overall is the b16 se-r better than the b15??

[blckspec-v06]

i have an 06 b15 spec-v is the 07-- b16 better?? if it is in what ways ??

[nametakennow]

07+ engine and trans are less problematic and make more power. More equipment is standard on the new ones (they're also bigger). Handling is virtually identical. Aside from that it's pretty much a personal preference issue.

[D3stro]

07+ engine and trans are less problematic and make more power.

More power yes, but when the new model weight nearly 300 lbs more than a b15 SpecV, the hp/ kg is the same at the end. But yes, numbers are numbers and true results are showed on a track.

[gotak]

The interior is also modern and quite well done. The lighted gauges, I think, are great. Crash rating was also hugely improved!

[Godofelru]

Stock B16's run about the same time's as mildly bolted B15 specs. So that should shed some light on you.

The cars are very nice, very fun to drive, very refined, and also rather economical as well.

They desperately need a drop and a new grill, so you should make those your first mods if you do so. I also have an intake and it makes a nice difference soundwise and maybe a marginal one performance wise.

Get springs though if you go through with it though, Its def my next mod.

Feel free to look at my introduction page a bit ways down, it gives a ton of pictures, as well as a few videos about the B16 spec.

[blckspec-v06]

so other than looks interior safety and mild performance theirs really no difference?? what did nissan do to pull 25 more horse power out of that engine?? considering its still the qr25de?? and can i do it to my 06?? 25 more hp in my 06 would be nice lol

[CentralFLSentraSE-R]

I still gotta support the B-15, I think the B-15 looks sleaker and more aero dynamic, the new b16 is kind of a box..... still very nice and yes i would love to get that extra power...... I would think that Nissan did some extensive re-tuning on the computer and probably opened up the intake and exhaust to let it breathe better.

[gotak]

The Spec-V gets new pistons and different compression ratio to the regular engine. Runs on premium gas to get that power.

[CentralFLSentraSE-R]

That's nice. I just read up on the B-15 specs and the B-16 specs. In the se-r (not spec-v) what did they do to get the 17 HP. I noticed that it lost some torque.

[djtorello]

The differeance is the piston shape, Higher compression, and a slightly different cam profile.

Also the crank in now balanced making the internal balancer useless, and supposedly has a better less friction inducing finish.

there are a few people that are making the new B16 a formidable ride. That would be Major Mods, and Rako for the Spec V. Stitch and myself for the SE-R.

[CentralFLSentraSE-R]

ok. so i hear that if i remove the balancer shaft from my engine that it will give about a 7 HP gain.

[gotak]

You get like 7 HP on a inertia dyno but not in real life. You don't actually get much power in actual scientific terms of power measurements from removing a rotating mass. Just the slight reduction in friction from not having to turn the bearings for the balance shaft.

In simpler terms. You might measure the car accelerating faster because the engine isn't accelerating the rotational mass of the balance shaft as well as the drive train and the car. But the ultimate top speed as limited by air resistance will not change much because there's really no extra energy being freed up by not having the balance shaft.

Does that make sense?

The 17 HP in the new SE R is most likely just a difference in tune or as been said some improvements in friction reduction. It could well be that the locking torque converter and the CVT together in the new car has less friction then the old drive trains. The CVT is suppose to be more efficient according to Nissan.

[nametakennow]

He only mentioned hp, so why the explanation of top speed?

7hp is 7hp. It's not a lot, but it helps. Technically the potential for this power (i.e. energy) already existed, if that's what you're getting at. A mod like this really just uses the existing energy more efficiently, but that's what most mods do. Also, BS removal is a mod that has a bigger effect when there is more power added on - ie, the reduction in mass is going to matter more when you do other mods to increase power (intake and exhaust, for instance).

Anyway, my point is that the 7hp is quite real. Put it on a dyno or put it on the street, the power is gained. Losing rotational mass attached to the engine is one method of gaining hp. It's why mods like lightened pulleys and flywheels exist - freeing energy from rotation/internal engine functions to be put down on the ground.

[CentralFLSentraSE-R]

Thanks for the in-depth explanation guys . The difference in rotational mass will make a big difference once I get my nitrous kit in.

