Smelly Clothes
03-23-2005, 05:55 AM
#31
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Join Date: Feb 2002
Location: Amityville, New York
Posts: 12,288
Drag cars are picking up horsepower, im not talking Billy Bob and his Monte, NHRA is going mufflers, both Dynomax and KOOKS have shown increses in horsepower running mufflers
soon anyone in NHRA is going to have to use mufflers that they are told to use, it will be either Dynomax or KOOKS.
There are plenty of cars that have shown ZERO powerloss running a exaust and some pick power up, you have to think new technology getting the exaust pulses just right with the combination of proper pipe size and cross over locations.
soon anyone in NHRA is going to have to use mufflers that they are told to use, it will be either Dynomax or KOOKS.
There are plenty of cars that have shown ZERO powerloss running a exaust and some pick power up, you have to think new technology getting the exaust pulses just right with the combination of proper pipe size and cross over locations.
03-24-2005, 06:10 AM
#33
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Join Date: Feb 2002
Location: Amityville, New York
Posts: 12,288
you need to think outside the box, you can quiet and clean up a car without losing horsepower, technology has come along way
look how many high performance cars have no gain when the exaust is changed, why? because it is set up perfect to the vehicle
put a 3" exaust on a viper and it loses horsepower compared to 2.5, change the exaust on a ZR-1 or a Zo6 and it loses power or gains nothing
the right exaust for a car will not steal power from it, its a matter of how much you want to put into it, its not as simple as bolting on the largest pipe you can get under the car and getting it to go the straightest you can.
its not muffler companies paying off people, its the NHRA doing the right thing for the enviroment
look how many high performance cars have no gain when the exaust is changed, why? because it is set up perfect to the vehicle
put a 3" exaust on a viper and it loses horsepower compared to 2.5, change the exaust on a ZR-1 or a Zo6 and it loses power or gains nothing
the right exaust for a car will not steal power from it, its a matter of how much you want to put into it, its not as simple as bolting on the largest pipe you can get under the car and getting it to go the straightest you can.
its not muffler companies paying off people, its the NHRA doing the right thing for the enviroment
03-25-2005, 07:59 AM
#34
Junior Member
Join Date: Jul 2003
Posts: 18
In the post that dissapeared i mentioned about exhaust design and if you search around on the net with google you will find lots of info on it, all i can say is that theres a lot of maths involved in making it right for your particular engine, different setups and different cams require different amounts of back pressure. drag cars and some race cars use open headers due to the fact they use a very wild cam designed for pure top end power, this requires that the gas is free flowing and hence an open header is better. However for most street applications we need backpressure or we will loose power. This was proved by myself on a turbo Renault 5 i had, with a free flow exhaust it liked to open up high in the revs but it was terrible to drive, so i worked out all the maths and had the correct muffler welded into it, result better driveability, better power delivery and more power.
Its not the size that counts, its what u do with it
Its not the size that counts, its what u do with it
03-25-2005, 02:06 PM
#36
Senior Member
Join Date: Oct 2001
Location: Peoria, AZ
Posts: 10,906
[quote name='Rob x-7' date='Mar 24 2005, 07:10 AM']you need to think outside the box, you can quiet and clean up a car without losing horsepower, technology has come along way
look how many high performance cars have no gain when the exaust is changed, why? because it is set up perfect to the vehicle
put a 3" exaust on a viper and it loses horsepower compared to 2.5, change the exaust on a ZR-1 or a Zo6 and it loses power or gains nothing
the right exaust for a car will not steal power from it, its a matter of how much you want to put into it, its not as simple as bolting on the largest pipe you can get under the car and getting it to go the straightest you can.
its not muffler companies paying off people, its the NHRA doing the right thing for the enviroment
[/quote]
Exhaust tuning technology is still a black art, still big mystery.
I was refering to mufflers in my earler posts.
look how many high performance cars have no gain when the exaust is changed, why? because it is set up perfect to the vehicle
put a 3" exaust on a viper and it loses horsepower compared to 2.5, change the exaust on a ZR-1 or a Zo6 and it loses power or gains nothing
the right exaust for a car will not steal power from it, its a matter of how much you want to put into it, its not as simple as bolting on the largest pipe you can get under the car and getting it to go the straightest you can.
its not muffler companies paying off people, its the NHRA doing the right thing for the enviroment
[snapback]690118[/snapback]
[/quote]
Exhaust tuning technology is still a black art, still big mystery.
I was refering to mufflers in my earler posts.
