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98 Exhaust Question?

skidoosummit

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skidoosummit Enthusiast

skidoosummit

Posted
Posted

Hi, I have a 1998 Gmc Sierra, 5.0L, stock exhaust and am looking to modify it. I know this my sound stupid, but if i remove my muffler, will it hurt my engine with a decrease in back pressure? I've been looking around and some people say it will destroy the valves, others say its ok to run open headers, so I'm just looking for a second opinion. Like I said, the system is all stock and would be leaving the cat, and just removing the muffler. Thanks

dietz4ibanez Senior Enthusiast

dietz4ibanez

Posted
Posted
Hi, I have a 1998 Gmc Sierra, 5.0L, stock exhaust and am looking to modify it. I know this my sound stupid, but if i remove my muffler, will it hurt my engine with a decrease in back pressure? I've been looking around and some people say it will destroy the valves, others say its ok to run open headers, so I'm just looking for a second opinion. Like I said, the system is all stock and would be leaving the cat, and just removing the muffler. Thanks

 

 

It may not directly hurt your engine but you will lose horse power for sure... I have a truck with the 350 5.7L with no mufflers... Its LOUD but I am wanting to welding some type of muffler in place to get back some of the HP AND Torque I have lost.. My truck currently has 200k....

2000DV4.8 Senior Enthusiast

2000DV4.8

Posted
Posted

If you're just replacing the muffler with a piece of straight pipe you'll be fine. Not going to give you any power (you might lose some down low), but you won't break anything.

skidoosummit Enthusiast

skidoosummit

Posted
  • Author
Posted

I forgot to mention that my truck has 132000 original kms on it. So if I lose low end power, can i not just shorten the throttle cable to give me more RPM's, if that has anything to do with it. I no on my old 91 5.7L it was gutless, until I shortened the throttle, which in return was a helluva lot snapier at lower RPM's. Any info would be greatly appreciated. Thanks...skidoosummit

Zembonez Senior Enthusiast

Zembonez

Posted
Posted

I think you should take some 3 inch wood screws and screw the accelerator pedal to the floor. It'll be hard to keep still at lights but OH WHAT FUN driving everywhere at WOT!

bflat Enthusiast

bflat

Posted
Posted

Sound like a great way to gain some torque! I say GO FOR IT! :lol:

 

As a side note to the rest of you, Natural Selection will be dominate in situations like this. Just let Nature take it's course! :fume:

Cowboy09 Enthusiast

Cowboy09

Posted
Posted

What the guys are trying to say is that you aren't actually gaining anything by shortening your throttle cable. Basically all you're doing is having the pedal depressed a little bit at all times (aka giving it gas). In fact, all you'll be getting is poorer gas mileage.

 

You will gain some power at the high end by having the muffler off, but if you want it back in the low end, you just need to get your system tuned. Just talk to an exhaust shop that knows what they're doing and they can advise you properly.

dzrick Enthusiast

dzrick

Posted
Posted

Hey Tyler,

 

When I bought my 98 Sierra 5.0 it had the exact exhaust your wanting to install. I don't know if it was tuned after or not but I haven't had any problems. It's just a little louder. :thumbs:

skidoosummit Enthusiast

skidoosummit

Posted
  • Author
Posted

Hey, thanks for the input everyone. I took a good look under the truck and noticed that the stock setup has duals running from the exhaust manifold to the muffler, then single out. So I went to a shop and arranged to get the stock muffler cut off in replace of two Purple Hornies, running dual out the back end. Thats what I wanted in the first place, but could not afford to go dual from the manifold back. Now that I found out that its almost dual anyway, I thought what the hay, might as well run dual with the Purple Hornies in staed of straight piping it. Plus I think that i will enjoy the snappy sound of those. And if it has decreased low end power, I'll take it into a shop like Cowboy09 said to get tuned. Again, thanks for all the input, its been a good help.

Scorps Enthusiast

Scorps

Posted
Posted

If a loud rumble is what your after just run what us muscle car guys call a "Muffler Dump" get a nice sounding muffler put it in place of the original but don't run a tail pipe after the muffler, trust me it will be loud I got dual 40 series Flowmasters with no tail pipes on my Malibu and its gawd damn loud :lol:

 

Hoping to the the same to the pick-up when I get it fixed

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