More gitty up?

robh2 · February 25, 2004

2004 2500HD Chevy, 6.0, auto 4x4. First, I am going to stay at 87octane! I did some research and found that the 6.0 and the 4L80E looses about 60hp and about 70 tq at the rear wheels, OUCH!

Is there anything out there that will tell me what add ons really work.

Alot of these companies claim more hp more tq but alot of times you get less. Its all confusing. I have spoken with Nelson, Westers and Hypertech. They all say you can get a little more out of the 6.0 at 87 but not alot I am looking for towing in the mountains power and keeping or gaining mpg.

160 thermostat- some say yes some say no, anything on paper? Biggest problem I have heard is double the engine wear with this one

Cold air intake- some say you lose tq and gain hp

Catback- again same as intake, some say good and bad

Programming- most bang for the buck but I hear alot of complaints about detonation/pinging

Does anyone have a similar setup to what I am looking at that is tried and true with dyno to back it up?

Thanks so much for your time.

Robert

Wingnut · February 25, 2004

Towing in the mountains?

Most of the things you list (a good tune is an exeption) have never impressed me all that much as far as noticeable gains. You want big gains? You have to spend big money. You want little gains?.....Nobody want's little gains, what am I thinking.

Go forced induction if you have the money.

Take the Whipple for example. 50% increase in power (claimed). It will not even dump until around 2000 rpms, so any driving below 2k rpms, you will get normal mileage, and a normal driving demeanor. Above that, and you get a big kick in the seat, and it will pull all d@mn day up that slope. Gas mileage will suffer at peak RPMs, but you are towing.

For about half the money of a S/C (if you are thrifty), you could go with port/polish on the heads, and full exhaust. Add a cam (and a new tune) to that, and you would probably be pretty impressed with the results...Oh, this scenario would be where a "high flow" intake system would actually help quite a bit.

That's my .02 anyway.

robh2 · February 27, 2004

Hey Wingnut--Thanks for the ideas. I am not real interested in tearing into the engine. I am more interested in bolt ons and plugins. A supercharger is way out of my pricerange. Thats why I have the 6.0 instead of the 8.1. I figured if I can keep my addons to about 1k and get back 30 or so hp and tq at least, that I will fell ok about it.

Anyone else have ideas?

Thanks,

Robert

WEEKEND WARRIOR · February 28, 2004

I'm with Wingnut.

As far as tunning goes I have had Hypertech and now have Westers, no comparrison. Although both with 93 octane use. The Hypertech 93 tune did help but not much. I don't think the 87 Hypertech tune would be noticeable. However it does work good for tire size recalibration ect. With Westers 93 tune my truck runs way better.

Thank you Lyndon

o4yukonxl · February 29, 2004

I have the 8.1 with the 4L85E trans. I will be doing some dyno testing next week and will post results. At the very least, I'll provide a comparison between stock and the Westers PCM I just installed. Stay tuned.

o4yukonxl · March 2, 2004

Check out my post in High Performance.

Durkin · March 2, 2004

Folks:

When I bought my 2003 Tahoe Z71, I knew that I would not be satisfied with the power of the stock 5.3 liter engine. Baseline stock dyno results run by AAA Muffler Auto Performance in Costa Mesa, CA at 90 MPH were: Rear wheel Horsepower = 207; Torque = 277 ft lbs; RPM = 3,950; the speed limiter was on, but we did not hit it. You loose a lot of power with a 4WD because of the transfer case.

After a few months, I started tinkering with the truck and added JBA shorty headers, a Flowmaster 40 cat-back exhaust with a single 3” side exhaust, MSD sparkplug wires, and a Predator tune. All of this got about 35 more RWHP measured on the dyno. Of all the mods, I think the Predator made the most difference and a lot of that was in the shift improvements.

See the rst of my story at: http://mct.truckmoxie.com/forums/topic.ten?id=68366

Hope this helps!

Regards,

Durkin

o4yukonxl · March 3, 2004

Durkin, nice Tahoe. I've gone the supercharger, nitrous, cam, heads, etc. route. This vehicle will stay "Stock" until I get the urge for more. I plan to get the new PCM from Westers and expect a realistic 10-20 RWHP and RWT increase which would put me at 410-420 lb ft of rear wheel torque and about 310 rwhp. All without supercharging! That's the advantage of 496 cubes. And I can't understand why GM does not put this package in the Tahoe. That would be one hauling machine.