[Godofelru]

I have a spec v dj

Quote »so other than looks interior safety and mild performance theirs really no difference?? what did nissan do to pull 25 more horse power out of that engine?? considering its still the qr25de?? and can i do it to my 06?? 25 more hp in my 06 would be nice lol [/quote]That's like 4 major concerns lol nothing to shrug at.

The B16 is a better car no doubt, but it's appreance is something you either like it or you don't, it very much so grew on me.

[gotak]

It looks better in person then in photos for sure. When I went to the dealer I was of the opinion I wouldn't much like the car just from the photos. When I saw it though it looks a lot better in person.

[Buzzman]

Last year I took a new Sentra for a test drive, and hated it.I couldn't get comfortable, and after 10 minutes my butt was already starting to hurt. The interior, especially the shifter allignment, was not to my taste, and the ride was noisy and a bit rough. I much prefer my '03.My apologies to B16 owners (don't take my dislike of the new Sentra personally, please).I also drove a Versa by the way, and I quite liked it.

[Godofelru]

That's interesting, I drove 4 hours to conneticut and I felt great afterward, no pains or anything, when I did it in my saturn I wanted to end my life, I couldn't feel my *** or anything.

The ride is noisy and rough, but it's a sport compact, they have to cut corners somewhere.

Versa come on now, my friend has one and it's nothing but an econo box subcompact how can you even compare them lol.

[gotak]

He only mentioned hp, so why the explanation of top speed?

7hp is 7hp. It's not a lot, but it helps. Technically the potential for this power (i.e. energy) already existed, if that's what you're getting at. A mod like this really just uses the existing energy more efficiently, but that's what most mods do. Also, BS removal is a mod that has a bigger effect when there is more power added on - ie, the reduction in mass is going to matter more when you do other mods to increase power (intake and exhaust, for instance).

Anyway, my point is that the 7hp is quite real. Put it on a dyno or put it on the street, the power is gained. Losing rotational mass attached to the engine is one method of gaining hp. It's why mods like lightened pulleys and flywheels exist - freeing energy from rotation/internal engine functions to be put down on the ground.

I mentioned top speed because it's a function of how much energy the engine can generate from fuel. And HP is a measurement of that. There's a differences between removing mass and getting better acceleration and getting more "power". It's all in the definition of those terms. And technically you don't get any more energy from the removal of a rotating mass except for the slight reduction in friction. When you dyno on a inertia dyno and it shows a HP gain from the removal of the shaft, what it is showing is the limitation of an inertia dyno. In that it does not measure actual energy/HP but rather estimate HP based on how fast the mass of the dyno's drum is accelerated.

A brake dyno is a much better device for measuring actual HP because it measures how the energy instead of acceleration. There's less chance to fudge the results as well by the use of "correction factors".

Wikipedia has a nice long bit about the differences:

http://en.wikipedia.org/wiki/D...eters

[nametakennow]

Right, my point is that you do gain power to the ground (so a wheel dyno would show it), and, therefore, you gain power. Less energy spent moving the balance shafts equates to more energy put through the wheels.

[djtorello]

Right, my point is that you do gain power to the ground (so a wheel dyno would show it), and, therefore, you gain power. Less energy spent moving the balance shafts equates to more energy put through the wheels.

ive seen the new balance shaft, it doesnt do anything, no moving parts. I think the reason its still there is because if you removed it, the engine block would have to be redesigned.

When i removed my crank to blueprint, knife edge and balance it, it was only off 2 oz on the #3 counter weight. Not bad at all. While i was down there, i added a crankscrapper as well.

Nissan did a good job.

[gotak]

Right, my point is that you do gain power to the ground (so a wheel dyno would show it), and, therefore, you gain power. Less energy spent moving the balance shafts equates to more energy put through the wheels.

You'd only gain the power/energy from not having to over come the friction of the BS bearings. Overall most likely insignificant. In other words not 7 HP's worth. That 7 HP only shows on a inertia dyno because the inertia dyno cannot really calculate the drive chain mass. On a brake dyno you'll notice next to no improvements.

