NOOB Here...Exhaust Question.

[Craig Brumley]

I’ve got an ‘04 G35 sedan; it’s my DD. I put a Stillen Z-Tube and K&N on it this weekend and I’m considering a cat-back. I’m leaning toward the Stillen Gen II. I don’t want the car to sound like a dragster, or like it’s got a fart-can. My main objective is better gas mileage. For folks with this system: is it loud? Did it improve your MPG?

Or does anyone have another system they like better?

Just so I don't sound too much like a "greenie", my other car is a modded Corvette, so I've got the big, loud carbon footprint thing covered.

Thanks!

[G_whizz]

Welcome to NICO!!

Nope...the Stillen will not rice out the G. It's a great exhaust. If you don't want to go as far as replacing the whole exhaust... just get a coupe mid-pipe. members who have done that are happy with the results.

[Sentientbydesign]

The coupe mid-pipe that Sean suggested will make the Sedan sound much nicer. I don't think it will do much for your fuel economy.

The Stillen exhaust MAY improve your gas bill, but I think most of our members can't keep their foot off the floor when they get an exhaust, so that doesn't help much.

Things that will help your fuel economy:

Radiator Fan upgrade- Most of the 03/04 sedans here on NICO have mechanical fans instead of electric fans. Pop your hood and see if your fan is being driven by a belt or a wire. Switching should greatly improve things.

Lightweight Pulleys- Unorthodox Racing makes stock diameter, lightweight pulleys that reduce rotating weight by 4 lbs X oz. This should do something to your gas bill too.

Grounding Kit- This is a shameless plug on my part. I can't personally attest to the fuel savings from having the grounding kit on, but a couple of other companies claim that it exists and since my kits are some of the highest quality made, I would say they should improve fuel economy too. Testing will commence once my new engine is broken in.

Lightweight Rims and Tires- Kind of self explanatory.

Good luck on your modding and WELCOME TO NICO!!!

[superchargedg]

The Stillen exhaust is a nice addition for a sedan as it sounds real good and dosent resonate at all.

[SVTCOBRA]

I did the mid-pipe that G is talking about on my 05 G35 sedan.I was very pleased with the slight increase in sound and +1 MPG even when 'flogging' it. I believe that I've heard that on the 03/04 there is an even bigger bang for the buck.

Here is what it sounded like on my 05 sedan. I say sounded cause I recently traded this one for a coupe. And welcome to NICO!!!

http://www.youtube.com/watch?v=NIF-GD-WaH8

[Craig Brumley]

I appreciate the responses. I will look into the mid-pipe. Is there a supplier that offers a kit that finishes out the exhaust, aft of the mid-pipe, in case I decide to do the remainder?

I don’t know what to think of the grounding kits. I understand that low resistance grounding is a good thing. It just surprises me that Nissan/Infiniti would skimp on this issue. There must be something to it as several after-marketers offer them. I don’t know about performance, but resistance is heat, and heat is wear, and wear is bad, so it seems like a good, low cost, insurance policy.

The intake manifold spacer: is this performance mod concept similar to a carb spacer? Extra mixing volume, cooler fuel/air mixture? Lots of folks here show this mod, is it worth the cost and effort?

Has anyone done the Stillen transmission valve body mod? My biggest complaint about the car is that when I get to really abusing it, the auto trans seems to loose its mind a bit, delays the downshift, then skips two gears, slipping the whole way; it can’t be good for it. The mod ain’t cheap, and it would certainly void my warranty, but it seems like it would prolong the transmission’s life.

Lots of questions here, any helpful knowledge and experience is appreciated.

[Sentientbydesign]

The Plenum spacers do two things. They increase the volume of air inside the plenum, but they also fix the slanted upper plenum that Infiniti/Nissan designed.

The slanted design essentially starved the front 2 cylinders of air. Adding the spacer sort of fixes that situation. I think it's good for 15 or so HP in the mid range depending on which engine/plenum you have.

Car manufacturers are shoving tons of electronics (read sensors) into cars, but provide poor grounding. So the sensors have the chassis to use as a return path. The grounding kits fix that situation. Including your hunt and peck transmission. The 4th gen maximas had a similar issue. When you slowed down to say a stop sign, but didn't come to a complete stop, they would stay in 2nd or 3rd gear and you'd have to floor it in order to get it to downshift. Grounding wires fixed that problem

I know I sound like I'm making a sales pitch, but honestly...I wouldn't have these on my car if I didn't know they worked.

The transmission valve job would be more suited if you were going to be boosting your G.

[tollboothwilley]

I appreciate the responses. I will look into the mid-pipe. Is there a supplier that offers a kit that finishes out the exhaust, aft of the mid-pipe, in case I decide to do the remainder?

Yes, you can get an HKS axle back like I did, (and i love the increase deep sound), or you can just get the stillen axle back as well.

You can buy the Y-pipe, high flow cats, and headers as well. Just depends on how you want to "finish" the exhaust.

[Craig Brumley]

I ended up buying the intermediate pipe this morning from the dealership; got it for $310 out the door. I put it on when I got home; took about an hour.

It's got a low growl to it now, not unpleasant. I couldn't feel any noticable power increase, hoping to see some improvement at the gas pump.

Now what do I do with this extra pipe with the big honkin' resonator on it?!

I ordered the Blox spacer yesterday; once that's on I'll look into the grounding kit. That'll be it for a while. Guess it's time to create a sig.