instant power

[jspec civic]

adding a 2.25 custom cat back will it gain instant power or needs tuning?

[rayb3na_]

depending what engine u have what displacement.. etc.. 2.25 usually better midrange.. but you should get it tuned after. my 2c.

[SeverAMV]

there is some power, but not much. the most important part of the exhaust is from the exhaust ports to the first bend underneath your car (after your cat and muffler/resonator). you'll make the best gains focusing on this part, so good extractors and a nice straight section in your exhaust, as this section has to clear the exhaust at a much more violent rate than at your catback (speeds of up to 0.8mach can be reached as exhaust gases are just leaving your ports).

[EuroAccord13]

You won't get much out of just a catback, it is there as a supplement to other mods...
To make a car fart better, you need it to breathe better, chuck an intake system so that the catback will be utilised more, you can also change the headers for better flow and inertia.

Tune the car with a basic A/F controller and you will get more out of it....

[Limbo]

you won't need a tune but you'll only get mininal gains and some noise

[beeza]

Just reset the ECU after the install to maximise the mod.

[jspec civic]

By adding in a resonator how much db will the system reduce, lets say from 100db?
How much are resonators these days?

[squish85]

Had mine done with one resonator.. cost of the whole cat back (excluding the muffler supplied by myself) 400 incl gst...

[bennjamin]

there is no extra power from a cat-back alone. it will alter your power band slightly , might free up the top end. but no actual power.

to make something out of it you need a combination of parts , a tuneable ecu and a tune.

[jspec civic]

Im running a blue emange atm…tuning it soon…might wait and buy some headers…

[55EXX]

just change your rear muffler/tip for sound and less restriction over stock. no power to really be made only sound.