• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


Big Turbo exhaust advice? Looking for minimum drone with GTX2554 (MRX)

Messages
19
Likes
1
Location
Metro Detroit
#1
Hey guys, I just installed the Mountune MRX turbo kit, and its great so far (working through the tune revision process). My car has a stock downpipe and a Tsudo 2.75" exhaust. The Tsudo, with stock turbo, is...droney. Pretty gnarly drone from 3k rpm to about 4500 rpm, where it entirely disappears. I installed some sound dampening in the trunk/spare tire area, but it didn't help much.

I was hoping that maybe the change in turbo might take the savage drone beast, but the opposite occurs. The car is even dronier with the MRX . I daily this car, drive my 5-year old son in it and drive it on the freeway a lot. Drone in that rev range isnt something I can live with. I have some sensitive ears apparently, which makes sense...I wasnt kind to my ears as a kid, going to lots of concerts and race events without ear protection. At age 37 I just cant handle drone. My kid doesn't like it either :)

Any suggestions on what to do, as far as an exhaust? I don't want to go any smaller than 2.5". I considered swapping mufflers or having a helmholtz resonator or "drone pipe" installed by a shop, but locally I cant seem to find anyone confident that they can figure out the math and cancel the drone properly. Also swapping mufflers is a pain because of the unusual 2.75" exhaust size.
 


Messages
186
Likes
57
Location
Dayton
#2
Maybe the Mountune turboback to match with the MRX? I have their turbo back on the stock turbo and it's pretty good about being growly under acceleration and pretty quiet otherwise.
 


Messages
223
Likes
28
Location
Miami
#3
I would recommend the mountune exhaust. It's really tame and has no drone. X37 and catless downpipe here.
 


V_2

Active member
Messages
504
Likes
166
Location
Murfreesboro
#4
Cobb is another good 2.5" exhaust option. Basically, whichever you can get cheaper since they are very similar.
 


Messages
397
Likes
104
Location
YYC
#5
OT: Shouldn't you have an aftermarket downpipe?

What you need

Upgraded intercooler such as mountune PN 2364 IC BA1
Cobb Accessport - Mountune supplies a base tune for your Accessport
mountune Intake or suitable option PN 2364-CAIS-AA
Upgraded High Flow Down Pipe
Replacement Blow Off Valve such as our PN 2364-BOV-KIT
You could try extending the tips a bit further out from the bumper - that helps with the in cabin noise
 


Messages
137
Likes
34
Location
flagstaff
#6
I have a resonated mishimoto catback with cat less dp. It's really quiet till over about 20psi. This is on a gtx2860. No drone.
 


re-rx7

1000 Post Club
Messages
1,639
Likes
215
Location
Ardmore
#7
Stock. Nothing to gain with exhaust even with this turbo. Multiple tuners have input. If you must have 2.5" FS Werks
 


KnockOff

1000 Post Club
Messages
1,348
Likes
450
Location
Menifee
#8
Really? Stock is big enough to flow?

Sent from my SM-G930P using Tapatalk
 


Last edited:
Messages
469
Likes
143
Location
Chicago
#9
Kinda surprised it's droning with the stock cat still in. There should be a lot of catback-only options work little to no drone.
 


Messages
186
Likes
57
Location
Dayton
#14
Hmmm, I noticed better spool times with the stock turbo (MP215 tune at the time) after adding the MT turbo back. Maybe you can still hit peak power but you're losing some room under the curve on the low end?
 


Messages
289
Likes
123
Location
Calgary
#17

koozy

3000 Post Club
Messages
3,209
Likes
1,889
Location
Los Angeles, CA, USA
#18
yes and similar to those running cat less downpipes. the conversation has been focused about the cat back being restrictive. This topic has come over so many times that people forget what the stock cat back has proven to be capable of.
 


Messages
98
Likes
8
Location
Alexandria
#20
I just got a CP-E. I have the depo catless and had just the stock muffler before this. It is louder in every sense from what I had before. It is louder inside than what you would expect with how relatively quiet it is outside the car. (Read this as, you won't get in trouble with the cops but people will know) you can tell that the resonator does its job. It has a little low end growl as you move up in rpm (not under load) and when you get above about 1.8k rpm till about 3k rpm there is almost no exhaust noise when cruising. Above that it can be completely down out with the radio at half volume. It is loud but not unbearable over 75mph. Like I said for a form of reference if your radio is at or above the middle marker you won't hear it even at 80.
 




Top