jdm prelude h22a

[h22a accord]

i dont want this to be a long thread and i have done searches but i cant find what im after. There must be a correct answer for this


Whats the best size in diameter that my exhaust piping should be.


I dont want stock, as stock is a pea shooter 5th accord pipe.

[bigteethygrin]

I have 2.25 inch piping in mine but I'm pretty sure that 2.5 inches will probably be a little better.

[WPN.22R]

2.25 is great, i wouldnt go bigger than that, i have had a great response with that size. AND DONT WHATEVER YOU DO CHANGE THE STANDARD HEADERS!! they are absolutely perfect from factory at tuned length!. i remember people always asking what brand mine were, and they would spin out cos theyre standard.

[bigteethygrin]

[off topic]hehehe elee with your turbo i dont know why your not going bigger dude.. [/off topic]

[azjs]

i dont want this to be a long thread and i have done searches but i cant find what im after. There must be a correct answer for this


Whats the best size in diameter that my exhaust piping should be.


I dont want stock, as stock is a pea shooter 5th accord pipe.

Mine's a 2.45 inch (just under 2.5 basically) and it delivers well across the powerband.

-az

[WPN.22R]

bigteethygrin Posted: Sun Jul 04, 2004 7:56 pm Post subject:

--------------------------------------------------------------------------------

[off topic]hehehe elee with your turbo i dont know why your not going bigger dude.. [/off topic]


$$$and time my friend in time ;)

[vtk94lude]

yes stock headers are fine, for daily driver occasional squirt. but are restrictive up top 6k rpm plus.
if you do or start doing alot of track days then you'll need to consider gettin some headers, coz you have to remember, the amount of air entering the motor, has to be expelled, you dont want to choke your motor at a consistent 7500rpm on track for sevreal minutes at a time. itll start to put abit of strain on there.
but yes the stock headers are very well designed.

As for exhuast size, my headers are for h22a, the collector is 2.5inch internal diamter, but my pipeing is pretty much like azz, 2.45 or just a fraction smaller than 2.5
2.5inch if you do track days, since you'll be reving at 5500rpm all teh way to the end often.
and 2.25 if its a daily driver, occasional squirt, but also good enough for track use.

note 2.5 will feel alittle slugish down low. not so noticeable but ye.


i dunno if you'll go track or not, but 2.25 would be wot i'd get if i didnt track it.

[Cvik_ryda]

dude you seem to know about H22A can you please tell me more about it like how much power, how heavy and stuff thanx man im thinking of buying it and fit it in my civic thanx again

[steve_civic]

H22a are a good engine Cvik ryda but way too big for your car...it will throw the geometry way off...understeering will become a more of a problem...wat i would recommend is a B18Cr from a type R integra...way more practical and it has been done before and if u get a front cut then u get everything u need...gearbox LSD everything...where as the preludes have and open diff(one wheel spinner)

[SiR JDM]

I say 2.5" definatly if your wanting to be going hard (Track)

[h22a accord]

jdm prelude h22a has lsd.

[DaViSoN]

smeagle ur a lost ****... 5.5" yeah ok....
If u've done that conversions b4 and still use 5.5"... you must be the dumbest shit eva.
Don't be such a sad **** and add stupid posts.... If your that bored u got issues bad

[McChook]

jdm prelude h22a has lsd.
Not all of them do....

anyways

I'm running the same as Az - 2.45inch, and it works... will prolly be better with the matching headers and an "open" cat.

With the headers, you have to be careful - don't just go buying any old header, because the H22s already have piped headers, not cast like a civic or integra, but piped like the JDM ITRs. They work well, and the Type S headers are a good upgrade.

