What's new in the 2001 LS1?

[Gripenfelter]

What's new in the 2001 LS1?

The new 2001 LS1 benefits now from a revised intake manifold that flows
better than the 97-00 LS1s. Its the same intake manifold found on the new LS6 motors.

The new intake manifold features an increase in plenum volume. This was done by dropping the plenum floor as low
as allowed by the engine block valley cover. Also, sharp edges at the joint between intake runners and plenum
were smoothed down.

The result is 10 more hp and an undisclosed amount of torque.

Other changes were in the liners. For 99, the liners allowed an overbore of 0.010-in, something that wasn't possible
in the 97-98 LS1 motors.

Also new on the 2001 models is the reluctor wheel which is attached to the crank to trigger the crankshaft position
sensor which is now redesigned to enhance signal output.

After 1999 all engine bolts such as the cap screws had their threads heat-treated. This came about after the ASA
race series during 1999.

Also new for 2001 LS1s and LS6s are new cast iron exhaust manifolds that replace the previous double wall design.
The catalytic converters have also been moved upstream to right under the exhaust manifolds from their previous
location under the floor. The new cats are reffered to as "pup-cats" and are supposed to be more efficient while
freer flowing at the same time. No horsepower gains were listed though for the new exhaust setup.

So all and all, look for upto 15hp in the new 2001 LS1s!

I think I'll wait for the larger MAF sensor and revised PCM to make its appearance first which are expected to add
another 10-15hp along with other "tweaks" to the valvetrain which might feature lighter valves and springs with
higher seat pressure and an oval shape rather than the traditional round.