RASP
06-13-2007, 09:30 PM
#81
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i dont own the tC anymore so i am sorry i cant get another vid.
but it was an auto, so i could hardly care about performance. And the muffler is no different than that of the SP2 or DC, it is not chambered, it is a magnaflow perforated core, it is straight through, it just has a u-bend, which all of the mufflers that arent a canister on a tC have.
i will most likely be making another exhaust, or simply buying a vibrant cat back for the current tC.
but it was an auto, so i could hardly care about performance. And the muffler is no different than that of the SP2 or DC, it is not chambered, it is a magnaflow perforated core, it is straight through, it just has a u-bend, which all of the mufflers that arent a canister on a tC have.
i will most likely be making another exhaust, or simply buying a vibrant cat back for the current tC.
06-14-2007, 01:26 PM
#82
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^^Too bad we can't look at your setup further. I'm curious because yours is one of the few aftermarket header/exhaust combos without a discrete resonator that didn't seem to have any rasp. (Again I think the 30" was a straight-through muffler marketed as a resonator.) So your system was heavily muffled, maybe just enough to keep any rasp down below weed-whacker level.
Do you remember how high in RPM you ever took this setup and if it was raspy then? (Know it was an auto but maybe you downshifted it and went up above 5000 once or twice?)
Another point of interest - your Megan header and custom exhaust. Only the Megan & Alphawerks headers (and of course stock exhaust manifold) have the OEM brackets at the bottom where they mount to the engine chassis. This keeps the header from vibrating, which in turn minimizes the vibration of the s-pipe and other pipes downstream.
Vibration is a cause of rasp & have read posts where securing the header and tightening up loose exhausts has cleared up rasp. Some swear that rasp is fully preventable with proper exhaust installation.
Do you remember how high in RPM you ever took this setup and if it was raspy then? (Know it was an auto but maybe you downshifted it and went up above 5000 once or twice?)
Another point of interest - your Megan header and custom exhaust. Only the Megan & Alphawerks headers (and of course stock exhaust manifold) have the OEM brackets at the bottom where they mount to the engine chassis. This keeps the header from vibrating, which in turn minimizes the vibration of the s-pipe and other pipes downstream.
Vibration is a cause of rasp & have read posts where securing the header and tightening up loose exhausts has cleared up rasp. Some swear that rasp is fully preventable with proper exhaust installation.
06-14-2007, 05:24 PM
#83
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Originally Posted by Mid_Life_tC-risis
Another point of interest - your Megan header and custom exhaust. Only the Megan & Alphawerks headers (and of course stock exhaust manifold) have the OEM brackets at the bottom where they mount to the engine chassis. This keeps the header from vibrating, which in turn minimizes the vibration of the s-pipe and other pipes downstream.
Vibration is a cause of rasp & have read posts where securing the header and tightening up loose exhausts has cleared up rasp. Some swear that rasp is fully preventable with proper exhaust installation.
Vibration is a cause of rasp & have read posts where securing the header and tightening up loose exhausts has cleared up rasp. Some swear that rasp is fully preventable with proper exhaust installation.
right now i'm running the Alpha/Invidia/ and the Tsudo N1 cat back with the stock 18" glass pack of the tsudo mid-pipe and a "CC insert" which is pretty much a velocity stack based resonator( very small ,about 7"long and 2.5" round) and the 10" canister on the tsudo axleback.
At idle and low rpms my car sounds incredible! at about 2500 to 3k i hit a small pocket of rasp that clears out at about 3500 then its back to a nice roar. but at WOT my exhaust has a strange hissing sound, almost like a silent leak, BUT i have had 2 exhaust shops go over my entire exhaust as well as me crawling under my car and there is NO LEAK!! i have come to the conclusion that its either the header or the CC inser.
06-14-2007, 07:30 PM
#84
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at any rpm it had no rasp.
i went up to redline before, because i did the 1-2-3-d and it sounded good at any rpm, ask anyone who has driven with or around me.
and a resonator basically is a long straight through muffler.
it was a perforated core, with packing, like a muffler basically, but it was pretty long. i think i could have done away with a 22" resonator.
on my next exhaust set up, i am going to run the MMW header with the vibrant cat back exhaust. that comes with a hi-flo cat and muffler. it doesnt come with a resonator so we wil see what happens, if i have rasp i am going to put a 22" resonator on and will take vids before and after.
i went up to redline before, because i did the 1-2-3-d and it sounded good at any rpm, ask anyone who has driven with or around me.
and a resonator basically is a long straight through muffler.
it was a perforated core, with packing, like a muffler basically, but it was pretty long. i think i could have done away with a 22" resonator.
on my next exhaust set up, i am going to run the MMW header with the vibrant cat back exhaust. that comes with a hi-flo cat and muffler. it doesnt come with a resonator so we wil see what happens, if i have rasp i am going to put a 22" resonator on and will take vids before and after.
06-15-2007, 02:56 AM
#85
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Originally Posted by tC9o9
and a resonator basically is a long straight through muffler.
