Twin Turbo Straight Six Cylinder Engine

[slip]

you sure about the 1Jay?

a guy i know has a JZA80 supra with the 1Jay and it seems to me that you can feel the 'sequentialness' as the second turbo kicks in

i may be wrong

you are. they are not sequential. The turbo's on a 1J are on separate manifolds. He might have one wastegate setup differently or a problem with his turbo's.

[342Four]

either that or i was imagining it....

[floody]

In comparrision all of the RB series engines are shit house in both design and function.

Nissan would not have had a hope in hell even with development against these engines.

These engines are far smoother, and nicer to use than enything nissan could ever have come out with in the RB series.

Well no surprises there given the RB's are all updates on a design that was released over two decades ago!

You cant compete with the direct injection system and its something that almost every manufacturer has struggled to get off the ground with and particularly nissan. Hats off to BMW who have successfully launched the system.

Even Hyundai have GDI in some vehicles (for some years now), I'm sure Nissan already do.

[_8OO5TED_]

you sure about the 1Jay?

a guy i know has a JZA80 supra with the 1Jay and it seems to me that you can feel the 'sequentialness' as the second turbo kicks in

i may be wrong

i think the series 4 to 6 rx7 13b's had sequential turbos of the same size

JZA80 Supra with a 1JZ? Why would he downgrade like that, I thought all JZA80 Supras (1993+) were fitted with the 2JZ.

[psybic]

Only JZA80 with a 1JZ would be someone who converted a 2JZGE to twin turbo and found it cheaper to go with a 1JZGTE.

The BMW is surely a different engine to the RB, no one is saying otherwise. Just that the RB makes more power per litre and thats what I personally like. Mum likes fuel economy and all that, so she'd probably still not be impressed with the BMW engine, she'd probably go a hybrid or desiel engine. So its just horses for courses, I don't see what the fuss is about still, especially if we are talking performance.

Show me an engine like the hydrogen prototype RX8 and I'll be impressed. Something that will drive the engines of the future would be a better award, not just more refined versions of last generation engines.

Whats the 280ps limit then? I saw on some doco it was to avoid the exotic sports car tax??? Meh, the why isn't important, but it IS a limited power figure. If its not, then why is the GTR so much faster than all the other cars with the same amount of power? And why did so many cars end up with EXACTLY the same peak power? I sniff incorrect figures...

[scathing]

The 280ps cap on JDM passenger cars was a "gentleman's agreement" between the Japanese auto makers and their department of transport. After a massive furore about dangerously fast supercars (etc), rather than get regulated the OEMs chose to voluntarily "limit" themselves to 280ps.

It had nothing to do with tax, and any car manufactured in Japan that was built purely for export wasn't subject to this power cap. It was also never "checked" by the government, so the OEMs kept printing 280ps on their brochures while making....however much power those cars made.

Otherwise, the cars where money was no object (the supercars like the GT-R and NSX) would have far exceeded that limit a long time ago. I doubt your average GT-R or NSX owner would have given a rat's bum about a "luxury car tax", if it meant their cars could go faster. Its not like those things were cheap to start off with.

However, for whatever reason that "agreement" didn't extend to the tuning arms of those manufacturers (only to OEM cars) so the 400R, Z-Tune and the various STis / RalliArt Evos were exempt.

The gentleman's agreement was abolished a year or two ago, and so we'll start to see more and more cars come out with proper power figures.

[predator]

Then there will be a further outcry, and they'll stop producing them again Especially here in our nanny state here of Australia getting worse and worse. With an SS commodore pushing 300kw (well on the lower side of that in reality), and the LS3 revision pushing even more than that over in the US, which we'll see soon no doubt - we'll see 350kw cars available for under $50k quite soon..

But a 3 series BMW in 10 years will make a GREAT tuners car.. when they drop to under $30k or so (which is about a year after you've bought one )

[WRRR]

In comparrision all of the RB series engines are shit house in both design and function.

Nissan would not have had a hope in hell even with development against these engines.

These engines are far smoother, and nicer to use than enything nissan could ever have come out with in the RB series. You cant compete with the direct injection system and its something that almost every manufacturer has struggled to get off the ground with and particularly nissan. Hats off to BMW who have successfully launched the system.

Nissans flagship engine is obviously the VQ35 and VQ40 which is tonnes better than the RB engines from a D & F perspective. Even these dont rate in the international engine awards because they are far to harsh and not nearly refined enough to compete.