[nametakennow]

BS removal in B15 SE-R/Specs has a dyno proven 7whp increase. I should have said WHP earlier. I can't find a blown up version of the dyno sheet on this page, but I've seen this same data from multiple vehicles.

Torello - The new QR has a redesigned balancing setup, so your findings don't surprise me at all. In fact, I wouldn't be surprised if the hp bump is one of the reasons Nissan went with an internally balanced crankshaft on the revised QR. The other being fewer moving parts and, therefore, lower cost and fewer points of failure.

Less energy spent spinning the balance shafts equates to more energy transferred to the flywheel, on to the transmission, the differential, and eventually to the wheels. Think of it as reducing drag on the crankshaft.

I've never heard this idea that removing mass on parts of the drivetrain does not mean an increase in power. It is an increase in the efficiency with which the energy produced by the engine is used. The energy produced by the engine, by definition, is the power of the engine, which, because the engine is connected to the wheels, means the power at the wheels.

This is the exact same principle under which practically every mod is based. The perfect example is a lightened crankshaft pulley, which is also proven to increase power at the wheels. The same can be said for installing a lightened flywheel, which is an especially effective method of increasing power output without actually modifying the engine at all.

[Buzzman]

That's interesting, I drove 4 hours to conneticut and I felt great afterward, no pains or anything, when I did it in my saturn I wanted to end my life, I couldn't feel my *** or anything.

The ride is noisy and rough, but it's a sport compact, they have to cut corners somewhere.

Versa come on now, my friend has one and it's nothing but an econo box subcompact. How can you even compare them lol.

The uncomfortable seating probably has more to do with my butt than the seat. I'm 6'3", and 180lbs., so that's probably part of the problem. (I have a difficult time finding any car that's comfortable on a long trip.) As for the Versa comment, I think you may have misunderstood. I wasn't comparing it to the Sentra. The Versa is what you say it is, an econobox. It was just a comment I threw in. It just so happened that I drove both cars while at the dealership, and I found the Versa to be a pleasant surprise, given what it is. That's all.

[Godofelru]

Ah I gotcha that makes sense.

I just got back from Penn State this weekend and the drive up there I actually had a slight cramp but I wasn't sitting comfortably to begin with I was all alert cause I had no idea where I was going and it was raining like hell.

[gotak]

BS removal in B15 SE-R/Specs has a dyno proven 7whp increase. I should have said WHP earlier. I can't find a blown up version of the dyno sheet on this page, but I've seen this same data from multiple vehicles.

Torello - The new QR has a redesigned balancing setup, so your findings don't surprise me at all. In fact, I wouldn't be surprised if the hp bump is one of the reasons Nissan went with an internally balanced crankshaft on the revised QR. The other being fewer moving parts and, therefore, lower cost and fewer points of failure.

Less energy spent spinning the balance shafts equates to more energy transferred to the flywheel, on to the transmission, the differential, and eventually to the wheels. Think of it as reducing drag on the crankshaft.

I've never heard this idea that removing mass on parts of the drivetrain does not mean an increase in power. It is an increase in the efficiency with which the energy produced by the engine is used. The energy produced by the engine, by definition, is the power of the engine, which, because the engine is connected to the wheels, means the power at the wheels.

This is the exact same principle under which practically every mod is based. The perfect example is a lightened crankshaft pulley, which is also proven to increase power at the wheels. The same can be said for installing a lightened flywheel, which is an especially effective method of increasing power output without actually modifying the engine at all.

The difference in what the dyno measures and what's real is based on the problem that everyone uses an inertia dyno. If everyone used a brake dyno we might well not have much of a modification scene because a lot of stuff people do would show up as not much of a gain.

It seems so many people confuses energy/power with acceleration. Sure you might get improvement in acceleration from removing a BS but you also get an improvement if you went on the treadmill for a year and lost some weight. Does that mean you get more power/energy out of the car? No. And that's the problem with inertial dyno. It measures how fast your car can accelerate the dyno's drum. So if you reduce the spinning mass in your drive chain it will shows a gain because less mass to accelerate. However, there's no more power to be had in reality so the max speed of the car as limited by air resistance (assuming other factors are insignificant) will not change. Because that max speed is limited by the ability of the engine to convert fuel into mechanical energy which is then absorbed by the air you are pushing out of your way.

