So I won't notice any low end torque loss, that's good. Will I notice any medium-high range gains? I was reading mixed reviews on zzperformance.com Some guys would say it throws you back in your seat more, others wouldn't, I heard the typical gains are 5-7HP, though some report gains as high 15, but that's the most. And does it give your car a better tone?

 

Correct me if im wrong, but...if anyone gained 5-15 HP, it is because they had other modifications to the engine already, and the new down pipe w/ a high flow cat allowed them to work closer to their full potential.

 

Then what are the expected gains of adding a 2.5 inch 304 stainless steel downpipe to a stock N/A 3800?

 

Peace of mind that your future mods will help you, and you will flow-better and have a slight increase in MPGs if you keep out of the gas. Also that you will have a higher quality pipe (if you get the 304) and in the future shouldn't have exhaust problems in that pipe.

Also if you couple it with a CAI your mpgs could see a good 1-2 mpg rise, and if you really really want an HP number... maybe 2? :P

You gotta start somewhere, you may not always feel it, but it's all part of the package.

 

If anyone says a downpipe change alone throws them back in their seats, they're leaving out an important piece of information:

A)they have a 600 horsepower engine with a stock downpipe

or

B)their cat was 99.9% plugged

Really, the gains from a downpipe, intake, underdrive pulleys, tstat, etc are all really small and barely noticeable to the average person.