Why +20 HP on 3800SC in MY04?

Does anyone know why the MY04 GTP has 20 more HP than the MY97-MY03? I have asked around but did not get a real good answer.
MY03 = 240HP
MY04 = 260HP

Elfin magic ?

It's my understanding that the '04s breath better. The intake (probably air box) is supposed to be more efficient and the supercharger, being the next generation, flows better as well. There may even be improved exhaust piping as well.

Marc

Want the facts? The Series III L36 engine has a much larger TB and a more efficient blower ( by about 13% ). It has no U-bend in the exhaust. It has a much faster processor in the PCM which may allow it to optimize power better.

The results are:
The lower parasitic losses from the blower and the exhaust = more hp.
The lower air discharge temperature from the blower = more hp.
The larger TB allows more air in = more hp.
The powdered metal connecting rods = no more hp.

"The powdered metal connecting rods = no more hp."

Ah, but if we could pinstripe those rods . . .
- Ray
For whom there is no such thing as too much hp / tq - let alone "enough" . . .

Hello,

Maybe the '04's have changed, but IIRC...
L36 is non Super Charged
L67 is Super Charged

That would be correct...

Actually, that was a typo, it should have read L32, not L36. The L32 is the blown SeriesIII engine. There is no L36 ( or L67 ) anymore - both are obsolete. The base 3800 is now the L26. Sorry.

is the pulley still a 3.8" or is it a 3.6" ?

Oppss... I misspoke. I'm still stuck in the past. Fluid is correct on the engine designation.

Sorry,
Marc

I haven't measured one myself, but a couple people who attended an auto show not long ago did and said the pulley size was 3.8".

Also, I asked (over a year ago) one of Pontiac's Marketing managers how the new GTP would be making the extra 20 ponies and he mentioned that all they did was make the intake and exhaust more efficient. I asked about a smaller pulley and he said the L32 had the same size pulley as the L67 which would be 3.8".

Marc

My pulley measures 4" maximum diameter, about 3.8" across the belt area. I don't have a SeriesII pulley to measure.... :rolleyes:

I know the U-bend is gone and some things mentioned better exhaust flow, but apparently the extra 20hp is touted by Pontiac (at least in it's marketing literature) as being from the new GEN 5 Eaton S/C w/coated rotors and ported housing.

I wonder what it would take to modify our MY97-MY03 Supercharger to get the 20+ ponies. There will still be a slight fuel trim learn issue, but I like the idea of not having to overdrive the supercharger (small pulley) which would cause more heat to the intake air charge (could cause knock retard or detonation). I am wondering if the supercharger you mentioned above has lower heat transfer because of the coated rotors (or seals) that could be applied to the older supercharger? I am also wondering if they got just a little more boost beacause of better seals. The porting couldn't hurt, but that is a lot of ponies for porting an induction area (not the valve area). Can you tell me where you got the marketing information? Even better would be the coating specs. Unfortunatly, I have no powertrain contacts that work on the 3800 to find out.

The marketing materials I had gotten from my dealer. I don't have them anymore, since I bought my car a month and a half ago.

I'm no mechanic and am just beginning to learn this stuff...so I couldn't tell you whether the claims are correct or not. I know that when I was looking to buy, I knew the previous MYs were 240 hp and this one was 260 so I had also asked the guys at the dealership and they said it was because of the new generation supercharger. But maybe the info you are looking for might be available from Eaton's website or via an e-mail inquiry to them at:
http://www.automotive.eaton.com/product/engine_controls/supercharger.html

Thanks for the information Wayne!
Can anyone confirm the GTP used the M90 Eaton supercharger?

Sure, go here:
http://www.eatonsupercharger.com/gm/index.shtml