n55 vs n55HP - How do we get that extra power and torque?

Simple solution go get your put your car on a dyno and see what the results are.. I'm sure they will be closer to 240/250 than that almighty 277 that happened once.

And here's why I am denying this so much. If our cars were 330/340 stock and we added these tunes that give us an extra 30 to 40 we'd be close to the 400 range and after owning a 360/380 e60 535 I can tell you with a tune we are not in that territory.

Originally Posted by K-A

Dyno's will range everywhere, but what's important is trap speed when trying to determine genuine power rate, IMO. So some N55's will dyno less, some more (and especially more when broken in some).

Remember, some guys with N55 3-Series' have apparently dyno'd in the 290's, stock.

See and this is where I have an issue with dyno's. A company like BMW that mass produces the N55 engine is not going to have this huge variances from engine to engine. I get it in a hand built engine but not in a mass produced one.

I tend to believe the SAE provided numbers BMW gives, rather than using what some yahoo gave me after tweaking all the parameters to what he thinks I want to see.

The really benefits of dynos is for before and after testing of an upgrade because you can use the same settings. Other than that, the only real way to test an engine is out of the car. Just my 2 cents.

Yet it is widely accepted that BMW underrates their engines. The N63 regularly dynos at 385-390rwhp even though it is rated at 400. There is a reason these cars have such impressive 0-60 and 1/4 mile stats considering how bloated they are....

Fact of the matter is, look at power-weight. There's NO WAY a 300 HP car will trap at 100 MPH when it weighs 4000+ lbs. It's just not gonna happen, unless you're looking at 5-10% drivetrain loss, which is not gonna happen.

I kept wondering, why would BMW underrate these engines, and my conclusion came when I got an insurance quote. This car is drastically cheaper to insure than even my 268 HP E350. I think that BMW knows if they put a 340 HP rating on an engine in so many mass produced cars sold to regular Joe/Jane's, the insurance reflection of a higher HP rating might cost them more sales than people who would buy for the extra few ponies. BMW may be an enthusiasts brand to us, and in the soul of the brand is still that, IMO, but the mass majority of their dough comes from non-car enthusiasts.

Originally Posted by K-A

Fact of the matter is, look at power-weight. There's NO WAY a 300 HP car will trap at 100 MPH when it weighs 4000+ lbs. It's just not gonna happen, unless you're looking at 5-10% drivetrain loss, which is not gonna happen.

Exactly!
The F10 535i traps way too high for a 300hp 4100lb car.
Another comparison is the Infiniti G37, it also traps at 13.9 seconds 100mph. But it have 330hp and only weights 3700lbs.
No way our 400lb heavier car with 30 less HP can trap the same speed.

Originally Posted by nick11

I have the power up kit in my 2011 335 - although the #s are low as far as increase it completely changed the car. Torque is very low and pulls hard to redline -also seems to build boost much faster. Looking to do Dinan on new 535 when they finally come out with it.

Bwahahahahaha.

Hope you are ready to wait a long time!

To OP question? Who knows? We'll never get a straight answer from BMW.
What all we enthusiast do know is that BMW underrates their motors and is very specific with their tune for regional and marketing reasons. That their engines are designed with plenty of "head room", is what allows the Dinan, et al, to magically pull horsepower/torque with some programming code.
Unless there is a specific induction, exhaust or valve modulating system difference between the N55 and N55HP, my guess is that it is just some proprietary ECU code reserved for premium applications (740i, 640i). So, my hunch is the horsepower/torque has always been there in the N55 but, unless your build code at the factory indicated a 740i or 640i, the ECU code that releases the extra juice is not there nor will BMW let you know how to get it.
Oh...don't get me started on why its a "x35i" in the 1,3, and 5 series but a "x40i" in the the 7 and 6 series. GOT to love them marketing guys!

Originally Posted by smashhell

Exactly!
The F10 535i traps way too high for a 300hp 4100lb car.
Another comparison is the Infiniti G37, it also traps at 13.9 seconds 100mph. But it have 330hp and only weights 3700lbs.
No way our 400lb heavier car with 30 less HP can trap the same speed.

Good comparo! Another good point. Trap speed tells the best story when factoring in weight. Dyno's can help confirm the factor, but as stated here, there are lots of variances there.

A real 300 HP 4k lb car will probably trap 95-96 mph at its HIGHEST. F10 N55 traps vary from publication to publication, but there have been a few 100's and I even saw one at 101-102, brand new and unbroken in yet.

