I'm in the market for a new H3. Ive been doing some research on what you current owners like and dislike. One of the big things Ive seen so far is the lack of power (I-5). Has anyone put on aftermarket parts such as a new air intake system, headers, cat-back exhaust, computer chip, etc? If so, did you find a noticeable difference it HP gains? Did those differences satisfy you with the lack of initial power? Thanks.

 

Do the BIG THREE! Cat back exhaust, intake, and a PCM tune....many of us here have and it wakes the I5 up quite nicely, increases drivability, perofrmance and mileage.

Search around for more specifics, if you still have questions, feel free to ask them.

 

Well I have an 07 with the 3.7 I-5. It's no rocket ship but it is adaquit. ( probably misspelled that) Anyway it really depends on what you want to do with it. Its an every day driver for me and I do some towing. When I tow I don't even notice the extra weight. But if I had known about the alfa I would have bought one. I bought mine on the spur of the moment without any research. The diference in mpg is negligible. The handling is going to be diferent between the 2.

 

Thank you. I figured most people would do the "Big Three." I would conservatively say the big three would give an extra 35HP or so. That is a pretty good boost to about 277HP.

 

I would be much more comfortable saying 25HP? From testing I know what the intaks will do, have some pretty good data on the mail order PCM tunes, and a CAT back by its lonesome does not really do squat...mabey 2-3HP. When you set the PCM tune for an intake and CAT back, they you get something.

 

You are probably correct. My figures are coming off my experiences with V-8s in sports cars. Probably less of an increase with an I-5. Even 25HP gain is good tho....242 to 267!

 

I don't know how these claims of gains from this combo has been documented. I mean, for 25 hp, would I want to go to the dyno twice (before and after) at $400 a pop. Probably not. Remember, this is 25 hp at the crank usually. I have spent thousands in my lifetime messing around with intake/exhaust and I have the ability to tune domestic PCM's. In the end, I don't think they get you enough for the money at all.

 

when you get a pcm tune do you have to run preium fuel?

 

That's a good question. I would say no because the I5 is not a high compression engine by modern standards, but you would have to ask your tuner.

 

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