Finally got rid of an annoying rasping sound!!

[diegorst]

Hello guys, I wanted to see if anyone else can relate to what I encountered with my 1M.
To give you a little background these are the mods I have on my car that could've had an effect on my problem:
- Evolve-R Tune
- AR Design downpipes
- Akra Slip-On with CF Tips + Wireless Kit
- Maddad Midpipe

So this started last year a little bit after I installed my Akra slip-on exhaust, I did't get the whole evolution system because I was already using the MadDad mid pipe with the stock exhaust and I simply loved that sound.
So a few months after I installed the Akra, I started getting a really annoying metallic rasping sound coming from the back. This happened only when I accelerated suddenly from low speed or if a low gear was engaged and I started accelerating, and this only happened for a small range of time during the acceleration.
I thought it could be something to do with the differential or the drive shaft, I was going nuts!
Anyway, a few months ago I installed a set of AR design downpipes and upgraded my Evolve tune. After this, the noise remained constant but more pronounced and louder if I had my Akra valve open.
So finally last week, the guys at the shop where I do all my installations, recommended that I try to switch my MadDad midpipe back to the stock one because it could be due to some resonating factor in the geometry of the different parts I had matched together.
To make the story short, today I went to the shop to pick up my car and the freaking rasping metallic sound is gone!!! I'm really happy that it's finally gone (it was REALLY annoying!!) but on the other hand I'm bummed out that I can't use my MadDad midpipe anymore and I feel the sound has been muffled a bit too much with the stock midpipe. I still have to drive it more to see how much this change has affected the sound.
Has anyone encountered a noise or situation like this?
Any ideas on what to do next? Find an N55 midpipe? It's going to be really tough to get an Akra midpipe, I believe they didn't sell it as a standalone, only in the Evolution system (Akra midpipe and Akra slip-on exhaust).

[diegorst]

I had the guys at the shop check that it was installed correctly before I swapped it back to the original one.

[1'M Blue]

Maybe its from the exhausts tips hitting the on the diffuser .

[dEvo6]

Originally Posted by diegorst

Hello guys, I wanted to see if anyone else can relate to what I encountered with my 1M.
To give you a little background these are the mods I have on my car that could've had an effect on my problem:
- Evolve-R Tune
- AR Design downpipes
- Akra Slip-On with CF Tips + Wireless Kit
- Maddad Midpipe

So this started last year a little bit after I installed my Akra slip-on exhaust, I did't get the whole evolution system because I was already using the MadDad mid pipe with the stock exhaust and I simply loved that sound.
So a few months after I installed the Akra, I started getting a really annoying metallic rasping sound coming from the back. This happened only when I accelerated suddenly from low speed or if a low gear was engaged and I started accelerating, and this only happened for a small range of time during the acceleration.
I thought it could be something to do with the differential or the drive shaft, I was going nuts!
Anyway, a few months ago I installed a set of AR design downpipes and upgraded my Evolve tune. After this, the noise remained constant but more pronounced and louder if I had my Akra valve open.
So finally last week, the guys at the shop where I do all my installations, recommended that I try to switch my MadDad midpipe back to the stock one because it could be due to some resonating factor in the geometry of the different parts I had matched together.
To make the story short, today I went to the shop to pick up my car and the freaking rasping metallic sound is gone!!! I'm really happy that it's finally gone (it was REALLY annoying!!) but on the other hand I'm bummed out that I can't use my MadDad midpipe anymore and I feel the sound has been muffled a bit too much with the stock midpipe. I still have to drive it more to see how much this change has affected the sound.
Has anyone encountered a noise or situation like this?
Any ideas on what to do next? Find an N55 midpipe? It's going to be really tough to get an Akra midpipe, I believe they didn't sell it as a standalone, only in the Evolution system (Akra midpipe and Akra slip-on exhaust).

I have the N55 midpipe (combined with cateless DPs and akra style muffler with valve) and exactly the same kind of rasping you describe (only when I accelerated suddenly from low speed or if a low gear was engaged and I started accelerating, and this only happened for a small range of time during the acceleration). I have done lots of investigations on muffler and DPs, but never on the N55 midpipe which I didn't think could be responsible for rasping. Anyway next week my car is doing some works at my workshop, I'll tell them to give a glance on it

[Plautos]

I had similar problem with my car, the muffler´s inlet pipe was touching the OEM aluminum deflector only when the engine was under load. I fixed it adjusting the muffler and the aluminum deflector.

[EldRick]

"Finally got rid of an annoying rasping sound!!"

I did too, and she took the cats with her...
6^)

[Dackelone]

Originally Posted by EldRick

"Finally got rid of an annoying rasping sound!!"

I did too, and she took the cats with her...
6^)

^^lol