The most basic exhause question known to man

[Scooby24]

also another major point is being missed. Notice rpm for rpm no torque is lost anywhere, even near idle its making more power.

Sure RPM for RPM it's going to do better than STOCK. We don't care about that. We want to know RPM for RPM what it does compared to the 2.5.

In my experiences I've seen time and time again cars with large exhausts make great power on the dyno and are good for bragging rights but they will get beat in actual races by cars with properly matched sizes for the flow of the engine.

Why are you guys defending so hard your 3" exhausts as "better" when you don't even know what a 2.5's dyno graph looks like?

Are you insulted by the idea that maybe you didn't pike a 100% ideal exhaust size?

[Bigvinnie]

thats an entirely bogus rebuttle because you know it was already equiped with that intake before and after the exhaust was bolted on. It a pretty damn good controlled dyno actually.

now you're just nit picking, why would you only want to see what a stock KA can do with a 3 inch? honeslty whoever put on an exhaust and called it a day? "oh this 140 wheel horse is pretty good, i better stop right here"

if you really, really wanted to nit pick, and thats what you are doing, you would be complaining about there not being dyno's of the mods you already have, so you could see the gains your car would get.

also another major point is being missed. Notice rpm for rpm no torque is lost anywhere, even near idle its making more power.

Insanity is still right, and others are just digging themselves deeper, just call it a day

The fact is the EXHAUST alone won't pull 14HP it won't even come close to 10HP as a seperate standalone modification. I'm not nitpicking nothing, you guys are misconstrueing mine and scoobs words, just to "SELL" the idea that 3" inch is better. You are SELLING. Me I'm selling nothing, and I don't ride peoples c*** like I'm on some sort of bandwagon, I follow rules... Exhaust is to compliment and tune your engine. I'm not debating with you or anybody else, and I never said that you coudln't use 3", I wouldn't recomend it on a stock KA....... But it's like they say opinions are like A$$holes everybody has one, so really I still give 2 shiats that you guys decide to use 3". Even though in all reallity most shops that have been in the business for years will still recomend the 2.5". Talk to ford mustang guys with 5.0 or 4.6 litres they still use dual 2.5". With a few exceptions of the Borla 3" which is recomended for super charged mustangs.Why not since we are on the subject why is it that most JEEP guys tune with 2.5" and the fact that JEEP engines have way more displacement than a KA. Really you guy's are riding on a "HYPED UP Bandwagon" That started just because you saw a dyno or 2 on a N1 exhaust, you guys defenitely don't get out much and look at dyno's.
Modified by Bigvinnie at 11:25 AM 9/1/2005

[2s4k0y09]

I run an Apexi N1 3inch on mine, it was kinda of sluggish starting in 1st gear. I got the exhaust a couple years ago, but recently this year I added a Hi-flow cat, polyurthene exhaust hangers, and a Hot Shots header. Yeah it is loud, but the car pulls like crazy in the mid to high RPMs. It also gives it a really nice rumble. My buddy has a 2.5" piping on his Spec-v and hes so jealous that his doesn't sound like mine.lol But I also bought the exhaust with the intent of an SR swap, hopefully coming next year.

[InsanityInc]

Let me say it again..... By itself it wont pull 10HP...............

And let me say it again: You're a flagrant moron.

An intake on the KA only adds about 4HP. That isn't going to suddenly make you need a bigger exhaust, or make your exhaust system add 10 wheel horsepower over what it would have otherwise. If it was a fully built race engine with every other part severly modified you might have a point. But it isn't, and you don't. Besides, does anyone have a fully different exhaust system and retain the stock intake? This is the most completely irrelevant point you could possibly choose to argue.

Quote »Sure RPM for RPM it's going to do better than STOCK. We don't care about that. We want to know RPM for RPM what it does compared to the 2.5.[/quote]Well. Look at the graph. It's a very even large increase in torque over the entire band. Do you really think that a 2.5" exhaust is going to produce a consistent improvement of about 8 ft-lbs from 3000+? I seriously doubt it, and talking about anything lower than that isn't relevant for racing. Hell, talking about anything lower than about 4600 isn't really relevant for racing this engine.

[Bigvinnie]

And let me say it again: You're a flagrant moron.

First off I don't call you names it's imature, secondly if I saw you face to face I would be twice as imature and knock your FUC$in' teeth out with a 3" exhaust.

An intake on the KA only adds about 4HP. That isn't going to suddenly make you need a bigger exhaust, or make your exhaust system add 10 wheel horsepower over what it would have otherwise. If it was a fully built race engine with every other part severly modified you might have a point. But it isn't, and you don't. Besides, does anyone have a fully different exhaust system and retain the stock intake? This is the most completely irrelevant point you could possibly choose to argue.

