Exhaust Work Question

[F20A CB7]

Hi cb7's

i have a 2.0 sohc motor
with 4-1 header and the collector pipe is 2.5 inch. now i wanted to get a test pipe or high flow cat. at 2.5 IN and 2" out. with 2" from cat or test pipe back.
i figured 2" because do to the test pise pr high flow cat the exhaust will b flowin more better. now im also gonna have a RES at 2" in/out and 2.25 aver all dia.

WITH A TEST PIPE OR HIGH FLOW CAT WHICH IS BETTER GAIN IN POWER??
and bein its a sohc 2.0 i WANT to keep back pressure we need it. so how would i go along with this SETUP i do want 2" pipin tho. AS FAR AS THE TEST PIPE OR HIGH FLOW CAT which 1???

[NAiL05]

Just do 2.5" all the way....The restriction is pointless. Read up what backpressure is. That slight increase isnt going to effect it much anyway.

[F20A CB7]

cb7 exhaust work setup

now i read the forum about backpressure. its about velocity and where you want ur powerband to be.... low mid high.
u can have 2out3 but never all 3.
im stickin with2" but b4 anything does any1 know the factory pipin for the cb7??

[NAiL05]

like 1.75" if even that....If your so worried just go 2.25" thats the minimum even for the f22a motors. Your just restricting power going from big to small thats all imma say.

[HondaB18]

now i read the forum about backpressure. its about velocity and where you want ur powerband to be.... low mid high.
u can have 2out3 but never all 3.
im stickin with2" but b4 anything does any1 know the factory pipin for the cb7??

Hm....

The backpressure issue seems incorrect.

Choosing the exhaust piping diameter does help with the powerband. You just have to choose which one you want to focus on and get the parts accordingly.

[Reason]

I'm not sure how it works in the Honda world but a 2.5" inch exhaust on a na seems wrong. IMO I would stay 2.25 all the way.

As for the test pipe and high flow cat- Test pipe is a pipe that replaces the cat, there's nothing to it. "Highflow cat" is different. They have higher flowing cats that have the function of a cat. Then there's the resonators they sell on ebay to past as "high flow cats".

[F20A CB7]

cb7 exhaust

if u was to read the backpressure "myth" its sayin that honda needs ZERO backpressure. its more of the velocity and powerbang. now my original idea was 2" with high flow cat.

my power band will b at high end power i guess 4500 and up.
now do to velocity 2 in seems the best for velocity. now i no 2 1/2 is jus lil 2much.

2 1/4 the velocity will b a lil slower than 2in.
bein that my power band will b at 4500 and up

which will u guys CHOOSE??? ANOTHER THING.HAVIN A RESONATOR will it sow down the exhuast velocity.???

thanks for all the post guys VERY HELPFUL INFO

[NAiL05]

I am running 2.5" on my h22a. 2.5" too much on all motor build? Your kidding right? A lot of people run 2.5" for NA builds. H22A obviously makes its power further in the power band...Thats why you want bigger piping to evacuate the exhaust gases instead of a restriction. I drove around for a few months with my stock accord exhaust then drove it with my new custom 2.5" exhaust and there is a difference. Doesnt feel like there is a restriction in the motor anymore.

[F20A CB7]

I understand wat u mean with 2.5 on h22. i understand that. I DONT have a dohc. i have sohc 2.0 of course u want 2.5 on a twim CAM. BEIN that i have a sohc u still didnt answer my question, if anything im goin with 2.25... I want a resonator. THRU cherry bomb. now i want to keep my deep tone thats why im gettin a res. NOW im gettin high flow cat el cheapo thru ebay. it will flow more better than STOCK!! BUt the RES will it restrict the VELOCITY of exhuast gases????????? thats wat i wanna no. NOW my power band will b for high end power! the barrel DIA of RES is 2.5 2.25 inandout. into 2.25 pipin.

[Reason]

Yes a resonator will slow it down. Check out this website, they claim there"muffler/resonator" speeds up the exhaust.

http://www.aeroexhaust.com/

[F20A CB7]

just looks pretty fancy. most likly my idea was all backwords then with this res. ill jus go without one.i ll jus stick with 2.25. from high flow cat back... but the thing is i have a bolt on muffler (AXLE BACK MUFFLER ) and the pipin on that is 2IN. SO thats y i wanted to keep 2IN from cat back... i figured ill have the proper velocity after cat since its high FLOW and i have the 4-1 header.

[Reason]

Why don't you just go catless. Then you don't have to worry about slowing the exhaust down.

[Robert Pinckney]

hmm

[F20A CB7]

cb7 exhaust

OK catless WITH 2IN pipin, how will that b ???
i believe in velocity over backpressure


BUt HAVIN CAT WILL JUS B ALL SMOKEY... i dont want that shit

[NAiL05]

DO you know what a cat does? And honda cats are really not that restrictive at all...IF you have emissions where your at I would NOT run a test pipe. I still dont see why you are going with the 2 in exhaust...