Exhaust raspiness - how raspy is too raspy?

[itsmehuey]

Hey guys, just had a check of my exhaust note after the Injen CAI install and noticed it's a bit raspier than before.

Just wondering whether it's due to the greater amount of air flow coming through? I read that having a hi-flow cat will also cause raspiness, especially if you don't have a resonator in there (I took out the stock reso and cat torpedo thing and replaced with the catco hi-flow cat).

Also read that having leaks in the exhaust could cause raspiness/buzzing/rattling but don't think my exhaust has any leaks - I turned on the car and left it for a while and the nlooked under the car, couldn't find any dripping/leaks.

took a quick sound clip to get everyone's opinion - is this too raspy?

http://img854.imageshack.us/img854/1137/5t6.mp4

[DJKOR]

... whether it's due to the greater amount of air flow coming through?

Sorry, but I have to do this..... LOL. Don't take it the wrong way.

...I took out the stock reso

Personally I think this is the cause of extra raspiness. You will find that the resonator is rather effective at reducing that.

[itsmehuey]

... whether it's due to the greater amount of air flow coming through?

Sorry, but I have to do this..... LOL. Don't take it the wrong way.

...I took out the stock reso

Personally I think this is the cause of extra raspiness. You will find that the resonator is rather effective at reducing that.

HUSH! Lol.

I'm thinking of whether I should chuck in a hotdog reso. Would that make the exhaust quieter and make it not sound as deep? or will it just kill the raspiness?

[ben yip]

Your exhaust has much more treble than I got. I got so much bass

After I changed my header, more treble

After I changed my CAI, more more treble

After I changed my cat convertor, more more more treble

and I think it correspond to your raspiness. That noise is due to I guess the air flow more freely

I am doing research of how to effectively detect for any exhaust leaks.

Thinking of something like a paper wrapped around the exhaust welding points and turns color when leaking

My exhaust gas also stinks after changing cat convertor, and have a little "turbo pop" sound when lift off the throttle

Edited July 19, 2011 by ben yip

[Kenshin X]

raspy? u heard mine... LOL!

[dutchie101]

The "buzz" or rasp at top end can also be from a loosened baffle in the muffler, it begins to resonate at certain flows... causing the unwanted sound.

Could be a possibility, just puttin it on the cards A resonator or loner hot dog may eliminate or lessen the rasp also..

[itsmehuey]

Your exhaust has much more treble than I got. I got so much bass

After I changed my header, more treble

After I changed my CAI, more more treble

After I changed my cat convertor, more more more treble

and I think it correspond to your raspiness. That noise is due to I guess the air flow more freely

I am doing research of how to effectively detect for any exhaust leaks.

Thinking of something like a paper wrapped around the exhaust welding points and turns color when leaking

My exhaust gas also stinks after changing cat convertor, and have a little "turbo pop" sound when lift off the throttle

My exhaust doesn't have that "pop" you refer to but the smell of the gas is much more noticeable after I changed the rear muffler and cat.

raspy? u heard mine... LOL!

LOL yeah but that's because you have leaks man! I'm not sure if mine has leaks but I'm yet to see any.

The "buzz" or rasp at top end can also be from a loosened baffle in the muffler, it begins to resonate at certain flows... causing the unwanted sound.

Could be a possibility, just puttin it on the cards A resonator or loner hot dog may eliminate or lessen the rasp also..

Hmmm.. Is there any way I could check the exhaust for "loosened baffles" myself? Or would I need to have the car set up on a hoist? The raspiness at the top end isn't really that bothering, was just something I picked up since installing the CAI - didn't have that much raspiness beforehand.

[Kenshin X]

I have no leaks as of present

[itsmehuey]

I have no leaks as of present

you got them all fixed? :D

[dutchie101]

No real way of telling if you have loose baffles, knocking the muffler can sometimes loosen them, or knocking when up on a hoist can sometimes reveal the source of the broken baffle. Not sure how the twinloop is set up.

Personally i cant stand the rasp/buzz... I normally link it to a poorly made muffler. Each to there own tho :)

[Kenshin X]

yes took it to another exhaust specialist n he went around with a stethoscope and didn't find anything. they fixed it right.

[itsmehuey]

yes took it to another exhaust specialist n he went around with a stethoscope and didn't find anything. they fixed it right.

nice! Not as buzzy/raspy now?

[clifton]

If I'm reading it correctly and you dont have a resonator in there, its probably due to that.

[itsmehuey]

yep middle resonator was taken out as it was a combined reso+cat torpedo looking thing. there was supposedly a front muffler too when I had a look under the car when it was hoisted up during the new hi-flow cat install so i thought that would have helped with reducing some of the raspiness, and it did, because I didn't have this raspiness in my exhaust note even after i removed the reso+cat and installed the hi-flow cat. only started noticing it after the CAI install.

