Exhaust Throttle of the future

I helped do some of the original dev work on this bad boy, but I wanted to get everyone's take on the Holset Rotary Turbine Control valve... It can restrict and/or move flow from one turbine to another in a compound setup. My understanding is old and slightly basic, but basically this valve allows the turbos to operate together or independently depending on conditions.

Thoughts? I hope they worked out the bugs.

http://www.cumminsturbotechnologies.com/ctt/navigationAction.do?url=SiteContent+en+HTML+ProductsAndTechnologies+Next_generation_products

http://blog.caranddriver.com/next-gen-nissan-titan-destined-for-detroit-we-detail-its-clever-new-diesel-engine/

Edit: Another good link: http://www.topspeed.com/trucks/truck-news/deep-dive-nissan-titan-xd-s-cummins-turbocharger-ar167368.html

It is being used on a 5.0 light duty DOHC v8. The engine was originally part of a government grant/EPA development program and, along with a v6 version, was destined for the ram 1500 before CARPOCOLYPSE 2008-09 when Fiat took over. Cummins built a plant for the engines but the orders never came.

I must reinforce this is a light duty engine, jamming 900 more lbs of boost through it stock will not happen.

I do hope that when the valve fails it defaults to the larger turbo so you are still able to reach full power it will just be laggy. I would hate to be hauling 20K lbs and have it fail and only using the small turbo.

And I currently work for cummins so i probably shouldnt voice my real opinion on the 5.0 v8's...

I don't see how it could be any less reliable than their current line of VG turbos with "sliding wall" actuators that throttle the turbine housing.

The engine itself, on the other hand, who knows.

The benefits of the new system are that the turbos are relatively "low tech" themselves. They can be easily replaced and semi-cheaply. The valve itself should be more resistant to FOD than the sliding wall VGT. However, the extra weight of piping, adding a 2nd turbo, more complexity.. I don't know yet.

Why?

Diesels have automatics. Automatics help turbos spool. The tradeoff for making 600tqs at 1500rpm is if you are below 1500rpm, you might have to wait a second, so basically the only issue is off-idle and who expects a 6500+lb vehicle to be responsive?

I don't like it. Too much complexity for such little gain.

not all diesels have automatics. The trucks I used to drive were all manual shifts.

mad_machine wrote: not all diesels have automatics. The trucks I used to drive were all manual shifts.

Please point out a light or heavy duty modern diesel truck with a manual. There aren't any, for multiple reasons. So while you have a point, it has no relevant value to this conversation about a new truck and hokey gimmicks for something that is a non-issue and will add cost and complexity.

Edit- Sorry if that came off a bit shiny happy person-ish. It seemed like you were trying to snub my opinion.

HiTempguy wrote: Please point out a light or heavy duty modern diesel truck with a manual. There aren't any, for multiple reasons.

That is only true if you exclude Dodge. Manual trans is still optional on all 2500 and 3500 models with diesel engines except Longhorn. Limited in 2WD.

Shiny happy person commentary withheld.

HiTempguy wrote: Why? Diesels have automatics. Automatics help turbos spool. The tradeoff for making 600tqs at 1500rpm is if you are below 1500rpm, you might have to wait a second, so basically the only issue is off-idle and who expects a 6500+lb vehicle to be responsive? I don't like it. Too much complexity for such little gain.

You're forgetting transient response. With a load, on hill... These will help you not loose as much speed.

You're also forgetting this is a light duty product. They are trying to woo the "gotta have a truck" suburban buyer with better fuel economy and the same performance as gas. This engine will not be used in a HD application.

HiTempguy wrote: Please point out a light or heavy duty modern diesel truck with a manual. There aren't any, for multiple reasons.

There are the Toyota Land Cruiser and Nissan Patrol utility pickups, although they're not available in the US, and their designs are arguably not modern There's also the Isuzu Dmax and Mahindra Pikup if modern "compact" pickups count.

In reply to SVreX:

And this is the last year they will be available as FCA will drop the Cummins.

Fueled by Caffeine wrote: You're also forgetting this is a light duty product. They are trying to woo the "gotta have a truck" suburban buyer with better fuel economy and the same performance as gas. This engine will not be used in a HD application.

The Nissan Titan and the Hummer H2 are the only trucks (in factory form) that make me instantly, instinctively pity the driver. They're not the biggest trucks out there, but they're the ones that make the biggest deal about being big, and they're clearly not big for any potential purpose. At least a Dodge 3500 or Ford F450 comes with some plausible deniability.

