I have the Stillen Cold Air box W/ Z Tube & Fast Intension Exhaust. I am debating my next mod. MREV2 & 5/16 spacer OR FI HFC. What are your opinions; & would like to hear some pros vs cons for both. Thank you!!!

 

get both FI HFC and MERV2 & 5/16 spacer


for better air flow in and out

 

Assuming you're rev-up, if you have to choose, you'll probably see the most out of the mrev/spacer combo. Check out motordyne's dyno:

http://motordyneengineering.com/imag...to-162-MPH.jpg

For comparison purposes, Crawford told me that their HFCs will give you roughly 5-6 hp/4-5 ft-lbs at the wheels, but that's mostly in the low to mid range. Don't know about the FI HFCs, but I'm assuming they produce similar gains.

One big con for HFCs (at least for the Crawfords) is that the heat shield on the cats (particularly on the drivers side) tends to bang against the frame. A lot of people (including myself) had to bend the heat shield to prevent this.

 

The MREV and spacer will give you more power for sure. The car will feel a lot nicer down low and through the midrange which the car doesn't have a lot of from the get go. My vote is for the MREV and 5/16" spacer, single best feeling mod I did to my car.

 

Thanks guys i have been leaning towards the MREV2 & spacer. ( yea i have a 05 6mt rev-up). Keep them comming.

 

+1 for spacer & MREV