Hello, I got my 2003 6MT Red Infiniti G35 Coupe 2 weeks ago and am wanting to update it so its not bone stock anymore. Yes I have read all 70 pages of the "What Mods to do to your G35 Coupe Thread"....

So the first mods i'm looking to do are the intake and MD spacer as that is what almost everybody suggests. For the intake I have a few questions. I was looking to get either the z-tube/JWT pop-charger combo or the Fujita intake. But as I read more and more some people say how the stock air box is the best performance way to go with an aftermarket filter like K&N

As for the "power loss" I will get with the pop charger or Fujita, nobody explains this...what power will you lose or is it even noticeable? I know the other thing about the Fujita intake is that it might suffer heat soak...

So basically i'm just looking for someone to elaborate a little bit on these few things...and possibly suggest future mods

Thanks for any Help!!

 

+1 for doing some research.

Can't really comment on the fujita or popcharger, though I know quite a few people do get the popcharger.

I purchased the Injen CAI and love it, the sound, and could feel a little more power in the higher RPM's. Just installed the MD 5/16" spacer yesterday and am also very satisfied.

 

I'm running ztube and popcharger and I love it, the sound is amazing. As far as power loss I don't really know if I ever felt a loss of power, the only thing is sometimes it may be a tiny bit sluggish in hot weather. But I am not looking to replace it anytime soon, the sound is amazing.

 

Yeah intakes sound cool but the powerloss comes from what is called heat soak (from my understanding) Spacer and z tube is a good call, but stick with a drop in filter like k&n as well

 

It isn't truly what is the definition of heat soak. Heat soak is just a term that has been applied to the phenomenon, but heat soak isn't the real name just fyi.

 

If I am not mistaken, heat soak is the term used for when the weather is considerably warm/hot and as the air goes through the intake system it stays warm and makes the car feel like it is running a bit sluggish. This occurs on all aftermarket intakes, that is why many say to stick with the stock box/ z-tube combo and getting a quality drop-in filter. Our cars run the most efficient with cooler air.

 

Warm Air Intake FTMFL....

Some of these short ram intakes that "dyno" their warm air intakes are showing misleading numbers. Especially when they dyno the car with the hood open and a big fan blowing on it.

Because we all drive with our hood open.... With the hood closed, these short ram intakes will suck in warm air.

So I would stick with the Stock intake. Since it's a closed system and takes in cold air from the grill area. Compared to short rams that suck in warm air under the hood.

 

Op, most if not all CAI's suffer from the metal tubing becoming hot, get a Z-tube. If you keep the stock air box, modify it so it actually works, the stock design is not that free flowing.

 

I always hear the same comments when people talk about intakes, "heat soak" and "std intake & filter" being the most common, heat soak is a recognised term, usually applied to turbo engines when stationary IE sitting in traffic turbos emit a lot more heat, and so tend to keep the under bonnet and pipework temps higher for longer until there is a decent amount of flow thought them to bring induction temps down.

However the same applies to a lesser degree in N/A engines, the std intake is a compromise of design to make the best of space available, filtration,and noise damping, it has damping chambers to cut induction noise, not good for air flow, and has a large filter area for low maintenance, it also has a reasonable cold air feed from the outside, but its not designed for performance as a pe requisite.

The best induction design is going to be a tube at least the same size as the throttle, with a filter of adequate size, with an internal intake design that does not cause turbulence, which is quite an important part of the design,
length does have a very small effect on torque, but its the area after the throttle body, and the design that will play the biggest part in torque, hence the plenum spacers etc.

Going back to the "heat soak" subject, the length of the intake and its material will play a small part in ability to absorb and retain heat, but the key is where and how much outside cold air it can pick up, so a short tube with the filter close to the engine, (as with most designs) will not perform as well as a longer design that takes its air source further from high engine temps,

But with a good cold air supply,both can perform well however i can hear the techys saying "are but if its longer and made of metal it will pick up and retain heat for longer etc, however you have to remember the same can be said of the inside of the metal tube, as it has a constant source of cold air cooling the inside as well.

I actually prefer a longer intake that can take its air from just above the bumper lower intake, so it has a constant cold air feed and is also shrouded from water.

 

I have the Injen CAI, a good designed intake IMO but should have been made out of plastic. You do notice the added performance on a cold start, but when the engine bay gets warm (and the intake) that extra power seems lost. I'm sure under hot conditions it still outperforms the stock intake but not by much. I was at the track last night and every time I stopped and let the engine cool the metallic piping was practically too hot to touch. Essentially, metal tubing does suck and if companies made these intakes out of plastic/carbon fiber they would perform better.

 

I hope the z tube/jwt popcharger combo is all I've read it to be

 

Everyone has an opinion....don't we? Motordynes 5/16" spacer is a very good first mod. I've had two intakes Stillens CAI/Z-Tube and never had issues losing power due to heat because it's made to prevent heat soak with composite plastic and enclosed K&N filter. After switching to my Fujita beautifully polished intake because it was pretty....LOL I did notice power loss on very warm days....but who cares when they look that good?
Gary

 

PM me if you are in Socal...I have the intake solution