Maximum OEM Turbo PSI?

"davesaddiction @ opposite-lock.com" (davesaddiction) 05/13/2014 at 11:30 • Filed to: boost

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Saw some comment about how easy and cheap it would be to make significantly more power from the new M3/4's engine, and was wondering how true this statement might be. Found some numbers: max. boost from the factory is ~19 psi. Seems pretty high for an OEM application, and was wondering what the highest factory pressure is for any passenger car, up to this point.

I assume OPPO knows.

"At the heart of BMW M division's new twin-turbocharged 3.0-liter inline six-cylinder, which is mounted longitudinally, is a patented induction process that uses two low-inertia turbochargers. Eschewing both twin-scroll and variable vane geometry, the IHI units provide a relatively conservative maximum boost pressure of just 18.9 psi."

For those of you experienced with "overboosting" (like overclocking?) turbo-ed engines, what pressure do you expect this engine to take comfortably, while maintaining reliability? Too early to tell?

Can an aluminum block handle less pressure than a cast iron one, by nature, or is that no longer the case?

Your boy, BJR > davesaddiction @ opposite-lock.com 05/13/2014 at 11:33

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The viggen came factory with20PSI

DailyTurismo > davesaddiction @ opposite-lock.com 05/13/2014 at 11:33

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This might be a surprise to you...but...its gonna be a diesel!

RazoE > davesaddiction @ opposite-lock.com 05/13/2014 at 11:36

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Late model Evos were at 19 psi, I believe.

E30Joe drives a Subaru > davesaddiction @ opposite-lock.com 05/13/2014 at 11:37

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Probably too early to tell but you see people running 30+ pounds on 20 year old cars so I'd imagine with a mild build you could get close to that.

Yowen - not necessarily not spaghetti and meatballs > davesaddiction @ opposite-lock.com 05/13/2014 at 11:38

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18.9 is pretty high, stock. My SHO (twin turbo) is 12 psi stock. i think when tuned I'll top out at about 16 psi.

Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW. > davesaddiction @ opposite-lock.com 05/13/2014 at 11:39

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hmmm

The Mercedes's "45" AMGs is using a 26.1 psi, BorgWarner Twin Scroll Turbo
http://en.wikipedia.org/wiki/Mercedes-…

davesaddiction @ opposite-lock.com > DailyTurismo 05/13/2014 at 11:42

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That's expected, but for comparison purposes, the highest OEM # for a gasoline engine would be the one I'd like to know.

davesaddiction @ opposite-lock.com > Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW. 05/13/2014 at 11:42

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Seems crazy high!

davesaddiction @ opposite-lock.com > E30Joe drives a Subaru 05/13/2014 at 11:43

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Most of those old ones would be iron blocks, correct?

Jake - Has Bad Luck So You Don't Have To > davesaddiction @ opposite-lock.com 05/13/2014 at 11:45

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Drove my buddies Ford Super Duty with a 6.3l turbodiesel. The boost gauge said I was getting 35lbs of boost at WOT in 2nd gear.

And it sounded FUCKING AWESOME

E30Joe drives a Subaru > davesaddiction @ opposite-lock.com 05/13/2014 at 11:47

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yep, first thing that comes to mind is 2JZ no shit.

grim > davesaddiction @ opposite-lock.com 05/13/2014 at 11:47

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I believe my stock boost on my evo 8 was 20 psi,but it would taper down on the top end. Now it holds 28psi all day with the 6262.

Nibbles > E30Joe drives a Subaru 05/13/2014 at 11:47

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I accidentally spat out 26 PSI on my 1987 900 SPG. Sure, I blew the head gasket and the rings on cylinder 2, but the rest of it held up well enough.

davesaddiction @ opposite-lock.com > Jake - Has Bad Luck So You Don't Have To 05/13/2014 at 11:50

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That's wild. I knew diesel's boost #s would be higher. My bro-in-law's truck sound like a frickin' train!

davesaddiction @ opposite-lock.com > grim 05/13/2014 at 11:51

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That cast iron block, amiright? What can the Evo Xs handle consistently?

grim > davesaddiction @ opposite-lock.com 05/13/2014 at 11:54

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yeah 4g63 is an iron block and the 4b11 is a aluminium. Im not exactly sure on the evo x but i want to say its pretty close. 28psi on my 6262 is considered lowish,people push 35+ in my car with that turbo.

Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW. > davesaddiction @ opposite-lock.com 05/13/2014 at 11:57

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yeah. I wonder how reliable this engine will be.

Jake - Has Bad Luck So You Don't Have To > davesaddiction @ opposite-lock.com 05/13/2014 at 12:00

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It's honestly the only good part of that truck, sadly. The frame is flimsy as hell and the interior is utter crap.

Opposite Locksmith > Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW. 05/13/2014 at 12:02

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I want to know the injector and piston situation

Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW. > Opposite Locksmith 05/13/2014 at 12:06

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just wait till the end of the year..

multiple wheels for each day of the week > davesaddiction @ opposite-lock.com 05/13/2014 at 12:10

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2013 Focus st ... 21psi for over-boost I'v seen as high as 23 with tuning.

