02 vette powertrain improvements
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Safety Car
Joined: Oct 2001
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From: Renaissance Festival TAZ the Wolfdog (R.I.P.)
02 vette powertrain improvements
This info was taken from http://www.chevrolet.com/corvette/
I know it's Z06, however there is interesting data which applies to the LS-1
"For the 2002 Z06, it would have been easy to rest on our laurels and be satisfied with what we had done in 2001," states Bill Nichols, powertrain vehicle system engineer for Corvette. "But that's not the nature of the Corvette Team. We're never satisfied with the status quo."
2002 LS6 IMPROVEMENTS
To take the 2002 LS6 past the 400-horsepower mark, a number of components were redesigned. To improve the flow of air into and through the engine and exhaust system, revisions to the air cleaner housing, the Mass Air Flow (MAF) sensor, the camshaft, and the emissions system were made. "The 2002 Z06 will accelerate from 0-60 mph in under 4 seconds. On a road course or a drag strip, it is now the quickest Vette we've ever produced," stated Dave Hill.
PUP Catalytic Converters Removed
In order to increase the exhaust flow out of the engine, the small catalytic converters in the LS6's takedown pipes — known as PUP converters because of their reduced size — were targeted for removal, leaving only the larger, primary under-floor converters further down the exhaust stream.
Removing the PUP converters reduced exhaust backpressure by 16 percent, from 15.2 to 12.7 inches of mercury. Removal of the PUP converters also represented a mass reduction of 2.2 kilograms (4.8 pounds).
Changes to the composition of the precious metals in the under-floor catalytic converters — the elements that turn most of the exhaust emissions into water vapor — enabled the removal of the smaller PUP converters. While the 2001 underfloor converter was a single "brick" design coated with a mixture of paladium and rodium, the 2002 converter is a dual "brick" design coated with paladium on the front brick, and a mixture of platinum and rodium on rear "brick". This combination allows sufficient aftertreatment of unburned exhaust gases with a minimum of volume to process the reaction.
High-Lift Camshaft
With the exhaust flow enabled, the camshaft was redesigned to allow the intake charge and exhaust gases to flow more quickly in and out of the combustion chambers. A new camshaft with higher-lift lobes increased maximum lift for the intake from 13.3 mm to 14.097 mm and 13.994 mm for the exhaust. The increased lift results in a 5% increase in air flow through the cylinder chamber.
The new LS6 camshaft is the highest total lift camshaft ever produced for a production Corvette small-block V-8.
BACK TO TOP
Hollow-Stem Valves
While the stems of last year's LS6 intake and exhaust valves were solid, the intake valve stems for the 2002 LS6 are hollow, while the stems of the '02 LS6 exhaust valves are filled with a liquid alloy of 78 percent potassium and 22 percent sodium. Since the exhaust valves operate at a much higher temperature than the intake valves, the liquid alloy enables better transference of heat from the exhaust valves to the valve guides and then to the engine coolant.
The new valves are also lighter than those they replace, with each valve weighing 23 grams (0.81 ounces) less than those of the 2001 LS6. The total mass of the valvetrain is reduced by 368 grams (0.81 pounds), which improves their ability to open quickly and close securely. Even with the new high-lift camshaft, the lighter valves maintain solid contact with the rocker arms during high-speed operation.
Low-Restriction Mass Air Flow (MAF) Sensor
Gridwork that had been used to smooth out air flow over the MAF sensor was removed, contributing to the overall 5 percent increase in air flow. MAF software in the new LS6 was recalibrated to read the air flow without the aid of the gridwork.
Low-Restriction Air Cleaner Housing
A new low-restriction air cleaner housing with a larger intake was designed, with the inlet on the top of the air cleaner housing expanded from 25.4 mm (1 inch) to 177.8 mm (7 inches). The larger opening allows more air to enter the intake, with air flow increased to 320 grams per second in the '02 LS6, up from 304 grams per second of air flow in the '01 LS6 — an improvement of approximately 5 percent. The air filter itself remains unchanged.
LS6 Clutch Improvements
The clutch was redesigned in the following ways to address the greater torque output of the new engine.
Clamp load has been increased seven percent, from 10,300 Newtons (2,316 lbs.) minimum to 11,000 Newtons (2,473 lbs.) minimum.
The damper assembly of the clutch-driven disc was redesigned, with the flange plate thickness increased by twenty percent, from 5 mm to 6 mm.
Damper springs were redesigned to increase wind-up rate, from 33 Newton-meters/degree to 35 Newton-meters/degree.
Premium alloy steel wires were used for the damper springs.
These changes should help ensure the long life and good performance of the LS6 clutch.
POWERTRAIN SUMMARY
2002 LS6 Specifications
OHV V-8, 5.7 liters (346 cid)
Power: 405 bhp @ 6,000 rpm
Torque: 400 lb-ft @ 4,800 rpm
Transmission: six-speed manual
Rear axle ratio: 3.42:1
Performance:
2002 Z06
2001 Z06
0 to 60 mph: Under 4 seconds
4.0 sec
Quarter-mile: 12.4 sec @ 116 mph
12.6 sec @ 114 mph
Top Speed: 171 mph (rev limited)
171 mph (rev limited)
I know it's Z06, however there is interesting data which applies to the LS-1
"For the 2002 Z06, it would have been easy to rest on our laurels and be satisfied with what we had done in 2001," states Bill Nichols, powertrain vehicle system engineer for Corvette. "But that's not the nature of the Corvette Team. We're never satisfied with the status quo."