Huh

Ward's Auto to release its 10 Best Engines list. The winners for 2007 - the 13th year for the awards - are as follows:

Audi AG 2L turbocharged DOHC I-4 (Audi A3)

BMW AG 3L DOHC I-6 (Z4 3.0si)

BMW AG 3L turbocharged DOHC I-6 (335i)

DaimlerChrysler AG 3L DOHC V-6 turbodiesel (Mercedes-Benz E320 Bluetec/Jeep Grand Cherokee CRD)

DaimlerChrysler AG Hemi 5.7L OHV V-8 (Chrysler 300C)

Ford Motor Co. Duratec 35 3.5L DOHC V-6 (Ford Edge/Lincoln MKX)

Ford Motor Co. 4.6L SOHC V-8 (Mustang GT/Mustang Shelby GT)

Mazda Motor Corp. 2.3L DISI turbocharged DOHC I-4 (Mazdaspeed3)

Nissan Motor Co. Ltd. 3.5L DOHC V-6 (Infiniti G35)

Toyota Motor Corp. 3.5L DOHC V-6 (Lexus IS 350)

Three of these - the pressurized Bimmer straight-six, Ford's Duratec, and the DCX turbodiesel - appear for the first time. Displaced from last year's list are GM's turbocharged Ecotec I-4 and HV V6, and Audi's V8 missed the cut as well. Nissan's VQ35 (above) makes its 13th appearance, and maintains its status as the only engine to appear on the list every year since the inception

RB series were produced in an era when NHV was not as important. Their robust nature and ability to take much higher levels of tune without major mods has given them an enviable reputation. The VQ35 has been an aclaimed engine from inception and still rates on a world basis - but it depends who is doing the reviewing.

[342Four]

Only JZA80 with a 1JZ would be someone who converted a 2JZGE to twin turbo and found it cheaper to go with a 1JZGTE.

woops finger slip JZA70 or whatever the japenese mark3 supras where called

[scathing]

RB series were produced in an era when NHV was not as important. Their robust nature and ability to take much higher levels of tune without major mods has given them an enviable reputation. The VQ35 has been an aclaimed engine from inception and still rates on a world basis - but it depends who is doing the reviewing.

Considering every "sports car" VQ has been NA, lets wait and see what the next GT-R is running before we make a call about which one is superior.

Turboing an RB25DE isn't going to net you massive power without "major mods" either. The VQ35DE was designed with a particular brief, and so its componentry reflects that.

Still, a standard VQ35DE out of a 350Z will make a reliable 300rwkW (at 9psi through the pair of Garrett GT2835Rs), with a near-linear power graph. The first guy in Australia to get the APS TT kit has been running those power levels for a couple of years (including a few track days) and the engine is still fuss-free. That's quite a bit of reliable power, and the engine is more responsive than a stock turbo RB or SR due to its high compression.

If the GT-R comes out this year (as its meant to) and has the rumoured VQ38DETT (or HRTT, since it'll probably be using the same dual-entry head as the VQ35HR you mentioned), I get the feeling that it'll give the VQ its 14th year at the next round of awards.

[swanny180]

TBH I think its a tad stupid trying to argue that RB26 is better or worse than this BMW inline 6.

RB26 = ~18 or so year old engine which was basically designed (more or less) as a homologated racing engine, and obviously with different emissions, power, noise etc restrictions.

BMW 6 = current engine meant for a luxury car, with current emissions standards etc.

Both are brilliant engines.

Both are rated relatively conservatively. (26 makes more power than claimed, BMW has potential to make plenty more simply through being detuned it would seem)

Most importantly:

Both although similar in configuration, are completely different in terms of purpose and design era.

Youll be going in circles trying to compare the two properly

Edited May 25, 2007 by swanny180

[shaolin]

The 1JZGTE uses twin CT12A's and the turbochargers are not sequential

The 2JZGTE uses twin CT12A's or CT20's and the turbochargers are sequential. This is achieved by the use of a special valve in the exhaust manifold that directs all of the exhaust gasses through one turbocharger until about 4000rpm where the valve opens and the exhaust gasses are then directed evenly between the turbo's.

On both the JZ series of engine, the turbochargers are identically sized.

Manufacturers have struggled over the years to design a sequential twin turbo setup that uses differnt sized turbochargers. Subaru had a crack at it with their early 2 litre Legacy/Liberty B4's and failed dismally. The B4 had a massive power hole between the 1st turbo and the 2nd turbo.

the sequential system on the supra doesn't work very well when you add a boost controller tho.

Stock it's excellent.

The RX-7 has different sized sequential turbos.

and I think the difference between Bi-turbo and Twin turbos is the engines.

Bi is for V engines with 1 turbo on each side with twins for inline engines as they are on the same side.

I may be wrong tho.

[Forged]

Some nice pictures of the car in subject.

[Forged]

Considering every "sports car" VQ has been NA, lets wait and see what the next GT-R is running before we make a call about which one is superior.

Turboing an RB25DE isn't going to net you massive power without "major mods" either. The VQ35DE was designed with a particular brief, and so its componentry reflects that.

Still, a standard VQ35DE out of a 350Z will make a reliable 300rwkW (at 9psi through the pair of Garrett GT2835Rs), with a near-linear power graph. The first guy in Australia to get the APS TT kit has been running those power levels for a couple of years (including a few track days) and the engine is still fuss-free. That's quite a bit of reliable power, and the engine is more responsive than a stock turbo RB or SR due to its high compression.

If the GT-R comes out this year (as its meant to) and has the rumoured VQ38DETT (or HRTT, since it'll probably be using the same dual-entry head as the VQ35HR you mentioned), I get the feeling that it'll give the VQ its 14th year at the next round of awards.

