Aerokitted

Right at around 2,800 to 2,900 RPM I'm getting this resonant vibration/rattling noise that I never felt/heard pre-bypass (stock). Mine's an 08 with 8K miles on it.

I had my indy take a look and he said it's not just the driver side door which I thought it was because if i pressed my elbow against it the overall noise would dissipate, but not completely eliminate the noises. The noise is also on the passenger side and in the rear area.

I can't and won't willfully take it to the P-car dealer because they're going to point straight at the bypass plus with the stock system there was zero noise of this type.

I'm not expecting Lexus quiet, but this added "feature" is unwelcome as it is not your normal seat belt rattling against the pillar, but more of a boomy, shakey effect. I also don't want to pay someone $1000 to go tearing up the car chasing after a noise that I can get rid of by uninstalling this aftermarket piece.

If I'm WOT, nothing because it passes that range so fast. It's your regular, on public roads type driving where it rears its ugly head. If I just stay right at 2800-2900, I can repeat it all day.

Anyone else experiencing a similar type of noise with their bypass units?

Thanks!

BBMGT3

With sport button on, some resonance can happen. My B-pillar buzzes from time to time, depending on the situation. But I am not sure that is because of the bypass or because of something else.

I will typically keep sport off while puttering around town or on sustained highway speeds.

Aerokitted

At that 2,800-900RPM at part throttle, it doesn't matter whether sport button is on or off. the valves are shut (i.e. in "quiet" mode). sport button on doesn't necessarily mean the valves are open. the ecu manipulates them according to speed and throttle by my observation.

if you rode in my car, you'd know it's not just straight up resonance. it's a bunch of rattling that's coming from all around the cabin. and i can replicate it at will.

thx for thinkin this thru with me

BBMGT3

Ok, next question - do you have ComfortSpec or ClupSport (cage etc)?

I had really weird screeching sounds coming from my dash, turned out to be loose stuff in the front bumper. (hard track day).

Why don't you try putting the old muffler on and see what happens? To rule out the source of the noise...

Who did you buy your bypass from?

tcsracing1

check you rearview mirror for vibration.

check your seat belt adjusters for vibration.

check your bi-pass exhaust clamps for loose fitment.

Aerokitted

no, it's completely stock besides the wheels, tires, and center exhaust.

i unfortunately don't have the time nor convenience to go swapping stuff out as i don't have a garage. i'm confident if i went to the stock exhaust the noises would be gone.

but it sounds like crap sans bypass so trying to avoid this route if at all possible

if you search my posts, you can find out what i'm rolling on - i just don't want to call it out until the final outcome. it's not like my car is malfunctioning - just really annoying and i'm fairly tolerant of rattles here and there esp ina car like this.

and guys, it's not just a rattle here and there. it's the entire cabin that's vibrating kinda noise. boooom buzzzzzzz at a specific RPM range or 2800-2900.

BBMGT3

Ok I know now which bypass you are rolling on...

In some cases, some users have complained of "boom" when using various bypasses. But rattle sounds wrong. Plus if you've got resonance you should be able to "cheat" by opening windows, cracking the sunroof or hell even opening your door (changes the natural frequency).

Sounds like something is loose. Has the car ever had an accident?

Aerokitted

when i open the windows, none of the boom/buzz (which is likely more accurate than calling it a rattle). that's why i thought it'd be a simple solution like insulating the door esp w/ the elbow move... turns out it's not as easy a target.

zippo accidents.

BBMGT3

Maybe the bypass fittings are not right. Maybe you can put something thick and "absorby" in the back "seat". I get buzzing when I have a passenger. Perfect excuse to drive solo lol.

I would have a mechanic who knows their gt3's ride along with you. He could probably pinpoint the source of the problem quite quickly.

tcsracing1

id put the car up on a ramp to inspect exhaust fittings.

Aerokitted

It's a harmonic noise, thus the reason why it only happens at a certain RPM.

I just got back from driving the car after they insulated the door panel and a lot of the boominess is now back like it was when stock. I'll have them finish it off and pick it up today.

So going to keep the bypass and about $400 lighter in the wallet!