And what publication would that be? Never mind. I think we have been beating this dead horse for days on end. This train de-railed from the beginning.

I wonder if I an OP can unsubscribe from his own thread. Thanks for the help Eddie, Miami and Ramble.

Here's 14.0 @ 99.3 MPH at 4007 lbs weight:
http://www.motortrend.com/roadtests/...5i_first_test/

Here's 101 MPH trap speed at a whopping 4075 lbs:
http://www.caranddriver.com/reviews/...ad-test-review

Here's 101 MPH @ 4100 (est) lbs:
http://www.motortrend.com/roadtests/...n/viewall.html

I had seen more with 100 MPH trap speeds pretty much on the nose, but haven't gotten into searching that much yet.

Here's the 277 RWHP 283 RWTQ off-the-floor 535i:

The 4165lb Audi A6 with 310hp traps at 102mph.

http://media.caranddriver.com/files/...0t-quattro.pdf

Originally Posted by dunderhi

The 4165lb Audi A6 with 310hp traps at 102mph.

http://media.caranddriver.com/files/...0t-quattro.pdf

The s/c V6 Audi uses is one of the most underrated motors out there.

Dp

Originally Posted by dunderhi

The 4165lb Audi A6 with 310hp traps at 102mph.

http://media.caranddriver.com/files/...0t-quattro.pdf

Audi underrate their engine just like BMW.
Also they are AWD so it doesn't count.
You can't compare a RWD with AWD car.

Audi and BMW (and various F/I cars I'm sure) seem to be rating their HP closer to wheel HP these days. I really think it logically would have to do with insurance rates. It won't be smart for Audi to try and sell a 380 HP low-mid line model to your average well to do businessman, as the insurance quotes would have to be quite a bit more expensive than a 310 HP rating.

Audi's S/C V6 is a beast. Talk about underrated.... I wouldn't be surprised if that thing was making close to its published HP at the wheels (which I understand is highly unlikely due to it being AWD with even more drivetrain loss, but to try and get the point across exaggeratedly, still....)

Originally Posted by Emilner

Yet it is widely accepted that BMW underrates their engines. The N63 regularly dynos at 385-390rwhp even though it is rated at 400. There is a reason these cars have such impressive 0-60 and 1/4 mile stats considering how bloated they are....

OK, lets say for a moment that is true, then you see how unreliable dyno's are since the results are all over the map. Just think of the 240-290 discussed here. That tells me that a technician through his adjustments can give you whatever they want.

Originally Posted by miamiboyca

OK, lets say for a moment that is true, then you see how unreliable dyno's are since the results are all over the map. Just think of the 240-290 discussed here. That tells me that a technician through his adjustments can give you whatever they want.

I have never seen a 535 dyno at 240 rwhp. It's not a rumor- it is widespread accepted knowledge that BMW (and Audi) underrates their engines. Even the rags mention it from time to time.

Originally Posted by Emilner

I have never seen a 535 dyno at 240 rwhp. It's not a rumor- it is widespread accepted knowledge that BMW (and Audi) underrates their engines. Even the rags mention it from time to time.

I am not arguing that point as nothing is confirmed either way.

My point is that you see dyno's reflected all over the place for stock engines - this makes dyno's untrustworthy except for before and after mods.

Originally Posted by smashhell

Audi underrate their engine just like BMW.
Also they are AWD so it doesn't count.
You can't compare a RWD with AWD car.

Originally Posted by K-A

The s/c V6 Audi uses is one of the most underrated motors out there.

Okay, since you all "know" which motors are under-rated, please tell me how you "know" this? A list of which motors that are underrated, correct, and overrated would be helpful. Thanks in advance!

BTW: AWD helps ET, not trap speed.

Originally Posted by smashhell

Audi underrate their engine just like BMW.
Also they are AWD so it doesn't count.
You can't compare a RWD with AWD car.

And again you are showing your noob-ness
AWD helps your time.. but not your speed.

dunderhi beat me to it.


Smash.. you already thought the BMS tune gave you 80/100.. So how does that 410/440 feel? Hahahaha

Originally Posted by dunderhi

Okay, since you all "know" which motors are under-rated, please tell me how you "know" this? A list of which motors that are underrated, correct, and overrated would be helpful. Thanks in advance!

BTW: AWD helps ET, not trap speed.

