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2003 6.0L power tips?

T

topless jackass

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I have a 2003 GMC w/a 6.0L gasser. I'm not real savvy on the newer LS engines and I'm looking to add some power without having to mess with the ECM. There's no place in Wyoming that programs stuff like this. Can I change camshafts without throwing check engine lights? I'd like to do a cam change and switch to 2 1/2" dual exhaust for better towing power. Maybe a chip too if I can find one. the 2003 seems to be a bastard child for some reason...also, anybody know of headers the will fit that cost less than $500? I don't want stainless or ceramic coated, just plain headers.
 
The best bang for the buck would be to reprogram the ECU. There is no "chip", rather you have to download a new "tune" into the existing ECU or completely replace the ECU with one with the new "tune". There are several mail order companies that perform this service. The most optimal way would be to have a shop actually drive or dyno the truck and tune it, but they can generally get pretty close with the generic mail order version.

A 2 1/2" dual exhaust won't do anything on this truck......it's actually smaller than what came on it factory. It has a nice set of dual 3" pipes that go into a dual inlet, dual outlet muffler and then Y's together before going into a single 3.5" tailpipe. You can change the muffler out for a different sound but don't expect any noticable performance change.

Not sure if you can get away with much of a cam change without a new tune in the ECU, and definitely wouldn't optimize the potential of the cam without a tune.

Most of the things I have read on the internet (always taken with some grains of salt) say that the engine respond well to full length headers but "shorties" really don't do much. Again, a tune is needed to optimize this.
 
What gearing does your truck have? You said that you wanted more power for towing, perhaps a r&p swap could be your best bet. We have a 03 2500hd with the 6.0 and with the 4.10's it does a decent job with a trailer behind it, it's not my cummins but it does well. It's bone stock and currently has right around 310k on the clock.
 
thanks for the info. I forgot to state that it does have 4.10 gears. it actually pulls ok, but I would like a little more if i can get it.
 
I did a few things to my 2003 2500hd, but it does have 8inches of lift and 37/12.50/17 km2s.

I added edelbrock shorty headers with the titech coating, jet performance spacer, bbk throttle body, granetelli air flow sensor, aem cold air intake, dual 2.5 exhaust with flowmaster 3 chamber 50 series, the 2.5 does give it a little better low end grunt.
 
i own a heavily modified LS engine, my advice to you is buy the tuning software and learn how to use it. It saves you so many headaches, when tuning a engine there are so many small things to change, that a mail order wont be that accurate, and tuning by a shop would cost a lot by the hour. Plus say you put headers on the truck have the ecm tuned, then you wana change tire size, you have to send the ecm out again. It is well worth the money to get the software, the LS engines are only going to become more common so knowing how to tune them could make you some cash on the side
 
6.2Blazer said:
A 2 1/2" dual exhaust won't do anything on this truck......it's actually smaller than what came on it factory. It has a nice set of dual 3" pipes that go into a dual inlet, dual outlet muffler and then Y's together before going into a single 3.5" tailpipe. You can change the muffler out for a different sound but don't expect any noticable performance change.
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Actually the muffler is a dual 3" in, which reduces down to 2 1/4 right inside the muffler, then comes out with a SINGLE 2 1/4 single in the muffler, 3" out of the muffler, then a 3.5" tailpipe. The other leg that looks like an exit is actually a reroute of the exhaust back into the muffler into a resonator chamber. So yeah the muffler is pretty restrictive.

I would put on a magnaflow dual 3" in dual 2.5" out with 2.5 tails. You'll retain your low end torque. Put 3" tails on with a magnaflow and you'll kill the low end. I have driven both setups, it's noticeable.

The 3" front pipes were put on these trucks for exhaust volume since the muffler is so restrictive.
 
Wow! thanks for all the advice. I think I may have to look into buying the software and playing with a few mods myself. Any recommendations on what software to buy. I'm kinda diggin' the thought of playing with it myself.
 
Cornfield creations said:
Actually the muffler is a dual 3" in, which reduces down to 2 1/4 right inside the muffler, then comes out with a SINGLE 2 1/4 single in the muffler, 3" out of the muffler, then a 3.5" tailpipe. The other leg that looks like an exit is actually a reroute of the exhaust back into the muffler into a resonator chamber. So yeah the muffler is pretty restrictive.

I would put on a magnaflow dual 3" in dual 2.5" out with 2.5 tails. You'll retain your low end torque. Put 3" tails on with a magnaflow and you'll kill the low end. I have driven both setups, it's noticeable.

The 3" front pipes were put on these trucks for exhaust volume since the muffler is so restrictive.
Click to expand...

I have the factory muffler and tailpipe laying in the garage so I will need to take a look at it. It was replaced with a Dynomax cat-back system. Dual 3" pipes coming in from the cats then Y-ing into a single 4" muffler and 4" tailpipe. Based on the "smaller pipes = more low end torque" my truck shouldn't be able to move at low RPM's:rolleyes:. Haven't towed my trailer yet but everyday driving I haven't noticed anything besides the sound.
 
6.2Blazer said:
I have the factory muffler and tailpipe laying in the garage so I will need to take a look at it. It was replaced with a Dynomax cat-back system. Dual 3" pipes coming in from the cats then Y-ing into a single 4" muffler and 4" tailpipe. Based on the "smaller pipes = more low end torque" my truck shouldn't be able to move at low RPM's:rolleyes:. Haven't towed my trailer yet but everyday driving I haven't noticed anything besides the sound.
Click to expand...


I was just going to order the dynomax system for my 2500 hd, is it a nice kit..? How does it look on there..? The flowmaster kit lasted me 3 years and was all rotted and fell apart, they warrantied it and that one lasted less. I had a shop do dual flomaster 50 series but i dont like it at all.
 
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