Aftermarket Turbo Plenum On Non Turbo R33 Gts25?

[Captain Natro]

Are Blitz back pressures better than the Greddy ones?

Yer but only on boost less then 12 pound, for natro applications you can't go past Hks parts

[Deza3000]

LOL did i say something wrong?? =[ I thought N/a cars rely on backpressure for better throttle response and more low end torque? Cause the car is manufactured to run with the back pressure created by the factory exhaust?

[Deza3000]

LOL just looked at my exhaust and noticed that my car had a butterfly exhaust from factory, hence why i lost power when i put that canon ==' Also did some research and found out that velocity as well as a warm exhaust increase flow and reduces back pressure, thats why proper exhaust systems produces more power than straight pipes. wider pipes = less velocity which = more time for the exhaust gases to escape. Had it wrong this whole time. Made my self look like an idiot across 5 different forums =='

Can anyone tell me if what i just said is true =p

Edited December 18, 2012 by Deza3000

[mad082]

Back pressure is the term used by the average punter who doesn't know what they are talking about and have just heard other people talking about it.

Back pressure is an unwanted side affect from having an exhaust that has optimum at lower rpm (the rpm where the majority of the population drive at, and for highway speeds). Once you increase the airflow in a restrictive exhaust, so does the back pressure, and the increase in power output slows. If you increase the exhaust size you increase the overall airflow capacity, but at low airflow you lose some of the scavenging effect and can have more turbulent airflow, resulting in lower power output (at low rpm) compared to the smaller exhaust. You would have a higher power output at higher revs though. So there is a trade off.

[Captain Natro]

Back pressure is the term used by the average punter who doesn't know what they are talking about and have just heard other people talking about it.

Exactly this, pisses me off when I hear people talking about it

Spoiler

WHY ELSE WOULD DRAG CARS RUN OPEN HEADERS!!!

Edited December 18, 2012 by Nikk_666

[mad082]

They are blown though. But still, they put a lot if time into getting the length of those headers right

[Captain Natro]

They are blown though. But still, they put a lot if time into getting the length of those headers right

Not all drag cars with open headers are blown, for example pro stock cars run open headers...

[Hanaldo]

LOL just looked at my exhaust and noticed that my car had a butterfly exhaust from factory, hence why i lost power when i put that canon =='

Wut?

Also did some research and found out that velocity as well as a warm exhaust increase flow and reduces back pressure, thats why proper exhaust systems produces more power than straight pipes.

Wut?

wider pipes = less velocity which = more time for the exhaust gases to escape. Had it wrong this whole time. Made my self look like an idiot across 5 different forums =='

And wut?

[Deza3000]

Wut?

Wut?

And wut?

Judging by your wuts, ive still got it wrong? Im just repeating what i read on a few articles lol.

1. my car does have a butterfly exhaust from factory, theres a valve on the right tip which opens under full throttle, it came factory from nissan. My mates r33 has it as well. Ill take a picture and show you if you want. That canon i used to have was from 2 years ago when all i wanted was noise but then realized it looked stupid and i lost a tonne of power so i chucked it out.

2. The article i read was explaining the dynamics of an exhaust system, it explained how in a straight pipe exhaust, the gases escaping the chamber tend to cool down as the travel through the exhaust pipe causing, the cold exhausts travels at a slower rate than warmer exhausts. I just repeated what it said. Which is probably why expensive exhausts are made of titanium, better conductors of heat.

3, With wider pipes, (im talking like 4inch all the way down) also moves exhaust gases at a slower rate, he used a metaphor describing how water comes out through a hose, a bigger wider hose causes the water to be released slowly while a more smaller hose releases water at a much quicker rate, Its the same principal with exhaust gases. So a straight pipe all the way down wont really perform as well as a proper exhaust. Hypothetically why else would you pay thousands of dollars for a exhaust system if a straight pipe does the exact same thing.

this is my understanding on what ive read about, however you seem to know better so maybe you'd care to explain.

