imported_~ILLEST CIV~

I was wondering what the effect would be if i shorten this pipe?.....the one that'z black stock?....the tube like one that runs from the back of ur engine bay from the filter to the front behind the right headlight if ur in the car in the drivers seat about to drive......lol what would happen if i shortened that? would i see a bit better acceleration?.....or would it make no difference?.....

and i don't wanna buy no intake.....lol i was just wondering.....to see if there would be any improvement.....even the slightest?.....cause my cousin is doing a project in high school on some crap stuff....lol and he is using my civic as a test.....lol supposedly he said that there would be a difference......cause more air would be forced into the area and there would be more air to pull in..........is that true?

Nova_Dust

What makes the performance (correct me if I am wrong) is the temp. of air and the filter itself. Colder and cleaner air will mix better with fuel. If you lose that air box in the front, keep your air filter box (the on that is on TB mouth) and remove the flat air filter, and add a cone to the front of that pipe, maybe it will be better?

I think that's what you want to do right?

imported_~ILLEST CIV~

HAHAHAH A HOMEMADE INTAKE.........sounds good....maybe i'll do this myself........for a permanent thing.....lol hmmmm.......but yah that was the general idea that i was getting at..........cause he was saying that the more air i push in there, cold air the better?....lol he said it'll work good cause it'z really cold right now.......and supposedly tuesday it'z suppose to get a bit warmer.......so i dunno what he wants to do.......however
i think i'm gonna do this myself now...haha make my homemade air intake.....lol

spracingsports

well if u switch the stock paper filter element with a K&N cone, im positive that will make a difference. also from what ive read on here the inside of the stock plastic pipe is not smooth, its all bumpy and such, so shortening that should theoretically reduce the amount of restriction, making more power. however, shortening the pipe will bring the filter more in towards the engine, which means warmer air will be "sucked" in the intake. thats about as far as my knowledge takes me, so from here id say its a toss up, less restriction, yet warmer air...... probably wont help much..... it will just be louder

Nova_Dust

Do a homemade heat shield while you are at this. Cause cutting that pipe is pretty simple, and so is remove that thin air filter. You might want to also custom a thin steel plate support since you will be adding weight to that PVC pipe, and you don't want tid dangling around the engine bay.

As for heatshield, get a moderately thin layer of aluminum (thin enough to cut and bent, thick enough to withstand some abuse) and cut the shape you wish and make cut lines and bent it. You know, like cut lightly on one side and bent it so you don't have to weld the two plates.

This should be one fun project.

spracingsports

i actually plan on doing the same thing, after i save up a little cash. i have a few projects lined up

imported_~ILLEST CIV~

Thanks Nova_Dust & spracingsports
thanks for the info
and good luck spracingsports on the project up and comming......i'll keep yah guys informed of what my cousin and i do or start to do tommorow...........lol

OH YAH spracingsports......i was viewing some thread about u and removing ur front grill....or like cutting it out.....so it looks like an SiR front grille.......how'z that comming along?......i was thinking of something similar...but that requires too much effort on my part.....hahahha hold on....haha i should do this...and run my stock pipe to the front where the grille is cut.....and put a nice filter on the pipe or in the pipe...........so nothing gets in.......hmm i wonder if that would work?....anyone know?....is there room to stick a pipe there?......lol just some wild ideas i'm throwing around right now......lol cause it'z friday and i'm about to go out and i'm bored.....lol

Blue Dream

its not really cold air you want, it does help with ambient temperatures in the combustion chamber, but on nights with "dense" air you will notice a difference with performance.

spracingsports

illest civ... about the type-r grille project, it got delayed to saturday cuz i had to work extra hours on thurs and fri. i plan on doing a full write up with step by step pics and instructions, so you should see it posted hopefully by monday or tuesday. actually it doesnt look like too much trouble, the ting that will be the hardest is making a nice clean cut!

slow_dx

How is your math?

http://www.grapeaperacing.com/GrapeA...ehelmholtz.cfm

imported_gatherer

changing the length of the intake changes the optium frequency of the pressure waves resulting in a change of when peak power is made.. the longer the tube the lower the frequency ... hence the lower on the RPM band the peak increase is ....

DirtyLude

Length of the intake pipe makes no difference as far as pressure waves are concerned. The air velocity is far too slow to support pressure waves. Finite amplitude waves don't even reach the opening of the throttle body at low RPM's.

bbarbulo

iTrader: (2)

I like you LOL and not in a gay way.

imported_moflex

if length makes no difference, then is the AEM V2 just a gimmick?
cuz i think it has two different length inner tubes that are supposed to have some effect on the frequency and stuff..therefore creating more power or sumthin.. i dunno..wut do u think?

DirtyLude

I actually went to the AEM site to look at the V2 and their explanation, is very confusing. They talk about sound waves for some reason, which have nothing to do with intake tuning. High pressure finite amplitude waves don't act at all like sound waves. What they are really trying to do is create a sudden widening right before the throttle body to create a compression wave.

