new Mercedes-Benz 2.1L 204hp 369 ft-lb

http://www.dieselforecast.com/ArticleDetails.php?articleID=476

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i dont know what you are talking about.????? the mb is to-stage turbocharging.. and how are you going to control that???....michael

everybody is doing two stage turbos now.

BMW and in America. . .Ford's new powerstroke. both the V6 and V8. .

I know there are more. . or at least more in develpoment.

the newest CR fuel systems can pretty much flow all the fuel you want, in a controlled matter. So you "need" more air. . .the time for twin-turbos has come (again) be happy

The future sure looks interesting!

Talk about fun cars!

Its really too bad engine makers are devolving from the superior VNT to complicated, bulky, expensive and obsolete sequential-compound turbos.

Umm, you owe my monitor a coffee-cleanup...

Obsolete?

Yes. BMW beat them to 100hp/L last year and the better VNT is being replaced by the inferrior two-turbo sequential-compound setup.

They are cutting production costs to offset some of the emissions add-on costs.

Diesel_Benz said:

Yes. BMW beat them to 100hp/L last year and the better VNT is being replaced by the inferrior two-turbo sequential-compound setup.

They are cutting production costs to offset some of the emissions add-on costs.

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VNT is good when you work with only one turbocharger.

But one turbocompressor cannot give full boost between 1000...4500 rpm which is what people nowadays want.
So you need two turbos (or mechanical chargers), one small and one large to cover the whole rpm range.

With two turbos vnt-technology loses it's advantages and only shows it's downside: worse turbine efficiency due to the vanes interfering exhaust gas flow.

TDIfreak said:

worse turbine efficiency due to the vanes interfering exhaust gas flow.

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So...adding a bunch of bends, valves and an another turbine is somehow...more efficient? BS. Its only about cost.

Don't understand how one VNT can cost more than a bespoke setup w/ two complete turbos with all associated plumbing and controls.

Lots of cast parts, less machining, no vane ring and no expensive inconel vanes.

"Mercedes has optimized the shape of the combustion chamber and reduced the compression ratio to 16.2:1 (down from 17.5:1). "

seams to me all this talk about the new engines lowering the CR. They are so lucky that they can do that with the new injection abilities.

"The engine designers at Mercedes have reduced the mass of many internal components of the engines and increased the strength. The lower reciprocating mass reduces the noise and vibration of the engine providing a more pleasant driving experience. "

This makes me happy! I am wondering how my project car will feel!

One VNT turbo would be about 1/3 of the cost of a sequential setup. Or even less when you consider the complexity of the controll system.

BTW vnt is not that superior...

VailPowder said:

The future sure looks interesting!

Talk about fun cars!

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When does the kerma twin turbo kit come out. That I will buy. lol

IMO...
2 turbos are required to preserve low speed responsiveness coupled to top end power. Use VNT to improve spool/reduce lag as much as possible. There's a finite amount of energy in the exhaust gasses. It's easier to spin up a small turbine/compressor combo than a larger one.

Lose efficiency by having backpressure in the exhaust system... as most/all factory road cars will do, and you need 2 turbos even more.

J.

Ive seen lots of gas aftermarket cars expirmenting with parallel twin turbo's as a way to decrease lag.

for example a pair of GT28R's (with the right hotside cold side combination) will support about 550 WHP on a Mazda 13B turbo, probably 600-650 on a small 4cyl. On C16 race gas.

They will also spool about 16PSI by 3K rpm, pumping enough air to make @160 WHP at that RPM vs a GT35R that will support a maximum of 550 WHP tuned to the max, that will spool about 7 PSI by 3K rpm, corresponding to about 120 WHP. (keep in mind, these cars rev and make power to 8K plus RPM, although the power starts up high the the power curve is still very broad).

The faster spooling is largley due to the lower rotating mass, a pair of small turbo's has over a larger turbo. They are also pushing more air, with less restriction in the hotside's, so 10 PSI corresponds to more air in the pair than it does in the larger single.

2 GT28R's also cost a hell of a lot less than any GT35R, plus with internal wastgates, there is no wastgate to worry about that saves 600+ dollars.

How does this relate to the TDI, not sure, it would be pretty dam hard to find a pair of turbo's small enough for the TDI.

Its really too bad engine makers are devolving from the superior VNT to complicated, bulky, expensive and obsolete sequential-compound turbos.

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I asked a question regarding the efficiency of a VNT vs a 2-stage turbo setup in another thread - http://forums.tdiclub.com/showthread.php?t=197998 . My question, and the reply from a couple of engineers who frequent this board, you can read there.

201hp, for that I just need a OEM pd150 with a hybrid..

@12MPGHWY do you have personal experience with spooling of 2 gt28r cartidges on a 13B? What A/R and compressor? something real mean would be a 20B with 3 of these babies, lol

The 1.4L Golf GT (gasser) produce 170hp using both a supercharger and a turbo.
That would be interresting in a TDI...

Don't remember the specs on the turbo's but I think they where the largest ones you can get, there are at least 8 different GT28R versions available.

Bassicly check the compressor maps a pick the ones that flow the most.


It was in an FC, with a fully dual exhaust, twin 3 in downpipes all the way back with 3 inch pre mufllers and mufflers. Running 100% methanol injection and a medium size VMIC.

