Before you say it....yes, I know these have been discussed on the board. And yes I have searched for info. And yes I have listened on youtube, etc, etc. But I still have a dilemma deciding on one of these two exhaust.

From what I have found...

Power: I assume a few peak HP and Lb-ft increase with both. Not my reason for doing this. I don't believe any increase will be a noticeable difference from stock. But I do NOT want to LOSE anything at lower RPMs. I have not located before and after dyno's on either - but maybe my search wasn't deep enough? Is either known for a + or - in the power department at say...<3k rpms? I'm sure the increases are (usually) mid-to-high RPMs.
EDIT: well DUH! http://www.fastintentions.com/produc...yno%20copy.pdf
although this dyno comparison is from a G35 - and evidently an older version of the exhaust - at least it shows that it doesn't lose hp/tq in the low RPM range.

Size: Yes - it matters (in this case)! LOL. Ark is 2.5" while FI is 2.25". I'm stock - so the 'win' in this one IMO may be FI. I ASSUME that size is consistent from Y pipe thru mid to axle back - yes? Also - What is stock size? I think it is: 1.75" Y to 2.5" mid and muffler section. Is that correct? (lets leave exhaust finisher out of this conversation). Going back to the 'not wanted to lose low rpm power' statement - 2.25" may be better for that 'want'? But if stock mid-to-end is 2.5"...isn't FI smaller than stock? This all get so very complex....

Sound: This is reason #1 for the change from stock. I have never heard either of these in person. I've listened on youtube - but give me a break. Laptop speakers cannot convey the sound of either system. Are there DBA readings at various RPM's available? Interior sound measurements at idle, 60mph cruise, and WOT? I'm guessing not - but it doesn't hurt to ask (I've seen what is on both websites). The recordings would have to be consistent between stock, FI, and ARK to be of value. Also - very interested in the sound at 'normal' acceleration rates, normal throttle openings, etc. Most videos are of people who love to show WOT and high speed passes. Valuable - yes. But not what happens on the daily drive to/from work.

Quality: both seem to be good. I have not read anything unexpected. Neither are perfect - but then again, what is?

Design: Ark seems to have a more 'exotic' deign. They add an X pipe along with the 'dual-chamber' system/mufflers. FI has what looks like a muffler at about the mid-pipe area - unsure if that functions as an X, H, or neither? Does the more 'interesting' or 'complex' design create a more 'exotic' sound?

Price: no significant difference IMO.

Anyway...interested in comments and opinions on any/all of the above points. Ultimately I'd love to hear these systems in person. (Short story - when I was shopping for an exhaust for my (then new) '06 350Zr, I heard the NISMO exhaust in person - I was sold immediately - called Grapevine Nissan and had it ordered in an hour!)

Thanks in advance!

 

You'll be waiting a while for FI system since they build em as ordered or so I hear. I will eventually get FI cuz I've not heard anything but good things and you'll be supporting American workers.

 

i had the Ark and you WILL lose low end RPM. I say go with FI, Ark is great but i feel like for the sedan the 2.25 inch piping is preferable. i also highly recommend hearing both systems in person. in my opinion the ark sounds SOO nice but it is pretty darn loud. i recently got rid of it and put my OEM exhaust back on, and its like i drive a hybrid lol.

 

Out of curiosity - why did you remove the Ark? Too loud? End of Lease?

 

On the Fast Intentions....what is the function of the center canister? Resonator? Crossover?

http://www.fastintentions.com/images...7-image139.jpg

 

It was a little loud for my taste but mainly because i was trying to scrape up as much money as i could for new michelin pilot super sports. i really do miss the exhaust though..

 

That is the old mid pipe. They now have a X pipe. With either 18' or 12' resonators on the X pipe . I have the 18' on mine and love it. Im alos running there TPs and have no noise issues. Its kinda loud but I think it sounds amazing.

 

Very nice - any pics of the exhaust pre-installed - and post-installed?

 

Please let me know if I can assist you in any way with your Fast Intention needs.

Tony's shipping is sitting at a straight 15 weeks right now, but by ordering through me we have an agreement for ship time to be 5-7 weeks from when the Purchase Order is placed.

The catbacks for coupes come in different options. We have a standard magnaflow X pipe, or an upgraded Xpipe option.

For sound, we have resonator options of none, 12", or 18".

For cosmetic we offer Carbon Fiber mufflers and Polished SS, also offered in oval or round canisters.

Please don't hesitate to ask or inquire about any other questions you may have.

Thanks!
-Lance