max size for catback exhaust?

[89accordboi]

well i was originally planning on getting 2.25", and i know most poeple here with 3rd gen accords do get that, but my friend with an 89 crx just got a 3" catback with dynomax and it sounds pretty good, could i go 3" or is it bad or is it not worth the money? cuz he got his done at some advanced mufflers place and he payed $170 for the piping, muffler and install.

[goldyaccord]

unless your turboed..... stick with 2.25


u need some backpressure for your lowend or something like that

[dXsquared]

i have run a 1.5 inch all the way to 3 inch. and i can tell u that a 2/2.25 inch pipe is the best for all around. the 1.5 inch was so loud and crackley all i did was rev to 6 grand and let it drop. it didnt rev to fast and the low end was good. the 3 inch had no lowend and it sounded broken untill 2300 Rpm. there was like 0 backpreasure and u could tell... after 2400, the Tach would just bury itself. it would rev like crazy! so go with a 2 or 2.25 inch pipe!

Travis

[88lxDCOE]

Some people say you will lose too much back pressure. All I know is that my 2.25 works. A good scale is probably:
1800-2000cc - 2.25-2.5
2200cc 2.5-2.75
turbo or s/c BIG
But dont take my word for it try 3". Maybe were all missing out?

[88lxDCOE]

whats the deal with no back pressure? no low-end?

[pmip]

Originally posted by 88lxDCOE
whats the deal with no back pressure? no low-end?

You need some back pressure for low end power. Most people who put on huge piping on naturally aspirated 4cylinders lose a lot of torque. With forced induction, you're pumping more air into the engine, so you need bigger piping for it to escape.

Edit* You need something to constrain exhaust gas volocity for low end power.

[A20A1]

well whats your plan for the car?
if you plan to do a swap and or turbo in the future get 3"
if you plan to have a n/a race or drag setup then use 2.50" - 2.75"
if you want something for the street go with 2.25"

[anchovies]

yeah..I agree with A20A1
Decide what you want to do with your car first, then go for the correct sizing.

[1988starter]

Baaaah :mad: All you guys seem to have no idea you need no back prexssure it does nothing for low end it is exhaust velocity that is important without it the gasses will leak back and choke the engine that is why there is a lack of power untill higher rpms it has nothing to do with back pressure. The goal is to have 0 back pressure with max exhaust velocity. There I feel better.

[Jims 86LXI HB]

If everyone that used the term "backpressure" could please change your choice of words to "exhaust gas volocity" you'll get your point across and not,.....upset anyone.;)

So 2.25" is what you should have to promote the most effecient exhaust gas volocity. Only if you plan on SERIOUS mods, like wild cam, ported and polished head, B16 intake manifold and reworking the valve train (an anything else) to rev into the 7K range. Only then should you condsider larger than 2.25:lol

As it stands now, you don't have the displacement, rev range, or tuning to make anything larger than 2.25 a worthwhile choice.

[89accordboi]

so when i get my 2.25 and dynomax will i be able to rev faster?

[1988starter]

Originally posted by 89accordboi
so when i get my 2.25 and dynomax will i be able to rev faster?

yes

[socal3rdgen]

but not by much

[HondaBoy]

im goin with a 2.25in pipe. 2.5 is not so good on our cars, because, well yes the back pressure. it does make a difference in ur low end power. now if ur all raced out, go biggest, cuz ur gonna need all top end power. but for more power for street type racing, go wit 2-2.25in. no smaller, no bigger. thats about it. also, u wanna get stainless steel pipe. i have heard of some that are just cat back exhausts rotting out on our cars. i guess im gonna get all of mine dont in SS. im also stayin with the cat. im gonna try gettin a 2.25in cat and a nice header. good to know, wut is a good header for our cars? maybe if someone can say them for the carb engine, and some for the FI engines.

[Tim Yoak]

If you get too big of an exaust system, you lose exaust velocity and you lose the scavenging effect that helps pull exaust out of the engine. This is why the wrong type of headers will cause you to lose eithier low end or top end power. If you just took the manifold off, the car would run terribly.

[1988starter]

Originally posted by HondaBoy
im goin with a 2.25in pipe. 2.5 is not so good on our cars, because, well yes the back pressure. it does make a difference in ur low end power. now if ur all raced out, go biggest, cuz ur gonna need all top end power. but for more power for street type racing, go wit 2-2.25in. no smaller, no bigger. thats about it. also, u wanna get stainless steel pipe. i have heard of some that are just cat back exhausts rotting out on our cars. i guess im gonna get all of mine dont in SS. im also stayin with the cat. im gonna try gettin a 2.25in cat and a nice header. good to know, wut is a good header for our cars? maybe if someone can say them for the carb engine, and some for the FI engines.


The dcsports are for efi not carb but they are on back order. The pacesetter does not have a flex section but one can be ordered for 30 bucks from www.jcwhitney.com I have a 4-2-1 pacesetter with a pacesetter highflow cat and 2.25 mandrel bent piping with a dynomax superturbo muffler it works very well.

[Grant2k]

i know a lot of people inquire about the DC headers for our cars, but does anybody ever look into the cat-back? they used to make one, but i think it might just be disscontinued.

[Tim Yoak]

:huh: anygood muffler shop can make you a cat back system for this car, i's not plumbed like the space shuttle. You don't need all of the resonators and so on. I prefer 2" pipe on this car for good exaust velocity, and I'm running a small cherry bomb, a REAL cherry bomb. I had someone tell me it sounds like a formula car. Plus when you let off the gas you get that cool brapbrapbrap sound.

[Grant2k]

i get that sound too. a cherry bomb and a stainless can are basically the same thing except for what they have tip wise. a cherry bomb might be louder though because they actually have less packing around the chamber.

[Jims 86LXI HB]

Originally posted by Grant2k
i know a lot of people inquire about the DC headers for our cars, but does anybody ever look into the cat-back? they used to make one, but i think it might just be disscontinued.

they made a itty bitty production run and they are long gone. I heard they did a trial production run of like 30 of them and never did it again. I used to spot them at some places, but everytime I called or emailed them I got the came story, not instock, discontinued by manufactuer. What a shame. One of these day's I wonder if a new member will show up that has one. That would be neat.:tongue:

[Grant2k]

i was wondering beccause the stock number is still in the computer at the warehouse where i used to work and it always just said out of stock. well, it was almost $400, so it was too rich for my blood right now anyway. i guess i'll just stick to dreaming.

[Janiel]

Pace Setter has one. I found it on www.nopi.com $160.92. I have had it on my car and its not rusted out. It's been on it for about two years now. And it's not too loud you can easly hear your intake over it. And still gives good power.

[1988starter]

I hated my pacesetter catback so I cut off the muffler and added my dynomax.