03-25-2005, 02:33 PM
#37
Super Moderator
Join Date: Feb 2002
Location: Amityville, New York
Posts: 12,288
same theory behind pipe size giving restrictions and mufflers, get the right combo and it can increase power
its a bad blanket statement to say adding a restrictor to the exaust and gaining power means something is wrong
its a bad blanket statement to say adding a restrictor to the exaust and gaining power means something is wrong
03-29-2005, 06:17 PM
#39
Member
Join Date: Apr 2002
Posts: 73
I got sick of the smell, so I switched back to the N-Tech high flow cat I had on the car some time ago. Problem solved. The car smells just like any other "clean" car now. And I don't have an air pump or any other emissions equipment.
I saw a muffler test on a Mustang magazine a while back where almost all the mufflers made more power than straight pipes. They all made similar power, though the sound level varied quite a bit. I don't think this 370RWHP car with dual exhast was quite pushing the limits of flow for the mufflers in the fashion that we are with 1 muffler on a 400+ RWHP car, but my impression was that you can run mufflers without killing power, and that flow capability and sound level are perhaps not as closely related as I once thought.
It does seem clear that straight-thru mufflers flow better than chambered mufflers, but I bet all the straight-thru (perf core) ones flow about the same as each other or a straight pipe, and it is just a matter of finding the quietest one you can fit under the car if you want to maximize sound comfort. Bigger muffler case usually means quieter.
There has been a lot of talk about metallic substrate cats lately. They seem to offer excellent packaging (small) and flow while keeping the exhast smelling clean. I ordered a Random Tech metallic unit from Martel Brothers, and both Summit and Jeg's sell the Dynatech metallic cats. This may be just what we need.
Overall, I want my car to be quiet (like 5x as loud as a normal car, not 20x as loud) and clean (or at least not smelly and eye-watering). I'm too old and value my hearing too much to drive a super-loud car around -- it's embarassing! If nothing else, it just attracts too much attention from the police. Super-loud cars rarely sound "good" to me, and two-rotors aren't exactly the prettiest sounding engines anyway. I bellieve that clean and quiet are reasonable goals and can be achieved without significant power loss, though admittedly I know it would make more power with straight pipes. It is worth 5, 10, 20 RWHP to me to keep it clean and quiet.
In terms of the racing organizations requiring a specific muffler -- it would be silly to think that the muffler company wasn't paying to be the approved muffler. People keep building houses next to racetracks and then getting annoyed that race cars are loud. So there is pressure on racing organizations to quiet the cars down. I don't think they are doing it because the organizers themselves are personally troubled by their races creating noise pollution.
-Max
I saw a muffler test on a Mustang magazine a while back where almost all the mufflers made more power than straight pipes. They all made similar power, though the sound level varied quite a bit. I don't think this 370RWHP car with dual exhast was quite pushing the limits of flow for the mufflers in the fashion that we are with 1 muffler on a 400+ RWHP car, but my impression was that you can run mufflers without killing power, and that flow capability and sound level are perhaps not as closely related as I once thought.
It does seem clear that straight-thru mufflers flow better than chambered mufflers, but I bet all the straight-thru (perf core) ones flow about the same as each other or a straight pipe, and it is just a matter of finding the quietest one you can fit under the car if you want to maximize sound comfort. Bigger muffler case usually means quieter.
There has been a lot of talk about metallic substrate cats lately. They seem to offer excellent packaging (small) and flow while keeping the exhast smelling clean. I ordered a Random Tech metallic unit from Martel Brothers, and both Summit and Jeg's sell the Dynatech metallic cats. This may be just what we need.
Overall, I want my car to be quiet (like 5x as loud as a normal car, not 20x as loud) and clean (or at least not smelly and eye-watering). I'm too old and value my hearing too much to drive a super-loud car around -- it's embarassing! If nothing else, it just attracts too much attention from the police. Super-loud cars rarely sound "good" to me, and two-rotors aren't exactly the prettiest sounding engines anyway. I bellieve that clean and quiet are reasonable goals and can be achieved without significant power loss, though admittedly I know it would make more power with straight pipes. It is worth 5, 10, 20 RWHP to me to keep it clean and quiet.
In terms of the racing organizations requiring a specific muffler -- it would be silly to think that the muffler company wasn't paying to be the approved muffler. People keep building houses next to racetracks and then getting annoyed that race cars are loud. So there is pressure on racing organizations to quiet the cars down. I don't think they are doing it because the organizers themselves are personally troubled by their races creating noise pollution.
-Max
03-29-2005, 06:45 PM
#40
Super Moderator
Join Date: Feb 2002
Location: Amityville, New York
Posts: 12,288
Kooks has a prototype converter I am probably going to put on my car after the swap, I am going to talk to them about doing a dyno test before and after with no other changes made to the car
this is a few months away, I will post the results when the time comes.
this is a few months away, I will post the results when the time comes.