Are the gains of losses in stright pipes? ? ?

[Sick300]

Does anyone know what kind of gains you get from running stright pipes on a 5.7?? its stock sized pipe, just cut outs where cats and mufflers were with welded in filler pipes. Or am i loseing and where? Thanks for your help!

[EvoATL]

Well, you would lose some back pressure, that's for sure... It MIGHT help on the top end, but probably not noticeably..

[HEMMISSEY]

I did mines before, and it felt like shi*! I wouldnt do it..

[FloridaRT]

You would lean out and run worse......................................

Bob

[dwhip]

i cut my reso's off and added straight pipes, it's not any noticeable gain or loss

[DA H.N.I.C.]

It's a low end torque loss. Sounds menacing though!

[HEMI~C~]

Thats interesting, as I have found my best MPH and ET came after I had to gut the cats when they were destroyed by an excessively rich tune. Keep in mind our cars are flowing a $hit load of air....more than any of your old school cars use to in similar heads/cam/header configurations.

Guys, back pressure or the lack of it is not what is required to build torque. What we are looking for is maximum velocity and the benefits of that velocity in regards to the scavanging effect which helps clear the cylinders of all that burnt mixture. There is probably a more technical explanation out there.....but consider this:

We use to purposely put 3 in collector extenders (sometimes up to 12 inches long) on the ends of the headers to maximize the torque curve. This effect needs to be tuned of course (typically gauged by cutting where the paint stopped burning off the extension), and then adjustments in the A/F to make for any leanness, but unless someone can show me a before/after dyno where they gained hp/tq from putting a restriction (i.e. catalyst element) in the exhaust I would chalk all the "I lost torque" inputs to seat of the pants misperceptions mostly caused by the extra noise you are undoubtedly hearing. As we all know, a quite exhaust always "feels faster".

[slideway]

Thats interesting, as I have found my best MPH and ET came after I had to gut the cats when they were destroyed by an excessively rich tune. Keep in mind our cars are flowing a $hit load of air....more than any of your old school cars use to in similar heads/cam/header configurations.

Guys, back pressure or the lack of it is not what is required to build torque. What we are looking for is maximum velocity and the benefits of that velocity in regards to the scavanging effect which helps clear the cylinders of all that burnt mixture. There is probably a more technical explanation out there.....but consider this:

We use to purposely put 3 in collector extenders (sometimes up to 12 inches long) on the ends of the headers to maximize the torque curve. This effect needs to be tuned of course (typically gauged by cutting where the paint stopped burning off the extension), and then adjustments in the A/F to make for any leanness, but unless someone can show me a before/after dyno where they gained hp/tq from putting a restriction (i.e. catalyst element) in the exhaust I would chalk all the "I lost torque" inputs to seat of the pants misperceptions mostly caused by the extra noise you are undoubtedly hearing. As we all know, a quite exhaust always "feels faster".

I hope your right Chris! Cause mine's not to quiet right now,lol

[Sick300]

Thats interesting, as I have found my best MPH and ET came after I had to gut the cats when they were destroyed by an excessively rich tune. Keep in mind our cars are flowing a $hit load of air....more than any of your old school cars use to in similar heads/cam/header configurations.

Guys, back pressure or the lack of it is not what is required to build torque. What we are looking for is maximum velocity and the benefits of that velocity in regards to the scavanging effect which helps clear the cylinders of all that burnt mixture. There is probably a more technical explanation out there.....but consider this:

We use to purposely put 3 in collector extenders (sometimes up to 12 inches long) on the ends of the headers to maximize the torque curve. This effect needs to be tuned of course (typically gauged by cutting where the paint stopped burning off the extension), and then adjustments in the A/F to make for any leanness, but unless someone can show me a before/after dyno where they gained hp/tq from putting a restriction (i.e. catalyst element) in the exhaust I would chalk all the "I lost torque" inputs to seat of the pants misperceptions mostly caused by the extra noise you are undoubtedly hearing. As we all know, a quite exhaust always "feels faster".

Thanks, you sound like you know what your talking about! i already cut mine off last summer and i didnt think i noticed much of a difference.... just noice... and as you said the noise prolly makes it feel faster..... lol It would be nice to see someone with Dyno run test's with befor and after cut-off's.... but until then, im going to keep running em loud.... Thanks for your help!!!

[Sick300]

i cut my reso's off and added straight pipes, it's not any noticeable gain or loss

Same here.... its hard to tell, that why i made this post. To find out the truth... thanks

[Gucci300C]

i heard if you straight pipe your car and i mean only stock manifolds and cats and then run it straight piped from there that i would burn out my valves..........

[8yourM5]

when I dynoed with a stock 6.1 with longtubes and my cutouts open I lost alot 15hp ad tq down low but picked up it all back up top and gain a little 7 or 8.

Now that I have a 426 long tubes and a blower I gain any where from 40-50 hp and toqrue all the way through the band.

So I guess what I am trying to say is. they make the car sound great but unless you have a major build that is going to need to release alot of air fast the cut outs will not help you, but they will make your car sounds amazing!!!

[Sick300]

i heard if you straight pipe your car and i mean only stock manifolds and cats and then run it straight piped from there that i would burn out my valves..........

Where did you hear this?? How would it cause them to burn out? considering you are realeasing the gases that would cause that...?? idk, lol thanks for you help...! Anyone??

[Sick300]

when I dynoed with a stock 6.1 with longtubes and my cutouts open I lost alot 15hp ad tq down low but picked up it all back up top and gain a little 7 or 8.

Now that I have a 426 long tubes and a blower I gain any where from 40-50 hp and toqrue all the way through the band.

So I guess what I am trying to say is. they make the car sound great but unless you have a major build that is going to need to release alot of air fast the cut outs will not help you, but they will make your car sounds amazing!!!

So loss in the beging, gain in the end? yea i have a stock 5.7 with stock size piping from the headers, the stock X pipe and strights all the way back. Do you know anything about possibly burning out the valves??? someone said that...?

[Sick300]

Thats interesting, as I have found my best MPH and ET came after I had to gut the cats when they were destroyed by an excessively rich tune. Keep in mind our cars are flowing a $hit load of air....more than any of your old school cars use to in similar heads/cam/header configurations.

Guys, back pressure or the lack of it is not what is required to build torque. What we are looking for is maximum velocity and the benefits of that velocity in regards to the scavanging effect which helps clear the cylinders of all that burnt mixture. There is probably a more technical explanation out there.....but consider this:

We use to purposely put 3 in collector extenders (sometimes up to 12 inches long) on the ends of the headers to maximize the torque curve. This effect needs to be tuned of course (typically gauged by cutting where the paint stopped burning off the extension), and then adjustments in the A/F to make for any leanness, but unless someone can show me a before/after dyno where they gained hp/tq from putting a restriction (i.e. catalyst element) in the exhaust I would chalk all the "I lost torque" inputs to seat of the pants misperceptions mostly caused by the extra noise you are undoubtedly hearing. As we all know, a quite exhaust always "feels faster".

Any knowalge of if burning out my valves can happen??