Is there a machine gun in my exhaust??
Thread Starter
Teching In
Joined: Oct 2006
Posts: 12
Likes: 0
From: Huntington, IN
Is there a machine gun in my exhaust?? This is my first post and thread on Ls1 tech and have asked this question on other sites before and never have gotten a good answer yet.
I own a 98 Formula and exhaust wise I have Jet Hot long tubes, Jet hot off road y-pipe and Borla exhaust.
Ever since I got my headers and y-pipe installed I have had to put up with this horrible sound from my exhaust at around 2,300-2,800 rpms. Especially when its cold, it honestly sounds like a machine gun or fire crackers going off in my exhaust just a horrible resonance that honestly is kinda embarassing.
I am 90% sure its my off road y-pipe causing this mess but I just wanted to know if anyone else here has had to deal with this problem and if so how you went about fixing it.
If anyone has any advice or a simple fix without me having to buy CATS I would appreciate it. thanks
I own a 98 Formula and exhaust wise I have Jet Hot long tubes, Jet hot off road y-pipe and Borla exhaust.
Ever since I got my headers and y-pipe installed I have had to put up with this horrible sound from my exhaust at around 2,300-2,800 rpms. Especially when its cold, it honestly sounds like a machine gun or fire crackers going off in my exhaust just a horrible resonance that honestly is kinda embarassing.
I am 90% sure its my off road y-pipe causing this mess but I just wanted to know if anyone else here has had to deal with this problem and if so how you went about fixing it.
If anyone has any advice or a simple fix without me having to buy CATS I would appreciate it. thanks
Thread Starter
Teching In
Joined: Oct 2006
Posts: 12
Likes: 0
From: Huntington, IN
No this is deff. coming from the exhaust, I havent felt any vibrating as far as my y-pipe hitting the floor it just does it at that certain rpm range then after that if I keep on the gas it mellows out into a sweet,sweet sound. If I just floor the car from a stop and dont let out I never even hear the noise! So i dont think its vibrations or anything
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The reason i asked if you deleted your EGR or not, is because if it is indeed backfiring (which from what your describing, it sounds like it is) it sounds like you have unburnt fuel going through your exhaust and then is combusting before it reaches the muffler(s). That's what I'm guessing the "popping" sound is that your describing. If that's the case, you may have an air/fuel ratio problem, and more fuel is being dumped into the engine than needed (that may be the case). I may or may not be right, but that is what it sounds like to me. Maybe somebody with a little more knowledge can chime in. Hope this helps.
Or it could be an exhaust leak like HellRaiser said.
Or it could be an exhaust leak like HellRaiser said.
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Originally Posted by farnoush
Its nothing, just rasp. The only solution without getting cats would be to get another catback.
I sort of have the same problem with my setup (and yes, I do have true duals). But I believe my problem is an uncompleted weld. I put the long-tubes in myself and had a shop weld up the rest of my system. Where the collector merges with the X-pipe, I don't think they completed the welds all the way and is causing the flange to rattle in that spot ever so slightly (but enough to make one hell of an annoying/embarassing noise). It only happens at <~2500 RPMs. Check your welds and see what's up.
Thread Starter
Teching In
Joined: Oct 2006
Posts: 12
Likes: 0
From: Huntington, IN
I'm sure some of you guys know Bob from EPP in columbia city IN he is the one who kinda turned me on to this site. His guys did all my exhaust system except my cat back which was first. There are no welds just clamps throughout my exhaust system. I asked them and they thought maybe it was just turbulance in the pipes since there really is no restrictions anymore. They also dyno tuned my car and I just had it up there for a check up a week ago and everything is great so I dont think its too much fuel/air.
The only options I really have I guess is another exhaust system which could possibly do the same thing which would **** me off a whole lot! or I thought of possibly having my local exhaust shop just put one of the SLP modular mufflers somewhere between the y-pipe and cat back?? I though that might disturb the air turbulance enough to kill this hillbilly a** sound!
Like I said this only happend AFTER I got headers and off road y-pipe so its gotta be something to do with more velocity or turbulance.
If anyone thinks my little SLP modular muffler trick would work please let me know cause thats cheaper than a new exhaust if not!!!!........................................... .........
Anyone interested in a 9 month old Borla system?