2002 LS6 IMPROVEMENTS
To take the 2002 LS6 past the 400-horsepower mark, a number of components were redesigned. To improve the flow of air into and through the engine and exhaust system, revisions to the air cleaner housing, the Mass Air Flow (MAF) sensor, the camshaft, and the emissions system were made. "The 2002 Z06 will accelerate from 0-60 mph in under 4 seconds. On a road course or a drag strip, it is now the quickest Vette we've ever produced," stated Dave Hill.
PUP Catalytic Converters Removed
In order to increase the exhaust flow out of the engine, the small catalytic converters in the LS6's takedown pipes — known as PUP converters because of their reduced size — were targeted for removal, leaving only the larger, primary under-floor converters further down the exhaust stream.
Removing the PUP converters reduced exhaust backpressure by 16 percent, from 15.2 to 12.7 inches of mercury. Removal of the PUP converters also represented a mass reduction of 2.2 kilograms (4.8 pounds).
Changes to the composition of the precious metals in the under-floor catalytic converters — the elements that turn most of the exhaust emissions into water vapor — enabled the removal of the smaller PUP converters. While the 2001 underfloor converter was a single "brick" design coated with a mixture of paladium and rodium, the 2002 converter is a dual "brick" design coated with paladium on the front brick, and a mixture of platinum and rodium on rear "brick". This combination allows sufficient aftertreatment of unburned exhaust gases with a minimum of volume to process the reaction.
High-Lift Camshaft
With the exhaust flow enabled, the camshaft was redesigned to allow the intake charge and exhaust gases to flow more quickly in and out of the combustion chambers. A new camshaft with higher-lift lobes increased maximum lift for the intake from 13.3 mm to 14.097 mm and 13.994 mm for the exhaust. The increased lift results in a 5% increase in air flow through the cylinder chamber.
The new LS6 camshaft is the highest total lift camshaft ever produced for a production Corvette small-block V-8.
BACK TO TOP
Hollow-Stem Valves
While the stems of last year's LS6 intake and exhaust valves were solid, the intake valve stems for the 2002 LS6 are hollow, while the stems of the '02 LS6 exhaust valves are filled with a liquid alloy of 78 percent potassium and 22 percent sodium. Since the exhaust valves operate at a much higher temperature than the intake valves, the liquid alloy enables better transference of heat from the exhaust valves to the valve guides and then to the engine coolant.
The new valves are also lighter than those they replace, with each valve weighing 23 grams (0.81 ounces) less than those of the 2001 LS6. The total mass of the valvetrain is reduced by 368 grams (0.81 pounds), which improves their ability to open quickly and close securely. Even with the new high-lift camshaft, the lighter valves maintain solid contact with the rocker arms during high-speed operation.
Low-Restriction Mass Air Flow (MAF) Sensor
Gridwork that had been used to smooth out air flow over the MAF sensor was removed, contributing to the overall 5 percent increase in air flow. MAF software in the new LS6 was recalibrated to read the air flow without the aid of the gridwork.
Low-Restriction Air Cleaner Housing
A new low-restriction air cleaner housing with a larger intake was designed, with the inlet on the top of the air cleaner housing expanded from 25.4 mm (1 inch) to 177.8 mm (7 inches). The larger opening allows more air to enter the intake, with air flow increased to 320 grams per second in the '02 LS6, up from 304 grams per second of air flow in the '01 LS6 — an improvement of approximately 5 percent. The air filter itself remains unchanged.
LS6 Clutch Improvements
The clutch was redesigned in the following ways to address the greater torque output of the new engine.
Clamp load has been increased seven percent, from 10,300 Newtons (2,316 lbs.) minimum to 11,000 Newtons (2,473 lbs.) minimum.
The damper assembly of the clutch-driven disc was redesigned, with the flange plate thickness increased by twenty percent, from 5 mm to 6 mm.
Damper springs were redesigned to increase wind-up rate, from 33 Newton-meters/degree to 35 Newton-meters/degree.
Premium alloy steel wires were used for the damper springs.
These changes should help ensure the long life and good performance of the LS6 clutch.
POWERTRAIN SUMMARY
2002 LS6 Specifications
OHV V-8, 5.7 liters (346 cid)
Power: 405 bhp @ 6,000 rpm
Torque: 400 lb-ft @ 4,800 rpm
Transmission: six-speed manual
Rear axle ratio: 3.42:1
Performance:
2002 Z06
2001 Z06
0 to 60 mph: Under 4 seconds
4.0 sec
Quarter-mile: 12.4 sec @ 116 mph
12.6 sec @ 114 mph
Top Speed: 171 mph (rev limited)
171 mph (rev limited)
Thread Starter
Safety Car
Joined: Oct 2001
Posts: 4,026
Likes: 0
From: Renaissance Festival TAZ the Wolfdog (R.I.P.)
Re: 02 vette powertrain improvements (Mike Mercury)
I posted here because of the data showing the improvements and gains which others may want to do w/ their LS-1, e.g., pup removal decreased backpressure by 3" Hg which equates to 3 HP, etc.
[Modified by Steve02C5, 10:14 AM 2/10/2002]
[Modified by Steve02C5, 10:14 AM 2/10/2002]
Melting Slicks
Joined: Jun 2001
Posts: 2,565
Likes: 2
From: Chicagoland Illinois
Re: 02 vette powertrain improvements (Steve02C5)
Not necessarily...maybe more or less due to different cam etc in Z06...removing pups will violate the law and you may not be able to get approved if your area checks the smog/pollution EPA tests...
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Re: 02 vette powertrain improvements (silversport)
removing pups ... you may not be able to get approved if your area checks the smog/pollution EPA tests...
I would like to buy the 2002 Z06 exhaust; but the shipping is a killer. I just hope someday that a set comes available from a local owner.