Yeah but when you add other bolt on's, HP numbers multiply smart a$$. You increase flow from front to rear with intake and exhaust that increases flow and increases HP numbers from both angles.

[Bigvinnie]

I run an Apexi N1 3inch on mine, it was kinda of sluggish starting in 1st gear.

Thank You very much, couldn't of been stated any better from a guy with a 3" exhaust. You don't get those problems with a 2.5". I'm done.....

One final note 2.5" is no better than 3", heres why. No bolt on EVER in history will increase your Crank Horse Power rating!!!! Well accept for turbo's, super chargers and nos. So tune your exhaust to where you want to use your power. If your the type of guy that only enjoys top end HP and is willing to sacrifice lowend torque, and HP numbers in the lower RPM's, please go out and buy yourself a 3" exhaust.If your the type of guy that want's power in a full range of the power band then please go out and buy a 2.5". I use 2.5" to smoke idiots that lost all those numbers in the bottom RPM's when I hit the track. TATA 3" losers!!!

Modified by Bigvinnie at 5:34 PM 9/1/2005

Modified by Bigvinnie at 5:36 PM 9/1/2005
Modified by Bigvinnie at 5:37 PM 9/1/2005

[Scooby24]

One final note 2.5" is no better than 3", heres why. No bolt on EVER in history will increase your Crank Horse Power rating!!!!

oh god...I'm sorry man but I have to correct you on this. This is the most inaccurate and insane statement I've ever heard.

If you add an exhaust and you gain 10 whp...where do you think that horsepower came from? Do you think the transmission just all of a sudden realeased 10 more crank horsepower to the wheels?

No man...I'm sorry I don't want to flame you but please....please never make a statement like this again.

[Bigvinnie]

No but really your freeing up space, not really changing crank HP, but rather the WHP.

Here let me reiderate so you can understand better. When Nissan tests there engines before being applied to the chassis, they test it for CHP, that means no exhaust header out, no drive train, and no filter. Maximum output of the engine at the crank is 155CHP.Once the engine is applied to the chassis you have the drive train, filter and exhaust. Which gives it about 123WHP output at stock. No matter what modifications you make as far as bolt ons are concerned the engine will never exceed it's 155CHP, it's just not possible unless internal work is done, or ems mapping. That means your just shifting numbers in the power band and freeing up space within the 155CHP.
Modified by Bigvinnie at 6:36 PM 9/1/2005

[Scooby24]

No but really your freeing up space, not really changing crank HP, but rather the WHP.

Here let me reiderate so you can understand better. When Nissan tests there engines before being applied to the chassis, they test it for CHP, that means no exhaust header out, no drive train, and no filter. Maximum output of the engine at the crank is 155CHP.Once the engine is applied to the chassis you have the drive train, filter and exhaust. Which gives it about 123WHP output at stock. No matter what modifications you make as far as bolt ons are concerned the engine will never exceed it's 155CHP, it's just not possible unless internal work is done, or ems mapping. That means your just shifting numbers in the power band and freeing up space within the 155CHP.

Modified by Bigvinnie at 6:36 PM 9/1/2005

No that's not right....

Your engine is making 155 whp but it's losing horsepower through a series of events. The largest drain on horsepower transferred to the wheels is through the transmission. There is a lot of friction on the transmission.

Think of it in terms of physics. Your transmission generates heat becauses it's generating friction. Friction is causes by power. Power is never created or destroyed, simply converted. So it's taking a portion of your crank horsepower, and changing that power from kenetic energy to heat which is sucking it away from the wheels. This is usually a percentage as the more power you are making the more frictiong you are generating and the more power lost.

AWD drivetrains have two sets of gears which generates more heat and causes more loss which is why on a 300 CHP RWD car you'll see about a 15 percent drivetrain loss and on a 300 CHP AWD car you'll see about a 25 percent drivetrain loss.

This explains why my some cars are able to generate MORE whp than chp. Take LS1's for example. I have a friend with only bolts who is making 5 more WHP than the car has at the crank stock.

Hope that explains it.

[InsanityInc]

No but really your freeing up space, not really changing crank HP, but rather the WHP.

Here let me reiderate so you can understand better. When Nissan tests there engines before being applied to the chassis, they test it for CHP, that means no exhaust header out, no drive train, and no filter. Maximum output of the engine at the crank is 155CHP.Once the engine is applied to the chassis you have the drive train, filter and exhaust. Which gives it about 123WHP output at stock. No matter what modifications you make as far as bolt ons are concerned the engine will never exceed it's 155CHP, it's just not possible unless internal work is done, or ems mapping. That means your just shifting numbers in the power band and freeing up space within the 155CHP.

