I ordered some catless downpipes from LMS, and had them put on. I still have all factory exhaust except for the downpipes. Around 4K RPM there is a rasp that has developed only in first and second gear. I was wondering if anyone else has run into this same issue.... I want to get a different catback system, but whatever I go with is going to just amplify the raspy sound. I had my 2 rear mufflers removed before the DP install and the rasp was unbearable, so I had the factory mufflers put back on after the DP were installed, and that took about 80-85% of the raspy sound away. just need opinions as to how I can fix the rasp so I can get a nice sounding catback system. Last thing I want is to spend $1,300 on a Corsa system just to have it sound like a Honda civic with a fart can.....
No way around it ....
non catted down pipes are going to be noisier ,think of the cats as mini mufflers of sort .
With the Corsa Catback added it WILL be very loud when ya put your foot in it.
At cruise mine had a deep tone to it that I personally loved ....
Not even close to being a ricer boy toy .
Quote from: SwampRat on September 16, 2014, 12:23:43 PM
No way around it ....
non catted down pipes are going to be noisier ,think of the cats as mini mufflers of sort .
With the Corsa Catback added it WILL be very loud when ya put your foot in it.
At cruise mine had a deep tone to it that I personally loved ....
Not even close to being a ricer boy toy .
Kinda depressing to hear.... I don't mind loud when I get on the throttle.... but I DO NOT want to hear rasp.... sounds cheap to me. I like a smooth tone while accelerating. Maybe I could sell my Catless pipes and get some catted ones! :) Sounds like a lot of trouble.... but may be the way I need to go to acheive the results I am looking for. I'd love to hear a Corsa system in person.... anyone near East Tennessee with Corsa?
Maybe a resonator like wasinger built would do the trick?
Quote from: SHOdded on September 16, 2014, 01:01:05 PM
Maybe a resonator like wasinger built would do the trick?
That may do it. I will talk to my exhaust guy here in town to see what he thinks about making something like that.
I don't get any rasp with my PPE catted and Corsa exhaust, FYI.
Much louder under acceleration ... But no rasp with my catted PPE DPs with AC on the in cabin rumble is cool too
When I was helping development of these also had non-catted on for awhile and no drone there... Of course I only drove about 80 miles with these and 3 dyno pulls. Rest of exhaust is OEM. Of course I don't hover the rpms at 4k and pass through it pretty quickly with hard acceleration and may not get there on easy acceleration... So maybe I just drive different.
Another possibility , are the LMS non catted downpipes made of thinner ss tubing than the PPE non catted ones that I had ? This could make them resonate differently through various rpms.
Mine had NO rasp .
LMS tunes the car for catted DP,what about non catted DP?I know returning the vehicle to stock gave my car a more aggressive louder sound? Question is did SHO-TYM receive a new revised tune related to the catless DP?
Quote from: ZSHO on September 16, 2014, 10:09:52 PM
LMS tunes the car for catted DP,what about non catted DP?I know returning the vehicle to stock gave my car a more aggressive louder sound? Question is did SHO-TYM receive a new revised tune related to the catless DP?
I just got the email saying that they sent me a revised tune. So I will be putting that on asap.
Quote from: SHO-TYM on September 16, 2014, 10:34:02 PM
Quote from: ZSHO on September 16, 2014, 10:09:52 PM
LMS tunes the car for catted DP,what about non catted DP?I know returning the vehicle to stock gave my car a more aggressive louder sound? Question is did SHO-TYM receive a new revised tune related to the catless DP?
I just got the email saying that they sent me a revised tune. So I will be putting that on asap.
As I understand it the only difference in the tune for non-catted DPs is to turn off the second O2 sensor so you don't throw a DTC/CEL every time the engine is run.
Quote from: SHO-TYM on September 16, 2014, 01:07:46 PM
Quote from: SHOdded on September 16, 2014, 01:01:05 PM
Maybe a resonator like wasinger built would do the trick?
That may do it. I will talk to my exhaust guy here in town to see what he thinks about making something like that.
It needs to be within 1 inch to work properly. If you do go this route make sure you use the app I linked and find the frequency that you want eliminated.