3.5 Altima Sedan Exhuast

[zmayhew3]

Hey guys. Noob to the site, but not to Nissans.

I have a 2011 Altima 3.5 Sedan. K&N Typhoon CAI is the only mod I've done so far. I have a Y pipe from RacingLine on the way and while it's at the shop having that installed I'd like to do something cat-back at the same time. I'm looking for suggestions on what to do. I'm leaning towards having a muffler shop custom bend 3 inch pipes from the cat to whatever muffler tips I want.

I'd rather not spend $900 on Borla or Magnaflow and still end up with 2 or 2.5 inch pipes.

Any suggestions?

[sprocketser]

I would take it to an Exhaust Shop & have a custom made catback built . But I guess the RL Y_Pipe is 2 1/2 inch diameter already , I would go with 2.5 for the back also .

[zmayhew3]

Thanks for the advice. Y pipe came in the mail today. I'll be putting that on myself since I've realized how easy it is. Then I think it's off to the muffler shop as soon as the tips come in.

I don't even know where to go from there. Maybe a little 1 inch drop? Nothing crazy.

[sprocketser]

Great man , is it installed yet !

[zmayhew3]

Sure is. May have lost a little in the bottom end but the mid to high RPM increases are ridiculously noticeable. I was expecting it to be a little louder since my exhaust is still stock, but it's not. It might even be a little more smooth and quiet. Great bang for your buck. Installation wasn't too bad either, especially since I'm a noob when it comes to doing the work for myself. Next is exhaust, then a tune.

[sprocketser]

Cool .

[CoupeVQ35CVT]

Unless you're planning turbo and MT swap, stick to 2.5" exhaust. Any bigger and you'll just lose power and especially at the lower everyday driving RPM's.

You should look around the 'tube for exhaust videos, as there are a LOT of great ones to give you inspiration and ideas, including a few videos of my car with an ebay one, the y-pipe, and Borla.

Personally I have NOT noticed a damn bit in power increase, and verified it when I went up against a stock 3.5 coupe a couple years back (I had the 2.5" catback and y-pipe) and he and I were dead even till MAYBE past 80 mph which personally makes no sense to me but whatever hehe.

Aside from that, A LOT of the exhaust on youtube sound way meaner than they really tend to be. My $175 Ebay catback unit was much more louder and aggressive sounding overall (not THAT loud but you get the meaning) than my current $700 Borla axleback, which sounds a bit too tame compared to just about every single Altima+Borla video on youtube. Had I known this before I'd have gone with some other Magnaflow, etc. custom setup for a 1/3 of the price.

With that said, I might sound pessimistic or Debby Downer, but I still love the car and the exhaust setup was worth it as my car does still sound different compared to keeping it stock, at the very least.

One more thing I do have yet to try is an intake. Maybe that may work better with my exhaust work and free up some actual noticeable power? Don't know.

Oh, the Bulldog GT is something you should check out if it's still sold for the 3.5 coupe. Ranga14 had that along with intake/exhaust mods and he was definitely walking my car every time we went at it.

[zmayhew3]

I've already done it. But there's a problem: I'm running a K&N Typhoon CAI, RacingLine Y pipe, and custom 2.5 inch cat-back to some cheap tips I bought on eBay. The problem is it is loud as hell, and the droning is killing me. I've only had it installed 4 days and some people say it will mellow out as CO2 builds up. What I can say good is that there has been a much noticeable increase in HP and I love the acceleration. I think the reason you may not be noticing your changes is because of the CVT (if that's what you have).

I'm going to wait for my warranty to be up before I mess with any kind of tune, but I was leaning towards the UpRev direction on that. I think it will really all come together once that is done.

Thanks for the response. Any suggestions on tips for the sound issue? Where do you guys live? I'd love to drive out there one day and get on a track with you guys.

[CoupeVQ35CVT]

Ranga14 and I are in the DFW area. And yes I have a CVT, but the power increase SHOULD still happen (it's not like the CVT should swallow any extra power, it just has more parasitic loss than an 6MT, hehe).

As for the drone, and any rasp at high RPM, a resonator will usually fix that for the most part. It'll usually make the drone a bit more tolerable and also get rid of any rice-can type rasp but also turn down the loudness overall.

How big of a resonator you want is up to you. Too big and you can't hear your exhaust as well as you want, and you get this weird paper-fluttering/fart after-effect when you let off. Not big enough and well, it's not enough to make the drone settle down enough. I believe something between 16-20" long for a resonator should be all you need (and 2.5" in / out to match your piping). Just have it put in anywhere after the y-pipe.

Drone also depends on the muffler. My ebay system had a large ~20" resonator, but this Borla setup I have now doesn't. The drone is a bit more because of that, but not bad.

I'm assuming you're getting this drone upon normal acceleration (1500-2000 RPM?) and some highway driving/under load?

Also, exhaust sound clip nao!

[zmayhew3]

I think you misunderstood me about the CVT comment. I meant that the transmission is so smooth, it's hard to notice a 10-15 HP gain.

The drone is only under load, and only between 2,000-3,000 rpm, which happens to be 90% of daily driving. Either it's mellowing out or I'm getting used to it. It's not raspy, I love the actual tone of it, it's just loud. I'm going to give it some time and think about a resonator.

I'll work on some exhaust clips and I need to upload some pics too. In the meantime, I'm thinking of the Eibach Pro kit.

[CoupeVQ35CVT]

Hmm, you're right, the CVT does not have that shift kick so perhaps that's one reason why subtle power changes are unnoticeable. However the head to head race showed me that we were pretty much even otherwise, so maybe a tune is needed to really bring out the aftermarket exhaust's advantages.

[zmayhew3]

Update: it has definitely mellowed out some. It's still a bit more than I anticipated, but I'll get used to it. And since the few mods I've done I'm actually averaging 25.4 MPG versus the stock 24.2 before. So that's a nice little kicker. I'm guessing it's the intake responsible for that and not the Y pipe or the exhaust.

[CoupeVQ35CVT]

Everywhere I've read, most have come to the conclusion that intakes of any kind don't add MPG. If anything, you have more air and oxygen going in so you are likely to burn more fuel (and a bit more power because of it) which means less MPG. But the gains/losses are so small for any given engine that you will most likely not notice the power, but might notice the MPG with hard numbers if you drive insanely consistently before and after and keep track every time. With that said I experience as much as 20-40 miles per tank of delta every time I fill up, just week to week, season to season. So really, it's almost impossible to scientifically prove if you're gaining/losing anything useful at all.

As such, I've put off doing any more aspiration mods, though I'm still kind of debating spending $200 on a tube and filter just to try it out once on my VQ.

Let us get some sound clips, at least these sorts of mods are good for that.

[Pitbullschicago]

Got my catback from topspeed pro 1 for $350 shipped and it sounds better than anything else on the market to me...