Exhaust Washer Mods

[Eureka]

I've recently come across this...

I mean this:

The common things I hear about:

1. It sounds bad
2. It is an exhaust leak/bad on system
3. Carbon monoxide fumes

From what I understand about cars though

1. Subjective
2. You do it far enough back (right before the muffler) that you still have enough backpressure from the rest of the piping. Isn't this the same as a muffler delete anyway?
3. This is done way past the cat so all the fumes should be catalyzed, and it's far enough back that you're inches away from the exhaust tip anyway

 

[phucheneh]

Um.

What?

 

[Eureka]

Apparently it's a thing.. you space out the pipes between your muffler and downpipe to get some noise going.

I've read a lot of debate about it. It's intriguing.

 

[LTC8K6]

It's stupidity.

And fumes aren't catalyzed...

 

[iamwiz82]

Nice weld there, as well.

 

[Eureka]

It's stupidity.

And fumes aren't catalyzed...

If you do it right before the muffler, shouldn't it be mostly catalyzed by then?

 

[phucheneh]

If you do it right before the muffler, shouldn't it be mostly catalyzed by then?

Reactions are catalyzed. I don't think it's proper to say a substance has been 'catalyzed.' It has been converted to another substance by a chemical reaction.

That bit of nit-picking aside, I don't think harmful gases like CO are at a high enough level in modern cars to make an under-car exhaust leak a serious concern.

You would probably need a combination of poor running condition and a way for exhaust to enter the cabin (unsealed hole around a manual shifter seems like a common one)...the kinds of things that kids that would do a 'washer mod' probably have, actually...

If you want your exhaust to be louder, get a muffler that...muffles less. Or replace one or more mufflers with a piece of pipe. It's not that hard/expensive. I still might hate you for it, but I'd wouldn't laugh at you quite so much. Spacing pipe connections apart with washers might as well be drilling random 'speed holes' in your exhaust.

 

[natto fire]

You forgot #4: looks ghetto as hell.

The people that say it sounds bad are spot on, because I am going to guess this "mod" is done on low displacement 4 cylinder engines, which sound annoying when their exhaust systems are forced to make more noise for the sake of making more noise. A heavy breathing V8 does not need crap like this to sound good, and when you get into exotic 10 and 12 cylinder engines it is probably completely unheard of.

If you really want your 4 banger to sound nice, then buy an exhaust system set up for it, and for the love of god have some forced induction in front of it. You need to be making 125hp per liter or more to even justify a noisy 4 cylinder, in my opinion.

 

[twinrider1]

This exhaust is Bubb Rubb approved.

 

[slag]

This exhaust is Bubb Rubb approved.

An' dats only in da mornin'... when you 'posta be makin' brefas' or sumpin'

 

[Gillbot]

That's dumb, do it right FFS.

 

[punjabiplaya]

ungh

 

[JCH13]

Agree with Gillbot.

That's probably heinous for exhaust flow... sudden, large, increase in flow diameter and then a re-entrant inlet...

Also, it's DEFINTELY horrible for exhaust structure... I bet the flanges like to snap off shortly after this 'mod'.

Not to mention hot exhaust gases like to melt/damage stuff, and the various acids created by the exhaust will ruin everything down-wind of the gaping exhaust hole.

 

[Eureka]

That's dumb, do it right FFS.

http://www.quicktimeperformance.com/OVAL/lightbox/photos/shot4c.jpg[IMG][/QUOTE]

I know a guy who's trying to get one installed on his car. That will be a fun mod to drive.

 

[Mark R]

Reactions are catalyzed. I don't think it's proper to say a substance has been 'catalyzed.' It has been converted to another substance by a chemical reaction.

That bit of nit-picking aside, I don't think harmful gases like CO are at a high enough level in modern cars to make an under-car exhaust leak a serious concern.

They might be pre-cat; but after cat, CO will be pretty much zero. With modern close-coupled cats, CO is going to be pretty much zero unless the leak is in your headers.

If you have tail-gas analysis emissions inspections, then any kind of leak in the exhaust will be a fail. The gap will suck in air, and a tail-sniffer emissions analyser will read a falsely high lambda. Lambda > 1.003 is usually a fail, and corresponds to a very small leak.

 

[Gillbot]

I had them on my Camaro, they were fun as hell. Sit at a light all quiet minding my own business then someone pulls up and gives the "rev, nod and point ahead" signaling they want to play. I'd hit the switch to open them up and the sound would change from calm & docile to "hell opened the flood gates of whoopass" and i'd get the horrified NO NO NO head shake. For some reason they no longer wanted to play...... Shrug.

 

[shabby]

That's dumb, do it right FFS.

Doing it right would be before the cat not after.

 

[Gillbot]

Doing it right would be before the cat not after.

[]http://imageshack.us/scaled/landing/53/co1.jpg[/img]

Sometimes that isn't an option. Plus if you have good cats, they really don't hurt flow that much anyway. Mine dynoed within 3hp with the Catted Y pipe on vs. off so good cats can flow well enough to not be restrictive.

 

[Throckmorton]

Doing it right would be before the cat not after.

If by "right" you mean polluting excessively and gassing yourself with fumes.

 

[SyndromeOCZ]

If by "right" you mean polluting excessively and gassing yourself with fumes.

Hey, those 3 extra HP could mean the difference between winning and losing..

Any good places to pick up a 'cutout kit'? I wouldn't mind putting them into the budget for my truck restoration.

 

[shabby]

Hey, those 3 extra HP could mean the difference between winning and losing..

Exactly ask any racer, any real racer. It don't matter if you win by an inch or a mile. Winning's winning.

 

[Gillbot]

If by "right" you mean polluting excessively and gassing yourself with fumes.

If you are worried about this stuff, you shouldn't be modding your car anyway.

 

[Throckmorton]

If you are worried about this stuff, you shouldn't be modding your car anyway.

That's BS. I just put a custom tune into my ECU. I didn't have to bypass the cat to gain power

 

[Gillbot]

That's BS. I just put a custom tune into my ECU. I didn't have to bypass the cat to gain power

I had no cats on mine AND I passed emissions testing that way since I took the time to tune it right. I also tested it with cats on and off the car and it basically made no difference in power. I liked the sound better with them off, so I left them off.

EDIT: Point being, if your main concern is pollution you shouldn't be modding since consuming more fuel inevitably means more exhaust pruduced with leads to more pollution regardless of if you have cats or not. Worried about pollution, buy a prius or volt not a hot rod car.

 

[Throckmorton]

I had no cats on mine AND I passed emissions testing that way since I took the time to tune it right. I also tested it with cats on and off the car and it basically made no difference in power. I liked the sound better with them off, so I left them off.

EDIT: Point being, if your main concern is pollution you shouldn't be modding since consuming more fuel inevitably means more exhaust pruduced with leads to more pollution regardless of if you have cats or not. Worried about pollution, buy a prius or volt not a hot rod car.

Catalytic convertors exist for a reason. You might be making little CO and NOx under certain conditions but not all. Pollution its a lot more important than amount of fuel burned. There is a reason a scooter pollutes 10x as much as a car... no cats