As a random question, how will my fuel economy be affected by changing the stock intake and exhaust? Do the mods significantly alter the fuel/air ratio, and if so, do I lose significant MPG's?

You probably wont even notice the difference in fuel economy for such basic mods.

:bigthumb: Great Mods !!!!

Most of mods just want to get more power, but drain the fuel tank very quickly. I need speed, but I also concern about environment.
My next mod is going to be rim replacement. Looking for 17" rim.. need to get a better handling.

What about a rear sway bar?

yes. a rear sway bar will make you get better fuel economy

cold air intake and exaust if anything will give you better MPG and a few more hp

Originally posted by Dblade
cold air intake and exaust if anything will give you better MPG and a few more hp

i fail to see the logic in that since the cold air intake is basically pulling in more compressed air which means more oxygen which would mean more fuel would be put in the mixture to create a larger explosion (thus the boost in performance) and the upgraded exhaust would only clear out any backed up exhaust to make things run so much smoother (creating a better sound and a performance boost).... so if any major difference it would be a minor loss... correct me if i'm wrong but i'm pretty confident that that's the basics in a nut shell.

On an N/A engine an Induction Kit doesnt get HUGE amounts of extra air into the engine since the air is drawn into the engine, not forced under pressure like in 'Charged applications. The emphasis is more on colder air reaching the engine, and [by removal of the excess intake piping] increasing throttle response by creating less resistance to the airflow.

The addition of a CAI will give you a few extra HP [dont expect more than 2 or 3 tho, depending on the engine & other mods] but this is from allowing the fuel to burn more efficiently by creating a better air/fuel ratio rather than adding so much more air that extra fuel is required - remember, there are narrow limits to how much fuel a stock ECU is able to allow into the cylinders regardless of the air present.

[This works slightly different with cars running on Carbs, since the air/fuel ratio is tuned manually & can be allowed to 'overfuel' more than an Injection setup]

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As for the exhaust, much the same is true as for intake that huge gains wont be realised for stock N/A applications, but performance CAN be released since most factory exhaust systems are set up to meet strict noise & pollution requirements - In some cars, these limits can be far stricter than neccesary for some countries. By fitting a free-er flowing exhaust and removing Catalytic converters, the exhaust gases can be allowed to leave then engine more freely, meaning less energy is wasted by the engine forcing this waste out, so that 'spare' energy can be transferred to the crank and increase output power.


I hope that helps folks understand the theory behind these mods a bit better, even though the main reasons for doing them [as has already been mentioned, I think] are to improve the SOUND your car makes under acceleration - and often deceleration too :cool:

Originally posted by Japmetal
On an N/A engine an Induction Kit doesnt get HUGE amounts of extra air into the engine since the air is drawn into the engine, not forced under pressure like in 'Charged applications. The emphasis is more on colder air reaching the engine, and [by removal of the excess intake piping] increasing throttle response by creating less resistance to the airflow.

The addition of a CAI will give you a few extra HP [dont expect more than 2 or 3 tho, depending on the engine & other mods] but this is from allowing the fuel to burn more efficiently by creating a better air/fuel ratio rather than adding so much more air that extra fuel is required - remember, there are narrow limits to how much fuel a stock ECU is able to allow into the cylinders regardless of the air present.

[This works slightly different with cars running on Carbs, since the air/fuel ratio is tuned manually & can be allowed to 'overfuel' more than an Injection setup]

-----------------------------------------------------------------------------------

As for the exhaust, much the same is true as for intake that huge gains wont be realised for stock N/A applications, but performance CAN be released since most factory exhaust systems are set up to meet strict noise & pollution requirements - In some cars, these limits can be far stricter than neccesary for some countries. By fitting a free-er flowing exhaust and removing Catalytic converters, the exhaust gases can be allowed to leave then engine more freely, meaning less energy is wasted by the engine forcing this waste out, so that 'spare' energy can be transferred to the crank and increase output power.


I hope that helps folks understand the theory behind these mods a bit better, even though the main reasons for doing them [as has already been mentioned, I think] are to improve the SOUND your car makes under acceleration - and often deceleration too :cool:

thanks for clearing that up.. though i still thought that with the excess air it would slightly boost the fuel intake...