+1

Originally Posted by RambleJ

And again you are showing your noob-ness
AWD helps your time.. but not your speed.

dunderhi beat me to it.


Smash.. you already thought the BMS tune gave you 80/100.. So how does that 410/440 feel? Hahahaha

+1

Even if we say that they are under-rated - the crazy swings on hp/lbs from something as precise as a mass machine produced German engine tells you everything you need to know about dynos.

Originally Posted by dunderhi

Okay, since you all "know" which motors are under-rated, please tell me how you "know" this? A list of which motors that are underrated, correct, and overrated would be helpful. Thanks in advance!

BTW: AWD helps ET, not trap speed.

I'm aware of that, which is why I believe the A6 to be extra underrated because it can still trap at 102 WITH AWD holding it back (in the Trap Speed regard).

Finding which motors are underrated is easy. Look at cars that actually dyno and trap to match their printed HP (I used a Mustang GT as an example to further prove my theory/point). Then look at other cars that show a different formula when weight and trap speed are taken into account.

I don't think anyone who truly believes a that 535i at 4100 lbs that traps comfortably at 100 MPH can have 240 RWHP understands how power/weight works. A 535i with 240 RWHP would be lucky to trap in the low 90's, at its best.

Most N55 dyno's are over 270 RWHP, with some posting in the 290's. Then you have the most solid evidence, a 100+ MPH trap speed on a 4100 lb car. Maybe with one cylinder unplugged it'll make 240 RWHP. Again, RWHP just gives you some extra basis. Trap Speed always tells the truth (when taking into account weight, drivetrain, etc.)

That all adds up to a car that HAS to make well over 300 HP, unless BMW's have some magical "no drivetrain loss" formula that they haven't utilized their marketing team to advertise yet.

EDIT: Just tried it on this website, which some dragsters find to be a very accurate one: http://www.ajdesigner.com/fl_horsepo...trap_speed.php

At 4200 lbs (race wight with a very light human being), Trapping at 101 MPH, you get 337.7 HP.
At 4080 lbs (as if the car drove itself down the track with no human in it), Trapping at 101 MPH, you get 328 HP.

Comparing that to my own "at home" math, i.e the comparison between a Mustang GT and what the 535i would NEED to make in order to post up an identical time to an 800 lbs lighter car (with less drivetrain loss to boot, being that it's a Manual) AND the Dyno's we have on file, it all perfectly adds up to come to the same conclusion: 325-340 crank HP.

Originally Posted by K-A

I'm aware of that, which is why I believe the A6 to be extra underrated because it can still trap at 102 WITH AWD holding it back (in the Trap Speed regard).

Finding which motors are underrated is easy. Look at cars that actually dyno and trap to match their printed HP (I used a Mustang GT as an example to further prove my theory/point). Then look at other cars that show a different formula when weight and trap speed are taken into account.

I don't think anyone who truly believes a that 535i at 4100 lbs that traps comfortably at 100 MPH can have 240 RWHP understands how power/weight works. A 535i with 240 RWHP would be lucky to trap in the low 90's, at its best.

Most N55 dyno's are over 270 RWHP, with some posting in the 290's. Then you have the most solid evidence, a 100+ MPH trap speed on a 4100 lb car. Maybe with one cylinder unplugged it'll make 240 RWHP. Again, RWHP just gives you some extra basis. Trap Speed always tells the truth (when taking into account weight, drivetrain, etc.)

That all adds up to a car that HAS to make well over 300 HP, unless BMW's have some magical "no drivetrain loss" formula that they haven't utilized their marketing team to advertise yet.

EDIT: Just tried it on this website, which some dragsters find to be a very accurate one: http://www.ajdesigner.com/fl_horsepo...trap_speed.php

At 4200 lbs (race wight with a very light human being), Trapping at 101 MPH, you get 337.7 HP.
At 4080 lbs (as if the car drove itself down the track with no human in it), Trapping at 101 MPH, you get 328 HP.

Comparing that to my own "at home" math, i.e the comparison between a Mustang GT and what the 535i would NEED to make in order to post up an identical time to an 800 lbs lighter car (with less drivetrain loss to boot, being that it's a Manual) AND the Dyno's we have on file, it all perfectly adds up to come to the same conclusion: 325-340 crank HP.

Let me use your "dragster accurate" calculator to look at three tets for the same model car.

