I just got finished installing an after market exhaust system form Gibson on my truck. (NOTE : my truck has a Volant cold air intake and ram air system , all transmission gear and motor oil is Royal Purple) I was lucky enough to have access to a dyno just up the road so early this AM we made three pulls for a baseline and got an average of 293 rear wheel horse power and 319ftlbs of torque , the exhaust system added 9hp and 14lbs ot torque with the computer set at factory spec reset the computer to performance and the power gain was another 21hp and 33lbs torque , the gain from the computer before the exhaust was only 18hp and 23lbs of torque so the exhause helps take advantage of the computer porgraming also. Thats a solid power gain from the exhaust only and any time you improved your power without adding fuel you gain milage !!
You guys might like to know that the after market Gibson exhaust I got is a direct replacement for the factory , istalled in less than 30 min after the old one was out , and its no louder in the cab than the factory system , well maybe a little bit if you stomp it , but at 40 , 60 and 80 mph cruse its no louder than factroy. I paid about $350 for the package with free shipping from Stillen , and it was delivered in about 8 days drop shipped from Gibson. I highly recomend the Volant cold air intake and ram air package with the Gibson exhaust that will give around 20 hp and increase your milage especialy at hwy speeds.
My truck is listed as having 310hp and 330lbs torque ( 05 5.3L ) and I'm pretty sure thats rated at the fly wheel of the engin and the the rear wheels. So as of right now my truck is making 323hp and 366ftlbs of torque at the rear wheels , its quite impressive to feel a truck with this kind of power at the rear wheel and still gets 20 mpg with the cruse set at 75mph with no traffic in front !!
Next is a set of JBA headers and they have proven to add 12-17hp and 15-30lbs of torque.
I have a 2007 Chev 2500HD Duramax (LBZ) Crewcab shortbox with a BullyDog upgrade. It gets a little better than 19mpg on the highway doing 65 to 70mph. I've got a little over 15,000 miles on it now and it is beginning to run a little better, less tight I guess. These truck engines (LBZ) are rated 360hp and mid 600ft/lbs torque factory with a three step hp increase setting with the BullyDog upgrade, ~ 40, 70 and 130.
The TripleDog PowerPup with Outlook is nice, I reprogrammed the speedometer to match the larger 285 BF Goodrich tires and really enjoy actually knowing how fast I'm traveling through the speed cameras.
I keep the system set on Performance rather than Tow/Haul (I don't haul or tow anything). I have put the Outlook in Extreme a few times but I'd need to train the Allison transmission at that power level, it is really too much power for me, sort of scary to drive like that.
Most folks that ride in the truck are very surprised at the thing, for a big pickup it really has proper performance. Merging into traffic is not a problem no matter the speed of the traffic. Driving on rain wet or snow/ice pavement is a bit of a challenge especially on hills (switching to 4-wheel drive helps a lot in these situations).
I haven't changed anything in the exhaust or intake area as I mostly wanted the speedometer reprogram option, I did install the exhaust gas temperature sensor as it came with the BullyDog kit. I figured that even with the near $1,000 I paid for the system it would save me much more than that if I got a speeding ticket (the traps and cameras are getting fairly numerous in the DC area).
Dave those Duramaxx trucks are awsome , I've got a friend that has a 4 door 4x4 2500HD , he got a bit more money than brains and has dumped ALOT of money into it , with 20" wheels and bigger tires lifter a bit all reworked suspension. He has a complete package with the intake , exhaust , computer and I think a new cooler , wehn it set for max performance and locked in 4 wheel drive it flat walks away from a GT mustang all the way through 120+mph !!! its amazing to see a 7000+lb truck accelerate that fast. He rarely runs in on max as when he does its not long before the U-joints need to be replaced and the cost of fuel is way higher than premium gas and it sucks it down.
I've got a built up 432 inch LT4 chevy small block that I'm threatening to put in my 1994 short wheel base Z71 hunting truck , its been built for about 6 yrs now and is just sitting in storage wanting to be run , the folks that built it estimate 500+hp on pump gas. I gotta do somthing with it as I'll never get close to my money back out of it.
Good post James! I've got a 5.3 in the Tahoe that should really do better for milage than it does(16 highway) Shoot my old 468 in the farm truck would get 20+ easy.
All the new advances in engines and such, there has got to be a way to easily improve the milage=It sure wasnt hard or all that cosly in the old days:o
Got any links to the parts you are talking about?
__________________ "Make everything as simple as possible, but not simpler." -Albert Einstein (1879-1955)
Some aftermarket products claim a 10-20% increase in fuel economy, but you will acually lose fuel economy with some of these. I buy into the cooler air theory, but more air = more fuel. Some of these filters also allow small dirt and dust particles to pass through, which means more headaches down the road. I've herd volant is the best and to stay away from K&N.
GET A DIESEL; U WILL LOVE IT!!!
I own an older model dodge diesel 2500 4x4 w/ manual trans. and get 18-20mpg in town and anywhere from 20-24mpg on the highway. If im pulling i still get around 18.5mpg(with the chip cranked up). stock i think the book said somthing like 245hp and 505ftlbs of torque. i think the chip adds like 150hp and 240ftlbs of torque cranked up. Also have a 5in. exaust. Beats the hell outta my old chevrolet; damn i loved that truck.