Originally Posted by Mid Life tc-risis
"Resonator" doesn't = "muffler", and this is an important point since we're talking about rasp. The solution for rasp, assuming the overall sound level of the exhaust is ok, is the proper resonator(s), like you said the Helmholtz, hollow type. If it's got packing then it's absorbing sound, and that's a muffler.
The first item you linked says "use as a resonator to reduce sound or for a more aggressive sound as a stand alone muffler" - that's misleading - they're trying to sell a product by making people think it will do both, but it can't. It's just another straight-through muffler. It will quiet ALL frequencies to some degree, including your rasp frequencies, but won't eliminate the rasp like the proper resonator will.
06-15-2007, 07:38 AM
#87
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If you wanna get down to brass tacks....... a muffler is anything that muffles sound. So "technically" a resonator is a type of muffler. But i don't see where this is going. Just something to argue about. I understand what you're saying about the frequency, but it's so hard to get into that. No one will build a custom resonator/muffler to fit your cars frequency.
06-15-2007, 07:47 AM
#88
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Originally Posted by tCizzler
Just something to argue about. .
I dont see what the problem is, i clearly posted a video, which clearly indicated i knew how to get rid of rasp.
If the dude wants to call up magnaflow and ask them, they will say that their resonators are basically mufflers.
06-15-2007, 09:19 PM
#89
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Originally Posted by tC9o9
Originally Posted by tCizzler
Just something to argue about. .
I dont see what the problem is, i clearly posted a video, which clearly indicated i knew how to get rid of rasp.
yes you got rid of rasp by "MUFFLING" the heck out of your exhaust almost to the
point of stock...the "cat" is what helped you get rid of the rasp.
If the dude wants to call up magnaflow and ask them, they will say that their resonators are basically mufflers.
yeah manufactures will tell you anything to get you to buy their stuff...
Yo! tcizzler waz up!
06-15-2007, 09:41 PM
#90
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as long as it it straight through, and it is perforated and not louvered, you will be fine.
and the cat as a metallic core and high flow, so it definately flowed ALOT better than stock.
and again, it was an auto, so i could care less about performance, i wanted sound.
this time its a different story.
and the cat as a metallic core and high flow, so it definately flowed ALOT better than stock.
and again, it was an auto, so i could care less about performance, i wanted sound.
this time its a different story.
06-16-2007, 04:06 PM
#93
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Originally Posted by tCizzler
^^About those aero resonators... I just checked my invoice cuz thats the only place it said it, but the resonator is only 10" and with the flanges it's 14". Very small and very effective
06-16-2007, 04:17 PM
#94
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Originally Posted by Keith
Hey tcizzler,
Can you make a sound clip of you car from the outside...
the one you made from the inside is nice but, I would like to hear it from the outside of the car....
Thanks...
Keith.
Can you make a sound clip of you car from the outside...
the one you made from the inside is nice but, I would like to hear it from the outside of the car....
Thanks...
Keith.
I'll try to get a friend to hold the camera outside as i drive by. But only one of my friends knows how to drive a standard, and he's out of town.
I'll see what i can do.
06-16-2007, 04:43 PM
#95
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Originally Posted by tCizzler
I can if you want, but it sounds the same inside as it does outside at an idle. HOWEVER The exhaust does have a definate rasp while under load. I'll try to record it but my phone kinda sucks with sound and the wind coming in the window drowns it out.
this is kinda sucky because the stock resonator is 18" long!! thats as big a resonator as you figure you would need. this means the only way to eliminate rasp from aftermarket headers is to muffle the shiz outta your exhaust like that one dude did...which kinda makes getting the header pointless...that or live with a tad bit of rasp...
06-16-2007, 08:19 PM
#96
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Originally Posted by Mugetsu
Originally Posted by tCizzler
I can if you want, but it sounds the same inside as it does outside at an idle. HOWEVER The exhaust does have a definate rasp while under load. I'll try to record it but my phone kinda sucks with sound and the wind coming in the window drowns it out.
this is kinda sucky because the stock resonator is 18" long!! thats as big a resonator as you figure you would need. this means the only way to eliminate rasp from aftermarket headers is to muffle the shiz outta your exhaust like that one dude did...which kinda makes getting the header pointless...that or live with a tad bit of rasp...
06-16-2007, 10:19 PM
#97
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^^No, remember the GSC header round-up showed decent gains - around 8-9whp each header - setup with just Greddy Evo2 axleback and stock midpipe with OEM cat.
Many people don't want to run cats with headers but I think they're important not only to fight rasp but to keep your low-end torque, and keep you from stinking out the car behind you. Have heard good things about aftermarket high-flow cats, particularly from Magnaflow and Random Technologies. They'll never flow as well as a true resonator but will give your high-end a boost over the very restrictive stock cat.
Many people don't want to run cats with headers but I think they're important not only to fight rasp but to keep your low-end torque, and keep you from stinking out the car behind you. Have heard good things about aftermarket high-flow cats, particularly from Magnaflow and Random Technologies. They'll never flow as well as a true resonator but will give your high-end a boost over the very restrictive stock cat.
