Oh man... if I had a 3.5 car garage, I'm 100% sure I wouldn't have my G. I'd have my wife's car, a reliable DD, and a toy that was just a toy.

Two girls here, too... 14 and 11. Very happy.

 

2.5" can be used for either in an NA or FI application. It is possible that you may net a few extra HP for the larger piping but don't put any sort of guarantee on that. Larger diameter piping will create more cabin drone when cruising at certain RPMs. Remember to keep that in mind when purchasing.

 

Also, I'd like to ask if anyone else has experienced an exhaust rattle with an aftermarket system that is similar to my scenario.

Current:
Fast Intentions RHFC
Fast Intentions CBE w/ X-pipe + no resonators
Mid-brace is REMOVED

I currently get a rattling noise around 3k RPM and it's +/- 100 RPM around the 3k RPM point. I've checked the shield around the mid pipe and it all seems to be nice and snug in place. Could it be my FI mufflers already? The system is less than a year old.

When I'm swapping my drive fluid this weekend or next week, I'll take a closer look at what may be causing the issue - just thought I pick the brains of all you geniuses here.

 

Did you check to make sure that all of your nuts and bolts are still tightened down?

 

I sure did, yes. Actually, I think I triple checked every single one - paranoia kicked in LOL. And something I noticed is that the noise takes place more often on a cold start and remains active when the car breaks 3k RPM. As it gets warmer, the rattle exists when give it a bit more throttle than regular "grandpa" driving. I'm starting to wonder if the heat shield is vibrating while it is cold and reduces the noise it makes as it gets heated up by the hot exhaust pipe? Just another thought.

I'll hop in the car while my buddy puts it up in the air and see if he can identify where the noise is coming from by being underneath the vehicle.

It's just a really embarrassing noise, TBH.

On a side note, I did find out I have a small leak between my FI RHFCs and my X-pipe. The new cats come with the Z1 metal gasket and I believe a regular 2-hole gasket - both of which have better reviews that the crap ones that I used for the install.

 

Check your heat shields and see if maybe one of them may have gotten bent and is vibrating against the body of the car.

 

Fingers are crossed that the heat shield is the culprit.

 

Dust shields behind the calipers can make all kinds of weird resonant noises when compromised. Worth a look.

No. Most aftermarket exhausts for this car have 2.5" pipes. And the OEM exhaust on the Coupe is closer to 2.5" than 2.25", IIRC. The wider pipes should (hope) give a deeper tone, and likely a few extra HP when tuned; but it also introduces in-cabin drone... hence the resonated cats, and 18" resonators on the catback; (knock on wood).

It's all pretty subjective, G37Xtreme. And qualifying the topic as a binary choice between what is "correct" or not is over-thinking things. I mean, you're right about having a large diameter exhaust with a custom FI setup. But in the context of bolt-on mods for a NA car, the difference between 2.25" and 2.5" doesn't really matter.

 

I'll check that out however I can produce the same noise by simply revving the motor.

 

I figured Either that or you had some pimpin' tractor you loved. You'll just be replacing strollers with bikes, scooters, and sports bags. I don't think it ever ends.

Thankfully my wife is A-OK at parking. She's got an end spot and can manage the hard 90 degree turn with no issue. Then again her QX has sensors front/rear and is pretty dummy proof. My buddy's wife struggles with getting her SUV into their 3 car garage. Granted it's got single doors on each bay but she's lost both side mirrors over the past 2 years even though it's a straight shot right up the driveway. Over 1K each on a Land Rover

 

With your girls ages, you're probably getting closer to getting that toy than me. My kids are 10, 6, & 4. I've got the 4 cars in my sig, but am strongly considering getting rid of my Miata. I love the go-cart feel, but I rarely drive it since it's only a two seater and the wife doesn't want the kids in it. She's obviously willing to sacrifice me in it though

I got the Q7 when we were pregnant with our 3rd and felt we had to have two large vehicles. I like it but find that I drive either the QX when all 5 of us go out or the G if it's me and less than 3 kids.

 

Had the same issue with just Berks and Tanabe axle back. It was a high pitched pinging raspy sound coming from the center... Embarrassing to say the least. So I bought a catback and upon installing I noticed some pebbles stuck between the center heat shield and the body. The noise is all be eliminated.

Is it safe to remove heat shields above mufflers and mid pipe?

 

That would be the coefficient of thermal expansion, or in this case, contraction. It's probably colder than when you had them installed. It's pretty accurate to figure a 1 psi change in air pressure for every 10°F of temperature change. I usually run 36 psi in the front and 34 in the rear because I love a taut ride.

BTW, Happy New Year everyone!

 

I will say that if I had the choice between paying cash for a car or financing it at a nice APR, I'll choose financing and using the bank's money any day of the week. The finance charge is negligible compared to what I can earn on my cash if I invest it. Yes that's a risk as well...but, it's pretty easy to get 8-10% returns by investing in safe investments.

I've played the lottery before and paid the tax because the elation of the idea of possibly winning overrides the reality of the math. But it's nice to dream for that short duration of time between the purchase of the ticket and the drawing.

 

Connor, does it sound like a pinging noise by chance? I'm experiencing that but only when I'm really getting on it...probably 70% throttle. It sounds like ball bearings in the cats or something metal reverberating like a heat shield somewhere. Need to have that checked out.