I'm a new owner to a recently purchased '05 g35 sport coupe A/T with 21k miles and I'm looking to make some modifications to it in the future. These are my qualifications.
1. Best bang for buck (as I do not have too much cash to throw around)
2. Easily installable by either me or someone I have to pay. (so I'm not paying $500 to a shop)
3. Doesn't kill my gas mileage around town or on trips
4. Sounds good but not obnoxiously loud
5. HP and torque increase



I've been searching around these forums and the internet for about two weeks and this is what I've come up with.

1. New Intake - I've pretty much decided against the Nismo/Injen/AEM CAI system because I don't want to deal with the pain of cleaning/installing it and rain/water risk but if I'm totally wrong please correct me. I think I'm either going with the Stillen CAI + Z-tube or Z-tube/PopCharger. I've heard the Z-tube can be relatively quieter than the stock g35 tube b/c of the resonator in the stock. I don't want my car to sound like a mouse going down the road but I've heard great things about Stillen's combo. Can anyone elaborate on this between the two choices? I've heard Stillen CAI and Z-tube don't have to worry about as much heat loss but I want a good sound.

2. Plenum Spacers/Manifolds - I've looked at Motordyne's isothermal spacers and manifolds. I've heard they are one of the best bang for your buck upgrades for HP and torgue for a g35 but what is it going to do to my g35 and how difficult are these things to install. Should I go with just the plenum spacer or go ahead and get the MREV2 manifold along with it? What are both of these things going to do to my gas mileage?

3. New Exhaust - I had pretty much decided to wait for this upgrade till a little later because I want to get a nice exhaust system and they can get a little pricey and I don't mind the stock system. I like the TopSpeed Pro1 exhaust catback system's sound the best though. I guess my question here is what is a good not so pricey exhaust system that has a good but not obnoxious sound, good hp increase, but doesn't kill my gas mileage.

*Any other recommendations of mods would be great also.

If you can answer all or any of these questions I would greatly appreciate the advice and help. The forums here have already been such a great help in narrowing my search.

Thanks again.

 

The Stillen CAI intake/Z-Tube is a great addition but you still must clean the
giant K&N filter every 5K miles. Even if you just got the drop in K&N filter it
still needs to be cleaned. What ever your choice will still require some
maintance....no escape! You're correct about the Stilllen unit it doesn't have
any issues with heat soak which we all know kills HP. The MotorDyne spacer
is without a doubt the best bang for your $. If you take your time and have
the ability to use a torq wrench won't take more than an hour to install.
HKS and Stillen both make cat-back systems that not only sound good but
work in conjunction with the intake/spacer to make more HP....got to love
that! Keep an eye on our Marketplace for one of our members demoding
there coupes for a good deal on the exhaust system. The guys at Riverside
Infiniti have the above mentioned items in stock for sale 1-800-919-8130.
Good Luck....
Gary

 

Thanks a lot for the info, it sounds like I'll be going with the Stillen CAI + Z-tube combo. I have one question about the spacer though. I see on your car you have the 1/2". I read on the site that the engine cover does not fit on the g35 coupe. Would I be better off going with the 5/16" or getting another engine cover? Thanks.

 

i have an apexi y-pipe and exhaust system on mine and i love the exhaust notes and get compliments all the time. my buddy used to have a top speed system and it sounded aggressive but at the same time had alot of drone in the car and was loud enough where i could hear him from 3 blocks away.

 

Just get a 5/16 spacer, z-tube and a drop in filter. You will notice a huge improvement in your HP. I would get a Stillen intake right now.

 

1. Intake - Get the stillen Intake with the Z-Tube. Its what i have and have had no regrets. The sound is amazing! You will feel a difference between the shifts in an automatic when using the manual mode. It doesn't feel like the engine loses power at the top end like its running out of steam.

2. Plenum Spacer - Get the Motordyne 5/16" spacer. Again its what i have and install is relatively easy to do yourself as I did it myself.

3. Exhaust - I chose to stick with a mostly stock exhaust since i loooooove the stock exhaust sound. I did recently get the stock 350Z "HR" Y-pipe. Its the the Y-pipe at came off the 07-08 350Z HR motors. It is a different design from our stock y-pipe as they used mandrel bends and a different "y" shape. The bolt up fits perfect since its an OEM part. I also recently got the Crawford High-Flow catalytic converters. That itself is one of the most noticeable increases in power. The stock cats are VERY restrictive. Now my exhaust sounds like stock but much more aggressive. There's no rasp and absolutely no drone when driving or revving and the performance increase is night and day.

One other mod to take note of is the grounding Kit. The two I would recommend is the SentinetbyDesign kit found here: http://forums.nicoclub.com/zerothread?id=345479 or the Gordgee's Grounding Gear found here: http://groundinggear.com/. The difference is most notable in the 5AT G35's since the shifts are smoother and a faster response time. I went with the SentinentbyDesign kit and was amazed by the quality of his kits and his price. Definitely recommend his kit to save money for the same performance.

 

Quoted for truth. That is almost exactly what I have done with mine and I couldn't be happier.

One thing that I might point out - look into the SxExCx grounding wires sold by a guy here on Driver. His stuff is made specifically for our car so the lengths are custom made to be exactly right...and they even come in multiple colors to suit your particular style. Just my two cents. Good luck with the modding! My only other suggestion would be to stay involved and understand WHAT it is that you are putting on and why.