Modified by Bigvinnie at 6:36 PM 9/1/2005

Oh jesus.

You aren't serious, are you?

This guy has to be a troll.

Your pistons are connected to your crankshaft. Your crankshaft is connected to your flywheel. Your flywheel is connected to your clutch, which connects you to the rest of the driveline. If your crankshaft horsepower doesn't go up, your wheel horsepower doesn't go up. I really have no clue how you could think otherwise. The way an exhaust makes more power for your ENGINE (read: at the crankshaft) is by:

1) improving exhaust scavenging. English: Makes all your exhaust get out of the cylinder, so it isn't taking up space that could otherwise be occupied by a fresh intake charge on your next intake stroke.

2) increasing air intake during the camshaft overlap phase. There is a time period when your intake and exhaust valves are both open at the same time during the start of the intake phase. Due to the aforementioned bernoulli effect, the exiting exhaust creates a low pressure zone inside the combustion chamber, which actually pulls intake air into the cylinder before the piston starts going down. The more easily and quickly your exhaust can exit, the more air gets pulled in during this phase.

Both of these create a larger cylinder charge, which creates a bigger boom, which creates more torque on the CRANK SHAFT. Which turns your driveline, and then powers the wheels.

Scooby at least has some semblence of a point, you're just retarded.

[Bigvinnie]

Oh jesus.

You aren't serious, are you?

This guy has to be a troll.

Your pistons are connected to your crankshaft. Your crankshaft is connected to your flywheel. Your flywheel is connected to your clutch, which connects you to the rest of the driveline. If your crankshaft horsepower doesn't go up, your wheel horsepower doesn't go up. I really have no clue how you could think otherwise. The way an exhaust makes more power for your ENGINE (read: at the crankshaft) is by:

1) improving exhaust scavenging. English: Makes all your exhaust get out of the cylinder, so it isn't taking up space that could otherwise be occupied by a fresh intake charge on your next intake stroke.

2) increasing air intake during the camshaft overlap phase. There is a time period when your intake and exhaust valves are both open at the same time during the start of the intake phase. Due to the aforementioned bernoulli effect, the exiting exhaust creates a low pressure zone inside the combustion chamber, which actually pulls intake air into the cylinder before the piston starts going down. The more easily and quickly your exhaust can exit, the more air gets pulled in during this phase.

Both of these create a larger cylinder charge, which creates a bigger boom, which creates more torque on the CRANK SHAFT. Which turns your driveline, and then powers the wheels.

Scooby at least has some semblence of a point, you're just retarded.

Everything you said I just ignored.......LOL

As you can see in the pic determining crank HP of the engine there is no exhaust to begin with, there are no filters, no drive train just bone stock engine. Unless you are boosted and blown those crank Horse power numbers wont increase. Infact adding exhaust and filters are already restrictive. 11% of degredation is consumed by the transmission "for the KA" while the other 4% is consumed by exhaust, filters and smog equipment such as the catylitic converter "for the KA". Like I said your not increasing crank HP only numbers at the wheel because you have made modifications to already restrictive equipment, your just shifting numbers in the power band. Go to school and learn something mister 3" 's.Mister insanity you are insane because you are not educated........Heres a lesson that I can use to schookl all you idiots on how crank HP is achieved and how its diferent from wheel Horse power.http://popularhotrodding.com/e...dsor2/

[Bigvinnie]

Now let me repost and see if it makes sence to you panzee a$$es... All I can say is OWENED, ouch thats gotta hurt.......LOLBUBUBUBU bolt ons DO NOT INCREASE CRANK HORSE POWER, JUST POWER AT THE WHEELS!!!!!!! LOL The ENGINE WILL NOT EXCEED IT'S 155CRANK HORSE POWER OUTPUT!!!!! LOL

No but really your freeing up space, not really changing crank HP, but rather the WHP.

Here let me reiderate so you can understand better. When Nissan tests there engines before being applied to the chassis, they test it for CHP, that means no exhaust header out, no drive train, and no filter. Maximum output of the engine at the crank is 155CHP.Once the engine is applied to the chassis you have the drive train, filter and exhaust. Which gives it about 123WHP output at stock. No matter what modifications you make as far as bolt ons are concerned the engine will never exceed it's 155CHP, it's just not possible unless internal work is done, or ems mapping. That means your just shifting numbers in the power band and freeing up space within the 155CHP.