Btw, if i install a hotdog reso, would that kill the loudness of my exhaust note or just kill some of the raspiness? I like the loudness at the moment and don't want to kill it anymore (xforce twinloop already silences it a fair bit). Also, any particular brand of hotdog reso / size i should look at getting? there's not that much rasp in the exhaust note, but wouldn't mind cutting it down a little bit more as to how it was before the CAI install.

[Cee-Lo]

Hotdog will reduce some raspyness/drone, and will also quieten down the exhuast somewhat. The bigger the hotdog, the greater the effect. So if you want to keep the system close to as loud as it is now, best to go for a small hotdog.

[DJKOR]

... only started noticing it after the CAI install.

That's not to say that it never did it before you changed your intake. I would be fairly certain that the intake is not the cause for such raspiness.

Remember you did make a change to your exhaust setup on the 2nd or there abouts. Your exhaust note can get some subtle changes in it over time when compared to what it was like when just fitted. This is while carbon etc builds up on the inside and heat changes may make things "break in" differently. Chances are, what you are getting is due to the resonator being removed and nothing to do with the intake itself.

[ben yip]

deleted

Edited July 21, 2011 by ben yip

[2times]

I just listened to your soundfile like 6 times, personally i dont think its too bad at all. it sounds interesting for a 4 banger...

imo your addition of a cai could have affected the "rasp", because more air in needs to get out. i think if you want to discern whether it is infact the added cai or lack of resonator what you should do is compare exhaust sounds at different air temps. listen to it early morning when its cold, and then in the middle of the day (pref a sunny day) when its the warmest. if the rasp changes because of this my money will be it was the addition of the cai - because colder air is denser so after it is burnt it expands more giving a greater gas volume, so if it is the cai doing this should help figure it out...

[itsmehuey]

I just listened to your soundfile like 6 times, personally i dont think its too bad at all. it sounds interesting for a 4 banger...

imo your addition of a cai could have affected the "rasp", because more air in needs to get out. i think if you want to discern whether it is infact the added cai or lack of resonator what you should do is compare exhaust sounds at different air temps. listen to it early morning when its cold, and then in the middle of the day (pref a sunny day) when its the warmest. if the rasp changes because of this my money will be it was the addition of the cai - because colder air is denser so after it is burnt it expands more giving a greater gas volume, so if it is the cai doing this should help figure it out...

hey mate, I tried this out during colder temps, their is a fair bit of raspiness, but when it's not so cold, the raspiness is pretty much not there at all. I read around some other forums that the cold temperature can make the exhaust sound raspy

[dutchie101]

I hate to play devils advocate here, but we do have Xforce/Varex as a major sponsor here, yet they never seem to chime in on any questions that need their input.

As the twin loop is one of their products, I firmly believe they should be giving some input into this conversation. Its all great to pay for advertising and a sub forum, but hell, how about giving something to the forum/members as well, such as info on their products and related issues...

-_-

[Guest]

I hate to play devils advocate here, but we do have Xforce/Varex as a major sponsor here, yet they never seem to chime in on any questions that need their input.

As the twin loop is one of their products, I firmly believe they should be giving some input into this conversation. Its all great to pay for advertising and a sub forum, but hell, how about giving something to the forum/members as well, such as info on their products and related issues...

-_-

couldn't agree more...

[dutchie101]

Maybe try a spot of fishing in the Xforce sub-forum Huey, see if you get any bites.

[itsmehuey]

thanks guys.

as I mentioned in my previous reply to the thread, rasp only seems apparent at really cold temps. but when it's not so cold, the rasp is pretty much nonexistent. do temps play much of a factor in exhaust sound/note? wondering if it's something that's normal with most/all exhaust systems.

[clifton]

thanks guys.

as I mentioned in my previous reply to the thread, rasp only seems apparent at really cold temps. but when it's not so cold, the rasp is pretty much nonexistent. do temps play much of a factor in exhaust sound/note? wondering if it's something that's normal with most/all exhaust systems.

If its like that its just due to the colder air being more dense there when its burnt there is more gas passing through the exhaust. IMO if you can live with the rapsy sound, dont worry about it but if it bothers you just chuck a resonator on.

[itsmehuey]

thanks guys.

as I mentioned in my previous reply to the thread, rasp only seems apparent at really cold temps. but when it's not so cold, the rasp is pretty much nonexistent. do temps play much of a factor in exhaust sound/note? wondering if it's something that's normal with most/all exhaust systems.

If its like that its just due to the colder air being more dense there when its burnt there is more gas passing through the exhaust. IMO if you can live with the rapsy sound, dont worry about it but if it bothers you just chuck a resonator on.

thanks bud. not really bothersome so I'll leave it for the time being. I think I'd rather save my dosh for now for some more bodykit related spendings