Personally, mine will be Mugen all the way back, but it ain't cheap, but you know its going to work. I lucked it out finding the cat-back, but I have to buy the Mugen headers new. :(

[SMEAGLE]

my car has 5.5" and it runs better then 2.5" or 2.25"..
i suggest u get 5.5" because ive done alot of h22a conversions and i am a well known mechanic.
if u want to do a conversion
contact me on 1300-090-203
or email me at h22a@conversionsonline.net.au

[DaViSoN]

yes.... 3.5" would be best..... wat are u well known for again???

[pornstar]

bu cu by any chance?

[DaViSoN]

wtf's bu cu?

[SiR JDM]

3.5" ? You would loose way too much low end u might benifit at the very very top end but even then possibly not..

I say 2.5" with minimal restriction (ie - minimal bends, high flow cat, 1 or no resos)

[azjs]

3.5'? Besides being a very well known mechanic, can we have numbers as well?

-az

[SMEAGLE]

gfh

[Teggy-Vtir]

3.5" is abit too big for a N/A car??

[McChook]

3.5" is abit too big for a N/A car??
No Shizzle...

[SiR JDM]

[edit : double post]

[SiR JDM]

wtf u on about smeagle...
if u dun even kno wtf ur talking about.. dont post and mislead other posters... and then go back and edit ur posts and be even more stupid..
dighead

[SMEAGLE]

I am a respected mechanic... dont bag me out cause i know heaps about cars... .. sounds like to me u know shit all... i think u should reconsider wat your trying to say before posting seeing that u have little knowledge about honda's. and yes. 5.5" would give u the most gain.. the bigget the exhaust.. the more power
its plain and simple.. big=more=power
thanks

[DaViSoN]

hahahha watta... ur a lost ****...
i didnt know ppl respect dumb shits these days..

[viperx]

wtf?! 5.5"? lets not talk about what gas expansion in exhaust does to flow rates, but I would like to see how a 5.5" would even FIT under a car (unless you drive a monsta truck or somethin) Seems to me if you really knew your stuff you wouldn't need to claim it to others. but then again.... if youd like to explain the physics of it to all of us, and give us some dyno figures (or better, a picture with your car with this 5.5" exhaust on it) then i'd be more than happy to take back my comments

yeah 2.5" might be good for the track, but it definitely is a bit laggy down low on a h22 from experience... i'd go the 2.25", unless the accord is your track car. but then again, exhausts are different depending on the number and type of bends you have... there are so many confounding factors to think about...

[toE]

my car has 5.5" and it runs better then 2.5" or 2.25"..
i suggest u get 5.5" because ive done alot of h22a conversions and i am a well known mechanic.
if u want to do a conversion
contact me on 1300-090-203
or email me at h22a@conversionsonline.net.au



I am a respected mechanic... dont bag me out cause i know heaps about cars... .. sounds like to me u know shit all... i think u should reconsider wat your trying to say before posting seeing that u have little knowledge about honda's. and yes. 5.5" would give u the most gain.. the bigget the exhaust.. the more power
its plain and simple.. big=more=power
thanks


Well, we'll noe who NOT to go to for exhaust or any mods now aye? ;)

[SiR JDM]

Well ill be taking my car to smeagle for sure...
5.5" ill be running high 20's with that! SICK MATE!!!!

go home smeagle mate, no one cares

[McChook]

So, who called that number??

[SiR JDM]

Yea i gave it ago, it said..
"The number you trying to dial is currently switched off, or made up by some faggot, please try again later"

[h22a accord]

Thanks for your opinions guys. erm, i dont think i will put a 5 inch zorst on it ever buahahahaha. At the moment the car has heaps of top end and it doesnt seem to be lagging down low but i have nothing to compare it too except for my old f22b sohc vtec motor and the h22a is faster in all areas.

I dont know what i'll do, i wait until my exhaust breaks or something before i replace it.