[Scooby24]

Every company measures crank hp differenty.

Nissan's Spec V is rated at 175Nissan's SE-R is rated at 165

The company has openly admitted the difference between the ratings is purely in the exhaust. That is the only difference performance wise between the two in terms of horsepower.

Crank horsepower changes with boltons. Trust me.

Like I said...my LS1 friend has a lid and cutout...and he's dynoing 325 whp...the car stock has 320 at the crank

[InsanityInc]

Everything you said I just ignored.......LOL

As you can see in the pic determining crank HP of the engine there is no exhaust to begin with, there are no filters, no drive train just bone stock engine. Unless you are boosted and blown those crank Horse power numbers wont increase. Infact adding exhaust and filters are already restrictive. 11% of degredation is consumed by the transmission "for the KA" while the other 4% is consumed by exhaust, filters and smog equipment such as the catylitic converter "for the KA". Like I said your not increasing crank HP only numbers at the wheel because you have made modifications to already restrictive equipment, your just shifting numbers in the power band. Go to school and learn something mister 3" 's.Mister insanity you are insane because you are not educated........Heres a lesson that I can use to schookl all you idiots on how crank HP is achieved and how its diferent from wheel Horse power.http://popularhotrodding.com/e...dsor2/

What the **** are you talking about? Seriously. Nobody ever claimed WHP was the same as CHP, but WHP is always less than your CHP, because it has to come from somewhere. How do you not get this?

Also, that engine very clearly has an exhaust system on it, so I don't know what kind of crack you're smoking. Apparently you're unaware of the difference between SAE gross and SAE net. I'm not even going to bother explaining it to you.

Quote »a$$es... All I can say is OWENED, ouch thats gotta hurt.......LOLBUBUBUBU bolt ons DO NOT INCREASE CRANK HORSE POWER, JUST POWER AT THE WHEELS!!!!!!! LOL The ENGINE WILL NOT EXCEED IT'S 155CRANK HORSE POWER OUTPUT!!!!! LOL[/quote]Holy crap, you're a bigger moron than I thought, AND you're delusional. You didn't own anyone, and I suggest you stop before you convince everyone that you're literally retarded.

If your CHP doesn't increase, logically explain how your WHP can increase. Where does the power come from? You are a ****ing cracky.

Oh, and you know absolutely nothing about engines, I suggest you never try to argue with me about anything again, or I'll just direct people to this thread.

[InsanityInc]

Every company measures crank hp differenty.

Nissan's Spec V is rated at 175Nissan's SE-R is rated at 165

The company has openly admitted the difference between the ratings is purely in the exhaust. That is the only difference performance wise between the two in terms of horsepower.

Crank horsepower changes with boltons. Trust me.

Like I said...my LS1 friend has a lid and cutout...and he's dynoing 325 whp...the car stock has 320 at the crank

I really don't think he's capable of a logical thought process.

[InsanityInc]

Tell you what, BigVinnie. Send an email asking the people at EngineMasters.com if you can increase WHP without increasing CHP, and then when they give you their response, post it here.

[Bigvinnie]

Tell you what, BigVinnie. Send an email asking the people at EngineMasters.com if you can increase WHP without increasing CHP, and then when they give you their response, post it here.

How bout this so you understand better. On Crank Horse Power dyno testing there is only a header... Right That means Max crank Horse powerout put is that of one 155CHP. Now you cant decipher Crank HP from Wheel HP. Once the engine is in the chassis the engine will always be using it's 155CHP maximum potential at peak RPM. Due to bolt ons, and drivetrain numbers at the wheels change. But the fact is the engine is always pulling 155CHP you just can't see it at the wheels. So now you have added an exhaust to the end of a header that already had a yeilded a maximum power out put of 155CHP. That means you are just moving numbers around because you have extended a pipe weither it be 2" or 3" I really don't care. That is why exhaust tuning is developed. Using different diameter pipes after the header will only shift numbers into the earlier or later rpm. That is why 2.5" in my opinion works better even constant flow that is slightly larger than my DC sports collector.

To scooby: all Nissan USDM engines go through this dyno testing, NO exceptions, and it's mandated by the EPA to measure pollutants from HP output.....

