Question about the +5 Stock Horsepower in 2001

**slimjim1284** · 11-09-2011, 10:10 AM

Hello all,

I am considering purchasing a 99 Trans Am and my question is "What is it exactly that gives the Trans Am/Camaro 5 more horsepower in the year 2001, and is it a mod that I can easily do myself to upgrade a 99 LS1?

Thank you in advance
-James

**WS6SP33D** · 11-09-2011, 10:19 AM

LS6 intake is the only real hp difference in the cars you posted. Which gives a little more than 5hp. On most upgrades when we dyno before (baseline) and after a LS6 intake over the LS1 intake it is around 9 hp on a lid only car.

**2002ssslp** · 11-09-2011, 10:19 AM

If you have ever seen a dyno sheet you can see the HP and TQ numbers change with each and every RPM. They probably rated one year at 4500 rpm and the next year at 4550 rpm. I do not think they changed any parts to gain the 5 hp. If I am wrong please let me know.

***SMWS6TA*** · 11-09-2011, 10:21 AM

I'd normally say welcome but I see you've been here for a while, just not posting.

You need to read this thread, it will let you know the differences between the yrs.

http://www.ls1.com/forums/f6/differe...y-years-27512/

The Hp numbers that were put out by GM were deliberately under rated because GM didn't want it to hurt their Corvette sales during those yrs. Many articles on the web about this subject.

The differences that I think you are looking for are in the thread above.

***SMWS6TA*** · 11-09-2011, 10:23 AM

Now if your looking at the 2 cars and trying to figure out which one to get, I myself would favor the 01 over the 99. but that depends on the condition of the cars.

**slimjim1284** · 11-09-2011, 10:53 AM

Cars for Sale: 1999 Pontiac Firebird Trans Am in Cumberland, RI 02864: Coupe Details - 307409231 - AutoTrader.com

Here is the link for the car. You can see how it has the ram air hood, does that necessarilly mean that it is a WS6?

**BrownsMillsAntz** · 11-10-2011, 03:29 AM

I would get a 99 up...intake is a pretty simple mod to make up the 01-02 differance...but any year LS1 is fine...

**Spaz** · 11-10-2011, 11:37 AM

Originally Posted by 2002ssslp

If you have ever seen a dyno sheet you can see the HP and TQ numbers change with each and every RPM. They probably rated one year at 4500 rpm and the next year at 4550 rpm. I do not think they changed any parts to gain the 5 hp. If I am wrong please let me know.

i doubt it... they'd go with the highest number hp rather than the rpm...

to the OP all years performance numbers are very close to each other... obviously the later year will be a better option (more time to get things right)...

**Spaz** · 11-10-2011, 11:39 AM

Originally Posted by slimjim1284

Cars for Sale: 1999 Pontiac Firebird Trans Am in Cumberland, RI 02864: Coupe Details - 307409231 - AutoTrader.com

Here is the link for the car. You can see how it has the ram air hood, does that necessarilly mean that it is a WS6?

nope... anyone can install a ram air hood... look on the drivers door for the code list sticker and look for "WS6"... (if i remember right)

**Firebirdjones** · 11-10-2011, 12:01 PM

There were 2 major changes made to the 01-02 Fbodies. The LS6 intake as mentioned above became standard, as well as the LQ4 truck camshaft being used in 01-02. It's a smaller camshaft (about ~.470 lift) compared to the previous 98-00 camshafts used in the F-body (~.500 lift).

The intake was an improvement but the camshaft was a trade off. Still somehow GM thought it necessary to boost the HP rating a tad. I'd bet the smaller camshaft probably gave a better torque curve.

Worth mentioning too, the exhaust manifolds were a better flowing design in 01-02, and the cylinder heads (the 241's) used on the 01-02 models were also introduced, and are said to be slightly better than the previous 851 castings used on previous years.

To most none of this matter anyway because alot of these things are swapped for aftermarket parts. It's up to you...

**WS6SP33D** · 11-10-2011, 12:37 PM

Here is the link for the car. You can see how it has the ram air hood, does that necessarilly mean that it is a WS6?

Just because the car has a ws6 hood does not mean it is a ws6. However the center caps also have ws6 so chances are better. It very easy to look at the sticker in the door jam and check for the ws6 code.