Originally Posted by Colby 04

The LQ4 should have 300HP and 360lb/ft of torque(at the crank). I think the 4L80E has a "longer" 1st gear(2.48 gear) than the 4L60E(3.06 gear), so off the line won't be as good with the 4L80E, but the increase in torque with the new 6.0 should make up for that. I've heard the same, the 80E eats more horsepower.

Originally Posted by JBT

But why do GM rate the lq4 in the suburbans to 335hp then?

Originally Posted by 6.0caddy

i made 310 rwhp and 360 ft lbs to the wheel with stock LQ4 out of a 01 denali, with tune and no cats.

Originally Posted by Trucktrend.com

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.

Originally Posted by Colby 04

If I remember correctly, BigMike9009 purchased a 2001 engine/tranny.

So here's your answer:

Originally Posted by Trucktrend.com
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.

Originally Posted by Zick

http://forum.ls1truck.com/index.php?showtopic=4726