Just thought I'd post my non-scientific observations.
When i bought my CL bone stock i drove it lightly because it was new to me and all that so when I got my intake only, I started driving harder etc. I didn't know if the fun I was having was just because i was enjoying the sounds of my car more as i ventured into VTEC range more often of if I was just driving harder. I got my exhaust later and noticed a slight difference in the high end power and during the time I've had my car I've become very attuned to how it feels and how to drive it at limits. However since I added intake and exhaust at different times I really had no evidence other than slightly better gas mileage as to the performance gains of these additions.

Well, I sold both intake and exhaust on the same day and am now back to bone stock paper filter, intake resonator and exhaust. I have not changed my shift points or driving style really over the past two weeks and I can now safely say the following:

1. I have at least 5 mpg LESS gas mileage with stock. I've always set the trip meter when I top off. I consistently got 400 mi to a tank city/hwy combined. I just got around 350 the last tank and this tank doesn't seem to be lasting either.
2. I have slightly better low end tourque, which breaks the tires loose a little bit sooner than with I,E (never got headers).
3. My car is more sluggish in the upper RPM band when downshifting to or going WOT in VTEC range.
4. Car is definitly breathless in the higher RPM band.

So there you have it, may be old news but it's a close observation of the immediate differences between merely a rear section exhaust and a short ram intake.

It's worth it for the gas savings alone...
Peace all

 

Damn, I didn't know gas mileage could improve that much with intake/exhaust.

Do you think that taking out the resonator and putting a drop-in K&N filter would improve the gas mileage?

 

I think it would.
I'm just convinced now that I'll always be upgrading intakes on any vehicle I buy now...
My Cherokee already has a K&N and I'm going to modify the intake on that too now.

My car's not as fun as it used to be... Hope it's sold soon.

 

Another fun trick is to put your stock rims back on. I've had to do it twice due to rim damage before and it is amazing how much slower the car becomes and how much worse it corners, making it soomuch less fun to drive.