This is true. People always say how tunable RB series engines are, but I am yet to see a standard RB25DET make 300rwkw reliably.

I remember Bavaria Motorsport or someone had an old 5 series with a turbo charged beemer 3.0l straight six which made 350rwkw in stock form. And the engine was never designed to have a turbo on it.

[SS8_Gohan]

yeah. they work well but are ineficant and under engineered.

i hope you're not referring to the new twin-turbo BMW straight 6? because, my goodness, that is the most non-sensical statement ever!

When i think about it, it's not that a fantastic engine. It's only putting out 75 kilowatts per litre which is pretty weak.

But the fuel economy is pretty amazing i must say.

Not a fantastic engine? This thing has NO LAG! If no one told you it had 2 hairdryers hanging off it, you would never know! This car is AS quick as the current M3, yet it has 30 kw's less than it! How can that not be a fantastic engine???? Such a narrow minded way to look at it by saying only 75kw's/litre. This engine DESTORYS my NEORB25, and mines got about 82kw's/litre.

Wank over BMW all you want, I am impressed with an RB26 which was built initially 18 years ago and has similar power output to this brand new engine. If you want to talk about awesome efficiency, what about the S2000 engine. 90kw per litre, no turbo. This engine has 75kw per litre of engine capacity with two turbo's hung off the side. Crap, even the RB26 with the documented 206kw(which we all know is lower than the real story to avoid extra tax due to Japanese law) has 79kw per litre.

Wank over design and bullshit all you want, how many of you have seen the design blue prints and physics calculations that went into all the design aspects of the engine? I'd say the ones that work in BMW engineering section and thats about all.... and thats probably no one contributing here.

Not impressed with awards which are obviously politically motivated.

What is with this poliferation of narrow mindedness!!!! The S2000 engine is USELESS unless revved. Amazing engineering to get that much power out of sooo little, but you have to rev its tit's off to do it. kw's/litre is not the be all and end all! So what is the 335i has only 225kw's, it has NO lag and despite being under powered compared to the current M3, it's just as quick! What does that tell you? The engine is more usable, more flexible, more balanced. By your reasoning, you can throw some MASSIVE f*ck off turbo on, get a 500kw engine (with supporting mods) for say, 3 litres, and claim to have a brilliant engine just because it had 166kw's/litre. It would be USELESS before say 5000rpm. Don't be so narrow minded.

What the hell does seeing blue prints have to do with anything? Have you ever even driven one? There are significant technological features used in this engine, that hasn't been seen in mass production before. And NO ONE has made such a responsive turbo engine before either. For goodness sake, they've got the sequential setup down pat, if that's not impressive, then i don't know what is.

These awards are obviously NOT politically motivated. The best engines have won these awards each year on their own MERRITS! BMW's V10, first in a mass produced car, the M3 engine, 256kw's out of 3.2 litres, no turbo. Then they got 265kw's out it! Now the 335i engine which is significant step forward in forced induction engines. More than happy to hear what YOU think should have one all these past years?

Oh, i should mention i drive a slightly modded R34, and my dad drives a 3 month old BMW 335i... i have driven both, have you?

[Rabid]

I think your looking at the wrong words. They didn't say it was the first twin turbo six. They said it was the first I-6TT. I think all the other cars you mentioned are V-6TT's. Also, as far as my opinion, I would say the Mazda Motor Corp. 2.3L DISI turbocharged DOHC I-4 (Mazdaspeed3) is the best engine to come out this year. I'm a pretty big Mazda fan in general though, so I guess you can take that into consideration before arguing with me . And as long as were mentioning older motors, why has no one considered the Chevy LS1 as one of the best motors out there?

Edited June 2, 2007 by Rabid

[pablo101]

225kw and uses only 9.5L per 100km is very impressive, looks like they deserved to win

[BaysideBlue]

And as long as were mentioning older motors, why has no one considered the Chevy LS1 as one of the best motors out there?

are you kidding me? yes it makes the power but push rod V8 in this day and age is hardly efficient. even ford has moved into multi valve twin cam years ago.

[Rabid]

are you kidding me? yes it makes the power but push rod V8 in this day and age is hardly efficient. even ford has moved into multi valve twin cam years ago.

Ohh, I'm sorry. The 4-500hp ZO6 Vette is really a piece of junk then. All that power and 20mpg. Very inefficient indeed.

[scathing]

I would say the Mazda Motor Corp. 2.3L DISI turbocharged DOHC I-4 (Mazdaspeed3) is the best engine to come out this year.

The next Mazda2's Miller Cycle engine looks interesting. From a technology standpoint alone (4.35L/100km, Miller Cycle) it might win a place on those awards (which are not based purely on specific power). That kind of mileage puts it in Prius territory, but without the complexity of a hybrid drivetrain. Its certainly a lot better than a Golf turbodiesel.

And as long as were mentioning older motors, why has no one considered the Chevy LS1 as one of the best motors out there?

From a technological, efficiency, power delivery, power output, sound and NVH standpoint....what does it bring to the table?