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Travis Pastrana rally racing?

Ok, maybe this is a stupid question, but I was just wondering if it would be a really bad thing to remove stock exhaust from mid-pipe back and just drive around like that. Not forever or anything, just to try it for a while. Or would there not be enough back pressure or something worse? Please let me know, just wanted to see how it would sound/feel. :lol:
 

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Discussion Starter #5
well, I just might try that one day. As long as no harm will be done, i'd like to hear it. I am in Oklahoma where we have no emissions testing, I'm curious to hear what it would sound like.
:wink:
RC
 

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i did that once on a grey market honda cbr250rr i had. i bought a yoshimura can, and when i put it on, i fired it up w/ no can. holy crap, it was soooooo loud! sounded like a ferrari. that was such a cool motor, 250/4cyl/4stroke/gear driven cams/19,000rpm redline. too bad it only made 38hp...
 

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Only 38hp! :lol: On a vehicle that weighs less than 300 lbs, that's still pretty quick. I learned on an eight horsepower motorcycle. :roll:
 

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My pushmower has 8.5 hp... Its a beast though :)
 

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I tried removing the exhaust from the downpipe back, and boy was it loud. You could hear me coming down the road! It really made the car rumble at idle, and then when you hit the gas, it got incredibly loud. I suppose its ok for a day or so, but I couldn't take it for more than that. Also, the check engine light comes on, and the cruise control light flashes at you the whole time. Not to mention, the exhaust now has no cats on it, and when you sit in one place for long, you get a really rank smell in the cabin (the exhaust will exit right under the cabin). I don't know if it adds any speed, or how much, because it really changes the feel of the car, and its hard to tell. Honestly, it seemed slower to me, but that doesn't make much sense.
 

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It may seem slower because you lose all the back pressure in the exhaust which accounts for some torque. The only other danger as described above, would be the carbon monoxide exiting the car right under neath of it, and possibliy seeping back into the interior, knocking you out (if you sit a stoplight for a long period of time with the windows up) or killing you.

:evil:
 

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Discussion Starter #12
STI EXTC

Holy Sti! I love the sound that it makes minus a cat and a muffler!! It does feel like it has less torque, and I'm sure it's b/c of having no back pressure. But I love the looks I get from it. Its fun to go up to mustangs and camaros and show them up at what they think is best. Ha. No check engine lights or anything yet, if I do get them, does anyone know if resetting the ECU would help any? I think I might keep the exhaust off until I get the Godspeed DP and blitz nur spec. I love to make noise! Ok, anyone with opinions on anything let me know please. :D

RC
 

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RCrown2 said:
It does feel like it has less torque, and I'm sure it's b/c of having no back pressure. But I love the looks I get from it. Its fun to go up to mustangs and camaros and show them up at what they think is best.
If you lost torque, then you aren't showing up any v-8's at what they think is best, cause torque is what v-8's are all about.

I don't know, I just think how the car goes is a lot more important than how it sounds. <shrug>
 

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Discussion Starter #14
E-brake usage

Ok, just letting everyone know that I put the exhaust back on. It's weird being able to hear road noise again. I didn't get any check engine lights or anything at all. You have a point Radar, I love the feeling of being put back in my seat again, now I can show up those mustangs and camaros....if they're stock that is. CRAP! I need mods! :x

RC
 

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When I was putting my blitz catback on... it sounded quieter with the stock downpipe and NO catback vs stock downpipe and blitz catback... lol

Robert~
 

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I ran around like that for a little while and i though it was loud, thought it was until i heard my current set up. My current set up is much louder than that. Me and my buddies try and see how far away we can hear it from, and so far we have been able to hear it from well over a mile on a quite night.
 

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Discussion Starter #18
Hey Ender, what kind of setup do you have? How is the performance with it? I am in the market for a complete aftermarket exhaust. As for sound clips, all I have are some videos of me driving down a road with the exhaust off. I can't post videos on hear, or i'm not sure how, so if someone wants to host for me, I'd be glad to share. :D

RC
 

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MethodX said:
It may seem slower because you lose all the back pressure in the exhaust which accounts for some torque. The only other danger as described above, would be the carbon monoxide exiting the car right under neath of it, and possibliy seeping back into the interior, knocking you out (if you sit a stoplight for a long period of time with the windows up) or killing you.

:evil:
This is not true. You do not need any sort of backpressure to build boost and as a result torque.

-st
 

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RadarOnPaws said:
RCrown2 said:
It does feel like it has less torque, and I'm sure it's b/c of having no back pressure. But I love the looks I get from it. Its fun to go up to mustangs and camaros and show them up at what they think is best.
If you lost torque, then you aren't showing up any v-8's at what they think is best, cause torque is what v-8's are all about.

I don't know, I just think how the car goes is a lot more important than how it sounds. <shrug>
There is no way he lost torque unless the ECM is doing something screwy. Assuming everything adapts properly, the ONLY thing he might see is that the torque curve would shift slightly in terms or peak torque at a given RPM. That being said, peak torque should rise. Of course, then we have the issues with boost creep, etc. so it is hard to predict the outcome.

But one thing is for certain, the best backpressure for a turbo charged engine is ZERO backpressure. The other things to consider in terms of exhaust design are the diameter, bends, components, and length of the exhaust. You want to keep the gasses flowing out of the exhaust. Bad bends, poor length, incorrect sizing can lead to obstructions, dead spots, etc. that will cause backpressure. Backpressure robs you of power.

Backpressure being necessary on a turbo-charged engine is one of the great myths of the internet.

-st
 
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