Civic exhaust size

[Zdster]

Hi all,

I know that this topic has been covered on many more than one occassion and yes I have searched. I would like to hear from people that actually have a big exhaust on your car.

I have the opportunity to purchase a 2.3" catback piping to fit to my ek1 hatch. For those that have large diameter exhaust piping on an ek1 has the responsiveness of your car dropped? If it were your choice would you go for something smaller (I realise that most people say 2" is optimum)?

[Vivski]

Some will say 2" and others will say 2.25". I dont think there are any real dramas having 2.3" as long as you have the headers/intake airflow to match so you get the most out of it.

EDIT: Stupid me, read the post!! Didn't realise it was for an EK1. Wouldn't go more than 2" mandrel, maybe just maybe 2.25" press bent. But that's me, opinions will differ.

[sivic]

its a bit more than having the right headers and intake. if the actual engine isnt going to benefit from it then theres no point.
i wouldnt go any bigger than 2.25" on an EK1. IMO thats even too big. 2" will be optimum.
on an Si 2.25" is only just better right near redline and that has a higher reving, more powerful engine so it unlikely the EK1 will benefit anymore from a 2.25" than a 2" exhaust.
the 2.3" (60mm) exhaust would most likely have been designed for an EK4/EK9

[Setanta]

Put it this way - I ran 1.75" on a '76 Civic that made more power than a EK1... that says it all. Get a nice shiny chrome tip and save your money until you get a motor that is actually worth doing a big exhaust for.

[jackosimm]

Get a nice shiny chrome tip and save your money until you get a motor that is actually worth doing a big exhaust for.

Always my stance, I just wacked a nice ricey cannon on when I had my EK1. You'll mainly just be helping it breath a little better, not worth the money for what you get IMO.

[A.G.System]

Just spoke with my mate who is an exhaust fitter. He said it really depends on what you are doing with the car future modifications wise.

If you are planning on Turbo/Super Charge then dont modify the exhaust at all and wait till you get the whole lot done at the same time. saves you haveing to change it more than once. Only mod you can do is fit a 2.5"-3" /4" tip with a baffel and then change the rest later.

If just going the Vtec route (engine swap) he was saying that a 2.25"-2.5" would be the max you would want to go. Otherwise you just get noise and no power benefit.

Stock SOHC NON Vtec EK1 with no plans to fit any other engine mods he reccomended 1.75"(stock)-2". Then fit a higher flow cat and larger exhaust like mentioned above. This would mean that the car isnt too loud, has a nice rumble and at the same time can breathe well.

Personally im going the turbo route so thats the option i went for but in the end its up to you.

[civicCXI]

I got 2.5" on my cxi, i wanted 2.25" but the guy told me 2.5" should be ok, and i was stupid enough to trust him. As a result, power loss on low rev, but if you sink ur foot and you shift right, it's really pulling.......but i'm gonna change it to 2".........2.5" is way too big for d series

[Qwooootz]

Ive got a hi-tech system 2.5" catback, with a magnaflow highflow cat on my EM1.. i was considering of changing down to a 2.25" as alot of people have nagged me too but knowing how well the car goes as soon as its got its momentum after 1st and 2nd gear, i think its worth it in the long run, as 3rd and 4th gears makes up for the lag..

if its enuff to munch up those 4L rust buckets im happy.

[TYPE-ONE]

my zorst is stock rite now. but i think i'll do a 2 to 2.25 inch catback with no resonator. From the cat to the axle will be 2 inch. then 2.25 from axle to muffler.

Any objections to this approach?

[civicCXI]

but knowing how well the car goes as soon as its got its momentum after 1st and 2nd gear, i think its worth it in the long run, as 3rd and 4th gears makes up for the lag..

i agree, 1st and 2nd are really going, but 3rd and 4th are so lagging with 2.5" on cxi

[TYPE-ONE]

i agree, 1st and 2nd are really going, but 3rd and 4th are so lagging with 2.5" on cxi

2.5 is just way too big. I really wonder where some of the exhaust fitters are educated. Same thing happened to my friend. He was recommended to use 2.25 inch in a ED GL. not good.

[Zdster]

Thanks guys for the practical feedback - seems as though I should be looking more closely to a 2" system .