If your farmillar with stock sequential FD twins (when the car is running good, and modified with at least a PFC and all bolt on mods and street port)

They will spool 15 PSI by 2600RPM or so,the GT28R's where spooling about 7 PSI at that RPM, but that 7 PSI is a hell of a lot more air. Basicly the car felt stronger everywhere. It had the best low end performance I have ever felt from a 13B better even than sequential twins, and without all that headache


On a 20B, that would be a killer setup, real easy to push 600 WHP on pump gas, and I immagine it might make 600 LB feet of torque. And still cheaper than a GT42R and a big wastegate.

Rub87 said:

201hp, for that I just need a OEM pd150 with a hybrid..

@12MPGHWY do you have personal experience with spooling of 2 gt28r cartidges on a 13B? What A/R and compressor? something real mean would be a 20B with 3 of these babies, lol

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Will consider ..

At we have a fully stock 20B in a cosmo with RE-Amemiya type B rom, everything else is stock.. at 0.8 bar it really pulls, has 400nm+ at 2000rpm, and definatly 350+hp from the butt dyno.. not bad if you look at the size of the turbo's..

Still wondering what there will be first: a retrofitted oem twin turbo setup, or a 3rd party for 8v 1.9 tdi's..

I think some member here already went with the twin turbo approach for a ~1.9 engine, like hatemi etc, but I didn't see the results..

Also allard went with it, with a devon's car, 2.0 16v engine but after half a year it's still silent around the topic so I'm affraid the results also weren't there, too bad..

If I only had the time and funds.. :/

One of the problems of a fairly large displacement (for a passenger car application) 4-cylinder engine is the long stroke at 99mm and the inherent reciprocating mass of a Diesel engine. I'd love to see the size and weight of the balance shafts for this engine.

Statements of weight reduction are nothing but PR-speak. Not a single OEM doesn't invest significant engineering resources to weight optimization, but different companies go about it differently. The claim seems to become diminished when M-B and VW are still using cast iron crankcases whilst BMW is leading the way with using aluminium as the crankcase material for its biturbo Diesel. The BMW also has an appreciably shorter stroke (90mm) than both the VW 2.0 TDI (95.5mm) and M-B 2.14 CDI (99mm).

As an engine engineer, of all the three biturbo inline-4 engines, I'd choose the BMW in a heartbeat, although the BMW biturbo inline-6 would still beat all in my books.

TDIMeister said:

One of the problems of a fairly large displacement (for a passenger car application) 4-cylinder engine is the long stroke at 99mm and the inherent reciprocating mass of a Diesel engine. I'd love to see the size and weight of the balance shafts for this engine.

Statements of weight reduction are nothing but PR-speak. Not a single OEM doesn't invest significant engineering resources to weight optimization, but different companies go about it differently. The claim seems to become diminished when M-B and VW are still using cast iron crankcases whilst BMW is leading the way with using aluminium as the crankcase material for its biturbo Diesel. The BMW also has an appreciably shorter stroke (90mm) than both the VW 2.0 TDI (95.5mm) and M-B 2.14 CDI (99mm).

As an engine engineer, of all the three biturbo inline-4 engines, I'd choose the BMW in a heartbeat, although the BMW biturbo inline-6 would still beat all in my books.

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Any interest in the honda 4cyl turbo diesel?

TDIMeister said:

One of the problems of a fairly large displacement (for a passenger car application) 4-cylinder engine is the long stroke at 99mm and the inherent reciprocating mass of a Diesel engine. I'd love to see the size and weight of the balance shafts for this engine.

Statements of weight reduction are nothing but PR-speak. Not a single OEM doesn't invest significant engineering resources to weight optimization, but different companies go about it differently. The claim seems to become diminished when M-B and VW are still using cast iron crankcases whilst BMW is leading the way with using aluminium as the crankcase material for its biturbo Diesel. The BMW also has an appreciably shorter stroke (90mm) than both the VW 2.0 TDI (95.5mm) and M-B 2.14 CDI (99mm).

As an engine engineer, of all the three biturbo inline-4 engines, I'd choose the BMW in a heartbeat, although the BMW biturbo inline-6 would still beat all in my books.

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Yeah, well if I show up at your doorstep in a 2008 MB C-300 CDI I want to see you say no when I throw you the keys

See ya tomorrow DUDE!


DB

Passenger Performance said:

Any interest in the honda 4cyl turbo diesel?

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If they do a biturbo version, sure, why not!

Drivbiwire said:

Yeah, well if I show up at your doorstep in a 2008 MB C-300 CDI I want to see you say no when I throw you the keys

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Meh, wouldn't be the first time I've driven one.

4 countries in 12 hours! Luxemburg, Belgium, Netherlands and Germany and the pinacle of the journey:


http://www.nuerburgring.de/home.324.0.html

TDIMeister, hope we didn't scare you too much at Nurburgring when I locked up the wheels after the hairpin turn entering the straghtaway, got a little sideways but kept it under control (mostly)... You also learned not to tell me to turn, now! Talk about a car that handles on rails









Great seeing ya, thanks for the hospitality and tour of Aachen!

DB

Where are the movies

Did you like Belgium? lol