[bennyfy]

2.25" is the best for your car mate

[Spoon-Accord]

hey camo..
i got 2.5 inch all the way..
but i find having a stock cat restrictive..

also.. H22a in a accord.. its hard to source extractors that fit accords.. due to the fact they have no mounting positions cause they were made for the preludes..

my extractors where sitting in the middle of no where.. the whole exhaust was moving around when it was hot and now the extractors are leaking.. leaking from the welds on the engine plate..(wateva u call it*)

but yeh.. it lags now.. with the leak.. take years to reach certain RPM..

camo.. give it a go.. should go hard!!

Ken

[Ozwolfbane]

Im thinking of getting some megan extractors from america...they are DC Sport copies and they have very clean welds.....should i get them for the JDM or keep em stock i dont wwant to loose low end or anything...

[azjs]

Where'd u hear that "megan" (*cough* sound familiar?) are DC sport copies? Not that the DC sport items are fantastic anyway... If you did get your hands on a jap spec engine, the standard extractors are quite good.

-az

[Ozwolfbane]

ok i leave em stock...was just thinkin u know swapin engine might aswell put extractors......flywheel :D stock are a light one ?

[antikz]

2.25 is perfect. I have 4-2-1 Headers, high flow Cat, into 2.25" piping to a Magnaflow muffler. 87Decibels. Perfect Flow, perfect legality.

[Ozwolfbane]

h22a@conversionsonline.net.au doesnt even exist pffffttttt

Why not run a 20" exaust on your Ford :honda: Festiva that u own the bigger the better :D


:wave:

[IMH-22A]

lol smeagle u funny ****

[WPN.22R]

5.5" aye... now thats what I call a -grade A -typeR- top of the range NUGGET!!

hahaha what a dipshit- good for a laugh though... maybe not even:confused:

:D

[Illegal]

I am a respected mechanic... dont bag me out cause i know heaps about cars... .. sounds like to me u know shit all... i think u should reconsider wat your trying to say before posting seeing that u have little knowledge about honda's. and yes. 5.5" would give u the most gain.. the bigget the exhaust.. the more power
its plain and simple.. big=more=power
thanks


"yeh well i want 2" springs for my accord
know wat type i should get that are reliable and good
and much will they cost and to install also????"

A "known" mechanic wouldnt ask shit like this. You are a god damn retard. You dont know shit about cars, stfu. Bigger exaust does not give you more power. That is the stupidest thing i have evar read you retard. Do me a favor, dont ever touch a car again. I wanna see pics of a 5.5 inch exaust.

[Illegal]

Read you retard


Backpressure: The myth and why it's wrong.

I. Introduction

One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure on message boards with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Hondas need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory

Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity

Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?

I often wonder how the myth "Hondas need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?

The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).

VI. Conclusion.

SO it turns out that Hondas don't need backpressure, they need as high a flow velocity as possible with as little backpressure as possible.

[h22a jdm]

my car has 5.5" and it runs better then 2.5" or 2.25"..
i suggest u get 5.5" because ive done alot of h22a conversions and i am a well known mechanic.
if u want to do a conversion
contact me on 1300-090-203
or email me at h22a@conversionsonline.net.au

5.5inch 4 na wtf he on bout :thumbdwn:

[bored]

2.5" on mine

[CUL8R]

wow, talk about bringing a thread back fromt he dead!
yeah i have 2.5" but unless u have it tuned there can be a small lag until vtec. Thing is stock headers are fantastic! the only thing u can have done is modify the collector (like i did) from the 2-1 pipe i modified it to have a 2.5" single pipe through to cat to the end.

[preludacris]

yep ..

on stock headers, and 2.5 inch cat back .. u will definately feel the lag b4 vtec.

when i got my cat back, i dont think i made much gains ... lagged a lil more down low . and revved a lil more freely up top .

after my aftermarket headers with modified collector to 2.5 and 2.5 hi flow cat , it made a massive difference.

dpends on ur plans . with vafc tune headers and intake , u can definately go 2.5 ..

[justrunit]

LOL Smeagle... That number and that address doesn't even exist!

[incoming]

bu cu by any chance?

hahahahha didnt know u was viet