2001 Silverado 2500 4x4 wants more power
Q: I own an 2001 Silverado 2500 4x4 with extended cab and 3.73:1 rearend. It's rated at 300 hp and 360 lb-ft of torque. While my truck has great power and performance, I note other GM models have this engine with higher power ratings (Sierra C3: 325 hp; Yukon Denali: 320 hp; and Escalade: 345 hp). Can you identify what GM has done to increase the power for these versions of the Vortec 6000 engine? I tow a 29-ft fifth-wheel trailer weighing 7700 lb, and while my truck seems to handle the job well, I wonder if there are some simple and relatively inexpensive things I can do to increase its power?

A: All the vehicles you've mentioned, with the exception of the Cadillac Escalade, utilize the Vortec 6000 LQ4 V-8 engine. The Caddy SUV is actually fitted with the Vortec HO 6000, option code LQ9, and uses a higher compression ratio, via a piston upgrade, which brings it up from the LQ4s 9.4:1 to a 10.0:1 ratio. This explains the significantly higher power rating of 345 hp at 5000 rpm. The Vortec LQ4 engines in the other 1/2-ton GM light-duty trucks, such as the Sierra and the Yukon, only have a slight horsepower variance. The plus or minus five horsepower is due to the different exhaust systems and air intake configurations in each model. Now here comes the tricky part. Your Silverado 2500 is considered a heavy-duty truck due to vehicle weight and therefore falls under certain federal regulations, one of them being the Transportation Equipment Noise Emission Controls. There was a problem with the Chevy and GMC 3/4- and 1-ton trucks equipped with the 6.0L V-8 engine producing excessive noise. Your truck's LQ4 engine actually had its potential horsepower downgraded. It now peaks at 300 hp at 4400 rpm because it was too noisy and would have failed the test pushing more horsepower at a higher rpm. According to the General Motors Engineering Communications Department, there were also driveability concerns involved with the decision, and the downgrade was accomplished through various means including the programming of the powertrain control module. One of the experts in GM performance reprogramming is Fastchip. You can log-on at www.fastchip.com or give them a call at 918/446-3019 for further details. You can pick up the K&N Generation II Fuel Injection Performance Kit to aid intake airflow for a few more horses. I also suggest not putting any money toward exhaust modifications on the 2500 series. The factory setup appears to have a good flow, and aftermarket performance systems are showing little or no advance in power.

 

Cool info!!!

 

interesting information, however a SS silverado or Escalade have more power cause they arn't considered "HD"? an HD truck w/ a comparable 6 litre has to be quieter? ever heard an F250 stupid duty powerstroke drive by? sounds like a school bus, so I question their whole myth. Reason why it has 300hp/360tq cause anything closer to 345hp could have stole a potential escalade sale.

 

diesels have a completely different set of rules to follow they are allowed to be noisier and pollute as much as they want, right now anyways.

It makes sense to me. Our trucks are pretty loud in stock form when compared to the others. I wouldnt doubt that they needed to quiet them down or something

 

I could have sworn even with all that black smoke they acutally pollute less. Is that true?

 

the particulate count in the diesel exhaust is higher...but the hydro-carbons and carbon-monoxide levels are less

 

So what is worse for the atmosphere?

 

Hydro-carbons and carbon-monoxide are what causes global warming.

 

I only wish my F-bodies would have come from the factory with an exhaust note like our Escalade!!! I am not sure if that is part of the noise test for the government, but GM really needs to get this exhaust note in the Vette!

Todd

 

There are federal guidelines on driveby noise levels of a certain decibel on stock vehicles. Then the aftermarket comes into play. Hence why you can barely hear the supercharger whine on Lightnings and Cobra's in stock form...but when you uncork them it sounds like a huge vacuum cleaner is coming down the street!

A stock Z06 catback sounds great!

But then you get people who think a K&N FIPK is too loud when full throttle. I love that sound!