When expansion waves hit an opening, a reverse compression wave is generated. The distance between the opening and the valve inlet is a tuned length. The individual runner to the intake valve are one length. The perfect timing where the expansion wave from the valve opening travels up the runner, hits the opening to the runner and travels back down as a compression wave to help compress air into the cylinder when the next valve opening event hits, only happens at a single rpm. The reason many Hondas have butterfly valves in the intake runners is to change the length of the runners. With only the long runners open, you get more power at low rpm because it takes longer for the wave to travel up and back again. When the short runner opens, the compression wave returns faster to catch the quicker intake event.

Once they get out into the intake plenum, they really don't have alot of power. At peak RPM, they might just have enough power to get past the throttle body and for this thing to manage to do something, but it's unlikely. You can see the widening is fairly close to the throttle body.

Though I said you're not going to get anything from pressure waves and tuning the length of the intake pipe, I don't mean that you wont get anything from the length of the intake pipe. There are other factors, like inertial sloshing and simple turbulance that the length of the pipe will effect.

I know I have a nice couple pages here in a book, somewhere, that describe high pressure waves and how they work. I'll try and scan it in.

BBarbulo: If you like me, then you need to come to my house and take the spindle nuts off my CRX, my impact gun wont budge them.

bbarbulo

iTrader: (2)

ahhh... i had the same problem. I drove the car to my local truck stop and had them hit it with a big **** 800 lb-ft torque gun and a 32 mm socket. I had already broken one 32 mm of mine, since all I had was a breaker bar, I wasn't gonna risk damaging my axles. Worked like a charm... they did it for free too!! Then I drove home and loosened them the rest of the way at home. Just have them budge them, so it's still safe to drive home. You did grind off those keyway tabs, right?

I'm in Windsor... 4 hrs from you.

DirtyLude

The car isn't really that driveable right now:



The spindle nuts have been taken off before. You can see it looks like they used a punch on the edges around the tab for some reason. This is the left one that I haven't touched, yet.

imported_gatherer

actually sound waves are like pressure waves because sound waves are compression waves (changes in pressure over time)and not energy amplification waves, like what you'd see at say the ocean (changes in energy (or hieght if your at the ocean) over time) (like light waves)

to see this look at speakers increase the volume on a bass speaker and it bounces forwards and back to compress and expand the air this motion in the air is carried through the air to your ears which turn it into electrical signals for your brain. and is like waves but a different form of modulation from what's been explained to you in school using sin waves and amplitude modulation. This is exactly whats happening in the engine... at different RPM's the Valves open and close at diffeent speeds for each cylinder this causes a depression in the intake because is being sucked into the cylinder now each cylinder opens at a different time. based on the CAM lobes they might overlap or not over lap. if they don't overlap then you a split period of time where the air is filling in that depression and since it's moving slightly compressing.... the speed of this action and consequencely the speed of air being sucked in changes with RPM the higher the RPM the more air being sucked in over time. This is why the engine sounds louder with higher RPM then low RPM it's also what determines the frequency of this sound. see F1 cars have high screaming high pitched sound while a low reving mustang has a lower pitched sound.... This is because of the sound waves (or pressure waves) that are created... now I'm not talking about changes of like 10 PSI or anything these changes are so small you couldn't get them to register on a pressure gauge.

now if the valve opening of different cylinders (intake side we are discussing not the overlap between the exhuast and intake sides just the over lap between the different cylinders) have overlap what happens is one valve opens causing the air to get sucked in (creating a pressure wave in it's wake) and near the end of this another wave starts in another intake tube. this results in the pressure wave interacting once they reach the intake manifold "log" as I call the thing... this results in the need to tune the length of the tubes going to the cylinders so that the pressure waves help suck air in the intake and don't negatively effect each other. once you get to the intake you get an assortment of pressure waves from the individual cylinders all lining up and these waves are effected by the length of the intake. the longer the intake the higher the RPM the power is made in other words the best positive effects of the pressure waves take place over a short range of RPM and intake length is one of the things that effect this.

want to prove me wrong ... book some dyno time ... I'll bring a nice long 2.5" pipe that we can cut down as we do runs.... you'll see a difference...

check out the discussion on the intake manifold and flow and swril design at www.theoldone.com that is where I learnt most of this stuff...

DirtyLude

I'm not certain if you even actually read my message. I've talked to Larry a good amount, years ago, and even bought some stuff from him. He's very knowlegeable, but don't assume you've learned anything from reading articles or forums on the internet, (that goes for whatever I write as well.) Buy some books or take some courses on this stuff if you want to be an authority.

Here is the pages I scanned in that describe the difference between sound waves and high pressure finite amplitude waves.
http://www.higginstribe.com/temp/pr...-amplitude1.pdf
http://www.higginstribe.com/temp/pr...-amplitude2.pdf
http://www.higginstribe.com/temp/pr...-amplitude3.pdf

Sorry for the multiple pages, but my scanner software wont knit them all together.

DirtyLude

I just wanted to add, that I'm no authority either, and could easily be proven wrong in this.