A spinning mass by itself in vacuum and free space (think of say a balance shaft spinning in orbit around the earth) does not "absorb" any energy beyond the amount needed to spin it up. In a steady state without friction from anything else it will keep spinning and spinning forever. There is energy stored in the spinning motion but the only loses inside an engine would be in the friction of the bearings and maybe some interaction with the oil. As such you can imagine how "useful" a lightened fly wheel or pulley really is in helping "make power". It doesn't help at all. They do help acceleration to a point but again any lightening would help that.

The stuff I am talking about is like high school Newtonian physics. It's simple stuff I don't get why there's so much confusion.

[nametakennow]

I agree, reducing weight in other areas has no effect on engine power. However, reducing weight on a spinning portion of the engine does equate to an increase in real power.

The balance shafts spin with the crankshaft. By removing them, you essentially reduce the amount of mechanical drag on the crankshaft. In doing so, it takes less energy to spin the crankshaft, which means more of that energy is transferred through the rest of the system to the wheels.

What I don't understand is why you're talking about top speed. You are correct in saying that this won't really change top speed, but the reason isn't the car's ability to cut through the air, it's actually the gearing. Given enough power, any engine could push a refrigerator to the top speed allowed by the gearing.

So, let's assume that the car has enough power to get to its gearing-limited top speed from the factory (it may not, but oh well). In this case, reductions in weight will only change how quickly it gets there. This goes for all reductions in weight, regardless of where they are on the car.

Now let's assume the car can't get to its mechanical top speed. Now, changes in aerodynamics will make the car cut through the air faster, getting to closer to its top speed. Similarly, reductions in overall vehicle weight will allow more of the engine's energy to go towards fighting aerodynamic drag. Reductions in weight on internal elements of the engine will do the same (though they will do this both as a reduction in overall weight and as a reduction on the amount of energy the engine uses to spin them directly).

In essence, your argument about wind resistance essentially assumes that there is some sort of barrier to how fast the car can go based purely on wind resistance. Power increases and weight losses will both help push through wind resistance.

However, what we're talking about here is beyond all of that. BSR will actually show up on a brake dyno too. You said yourself that it takes energy to spin the shaft up, and that's what we're talking about. Getting rid of the shaft means that energy doesn't have to be spent, so the engine is putting more energy through to the wheels. The effect, as you said, is increased acceleration. The change in top speed is based on the more efficient use of this energy in propelling the car against wind resistance, assuming that it is not held back by gearing.

From Wikipedia - A Brake dynamometer applies variable load on the engine and measures the engine's ability to move or hold the rpm as related to the "braking force" applied. It is usually connected to a computer which records the applied braking torque and calculates the power output of the engine based on information from a "load cell" or "strain gauge" and rpm (speed sensor).

The engine's ability to move or hold rpm is directly related to how much mechanical "drag" is on the crankshaft. This mechanical drag is exactly what the brake dyno is using to measure power. Mods like BSR are based on the same principle as a brake dyno - the balance shafts effectively act as a "braking force" on the engine, since it takes energy to spin them up.

[gotak]

The balance shaft only takes energy to spin up because kinetic energy in a mass works under the equation of E=1/2MV^2. So reducing mass will decrease the energy required to spin up the drive chain but end result is that power generated by the engine burning fuel does not increase. You did not magically made the engine more powerful. If you measure the power the engine outputs at a steady RPM on a brake dyno there will be only slight differences between having the BS or not due to reduction in drag associated with the BS bearings and any interaction with engine oil by the BS. That energy that goes into spinning the balance shaft up does not disappear it's still there in the rotational inertia of the shaft and comes back out when you lift on the gas in the form of the engine spinning longer then without the BS. A BS ALREADY SPUN UP DOES NOT TAKE UP ANY MORE ENERGY. Only the bearings and oil interaction does.

