6.0 Performance

SS Crew · November 19, 2004

I've got an '04 2500 crew with the 6.0 - what a dog that engine is! And the gas mileage sucks. I drove my friend's '04 Sub with the 5.3 and man, that thing was like a hot rod compared to my truck. I've inquired to some performance shops, they all say open up the the air box, open the exhaust.

Everyone I've talked to that has done the air box (either K&N or Volant) say the increase is either non noticeable or not worth the cost.

As for the exhaust, I kind of like it quiet and no one seems to know of a muffler that flows and is quiet. Flowmaster does not reccommend any of their mufflers for the 6.0 as the tend to resonate at cruising rpm.

I did pony up for the Hypertech unit - all that did was make the engine ping on the performance setting, and the only shift firmness I did get was when it shifts into fourth.

Any suggestions?

04-silver · November 19, 2004

I have almost the same truck except its an E/C.

What I have read on this forum and personally experienced, the MPG are not the greatest and 4.1 ratio isn't helping in that department.

If you want MPG and speed I think the SSR would be better but its going to be a beach pulling the fifth wheel or yard of gravel.

Sit back, relax and enjoy the ride, its a nice (work) truck.

John

Edit: my .02

1meanchevy · November 19, 2004

On the research I've done so far the list goes as follows:

Flowmaster = Agressive sound but restrictive which means loss of power. Inexpensive

Borla = A tad quieter but still loud, but increases power and torque. A tad pricey

Magnaflow = Even quieter but still sounds like a truck, also increase in power and torque. Reasonably priced

Corsa = Quietest of all, increase in power and torque. Very pricey

Thats about it. The rest of the companies aren't really worth mentioning because I have no knowledge of them and wouldn't want to give false info.

hope that helps.

SS Crew · November 19, 2004

I put a Magnaflow on my "99 with a 5.3 on reccommendations form many muffler shops (maybe there's a huge profit margin on those). It sounded okay, but it was at it's loudest at cruising range - 1800 to 2300 rpm. it drove me nuts, I had it removed and put on a Dynomax. I didn't notice any power increase with either muffler. I have reservations about using a Magnaflow product again. I've been reading threads in the performance section and it seems like custom programming in the hot ticket dollar to horsepower ratio.

RossT · November 19, 2004

You may want to drive a few other 6.0's, to see if maybee yours isn't out of line as far as perfomance. My 2003 kicks butt! I test drove many last summer before I bought mine and they were all awesome. I really haven't heard to many complaints on the forum about them either.

As far as mileage, I get 10-12 in the city and 13-16 on the highway with 3.73

apache sierra · November 19, 2004

I went the k&n drop in filter and the magna flow exhaust with the 4" exhaust single outlet. This combination seemed to help a little and the noise isn"t bad(no drone)at highway speed. You don't notice the sound until you run it up the rpm range a bit. The biggest gain was defenitaly the westers pcm. That change was night and day If you go that route you might want to do the other add ons first(exhaust etc.) That way they can program the pcm for the better breathing.

Kgry · November 19, 2004

Well first off, you have a crew cab HD. That's heavier than a Suburban 1500 (I think). So right there your losing MPG. The 4.10's will help a lot better than the 3.73's I have. Right now with my 04 1500 with only 1300 miles I'm only averaging 13.5 MPG, city.

Intake and exhaust will add about 2-3 MPG total, not much more.

mmayo · November 19, 2004

You'll get the biggest performance gain w/ a custom tune. I went with a Westers 93 hot tune & couldn't be happier. HUGE gain in performance over stock, even my wife can tell & its much faster than her tahoe w/ the 5.3.

builderpaul · November 19, 2004

Your truck is a dog because of torque managment. These fly by wire throttles are really bad since you can't get full throttle till 3000RPM. For the money you spend fooling around with the gismo of the month (KN Flowmaster etc) You can get proven results with a custom tune. Or, better yet, if you are semi literate you can get tuning software (hptunner)and do it yourself. The biggest gain in tuning is the elimination of TM. In other words it lets you use the power you paid for. As long as you retain the factory TM any thing you add for extra power is not going to show any gain, since the TM won't let you use the power you already have.