hey guys,

any suggestions on how to improve engine performance by upgrading my intake and exhaust system?

i plan to join autocross and circuit races

my friends told me the first step is to upgrade my intake and exhaust

i have a 97 mirage w/ a 4g92 engine (1.6L SOHC)

i have so many questions like:
-do i resize my pipes?
-do i do port and polish?
-do i have to adjust my fueling?
-etc...

what brands are best for my car?

any input will be appreciated. (IMG:style_emoticons/default/biggrin.gif)

with the 1.6 SOHC its going to be rough at the track or in the circiuts unless there aren't turbos or anything there but its always worth a shot i guess.
you have about 100HP and with the intake and exhaust you'll have about 105-110 at best. now an intake is a very easy mod and no you shouldn't have to modify anything to install it. and its very cheap. this will give you 2-5 horsepower.
the exhaust is a lot more expencive (as long as you don't weld a fart can on the back)
its going to cost between 150 (custom at a shop with a straight pipe and muffler) and upwards for any name brand. name brands going to give you a better preformance and sound, but you pay for it. and again, you'll get anywhere from 2-5 horsepower out of it.

and as for your other questions,
no real pipe changing is required
you CAN port and polish if you want, but its spendy and on a N/A (naturally asperated) engine its not going to help that much.
and no fuel adjustments will be nessasary.

this is great info!

thanks a lot! (IMG:style_emoticons/default/liebe011.gif)

of course when i join races i'll be in my N/A and SOHC category.. (IMG:style_emoticons/default/thumbsup.gif)

i'll take it one step at a time..

i'll probably go turbo charged or change engine when i gain more experience in the tracks and when i have the budget for it. (IMG:style_emoticons/default/grin.gif)

so as of now i'll try to do a little upgrading on my current engine.

additional infos are still welcome (IMG:style_emoticons/default/smile.gif)

what i would do if i were you is....

grab an intake off of ebay (40 bucks or so) and put that on.
as well as get a new set of good spark plugs and wires (also available on ebay, though your car may be harder to find parts for)
make sure your fuel filter is good or replace (only 10 bucks or so)
if you can take your intake manifold off easily then do so and clean it if its at all dirty.

this will get your car running back at peak preformance.

from there if your considering sticking with N/A then get a lightened drive pulley, alluminium driveshaft and lighter rims. this will all help your HP lose threw your drivetrain. it doesn't increase crank shaft HP but it DOES increase Wheel HP (which is what matters)
there are other things you can do as well but those are fairly easy and require no tuning.

should i get a free flow muffler or a chambered muffler?

i read that free flow mufflers have less back pressure..

how does this affect performance?

the difference is most N/A's aren't going to see much form a free flow exhaust. there is a whole pin up on this topic. search it and you'll get all the answers you can dream of on that exact question.

but if you want to save some time and skip the learning......... (which i don't reccommend) just get the chambered one.

thanks for the advise! (IMG:style_emoticons/default/biggrin.gif)

still trying to find that thread you recommended..

but i was able to read about chambered and free flow mufflers,

and it was explained where better applications are for.

i guess, i need more advise on steps in tuning or improving and upgrading my engine... (IMG:style_emoticons/default/auto.gif)