The key to what I am trying to say is that reducing mass does not "make" power. A lot of people seems to think so but reality is that you can get ubobtanium that has no mass and make the engine out of it and it will spin up a lot faster then our steel and aluminum engine in reality but you do not generate more power. That's why the air resistance part is mentioned.

The max speed of a car is not simply determined by gearing, in most case anyhow. If you have a infinitely powerful engine under the hood which has a RPM limit then yes your speed is limited by the gearing. However, we don't have such engines and our max speed is actually limited by air and other resistance the car encounters. Air resistance comes about from the car pushing air side. To do this the car has to input energy into the air. The faster you want to move the faster you need to move the air out of your way so the more energy you need to give the air (again E=1/2MV^2).

To tie it all up if you understand what I just said you'll see that the max speed due to air resistance is indeed due to limited engine power (if you don't believe me look at top speed numbers for various super cars, veyron for example, where some cars with a lot of HP are actually slower then cars with less even though they weight less then the car with less HP. It's all down to the aero drag the body has). And that it will not change significantly if you reduce drive chain rotation mass because that does not actually free up energy in a steady state.

[Hijacker]

The problem with your analogy is that the motor has to fight itself to spin. Everything inside the motor fights itself when the motor is in operation. Anything you can do to lighten the powertrain components or lessen the drag on the system is beneficial. You may not see a massive 10hp gain, but you get a freer revving motor, which means you get to use the powerband more effeciently.

Balance shaft removal is a way to lessen powertrain mass. Much like using titanium valves, or aluminum-titanium allow pistons. You're helping the motor by not helping it fight itself to spin. This all adds up to a realized increase in power production.

Let's take for example, you have power steering on your car. The SAE net number of power is produced with the pump attached. Nissan states your motor makes X power SAE. Now you remove the power steering pump and you lessen the drag on the powertrain. It no longer has to spin something else extra. You might only see 1 horsepower returned, but that's 1 horsepower the motor should be producing, had it not been for something an engineer had added. You're not adding power, you're gaining it back.

Now, balance shafts are designed for noise harmonics. It's only purpose is to make the motor quieter. It's not meant to aid power production. By removing it, all you're doing is helping the motor to breath easier.

Why would race teams around the world utilize state of the art alloys and coatings on their powertrain components? It's not for weight savings. I can save more weight by using the bathroom before a race. The miniscule amount of weight saved or drag reduced on each component add into the motor being able to realize it's full power potential.

As far as dynos go, an inertial dyno is not the best. That's a known fact. However, it's the most accessible and easiest to set up. But in the end, it all comes down to calibration. In a perfect world, power would be measured at the crank, with the motor on an engine stand. Inertia dynos at least give you a number of actual power produced at the wheels. Usable power.

I really don't see where you get this whole "in a vacuum" analogy. It's proposterous. Nothing should ever be "in perfect conditions". In a perfect world, I would be making 7 digits a year, but I'm not. Motors always have, and always will have, frictional forces to overcome and fight. The point is to lessen those forces through bearing/piston coatings, handling of crank case oil misting, and overall good engineering.

Your mention of air drag should not be confused with power production. Air drag coefficient is a factor in overall speed of a car, however, driving the aerodynamics of a car do not play a factor into how much power a motor can deliver.

I really suggest you should read up on some mid level motor building books. Get an idea of what race teams look at when they are trying to maximize a motor's output.

[gotak]

I mentioned the in a vacuum analogy to illustrate a point. Which is that the spinning mass does not soak up energy as so many people seems to believe. It's there spinning by itself and does not require any more input to keep spinning.

If you read what I said I did mention that in reality you have the friction from the bearings and oil interaction to overcome. However, how much is that ? And how do you measure that when your inertial dyno is measuring acceleration of the drive chain and dyno drum and not actual power out put? That's my point.

Anyhow I am done. If you guys want to believe that removing some mass free up energy and that air resistance (F1 cars have huge resources devoted to balancing drag and down force) is not a limiting factor then fine. I need to get back to writing my Masters thesis in engineering and I don't want to explain high school physics anymore.