[lostsurfingn5]

if i run straight pipes (get rid of the cats) on my 2001 mustang v6 will i loose compression and hurt the engine?

[Wataru]

Im not 100% on the compression problem but I know that not having catalytic converters is illegal. And if you live in a state with car inspection, you wont get a decal.

[mcqueen]

From what I understand straight pipes and removing cats will lower your back-pressure. It's not going to damage your engine, but you will lose a little power. I see a lot of people go with xpipes instead (I still like my divorced duals )

Anyone more knowledgeable, feel free to correct me if I'm wrong.

[mcqueen]

Originally Posted by Wataru Im not 100% on the compression problem but I know that not having catalytic converters is illegal. And if you live in a state with car inspection, you wont get a decal.

As long as his state doesn't have emissions testing, I think he could probably get away with it. Here in Iowa, I have a few friends who run without cats and they've never had any legal troubles. Maybe some mental ones since they think they're getting an insane power boost on their Hondas

[Codeman]

I would go divorced duals that is what i have on my car. I have mufflers and cats. As far as compression you will not loose compression, you will loose back pressure. As far as damaging your engine. It all depends. If you live in a place where it gets cold at all and plan on driving your car in the cold then you may end up bending valves. This is because the decrease in back pressure will allow cold air into your heads possibly bending valves. I would just leave the mufflers on at least. A v6 with no mufflers or cats won't sound that great.

[Wataru]

Originally Posted by mcqueen As long as his state doesn't have emissions testing, I think he could probably get away with it. Here in Iowa, I have a few friends who run without cats and they've never had any legal troubles. Maybe some mental ones since they think they're getting an insane power boost on their Hondas

In FL we dont have testing, but you have to have them. Ive seen cops going around Downtown checking bumpers with tape measures to check the bumper clearances.

[winnie51189]

Originally Posted by Codeman It all depends. If you live in a place where it gets cold at all and plan on driving your car in the cold then you may end up bending valves. This is because the decrease in back pressure will allow cold air into your heads possibly bending valves.

I think that's a little extreme. Never heard of someone getting dual exhaust causing bent valves.

[McMustang5.0]

My friend has a BMW 325I that has a 02 mustang V6 with a vortech supercharger on it. He had it for two weeks and took off the exhaust(said it didn't sound cool), he put strait stainless pipes of his headers. He blew his engine. The mechanic he visited said the he had no back pressure what so ever and that he had to buy a new engine because this one was beyond repair.

i honestly dont know if the whole new engine part is right but he didn't have any back pressure in what i think caused his motor to seize.

[Safi]

Originally Posted by McMustang5.0 My friend has a BMW 325I that has a 02 mustang V6 with a vortech supercharger on it. He had it for two weeks and took off the exhaust(said it didn't sound cool), he put strait stainless pipes of his headers. He blew his engine. The mechanic he visited said the he had no back pressure what so ever and that he had to buy a new engine because this one was beyond repair. i honestly dont know if the whole new engine part is right but he didn't have any back pressure in what i think caused his motor to seize.

There was probably other reasons....If he had headers on there he for sure didn't blow JUST because of that.

And yes, you will lose backpressure, but to say you loose hp is not completely true. You will just be moving your power band up. So you will be a bit more sluggish down low, but up top you will have more power than before

And I run divorced duals with thrush mufflers

My Stang :: MVI_0921.flv video by commandersafi -...

[winnie51189]

Originally Posted by McMustang5.0 My friend has a BMW 325I that has a 02 mustang V6 with a vortech supercharger on it. He had it for two weeks and took off the exhaust(said it didn't sound cool), he put strait stainless pipes of his headers. He blew his engine. The mechanic he visited said the he had no back pressure what so ever and that he had to buy a new engine because this one was beyond repair. i honestly dont know if the whole new engine part is right but he didn't have any back pressure in what i think caused his motor to seize.

Again that's a little extreme to blame engine failure on dual exhuast, especially when he was running FI. I would almost guarantee it was atleast partially caused by a few things other than his exhuast.

[lostsurfingn5]

okay thanks guys . . if i were toi run x pipes with no cats would i still loose back pressure or maybe hurt my engine or valvues or anything?

[winnie51189]

No it wouldn't hurt your valves. It would definitely look back pressure and you would loose some torque down low but make up for it up top just like Safi said. I would suggest just getting some mufflers and having a shop fab up your exhaust for you.

[Safi]

Originally Posted by winnie51189 No it wouldn't hurt your valves. It would definitely look back pressure and you would loose some torque or atleast it would feel like you did. I would suggest just getting some mufflers and having a shop fab up your exhaust for you.

Like i said before...you don't loose anything, you are just moving your powerband higher up into the RPMs