Geo with 3 straight pipes?

[notwhouthink]

I am thinking about getting a 3 cylinder geo metro for like $2000, and I am wondering if it would be at all possible to cut part of the exhaust manifold off, and weld 3 cheap straight pipes from each cylinder coming literally straight down and out the back (or maybe the side) of the car.

I have some common sense/knowledge of how a car works, and I know it could be possible, the only problem I would foresee is that the pipes couldn't withstand the heat since they wouldn't be as thick as the manifold itself. Also, there might be an issue with the back pressure since I'd be removing the muffler.

I might be talking stupidity, and some of you smart guys might be laughing because this may not be possible at all, but coach me thru on this.

[vgames33]

You'd be better off making a 3 piece tip or something. As long as you tap into the exhaust after the oxygen sensors there won't be any issues, but the increased pipe area could reduce what little power you have

[oldblu65]

My first question would be why ? What are you expecting to gain from the straight pipes ? More HP, cooler sounding exhaust , what ? I really don't have a lot of knowledge on this particular vehicle . Does it have a carburetor or is it fuel injected ? Does your local area have emission testing ? If so , it would be a definite no - no ! The manifold could be replaced with the three pipes if you have a suitable exhaust flange to weld the pipes onto . Since this is a FWD / transverse mounted engine ( I'm assuming ? ) , then space in the engine compartment is at a premium and I'm not sure there would be enough space for three separate pipes to snake through there and then all the way to the back ? Anything is possible if you are determined to do so . What year is the Geo Metro ? Sounds like the $ 2000 price tag might be a little steep unless it is in mint condition ? If so , you would be killing the value of the car to go through with your plan ! Just my , take it for what it's worth ! Good luck with the direction you choose to take .

[curtis73]

What concerns me is that someone is thinking about spending $2000 on a METRO???

Is there an extra zero in there???

Your main concern will be welding steel tubing to cast iron. Not easy.

[jdmccright]

He could probably have a custom header welded up for a few hundred bucks. Heck some high school weld shop might have fun with it and do it for free with scraps!

Just know that you'd be defeating the emissions controls by removing the oxygen sensors and cat...you'll have a glowing "check engine" light on the whole time and annual inspections of vehicles would be impossible to pass.

Performance-wise, I doubt you'd gain anything and as mentioned, too little back pressure can actually drop performance. Besides, bwappy 4-banger exhausts sound bad enough. Yours would sound more like a dirt bike...bring earplugs for you and all your passengers.

Have fun!

[carpenter_jai]

96' and later models have two O2 sensors. One in the manifold and one after the cat. 95' and before just have the manifold cat. The 3 cylinder metro has plenty of room to accomodate the pipes you are talking about and very doubtfull you'd overheat them. (That extra space is for the even more gas friendly version which sports a gerbil cage with wheel that turns the crank gear ).

I had my cat cut out of my 95 3 cyl. (still no emission testing in my province...) I kept the resonator and muffler. The noise level went up as much as 10 dB I'd guess. Having blown a whole in the muffler pipe I can tell you that it probably doesn't need the back pressure but definitely the earplugs! I had the stock exhaust which I think is 1.5" replaced with 1.75". There was a small improvement in power for sure.

Last thing is if you really want a small car sleeper try to find a swift for $2000
Metro 3 cyl 55Hp
Metro 4 cyl SOHC ~70 Hp
Swift 4 cyl DOHC 110 Hp

Jai