[Scooby24]

How bout this so you understand better. On Crank Horse Power dyno testing there is only a header... Right That means Max crank Horse powerout put is that of one 155CHP. Now you cant decipher Crank HP from Wheel HP. Once the engine is in the chassis the engine will always be using it's 155CHP maximum potential at peak RPM. Due to bolt ons, and drivetrain numbers at the wheels change. But the fact is the engine is always pulling 155CHP you just can't see it at the wheels. So now you have added an exhaust to the end of a header that already had a yeilded a maximum power out put of 155CHP. That means you are just moving numbers around because you have extended a pipe weither it be 2" or 3" I really don't care. That is why exhaust tuning is developed. Using different diameter pipes after the header will only shift numbers into the earlier or later rpm. That is why 2.5" in my opinion works better even constant flow that is slightly larger than my DC sports collector.

To scooby: all Nissan USDM engines go through this dyno testing, NO exceptions, and it's mandated by the EPA to measure pollutants from HP output.....

Okay try to invision this.

Nissan measures power to their engines with their exhausts on.

This is why Spec-V's claim 175 crank hp versus the SE-R's 165 crank hp.

The exhaust difference increases the Spec-V's Crank HP. Nissan has announced this. The dealers will tell you this.

Exhausts and intakes CAN and DO increase crank hp. There are a few bolt on products however that do NOT add crank hp but DO increase more whp.

These are products that do not adjust how the engine breathes and produces power. These are things like crank pulleys, lighter driveshafts, hell even synthetic transmission fluid has shown to release a few more ponies to the ground.... but if you look at the dynos of these mods the power increase is linear....meaning it's obvious the engine is operating no differently...no changes to engine power.

Adding exhausts, intakes, and other bolt ons DO change engine power. Fact.

From what it sounds like you're saying and what I'm interpreting is this:

Car companies rate their engines without any power robbing add ons like exhaust, intake, etc.

Then they throw the engine in there which reduces the engine's output taking the crank hp rating down from what they advertise.

They cannot do this: Why? False advertisement. The most recent example has been RX-8s. They were overrated hp numbers because of this reason and the company recalled those customer's cars IIRC.

Therefore The engine going into a 240sx is making 155 horsepower at the crank. At the wheels it is losing ~15% of it's power so it's around 130 to the wheels.

If you add an exhaust and you gain 10 whp to total 140 whp....you are now making around 166 or 167 Crank HP.

Simple as that.

Point. Period. Paragraph.

-Greg

[InsanityInc]

From what it sounds like you're saying and what I'm interpreting is this:

Car companies rate their engines without any power robbing add ons like exhaust, intake, etc.

Then they throw the engine in there which reduces the engine's output taking the crank hp rating down from what they advertise.

They cannot do this: Why? False advertisement.

Actually, they used to do this, which is why old cars had really big horsepower/torque ratings, like the chevy 502. The reason why horsepower figures these days say SAE NET after them is designating the SAE standard by which that horsepower number was attained. It has a temperature and humidity component, and also specifies what has to be attached to the engine. Under SAE NET, you have to have all accessories, belts, both manifolds, a full exhaust with muffler and cat and the intake system attached to the engine while rating it. In days of yore (read: pre-1970 or so), engines were rated with the rather bogus SAE GROSS number, which was much more lax, and didn't require a full exhaust or even an exhaust manifold if I recall. nor did it require any accessories to be hooked up, or the intake system to really even resemble stock. That's why horsepower numbers took a massive perceived dive when SAE NET started being used.

[Bigvinnie]

Okay try to invision this.

Nissan measures power to their engines with their exhausts on.

This is why Spec-V's claim 175 crank hp versus the SE-R's 165 crank hp.

The dealers will tell you this.

Not to say you are wrong Greg but I read an article in road and track that the ecu has a more aggresive and leaner tune than the SE-r. I could be wrong, but I am also very sceptical what a dealer tells me. They are the biggest liars in the world, and there always blowing hotair out there A$$.

[Bigvinnie]

Actually, they used to do this, which is why old cars had really big horsepower/torque ratings, like the chevy 502.

Actually car manufacturers still do it to this day. When the Mazda RX-8 was sold Mazda boasted big numbers at the crank. About a year later guys that dyno tested there ride and worked out the degredation numbers found out that Mazda was selling FAKE crank HP numbers.

[InsanityInc]

Actually car manufacturers still do it to this day. When the Mazda RX-8 was sold Mazda boasted big numbers at the crank. About a year later guys that dyno tested there ride and worked out the degredation numbers found out that Mazda was selling FAKE crank HP numbers.

Yes, but that wasn't because of improper testing procedures. They conformed to SAE NET as far as I know. The old engines had inflated numbers due to the crappy SAE GROSS testing standard.

[Riley2.4L]

Wow you guys are still going at it? Honestly not to play the guy who calls for peace and loving campfires but c'mon you three have been arguing over my question forever. just take a break. If you live neat each other. run the 1320 and see who wins 2.5 or 3"