HELP. Exaust upgrade non-turbo

[jaymar91]

i was looking to buy an exaust upgrade,
2.5" KO Racing exhaust w/ 7" mufflers and i was wondering
if will it work on a 91 non turbo.
i heard some exhausts are only for turbo models only and that putting an exhaust that has too big of piping, could blow the motor because of fuel to air ratio.

any advice would help

[fvillota]

lol it wont blow the motor. it will just run really sluggish
i dont know much about exhaust but i know it just runs like **** with no backpressure.

[jaymar91]

what do u mean by runing slugishly.

[fvillota]

it will loose power because it has no back pressure.
i don't think it'll run lean.. i think it'll go crazy rich.
like i said.. don't quote me on this.
but this is what i have learned from reading around and personal experience.

[MRH]

I think ultimately headers are what you have to worry about for back pressure. from the cat on is what I know should be free flowing.

get the EMS brand headers and pipe, then what ever muffler you like and you will be up in HP and neat on sound.

1990-1995 Toyota MR2 5sfe headers - $159.99 : EMSPowered, High Quality, Great Service, Low Prices

-H

[328FTW]

No backpressure is not a problem its exhaust speed if the pipe diameter is too large for an n/a engine then the exhaust speed is lost and you loose the scavenging effect of having a high exhaust speed. Ideally you want the a high exhaust speed at all rpms but its impossible since you will either not have enough flow to create the "vacuum" effect that helps an n/a or too much (for the given pipe size) so it chokes on itself and you get large backpressure. There is a balance going on to get the most ideal for the engine size and rev range/airflow.

Now i am done ranting on about backpressure (its one of those things that gets to me) what you are loooking for headers with quality Y joints since (mandrel bent pipe headers are good to look for them). The stock ones kinda suck since they are made to help cancel noise. From there on your piping size should be about 2 1/4 inch or so a 3 inch will not do any good and too small it chokes up. I'm tired but the jist of what I'm trying to say is there.

[SilkkTheShocker]

Originally Posted by MRH

I think ultimately headers are what you have to worry about for back pressure. from the cat on is what I know should be free flowing.

get the EMS brand headers and pipe, then what ever muffler you like and you will be up in HP and neat on sound.

1990-1995 Toyota MR2 5sfe headers - $159.99 : EMSPowered, High Quality, Great Service, Low Prices

-H

hi do these headers tend to rust at all? and are they louder then stock?

[MRH]

I have not installed them personally, there are tons of youtube videos of the whole exhaust, they sound really good to me. I'll let you know when I get them ordered and installed in the coming month. I'll probably get some hear wrap too, I would assume that would help prevent rust as well.

-H

[jaymar91]

so if I'm correct.
i have to change out the stock headers to adjust for the back pressure.
with exhaust piping of 2-1/4
then the pressure should be good enough, to where it runs strong, with no loss in exaust speed?

[baktasht]

You're in luck. we have our Non-turbo exhaust on sale! I have 7 of the non-turbo exhausts left in stock: FS: 5sfe Exhaust for MR2 SW20

[MRH]

Originally Posted by baktasht

You're in luck. we have our Non-turbo exhaust on sale! I have 7 of the non-turbo exhausts left in stock: FS: 5sfe Exhaust for MR2 SW20

I'll be ordering mine October 10th I believe. maybe the fans on 27th for muh b-day!

-H

[baktasht]

Originally Posted by MRH

I'll be ordering mine October 10th I believe. maybe the fans on 27th for muh b-day!

-H

Let me know if you have any questions.