Racescort666 > davesaddiction @ opposite-lock.com 05/13/2014 at 12:12

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International's 13L (actual displacement is 12.4L) runs up to 45 lbs in the 475 hp rating.

BKRM3 > davesaddiction @ opposite-lock.com 05/13/2014 at 12:48

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Warning: this answers none of your questions, but relates my own experience and opinion regarding this engine's ancestor, the N54.

The N54 from the 2007 335i maxed out at something like 8.75psi stock. That seemed to check out with what I "verified" in a very non-scientific way by the real-time readouts on my Cobb AP (with the stock tune on the car). With the Cobb AP stage 1 tune that I ran (93 octane), the peak boost would be ~15psi and was designed to be safe with no hardware changes (i.e., exhaust, cooling, induction, etc.). I never had any reliability issues with my car that were related to the amount of boost - the 10 billion issues I had were all in ancillary systems. It's easy to see how the 19psi you mention SHOULD be plenty reliable in the new engine with enhanced cooling and the other improvements made since the N54's release in 2007. Six years down the road, it's widely accepted that even an old N54 can reliably tolerate considerably more boost than was required to reach the load targets at the stock tuning level. That engine was considerably de-tuned so that BMW didn't have to explain why a 335 was faster than an E9X M3 in a straight line. Also, middle-aged women with bob haircuts (the main demographic of 335 owners in my area) do not need 400+ lb-ft of torque beginning at 1,400rpm to get to the mall. It seemed to be that BMW recognized the potential of the twin-turbo design when the N54 was selected for use in the 335is and the 1 series M coupe, and began to incorporate this "overboost" function - i.e., here kids, have a LITTLE more fun, but not as much as the M that's still currently for sale.

davesaddiction @ opposite-lock.com > BKRM3 05/13/2014 at 13:00

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Nice disclaimer. My friend just found out he's having twins to go along with his 2 year old, and I told him he should get a 535i manual wagon with the N54 and a tune.

BKRM3 > davesaddiction @ opposite-lock.com 05/13/2014 at 13:05

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That's an excellent suggestion. With a few things - tune, exhaust, air filter and mayyyyybe an intercooler, that car would be an absolute rocket when you wanted it to be. Otherwise? Family wagon.

davesaddiction @ opposite-lock.com > BKRM3 05/13/2014 at 13:22

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Would be a hell of a sleeper. Probably best owned with a CarMax warranty...

asindhidude > davesaddiction @ opposite-lock.com 05/13/2014 at 13:31

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my 15 wrx hits 22 psi on the reg.

davesaddiction @ opposite-lock.com > asindhidude 05/13/2014 at 13:32

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How are you liking it? I need to get a test drive (I honestly wasn't impressed when I drove the previous model two years ago).

BKRM3 > davesaddiction @ opposite-lock.com 05/13/2014 at 13:44

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Yes, as is the case with pretty much any luxury car with forced induction, though some are more reliable than others.

7:07 > davesaddiction @ opposite-lock.com 05/13/2014 at 13:58

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Modern (2004+) Cummins powerplants run at close to 30psi stock. A few add-on's take you into the 40+ range. Race-prepped engines are at or around 140psi.

My 1992 Cummins was in the 40psi range after some minor adjustments to fuel delivery.

asindhidude > davesaddiction @ opposite-lock.com 05/13/2014 at 14:19

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i really like it. it is the first awd car i have ever owned, and the grip/handling is amazing. i also got the auto (cue ragging about me being soft) and i find the paddles to be a riot.

davesaddiction @ opposite-lock.com > asindhidude 05/13/2014 at 14:20

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Next stop - RallyCross!

asindhidude > davesaddiction @ opposite-lock.com 05/13/2014 at 14:28

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i have been driving around town with my helmet on just in case the opportunity pops up hahahaha

MINI STIG > davesaddiction @ opposite-lock.com 05/13/2014 at 17:03

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Stock boost on my MINI Cooper S is about 15PSI and I know it can be turned up to about 21 PSI before you hit the fuel cut. They are totally reliable at around 18PSI since that is what a JCW version runs. So I bet they are still good to go at 20.

Now where is the money for that damned tune!

davesaddiction @ opposite-lock.com > MINI STIG 05/13/2014 at 17:21

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I drove a friend's Cooper S again one night last week, and man, that thing is a hoot. Lightweight, and that little engine sure is willing. Very easy to go way too fast in that thing.

BKRM3 > davesaddiction @ opposite-lock.com 05/14/2014 at 07:06

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Just stumbled across this. 29psi. Carmax warranty voided though =)

davesaddiction @ opposite-lock.com > BKRM3 05/14/2014 at 08:43

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Whoa.

Zach > davesaddiction @ opposite-lock.com 05/18/2014 at 10:25

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My 2008 Jeep Grand Cherokee CRD runs 25psi factory stock. That same engine is in the Mercedes Benz E-Class of around the same year. To be fair, it is a diesel...

Kevin Rhodes > davesaddiction @ opposite-lock.com 06/17/2014 at 23:52

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My Abarth runs 22psi stock in "sport mode". One of the guys I work with has one with all sorts of crazy upgrades including a bigger turbo that gets to 30+.