Guys,

I am looking for real world imput on this subject at hand. Here is the situation: Lets say money is not an object as far as EITHER getting an exhaust or the high flow cats to boost my performance a little bit. I realize that exhaust tone is subjective for all, but keeping the car NON forced induction, is the $1200 or so REALLY worth it? Or do I just say F it and go with a nice set of high flow cats from Kinetix or somebody? I heard a sound clip of a stock exhaust with HF cats on it and it sounded real good. I already know that my choice of exhausts, fast Intentions, sounds really good as well. Honestly, I could likely get the cats for $500, and the exhaust for $1200. Why not save the $700 for something else if the difference in HP from just cats to a true dual set up is little?

All opinions are welcomed....

Don

 

After doing all mods while trying to stay N/A, I would highly recommend not modding for power, unless you just save for FI. I would recommend doing styling mods rather than the bolt ons to try and squeeze minimal HP out of the VQ.

 

high flow cats and a y pipe will do lots for the stock exhaust (so says the guys at nismo)

 

hmmmmmm

 

high flow cats and the catback will yield about 20HP and 18TQ - that's all FI equipment.

The CATS and catback basically dyno out at the same gains - so you double either one with the second.

As far as the order of implementation - start with the catback and move forward...If your going FI - the better the flow the more go.

As far as NA - increasing exhaust flow, without substantially increasing intake as well, will only yield the dyno'd results. After my tests, the exhaust yielded even more power after intake mods, as it's complimentary intake mods allowed the entire car to work more efficiently.

If you going FI - wait on the intake mods - as your FI choice will likely handle it for you, unless you go Turbo. For turbo, you should do them anyway.

So it sounds like the choice is really, if you go FI, which one do you go with, and no matter what, you need/want the exhaust. Depending on the FI choice, your intake mods can then be determined.

Rick

 

Well, currently I have a K&N drop in with the Z-Tube and MD spacer, so my intake is slightly modded anyway, so I was figuring the exhaust and or cats would be next.

Leaning toward the cat-back for now. But $1200 is ALOT to spend on a system, that is not chump change for another 10-15 rwhp.....

Don

 

within this calender year i plan on high flow cats for sure. i am leaning toward crawford high flow cats b/c my friend at nismo says they should pass smog (but crawford must legally say its for off road use only).

ISMSOLUTIONS, will the FI HFCs pass smog here in cali? if so, then i will probably go with FI. the only reason im leaning toward crawford is because i dont want to deal with switching my cats every time i need a smog.

if the FI cats will pass smog then i will most likely get theirs because i have heard nothing but good in terms of quality from their products.

imo, i think you should do cats then exhaust.

 

toward the bottom of this page http://digitalwheelz.com/diy/exhaust/index.html there is a link for a sound clip of a g with stock exhaust and HFC (helix). IMO it sounds really good ... obviously keeps the stock sound while simply amplifying it slightly

 

That's why I am thinking about getting the Fast Intentions exhaust....it it close to stock decibel levels at the low RPMs and sounds real good at the higher RPMs. I never really heard the stock exhaust on a sound byte at high RPMs so I really don't have a barometer of the sound levels. I think the Fast Intentions is my choice for a catback right now.

 

If someone from Fast Intentions is on the boards; is it possible to pass smog with your HFC's. I know you can't cay for sure, but is it possible.

 

hmm..im hoping rick will chime in on this..

 

The answer you've been waiting for:

HFC's are for off-road use only...

HOWEVER -

In MY tests of the FI ceramic CATS - they pass the sniff test, but you'll never pass visual.

You will not pass visual with the Crawford's either, and not sure about sniff test on those.

Rick

 

^^^ interesting.thanks

 

if your choices are only one or the other, i vote hfc...

with a cat back exhaust you'll lose a good amount of low end power
yeah, you'll make some up in the mid to high end but...

with hfc, you really don't lose anything, you just gain throughout the whole range. plus it costs less and its more stealthy

 

I hear what you are saying techi13, that's why I originally posted this. If I could have saved the money, I will.

However, I would like to see some documented low end torque loss. I mean the 2004 has 270 torque, which is nothing to sneeze at, but the thing is kind of sluggish below 3000 rpms, I can't lie. I am also comparing this to the plethora of V8 Fords I have owned over the years, so maybe it's just me.

I see dynos from MANUFACTURERS that claim increases in both torque and horsepower, and tried to find reviews of certain exhausts, but I haven't had any luck as of yet. I know enough about the sound of the exhausts I have it narrowed down to. they are Stillen, Fast Intentions, and Nismo. Yes, I like them QUIET.....but powerful.....