How I killed the highway drone (and some of the power benefit) of my Corsa exhaust
08-22-2007, 11:11 PM
#1
How I killed the highway drone (and some of the power benefit) of my Corsa exhaust This is a story about how and why I quieted down my Corsa exhaust. Let me start by saying I know I'm going to take a lot of crap about this. But my attitude in general has always been if it helps just one person in the same situation, then it is worth it.
Short version:
For those not interested in the background, I simply used a 2.25" to 2" reducer, cut four notches in the 2" end, and bent them over to leave about a 1" opening. Gave it a couple coats of high temp paint, and then mounted the reducer into the passenger side tailpipe right in front of the tip, by drilling into the tailpipe and using a simple stainless set screw to lock it in. Still looks unmodified, still has some flow through the pass pipe. Reversible except for the small hole in the tailpipe, which I guess you could weld if it really bothered you.
The end result is I have essentially no drone at highway cruising anymore. It's just gone. There is a tiny hint of it left at ~70-71mph, but above or below that just burbles along. This is opposed to before when about 68-82mph was just droning, to the point of conversation not really being possible. I realize the Corsa is very well behaved overall, but it was still too much for me with how I use the car these days. I have no rasp, no popping, really no negative tone changes at all.
Everything is calmer, but imho the overall tone of the system is very similar. It still has a nice strong idle, and still has a very nice scream at WOT. Imho I kept 90% of the tonal quality and WOT scream and eliminated almost completely the highway drone (2.2-2.5k drone).
My car is a A4 with 3.42's. So it does run higher than many at highway. Prior to the 3.42's the drone didn't get me so bad, because I wasn't running in that RPM range much. I also have no effective manner of doing any sort of A-B comparison about power loss. If there was any improvement with the Corsa, I suspect I just lost a little bit of it. But I am not really of the belief that a bolt-on catback can make a big SOTP improvement. So I am just happy to have the tonal quality and volume I want from the system.
More background, to see if you might be the same as me:
I have a simple bolt on 2000 Convertible Z28. When I bought it a couple years ago, it was bone stock with about 45k on the clock, 2.73's, auto. And the exhaust was silent. Literally silent. I hated it.
The car was a replacement for a '93 hardtop LT1 car. That LT1 car had stock, flowmaster, and SLP 2otl exhaust on it during it's life long and enjoyable life. I loved the sound of the flowmaster+LT1. The SLP was a bit too quiet, but also had great tone to it imho.
So, I did what all dumb people do and went about messing with my new car. First thing I tried was a SLP LMII. I'm sorry, but I hated it. I didn't like the tone at all, and it was way too loud. I should admit I'm 30 years old now and often have to drive the car 200+ miles at 80mph. The LMII made it all of about 2 months before I ditched it for the Corsa. My girlfriend missed talking in the car. That was somewhat of a mixed blessing, I guess.
I loved the Corsa at first. Still a little loud, but I really liked the overall tone of it, and the range from cruising to WOT was imho really great. But over time, the drone became more annoying to me, and then I decided to do an axle swap from 2.73's to 3.42's. After that, I just couldn't take highway cruising (75-80mph) anymore. The car would just wear me out and give me a headache after a couple hours of driving.
So, if you are in a similar position, and would like to tone down your Corsa a little bit, this is one way to do it. I'll admit that a visit to a muffler shop would be more finished, but my method is cheap, do it yourself, and easily reversible.
If you think you might be interested in this mod, I should mention that you can try out the effect by simply blocking (to one degree or another) your passenger side tips. I found completely blocking the right side pipe to be too much, almost back to stock sound levels. So I think it is important to find the right balance of reducer.
Short version:
For those not interested in the background, I simply used a 2.25" to 2" reducer, cut four notches in the 2" end, and bent them over to leave about a 1" opening. Gave it a couple coats of high temp paint, and then mounted the reducer into the passenger side tailpipe right in front of the tip, by drilling into the tailpipe and using a simple stainless set screw to lock it in. Still looks unmodified, still has some flow through the pass pipe. Reversible except for the small hole in the tailpipe, which I guess you could weld if it really bothered you.
The end result is I have essentially no drone at highway cruising anymore. It's just gone. There is a tiny hint of it left at ~70-71mph, but above or below that just burbles along. This is opposed to before when about 68-82mph was just droning, to the point of conversation not really being possible. I realize the Corsa is very well behaved overall, but it was still too much for me with how I use the car these days. I have no rasp, no popping, really no negative tone changes at all.