In reply to GameboyRMH:

The Nissan Titan and the Hummer H2 are the only trucks (in factory form) that make me instantly, instinctively pity the driver. They're not the biggest trucks out there, but they're the ones that make the biggest deal about being big, and they're clearly not big for any potential purpose. At least a Dodge 3500 or Ford F450 comes with some plausible deniability.

???

The Titan is about the size of all the other full size trucks. Because people buy full size trucks, since they can carry more than smaller trucks. They didn't invent the segment. Dodge started the "Look at me, I'm a big truck" styling trend in the '90's. Nissan did it second. Now every full size is styled like that. Nissan "had" to. They didn't want to get grouped in with Toyota and their almost full sized trucks back when the Titan came out.

The H2 is a restyled Tahoe, meant to look like an H1. Do you pity people driving Tahoes?

Like I said, it's not just about the truck's size, it's about the truck's styling, and branding plays a part too - precisely why I don't pity people in Tahoes.

SVreX wrote: That is only true if you exclude Dodge. Manual trans is still optional on all 2500 and 3500 models with diesel engines except Longhorn. Limited in 2WD. Shiny happy person commentary withheld.

While I will give you that, they are derated to 610tq while the auto is 800 (now something like 850). I have never seen one in the wild, and why somebody would go with a weaker option with very little benefit is beyond me. So in theory, I admit defeat, in reality, it just isn't relevant, and that was my original point. It is simply not needed.

Fueled by Caffeine wrote: You're forgetting transient response. With a load, on hill... These will help you not loose as much speed. You're also forgetting this is a light duty product. They are trying to woo the "gotta have a truck" suburban buyer with better fuel economy and the same performance as gas. This engine will not be used in a HD application.

I'm not forgetting at all. I honestly would LOVE to see the data to back up the claim that response time of an already under-load at cruising speed loaded diesel does not have virtually instantaneous response at almost any engine rpm above idle. My duramax is annoying with how responsive it is at highway speeds.

I will agree about the performance aspects. I've heard so many people slam the Dodge Ecodiesel because it is "slower" then the hemi. And then I point out it has the same tq at 2000rpm as the hemi has at 4k rpm and they go "its still slower" and I'm all "the truck and trailer won't notice that while towing up a hill and delivering 40% better mpg".

GameboyRMH wrote: There are the Toyota Land Cruiser and Nissan Patrol utility pickups, although they're not available in the US, and their designs are arguably not modern There's also the Isuzu Dmax and Mahindra Pikup if modern "compact" pickups count.

North America is the world, everyone knows that. I await your further smoke signals from the island

HiTempguy wrote: I will agree about the performance aspects. I've heard so many people slam the Dodge Ecodiesel because it is "slower" then the hemi. And then I point out it has the same tq at 2000rpm as the hemi has at 4k rpm and they go "its still slower" and I'm all "the truck and trailer won't notice that while towing up a hill and delivering 40% better mpg".

that answers so many questions about people who drive hemi pickups...

seriously, maybe Dodge should have branded their ecodiesel the "hemidiesel"

BTW.. diesel is 2 cents cheaper than regular around here

Fueled by Caffeine wrote: I helped do some of the original dev work on this bad boy, but I wanted to get everyone's take on the Holset Rotary Turbine Control valve... It can restrict and/or move flow from one turbine to another in a compound setup. My understanding is old and slightly basic, but basically this valve allows the turbos to operate together or independently depending on conditions. Thoughts? I hope they worked out the bugs. http://www.cumminsturbotechnologies.com/ctt/navigationAction.do?url=SiteContent+en+HTML+ProductsAndTechnologies+Next_generation_products http://blog.caranddriver.com/next-gen-nissan-titan-destined-for-detroit-we-detail-its-clever-new-diesel-engine/ Edit: Another good link: http://www.topspeed.com/trucks/truck-news/deep-dive-nissan-titan-xd-s-cummins-turbocharger-ar167368.html It is being used on a 5.0 light duty DOHC v8. The engine was originally part of a government grant/EPA development program and, along with a v6 version, was destined for the ram 1500 before CARPOCOLYPSE 2008-09 when Fiat took over. Cummins built a plant for the engines but the orders never came. I must reinforce this is a light duty engine, jamming 900 more lbs of boost through it stock will not happen.

I watched the video at that last link, and I can't pick the difference between Mode 1 and Mode 4 (High Pressure Mode and Regen Mode). Does anyone know? Seems unnecessarily complex and all those bends in the piping have got to be robbing some power.