheel, which is actually hidden by the vanes and unison ring. Did you read the article?

It even uses the same solenoid to control the vanes. I have two of them in my garage.




I'm not sure if the pic was depicted correctly. The compressor wheel is actually two wheels back to back. They each have their own inlet. According to Garrett (via the article) this layout provides a much wider range of operation, hence their reference to the compressor map. I'd really like to see said map.


It is called a "twin" because the two compressor wheels act as their own unit with their own inlet, thus allowing them to use completely different wheel profiles with their own flow functions. Simple, yet clever.




Also, LOL at thinking that Germany has a fantastic build quality compared to what comes out of mexico. German cars are lagging behind the Koreans in terms of reliability. You mention numbers, so where are they?

[Legacy777]

Definitely some interesting design aspects of the turbo and engine...

[555BCTurbo]

Still a Powerjoke...

[entirelyturbo]

Well, this engine is actually made by Ford for once, not International... although it's apparently still built in Mexico

Dan, most all of VW's and Nissan's reliability problems come from Mexico. The Mexican-built Beetle and Golf/Rabbit and Jetta are usually their worst, while Nissan's had a lot of problems with Sentras and Versas... both Mexican-built.

Yeah, Sprinters have VNT turbos. I don't have a boost gauge (yet) for my work Sprinter, but it feels like it's on full boost at 1200rpm. It's awesome.