Btw cheers for making me feel like an idiot =)

[Miguelone]

That butterfly has nothing to do with performance, it's for those who want their car quiet as fark when tootling around but to have a bit of a note to it when they put the foot down.

[Deza3000]

That butterfly has nothing to do with performance, it's for those who want their car quiet as fark when tootling around but to have a bit of a note to it when they put the foot down.

You sure about that, ive opened the valve manually before, the note does sound much deeper but from what ive seen, in any butterfly exhaust when the valve opens up it does give a bit more performance in the higher rpm. Lower rpm the valve remains closed to increase velocity (quicker flow rate for the exhaust gases to escape) since theirs limited exhaust pulses being released,

http://www.gomog.com...ckpressure.html

The link explained everything pretty well. It also indirectly explains why straight pipes are silly.

Edited December 20, 2012 by Deza3000

[Captain Natro]

Who cares!

Either way max gain < 10rwkw....

Best way to make a natro rb go faster, kick your fat ass mate out of the passenger seat

[Deza3000]

LOL yea that sounds about right =p

[mad082]

ok, for starters, you can't compare water coming out a hose to an exhaust. there are very much different principles going on (as far as the source of the pressure, and the lack of temp change). there are a few similarities, but also some big differences. water coming out a small hose will have a much higher pressure, meaning that it takes more pressure to move. in an engine, that means more pressure/resistance on the piston trying to force the gases out of the combustion chamber, or slowing down the speed of a turbo.

secondly, the reason they make expensive exhausts out of Ti is because of weight. Ti is a poor conductor of heat compared to mild steel.

you don't get a straight pipe exhaust because you need mufflers and the exhaust has to fit under the car. if you were to have an exhaust that was designed perfectly to accomodate the cooling gas, it would start big and get smaller, but not with steps to make it smaller. it would be like a long extruded cone.

when it comes to headers though, there is many theories on what works, and how they deliver power. you will see ones that are a 4 into 1 design, while others are a 4-2-1 design. this will alter performance, as will the length of the primaries and secondaries.

at the end of the day, discussing the finer details of exhaust design is best left to people who have a decent grasp on the principles (which i don't really class myself as having. i have enough to get me a somewhat decent idea, but am a dunce compared to someone who has studied aero-thermodynamics). it's fine for the average punter to discuss it in a broad discussion as they will often be debating things that will make bugger all difference (like debating the difference between 2.25" and 2.5" on a NA skyline).

[Captain Natro]

ok, for starters, you can't compare water coming out a hose to an exhaust. there are very much different principles going on (as far as the source of the pressure, and the lack of temp change). there are a few similarities, but also some big differences. water coming out a small hose will have a much higher pressure, meaning that it takes more pressure to move. in an engine, that means more pressure/resistance on the piston trying to force the gases out of the combustion chamber, or slowing down the speed of a turbo.

secondly, the reason they make expensive exhausts out of Ti is because of weight. Ti is a poor conductor of heat compared to mild steel.

you don't get a straight pipe exhaust because you need mufflers and the exhaust has to fit under the car. if you were to have an exhaust that was designed perfectly to accomodate the cooling gas, it would start big and get smaller, but not with steps to make it smaller. it would be like a long extruded cone.

when it comes to headers though, there is many theories on what works, and how they deliver power. you will see ones that are a 4 into 1 design, while others are a 4-2-1 design. this will alter performance, as will the length of the primaries and secondaries.

at the end of the day, discussing the finer details of exhaust design is best left to people who have a decent grasp on the principles (which i don't really class myself as having. i have enough to get me a somewhat decent idea, but am a dunce compared to someone who has studied aero-thermodynamics). it's fine for the average punter to discuss it in a broad discussion as they will often be debating things that will make bugger all difference (like debating the difference between 2.25" and 2.5" on a NA skyline).

TLDR