The only options I really have I guess is another exhaust system which could possibly do the same thing which would **** me off a whole lot! or I thought of possibly having my local exhaust shop just put one of the SLP modular mufflers somewhere between the y-pipe and cat back?? I though that might disturb the air turbulance enough to kill this hillbilly a** sound!
Like I said this only happend AFTER I got headers and off road y-pipe so its gotta be something to do with more velocity or turbulance.
If anyone thinks my little SLP modular muffler trick would work please let me know cause thats cheaper than a new exhaust if not!!!!........................................... .........
Anyone interested in a 9 month old Borla system?
It's rasp, and you are gonna have it with pretty much any cat-back when you have an ory. I had a stock 98 WS6 single-out on my car, had it then, now with the spintech/mufflex set-up I still have it. I have heard it on almost every car with an ORY.
I just learned to deal with it.
I just learned to deal with it.
TECH Fanatic
Joined: Nov 2003
Posts: 1,241
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From: MD
The Jet Hot y-pipe if they haven't changed the design is a piece of crap. That's your problem, rasp. I had the exact same sound until the jethot y-pipe broke in half at the merge. I had a custom y-pipe made and welded up most of the exhaust. Completely changed the sound of the exhaust. Probably gained a few horsepower too.
TECH Addict
Joined: Jun 2005
Posts: 2,660
Likes: 14
From: England
Well lokking at the available evidence you say this occurs at a particulary rpm, i.e. frequency and mostly when cold. So one can assume that once the exhaust heats up it expands.
Obvious thinigs to check is for anything loose that might be causeing such as clamp or worn rubber bush/bracket.
Also try and narrow down the noise, does it occur while stationary or only moving, does it happen in every gear?
Also is this noise noticable from outside the car as well as in?
My exhuast becomes very loud at 2000rpm. This is because the body of the car must be attuned to that particulary frequency and wave lenght and amplifies it in the cabin, similar to how an acoustic works.
Do you have T-tops? Because if I remove the tops and roll the windows down in mine I no longer get this louder resonance at 2000rpm at all. This is because I hae change the harmonic porperties of the bodyshell by removing the roof panels and lowering the windows.
Also it's worth noting, when at 2000rpm and it is very loud in the car, there is no noticable different outside. A pedestrian would not notice any difference.
Obvious thinigs to check is for anything loose that might be causeing such as clamp or worn rubber bush/bracket.
Also try and narrow down the noise, does it occur while stationary or only moving, does it happen in every gear?
Also is this noise noticable from outside the car as well as in?
My exhuast becomes very loud at 2000rpm. This is because the body of the car must be attuned to that particulary frequency and wave lenght and amplifies it in the cabin, similar to how an acoustic works.
Do you have T-tops? Because if I remove the tops and roll the windows down in mine I no longer get this louder resonance at 2000rpm at all. This is because I hae change the harmonic porperties of the bodyshell by removing the roof panels and lowering the windows.
Also it's worth noting, when at 2000rpm and it is very loud in the car, there is no noticable different outside. A pedestrian would not notice any difference.
TECH Resident
Joined: Dec 2004
Posts: 905
Likes: 0
Originally Posted by 00 SLVR Z
The reason i asked if you deleted your EGR or not, is because if it is indeed backfiring (which from what your describing, it sounds like it is) it sounds like you have unburnt fuel going through your exhaust and then is combusting before it reaches the muffler(s). That's what I'm guessing the "popping" sound is that your describing. If that's the case, you may have an air/fuel ratio problem, and more fuel is being dumped into the engine than needed (that may be the case). I may or may not be right, but that is what it sounds like to me. Maybe somebody with a little more knowledge can chime in. Hope this helps.
Or it could be an exhaust leak like HellRaiser said.
Or it could be an exhaust leak like HellRaiser said.
For those who say rasp, thats retarded. Rasp does in no way, shape or form sound like a damn machine gun. If, to you, it does sound like a machine gun then it's time to get your asses from behind that damn monitor and get to a range.
some people put a bullet in the I pipe to tame down the rasp.
I had the same exact setup (long tubes, ORY, borla) and I just bought a catted y pipe because I was sick of the BLAT BLAT BLAT. Sure it was loud.. but it was quite annoying. So again if you dont want cats, look for a bullet to weld in.
I had the same exact setup (long tubes, ORY, borla) and I just bought a catted y pipe because I was sick of the BLAT BLAT BLAT. Sure it was loud.. but it was quite annoying. So again if you dont want cats, look for a bullet to weld in.