Exhaust=gains?

Question

Will aftermarket exhaust give you more horses or do you need the headers also? Is there a downside to upgrading your exhaust and keeping the factory catalytic converter? It is on a 1990 Honda Accord dx with an f series motor, 125hp and 137 torque. Thanks! serious responses only please!

Answer 1

the problem here is not just air flow, it is matched airflow sure you can add a little horse power with a free flow exhaust but what is the actual flow rate of air at peak torque and at max hp any restriction will nullify the potential gain of any one part.thereby leading to the next question "do i wish to make power or do i wish to make noise if it is power you want you must figure out how many cfm of air your engine is capable of moving and adjust inlet and outlet accordingly remembering that the spent exhaust gasses are still expanding as they leave the exhaust manifold [headers help but if too large the gasses will slow down[at this point that's unwanted] as for the converter most stock ones are only allow 2/3 of the required flow potential of whats actually necessary[add cam, intake, throttlebody, nitrous, turbo, etc. and you will need even more] after the cat piping typically should be 1.5 times larger than inlet the rest of the way back

Answer 2

With a cat back exhaust system -
which is from the cat converter back

you will not really notice a difference in power or torque.

If you want the best bang for the buck:

cold air intake
bigger muffler
larger inside diameter exhaust tube
better clutch

Answer 3

yes a cat-back exhaust will gain you some more hp, 5 at the most. if you get an aftermarket header, then yes you might get 2-3 more hp, check out dc sports for those. there wont be any problems leaving the stock cat on.

Answer 4

Any aftermarket exhaust upgrade that provides better flow will increase your power. If I were you I would replace the whole system from the header to the tip.

Answer 5

there isn't any damaging downfall to upgrading your exhaust and keeping the factory catalytic converter but it could make it to loud so depending on where you live will depend on whether you get into trouble for it. if you keep the cat on it i would imagine it wont be illegally loud. as for adding more horses then yeah it would but not a noticeable amount.

Answer 6

Watch the law. It is against the law in my state.

Source:
Colorado Statutes/Colorado Revised Statutes /TITLE 42 VEHICLES AND TRAFFIC/REGULATION OF VEHICLES AND TRAFFIC/ARTICLE 4 REGULATION OF VEHICLES AND TRAFFIC/PART 2 EQUIPMENT/42-4-225. Mufflers - prevention of noise.

42-4-225. Mufflers - prevention of noise.
Statute text
(1) Every motor vehicle subject to registration and operated on a highway shall at all times be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and no such muffler or exhaust system shall be equipped with a cut-off, bypass, or similar device. No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all of the requirements of this section.

Answer 7

its best to change from the header to the tip if not u will have a feel of restriant