Open Downpipe

[Mitsu725]

I have a 97 eclipse that i only drive during the weekend and i was wondering if u unbolt the exhaust from the down pipe and run open down pipe will that kill my car.

 

[swing lo]

No your car will be fine, but you will get shitty gas mileage.

 

[clownface]

Originally posted by swing lo
No your car will be fine, but you will get shitty gas mileage.

i dont see how that would mess up the gas mileage.

You prolly dont want exhaust gas coming out right underneath your car though right in the dead center of it. You should at least run it over to the side of the car or something...or just buy a 3" cat back or something.

 

[L2RTSiAWD]

Originally posted by Mitsu725
I have a 97 eclipse that i only drive during the weekend and i was wondering if u unbolt the exhaust from the down pipe and run open down pipe will that kill my car.

It will be really ####ing annoying.

 

[clownface]

Originally posted by L2RTSiAWD
It will be really ####ing annoying.

yeah, , thats true. Just think of how frigin loud its gonna be.

 

[swing lo]

Originally posted by clownface
i dont see how that would mess up the gas mileage.

You prolly dont want exhaust gas coming out right underneath your car though right in the dead center of it. You should at least run it over to the side of the car or something...or just buy a 3" cat back or something.

Trust me man it does, and it is annoying as hell, but performance is off the chain doggggggggggggg

 

[talon1979]

You can run open downpipe as much as you want. I know people who never run a full exhaust. In fact, since the engine will have an easier time getting the air out it will put less stress on the motor. You will be flowing more air, so I would make sure you don't need more fuel. Open downpipe just like others have mentioned is quite noisy.

 

[clownface]

Originally posted by swing lo
Trust me man it does, and it is annoying as hell, but performance is off the chain doggggggggggggg

, i dont really trust you, any change it would make in the mpg would be miniscule i would think. I mean it would be compairable to a 3" or 3.5" cat back woudlnt it?

 

[swing lo]

No, i don't know the detail's about how it affects gas mileage, but i've been driving around for about a month with my 3" system and cut-out off. I have noticed a drop n gas mileage and i have purposley gone a month without spirited driving, and it suck's, but performance is tight.

 

[clownface]

Originally posted by swing lo
No, i don't know the detail's about how it affects gas mileage, but i've been driving around for about a month with my 3" system and cut-out off. I have noticed a drop n gas mileage and i have purposley gone a month without spirited driving, and it suck's, but performance is tight.

Honestly you must have another problem then. I dont think its the 3" exhaust that is making your mpg go down alot, i mean a extremely open exhaust could make a small diffence but i dout you wouldnt notice it. I have a full 3" and my mpg is great. I get somewhere in the mid-low 20's i think.

 

[swing lo]

Not my 3-inch man, I'm running open downpipe.

How about this, open your downpipe for a month with non-spirited driving, and see what happen's, and then get back with me.

 

[clownface]

Originally posted by swing lo
Not my 3-inch man, I'm running open downpipe.

How about this, open your downpipe for a month with non-spirited driving, and see what happen's, and then get back with me.

okay my bad. I still dont see how it would ruine your millage. Can you tell my WHY it messed up your mpg? Then if it makes sense ill take your word for it, but i just cant seem to figure out why it would make much of a difference so i really dont think your gonna be able to tell me something that makes any sense. O and dont tell me to go see for myself cause thats a silly thing to do on a street car.

edit- I know that you slightly, SLIGHTLY, lose some mpg with almost any increase in HP, but your making it sound like you had say...20mpg on average and once you took your catback section off it dropped to 15 or 10 or something like that and i just dont think that a open DP would just ruine your mpg like that, it just dosnt make sense. I know one might say that since the exhaust is flowing alot better that its more air flowing through the entire system and that the computer would richen it up to keep it from being to lean and thus lower mpg, i figure that would be the only way to explain what your saying but i really really really dout that open DP in itself would ruine your mpg in that way.

 

[swing lo]

How is it silly to do on a street car It's loud ,but it's not like you can't deal with it.

 

[boosted dsm]

i ran open downpipe for about 9 months daily driver before i bought a 3 in exhaust. it won't hurt your car engine wise, but will coat your underneath with carbon depending how long you run it like that (that is why i bought my exhaust). It does get annoying on long drives, but you can't beat it being that it is a free upgrade. Plus it is great when people thnk your car is a slow junker with no exhaust..haha

 

[clownface]

Originally posted by swing lo
How is it silly to do on a street car It's loud ,but it's not like you can't deal with it.

because it is silly for a daily street car, it would be to loud to deal with IMO, my system bothers me on the interstate so i know yours would, cant hear music as well and stuff. If a cop got behind me and heard a crazy loud exhaust and noticed that i didnt have a muffler sticking out the back of my car im almost sure i would get pulled over, I guess you could just hang a muffler back there and solve that though, but seriously how much are you gaining from that mod on your street car to justify the sound and mess when you can just get a 3" or 3.5" made?

hey but that my opinion, yours is as good as mine. What i really wanna figure out is why you think your open downpipe would ruine your mpg.