2011 535i Edmunds: 4056lbs, 95mph => 271hp => overrated?
2011 535i MotorTrend: 4007lbs, 99mph => 303hp => aligned?
2011 535i Car and Driver: 4075lbs, 101mph => 328hp => underrated?

So what does this tell us? BMW has inconsistent manufacturing processes? Testing can't be trusted? I'm wasting my time here?

So what is the basis in reality here? Is it an online calculator that uses a simple formula that only uses weight and peak horsepower? Based on this formula two cars with same weight and the same horsepower, but with different numbers of gears, different types of transmissions, different final drive ratios, different amounts of driveline losses, different drag coefficients, different amounts of torque, different power curves, different red lines, etc will have identical trap times. Does the truth lie at the local rolling dyno? Do we believe DynoJets dynos over Mustang dynos because they tell us we have 10% more horsepower? Can it be that rolling dynos tend to report higher horsepower results for turbo cars than normally aspirated? Maybe we should trust someone who uses a crank dyno in a professional testing environment... maybe someone like an OEM.

BTW, the Ford Mustang with a 6 speed manual - which hurts (not helps) the trap speed:
2011 Mustang C&D: 3520lbs, 104mph => 309hp => aligned?

Originally Posted by dunderhi

Let me use your "dragster accurate" calculator to look at three tets for the same model car.

2011 535i Edmunds: 4056lbs, 95mph => 271hp => overrated?
2011 535i MotorTrend: 4007lbs, 99mph => 303hp => aligned?
2011 535i Car and Driver: 4075lbs, 101mph => 328hp => underrated?

So what does this tell us? BMW has inconsistent manufacturing processes? Testing can't be trusted? I'm wasting my time here?

So what is the basis in reality here? Is it an online calculator that uses a simple formula that only uses weight and peak horsepower? Based on this formula two cars with same weight and the same horsepower, but with different numbers of gears, different types of transmissions, different final drive ratios, different amounts of driveline losses, different drag coefficients, different amounts of torque, different power curves, different red lines, etc will have identical trap times. Does the truth lie at the local rolling dyno? Do we believe DynoJets dynos over Mustang dynos because they tell us we have 10% more horsepower? Can it be that rolling dynos tend to report higher horsepower results for turbo cars than normally aspirated? Maybe we should trust someone who uses a crank dyno in a professional testing environment... maybe someone like an OEM.

BTW, the Ford Mustang with a 6 speed manual - which hurts (not helps) the trap speed:
2011 Mustang C&D: 3520lbs, 104mph => 309hp => aligned?

Actually the Mustang comparo I was using is a 2003 GT which I find is a very accurate basis of HP/Weight/RWHP/Trap Speed aligning. It gets 225 RWHP with a 5 Speed Manual which equated to 260 crank HP.

It does EXACT times the 535i does, 14.0 @ 100 as a solid basis. Sometimes under, sometimes (but rarely) over. The 535i on the other hand has trapped OVER 100 MPH.

The GT is almost 3200 lbs, the 535i almost 4100 lbs. So you can quickly figure the 535i needs an extra 80 crank HP to simply tie it. Now, you can make the argument that the 535i has more gears, etc., but IMO that would be matched or even overshadowed by the GT's lack of drivetrain loss, comparatively speaking, with a Manual.

About the drag times website. First off, to make it accurate, since it's determining numbers based on race weight, you have to add a human being to the car, taking the 535i's weight easily over 4200 lbs. Then, we all can come to a conclusion that the Edmunds time was in a lousy environmental condition rendering its time freakishly low, considering we have several stats of 99-101 MPH.

Again, every single way I can look at this, be it on a "VS 2003 Mustang GT who puts out identical numbers in an 800 lb less frame and less drivetrain loss due to being a Manual", 20% HP addition over the 277-280+ RWHP we've seen from N55's, using that 'Calculator", comparing to a G37 which traps similarly with 330 HP AND less weight.... it all draws to the same crank HP figure required to make the average 535i stat (including documented trap speeds and RWHP), which is 325-340 HP.

I'm trying to find stats for a 2012 Mercedes E350 which makes like 306 crank HP, probably accurately rated considering it's an N/A engine and doesn't feel as fast as a heavier 535i or Audi A6, but remember hearing that it was predicted to make mid-high 14's, at a trap of mid 90's. Again, that's a lighter car, with "apparently" more HP, trapping a good 5 MPH less. However, unfortunately I can't confirm that until I find a test link to it somewhere.