Everything is calmer, but imho the overall tone of the system is very similar. It still has a nice strong idle, and still has a very nice scream at WOT. Imho I kept 90% of the tonal quality and WOT scream and eliminated almost completely the highway drone (2.2-2.5k drone).
My car is a A4 with 3.42's. So it does run higher than many at highway. Prior to the 3.42's the drone didn't get me so bad, because I wasn't running in that RPM range much. I also have no effective manner of doing any sort of A-B comparison about power loss. If there was any improvement with the Corsa, I suspect I just lost a little bit of it. But I am not really of the belief that a bolt-on catback can make a big SOTP improvement. So I am just happy to have the tonal quality and volume I want from the system.
More background, to see if you might be the same as me:
I have a simple bolt on 2000 Convertible Z28. When I bought it a couple years ago, it was bone stock with about 45k on the clock, 2.73's, auto. And the exhaust was silent. Literally silent. I hated it.
The car was a replacement for a '93 hardtop LT1 car. That LT1 car had stock, flowmaster, and SLP 2otl exhaust on it during it's life long and enjoyable life. I loved the sound of the flowmaster+LT1. The SLP was a bit too quiet, but also had great tone to it imho.
So, I did what all dumb people do and went about messing with my new car. First thing I tried was a SLP LMII. I'm sorry, but I hated it. I didn't like the tone at all, and it was way too loud. I should admit I'm 30 years old now and often have to drive the car 200+ miles at 80mph. The LMII made it all of about 2 months before I ditched it for the Corsa. My girlfriend missed talking in the car. That was somewhat of a mixed blessing, I guess.
I loved the Corsa at first. Still a little loud, but I really liked the overall tone of it, and the range from cruising to WOT was imho really great. But over time, the drone became more annoying to me, and then I decided to do an axle swap from 2.73's to 3.42's. After that, I just couldn't take highway cruising (75-80mph) anymore. The car would just wear me out and give me a headache after a couple hours of driving.
So, if you are in a similar position, and would like to tone down your Corsa a little bit, this is one way to do it. I'll admit that a visit to a muffler shop would be more finished, but my method is cheap, do it yourself, and easily reversible.
If you think you might be interested in this mod, I should mention that you can try out the effect by simply blocking (to one degree or another) your passenger side tips. I found completely blocking the right side pipe to be too much, almost back to stock sound levels. So I think it is important to find the right balance of reducer.
08-23-2007, 11:51 AM
#2
On The Tree
iTrader: (5)
Join Date: Mar 2007
Location: Fresno, ca
Posts: 118
Likes: 0
Received 0 Likes
on
0 Posts
Good post, I too dont like my cars as loud anymore.
First car: 1970 Chevelle 355 w' 2.5 2 chamber dumped Flowmasters, couldn't hear yourself think.
Years down the road and you want "tone" and not "loud".
First car: 1970 Chevelle 355 w' 2.5 2 chamber dumped Flowmasters, couldn't hear yourself think.
Years down the road and you want "tone" and not "loud".
09-28-2007, 12:27 AM
#4
Well I will say people's tolerance levels for what is ok and not ok in exhaust definitely a very wide range. There are people running loudmouths and saying they aren't loud, which I think is just a ridiculous statement.
My car was loud enough at 75-80mph that it was hard to carry on any sort of conversation outside of "yup" and "uh-huh", and the overwhelming source of noise was very easily identifiable on/off throttle due to the pipes.
I know these cars aren't family sedans, but using the car for 2-3+ hour trips fairly regularly now really lowered what I could put up with. I've found this to be an excellent compromise for me.
My car was loud enough at 75-80mph that it was hard to carry on any sort of conversation outside of "yup" and "uh-huh", and the overwhelming source of noise was very easily identifiable on/off throttle due to the pipes.
I know these cars aren't family sedans, but using the car for 2-3+ hour trips fairly regularly now really lowered what I could put up with. I've found this to be an excellent compromise for me.
09-28-2007, 06:43 AM
#5
TECH Resident
iTrader: (21)
Join Date: Sep 2005
Location: New Jersey
Posts: 820
Likes: 0
Received 0 Likes
on
0 Posts
that's not a bad idea hehe. I take my car on 16 hour road trips at around 75mph once in a while and by the end I'm really tired of the drone in the car. Enough that I don't even want to really drive it for a few days. I'll have to try this out!!
