Since I am very new to this, I thought I would lobby the crowd to see what they thought.

I have a 2006 SS 2-door automatic.

I was thinking about getting these 4 upgrades but curious to see what results I would get as far as Horsepower increases and Gas Mileage effecting.

1) A New K & M air filter for about 50 bux

2) GM's Cold Air Kit

3) Cat-Back Exhaust System

4) Extrude Honed Exhaust Manifold

Thanks for your help guys!

 

If you're going to get "2)" don't waste your money on "1)". Everyone's estimate is that with the 3 GM additions you listed above you will free up around 20 WHP. If you have the money go for it and enjoy the ride!

 

Any idea on how this will affect my gas mileage?

 

I think you might get 2-3 more mpg with the above changes - if you don't put your foot in it all the time.

Instead of the gmpp manifold, I went with the cobalt Addiction header. It's only $199 now, while supplies last (not a commercial, but the deal is limited to stock on hand). The engine runs much smoother too. They claim a 8-10 WHP increase on a stock 2.4 for this stainless, equal length shorty that bolts right up.

One other thing I would add - after you get the above mentioned mods - is a Wester's tune. You can tell them if you want more performance, more mileage or somewhere in between. I went strictly performance and I noticed my mileage increased slightly as well. I can't imagine what a strictly mileage tune would do. BTW, they will tune your auto trans too!

 

I thing 20hp is on the high side. Extrdue honed manifold and GM exhaust don't do much at all for hp. IMO, anyhow.

I would agree your gas m9ileage should rise. Westers did nothing for my gas mileage---I keep track and it was the same.

 

20 whp is on the high side. id say 15-17 whp

 

I was getting 25-27mpg for my daily commute. Now I get 27-29mpg (this is before the header which I just installed - too soon to tell anything from it yet). The mileage comparison is according to my DIC, which I reset with every tank. Maybe the slight mileage increase I noticed is due to transmission tuning rather than engine tuning. I guess they do more for us auto guys than you 5sp guys.

 

my bad I did not see you were auto. I too, think a tune is of more benefit to an automatic.

 

Agreed,btw if you want real gains jbp is comming out with cams for the 2.4

 

With just the GMPP intake I saw no particular improvement. I'm interested to see if the exhaust does anything. Headers may be next.

 

uh never mind

 

Jonel,our site admin dynoed the exaust at 14hp on the ss/sc so maybe on a ss/na maybe 8-9hp