 

[BoostinAWD]

Only reason it would effect gas mileage would be from all the extra air your engine is ingesting.

Easier to get out, easier to get in. Not to mention your HP #'s will go up throughout the entire powerband.

I ran open o2 housing on my gsx for about an hour, the throttle response, offboost power, not to mention topend were amazing compared to the stock exhaust. The dsmlink recorded a 3hp gain at idle

I for one love the sound, if it was half as loud it would be perfect.

 

[swing lo]

Originally posted by BoostinAWD
Only reason it would effect gas mileage would be from all the extra air your engine is ingesting.

Easier to get out, easier to get in. Not to mention your HP #'s will go up throughout the entire powerband.

I ran open o2 housing on my gsx for about an hour, the throttle response, offboost power, not to mention topend were amazing compared to the stock exhaust. The dsmlink recorded a 3hp gain at idle

I for one love the sound, if it was half as loud it would be perfect.

Thank you, oh and for old boy in virginia.............Move to florida.......the land of no emissions

 

[swing lo]

Originally posted by clownface
because it is silly for a daily street car, it would be to loud to deal with IMO, my system bothers me on the interstate so i know yours would, cant hear music as well and stuff. If a cop got behind me and heard a crazy loud exhaust and noticed that i didnt have a muffler sticking out the back of my car im almost sure i would get pulled over, I guess you could just hang a muffler back there and solve that though, but seriously how much are you gaining from that mod on your street car to justify the sound and mess when you can just get a 3" or 3.5" made?

hey but that my opinion, yours is as good as mine. What i really wanna figure out is why you think your open downpipe would ruine your mpg.

You must be stupid to ask a question like how much power will you gain from running open downpipe or having a cut-out as close to the o/2 housing as possible. And why do you keep emphasizing (that mod on the street)? How much time does your car spend garaged, and only to come out at the track?

 

[clownface]

Originally posted by swing lo
You must be stupid to ask a question like how much power will you gain from running open downpipe or having a cut-out as close to the o/2 housing as possible. And why do you keep emphasizing (that mod on the street)? How much time does your car spend garaged, and only to come out at the track?

No im not stupid, however im begining to think you are, . I just dont think its worth the extra power to do this mod on a street car or i would do it to mine, i know itll make more power that way i just dont wanna hear it all the damn time, thats my opinion and its a damn good one in my book, your opinion is fine also so go enjoy your extra power.

I already said that the only reason you would lose mpg is cause of the exta air, look a few posts up, i know this. I just dont think its gonna make enough of a difference to make your mpg horrible, if that mod made you get that much more air in the system to cause the car to richen it up enough to lose that much fuel economy im sure you be seeing alot more horsepower from that mod then what you are and that a ton of people would be doing it on there daily cars.

The only point im trying to make is that open DP wont kill your mpg but yeah sure its gonna go down alittle, just like with almost every other mod but its not gonna kill your mpg to the point of having to worry about it more then you did before. I just wanna tell the thread starter that this mod in itself will not kill your mpg.

 

[TimG]

I've been running an open downpipe for about 5 months now. With my ported 14b, 2.5" IC piping, Kinetic FMIC and larger n/t t-body, I hit 17psi in a matter of milliseconds after hammering the throttle in low-mid rpm range (3000-4000rpms).

Smells funny when you are stopped at a light. Windows must be down at all times so you don't die from fumes. The spool-up sound and spool-down sounds are incredible.

To make a long story short though, I'm going with a 3" custom exhaust system when the weather heats up.

 

[Venom69]

I unbolted my exhaust for two months, from catback. Topend power was really improved on the 14b, gas mileage was horrible. I probably lost 7 to 8 miles to the gallon. Performance was improved though. I get better gas mileage from my 3inch tubo back than I did with a missing stock catback, and more horsepower. Every car is different though but I would expect yours to be similar. Oh and by the way you'll drive like that for a few days before you'll start getting these massive Migraine Headaches.

 

[4g63GSX]

in my experience the open downpipe caused my car to lean out from lack of fuel and that wasnt the greatest feeling
i ran it like that for about 2 months befor it blew but now its fine with the fuel pump injectors and safc
??????///

 

[1993eclipseGS]

I had my full exhaust on with only a broken flex section and it was way too obnoxious sounding. Especially coming up my main road 2am passing all the houses where the exhaust echoes

It sounded like a tractor-trailor at idle and when i would just rev it up a little bit in neutral you could hear the turbo 'spool'. That sounded neat at least

It was definatly annoying and everyone looked at me weird

 

[Black95_TURBO]

I can see a loss in mpg do to the missing o2 senssor.

Has anyone tried putting a muffler where the cat is, that might deal with the sound issue and if you weld on a o2 bung that might solve the gas issue as well. Just a thought.

 

[CanadianTalon]

Not my 3-inch man, I'm running open downpipe.

How about this, open your downpipe for a month with non-spirited driving, and see what happen's, and then get back with me.

Going to open downpipe did piss-all to my gas mileage. I don't know what you're smoking, but it must be good.