DamSedan

Hey guys,
I can say that I am an official owner at this point of an I35! None the less, I have been reading and checking up on things. I did not want to add this into the existing "What exhaust do you guys have?" thread however if a mod chooses to combine that is fine.

I just want to make sure I am understanding this correctly here. My understanding is that the exhaust layout goes as such:

exhaust manifold (header)
Y pipe
Mid pipe
Cat
Cat back

From past experience with NA cars I have found that they seem to get louder when the exhaust manifold is replaced with a true header. While I would like to get the extra hp, I can not deal with the noise level increase on this car. So, I am assuming that I can still swap out the Y pipe back right? Has anyone done this? (I am sure several have) How much louder did the car get? My goal is to end up with a set up that sounds no louder than say a stock 350z or G35... I have thought about doing the Catman as it seems quite a few of you have had good success with those and like them. But sound level is an issue this time around for me.

Thanks in advance.
Chris

n3985

iTrader: (36)

It's actually cat then cat back...as given by the name .

On the VQ35, the pre-cats on the headers are a major power robber, and simply replacing it will yield +20HP. You could also just get a y-pipe, but the gains won't be as big. Both will increase you exhaust noise by a lot, and even louder with an aftermarket cat-back system. Check out steven88's vid clips.

clayman88

iTrader: (1)

Check out this thread in the 5th gen forums. Theres a ton of different sound/video clips of all different types of exhaust setups:
http://forums.maxima.org/showthread.php?t=407975

Also, do some searches on YouTube for VQ30/35, cattman, frankencar..etc.

I can't find it at the moment, but somewhere theres a pic floating around the org that has each of the exhaust segments labeled.

leeI35

20+hp is a little high for just headers.

If you are going to replace the headers with hotshot headers or cattman headers than you will lose the pre-cats. Gains are significant but you will not have gain the maximum amount of HP unless you replace everything.

Just replacing the mid-pipe will yield a good amount of power than stock. If you want a decent setup with out the noise, just get the cat-back exhaust and mid-pipe. Remember, if you buy a y-pipe and then decide to buy headers, then you just wasted money because the headers come with the y-pipe.

With a mild tune with all of cattman parts underneath the car i dynoed at 234hp - 233tq in 90 degree weather. With more tuning and new race cat from cattman i am at 242hp-236tq.

DamSedan

I will be honest when I say that I am not out to crush the HP record hear. Just want it to sound a little better than it does now so perhaps the cat back set up may be the direction I take. My past two suby's were quite loud and had quite a bit more power. The Forester was making about 368 to the wheels and the 06 was sitting right at 299. But this car is more of a, well, nice car and I do not want it to be all about power and noise. But I would also like to know that the car is indeed running.

I will check out some of the clips and see what I can find. Thanks for the links.

Where do you live leeI35? I am out in Gaithersburg. I would love to link up some time and check out your car. PM me when you get a chance and maybe we can set something up in the next couple of weeks.

clayman88

iTrader: (1)

Why are you more concerned about sound rather than power? A louder exhaust doesn't make for a better driving experience, in fact...the exact opposite. More power is ALWAYS better and always makes driving more enjoyable.

leeI35

Sup DamSedan -

That's understandable. If I wanted high hp, I would have got an sti myself. (My cousin is running stage 3 setup on his).

Anyway, you are better off just getting the rear section done on the I35. Go for the cat-back and mid pipe to give it an almost G35 sound. To be quite frank, I could have just left my car like that without adding headers.

Oh and I am in the infamous pg county (LOL) upper marlboro, perrywood community to be exact. I wiil pm you.

DamSedan

As I stated before. I have had fast cars. I chose this car because I liked the lines and the refinement that some of my past cars did not have. I also bought this car so my wife would shut up. Not that she had her heart set on this one but anything that was not making so much noise at the unGodly hour I get up to go work out and head to work every morning.

I could not agree with you more in regards to more power adding to the driving experience. Also keep in mind the saying, "Power is nothing without control". Brakes are good too.

None the less, the by product of power is sound. Unfortunately I am not in the market to make much sound so there will be some power left on the table this time. That is a sacrifice I already made when I sold my Subaru! Please keep in mind that I am not downing this car. I would not have bought it if I did not like it. But if power is the name of the game then there are alot of other vehicles out there better suited for that task and that is just the facts. I really wanted to get a G35 but with twin 8 year olds and a 2 year old it just was not practical. So here I am.

I plan on doing the following as time goes on.
probably coilovers as I like being able to fine tune the ride height as well as dampening force/rebound.
18" wheels with some sort of polished lip
Intake, not sure which one just yet but stuck a KN drop in yesterday for now
Cat back most likely and maybe a high flow cat or headers and high flow cat with stock cat back. Just not sure.

After that it will just be cosmetic crap, like different lights and maybe some sort of front lip, grill and ...

leeI35, Suby's are nice and if I had the money and could get my hands on one I would seriously have considered doing the STI limited as it at least has leather and what not in it! Still rides stiff as hell out of the box though.

n3985

iTrader: (36)

If you have a K&N filter already, do the GAB mod, free and yields 4WHP and more sound.

NmexMAX

iTrader: (22)

I know I'm being meticulous, but it's actually 9whp. It has been proven by 3 different members.

2 manual transmissions, and 1 auto.

n3985

iTrader: (36)

Only a better reason to do a free mod then!

DamSedan

After trying the google search technique I found the GAB. I am liking the creativity but would think that you could get just as good of air flow if you were able to free up some of the flow right from the ram air duct if you will. The air would then be cooler instead of sucking in heated engine bay air. For now I am going to leave the box sealed and eventually just do some form of cai. I do not really want to drill a hole in my car however so I may consider creaing some form of intake myself. I still have a couple of cone filters at the house as well as some older intake pipes that I may try to cut up and create something. But for now the drop in is fine.

BTW, I am wondering what the next box thing is past the filter box in the intake stream. It is the one that has the vent hose going to it. I have not had the time to crack into this thing yet so I am just curious at this point. I notice that on some of the aftermarket intakes that this has been removed.

NmexMAX

iTrader: (22)

Helmholtz type resonator.

Not sure if you have an I35 or I30, but here are some mid pipe results for the 3.5L.

http://forums.maxima.org/showthread.php?t=376123

DamSedan

That was some good reading. BTW, I have an I35.

Please do not take this the wrong way guys. I find it hard to get excited about some of these HP numbers but that is largely due to my just coming out of a Subaru that made quite a bit more than what we are seeing here. None the less, my I35 is so much nicer than my past Suby's that I have had no regrets of dumping them thus far other than missing some boost a little here and there. But I have enough friends that I can bumb rides from if I get the itch.

I may try the GAB this weekend if time permits (ie the wife is out of the house for me to play) I may end up with just the Frankencar style and maybe their rear section exhaust as far as power type junk goes. Right now the car needs an fn rsb! That will be happening very soon I am afraid.

DamSedan

Now that we have switched this thread from exhaust to intake, I can see the proven hp gains from doing the GAB and it just seems odd that you can actually make more power sucking in warmer engine bay air. None the less, it is free and I have coat hangers at the house so why not give it a shot. Pretty cool actually. Maybe I am just stuck on my past turbo set ups where we are all focused on getting the coolest air possible flowing through it.