On my 1949 Studebaker pickup truck with a Chevy 307 in it, the previous owner had installed catalytic converters along with turbo mufflers in the 2" exhaust system(not exactly sure why). I wanted to get a little more of the old school, rumble and rapp exhaust sound so I installed glass packs. This made no difference at all. In hind site, I should have started the truck with just the converters on it to see what that sounded like, but I did not do that. Do you think the converters could be restricting the sound/exhaust? In addition, do you think having converters on a truck without a computerized, monitored fuel system, would have any negative effects? I do have an obnoxious smell from the exhaust. Thank you
Converters can cause problems if they are plugged, they don't tolerate an overly rich fuel mixture. Connect a mechanic's vacuum gauge to manifold source, it will show any type of restriction in the exhaust system right away.
Converters are useless without the proper mixture. They also alter the sound. The smell shows you are running too rich so you may as well get rid of them.
if there is no legal requirement to have catalytic converters, you ought to remove them. Might check to make sure the truck is not registered and some kind of reconstructed vehicle or something...???? that's the only wild reason I can imagine that it would have them.
from Illinois and know Illinois emissions laws , they are only by Model Year of vehicle, not engine year , so the convertors can be removed as the first year is MY 1976 , so take them pigs off and open it up ! and testing is only for OBDII vehicles ( and some of them are even exempt ( 2006 and older trucks over 8501 Gvwr )
Take them off and sell them. ( there worth more than scrap if you can find a core buyer) Use the money towered your new exhaust. My .02. Brian Sent from my iPhone using H.A.M.B.
almost impossible to sell them now here as you have to have the VIN ID numbers on them as people are stealing them ( like the 2 off my pick up truck which cost me $800 for the pair not including installation ) and they passed a state law on selling and buying requirements , basically only shops can sell them to recyclers , ( but not saying it hasn't been done but they are cracking down on it around here ) one of the local yards is out of business and owner is in jail because Sec of state went in and did a inspection .
Converters are basically wide band frequency attenuators - I am quite certain they are restricting the sound. Which isn't to say you can't make a car with converters sound good but adding them to something like what you have seems pointless. As mentioned they can also plug up or even melt if the mixture isn't correct.
I ran an OT Firebird with just the cat and a tailpipe for years when the muffler(s) rotted away. Sounded good, ran good.
Ditch the cats. They kill exhaust flow and sound like strapping a Honda Civic muffler on a big block.
I had the muffler shop remove the cats and after trying different glass packs, I decided on going with straight pipes out the back under the rear bumper. Idling, and once up to speed, the sound is not bad, getting up to speed can get loud but not too bad in the cab. I still have the original turbo mufflers and glass packs if I decide to re-install . I do think removing the cats was a good idea, though I don't think it was restricting the sound much.
come down by me on I-55 on a race day and the state police might give you a IL Code 12-602 ticket ( and do not drive thru the local towns as they enforce it specially Frankfort and New lenox ) for being too loud and no muffler ( by Illinois law you have to have a muffler, supposed to be stock type ) and now they take pictures of the systems if its not in compliance . ( Frankfort and New Lenox make you post bond on the spot to drive away and a must appear in court with the vehicle later to show its been muffled ) and many of the sw subs also do it . I have fought it several times as they do not use the SAE guidelines ( J1169 and J986 ) for enforcement and thats what the feds use for rules to sell cars . ( California is the only state to my Knowlege that has the proper set up at the state inspection stations ) most cops do not do anything as long as your not rapping it like the ricer crowd does .
I am not enjoying the sound from the straight pipes (pretty annoying getting up to speed). The muffler shop suggest trying adding resonators. I have absolutely no experience with just resonators and no mufflers. From what I have read on the internet, a resonator doesn't really quiet the exhaust rather it tunes it. Does anyone have any experience with just resonators? Thank you
Have you ever heard the Auger style mufflers from Speedway ? Gives the appearance of straight pipes .but sounds amazing nice and mellow at cruising speed ,but rips when you are full throttle . Almost no restriction, weigh next nothing and are cheap. Used them on two cars .
My wife's '67 Caddy has a resonator from the factory. It looks like a 4 foot long Cherry Bomb, and I don't really know what it does. The exhaust is quiet, but you can still hear the unmistakable muscle of the 429.
No I have never heard of the Auger style muffler. Interesting concept. Unfortunately I have 2" pipes and it fits 3" and larger. Thank you
Resonators are a type of muffler. Speaking in generic terms it's hard to say what will do what - there are no rules on what is in a resonator and what is in a muffler. The aftermarket "mufflers" on 90% of the bikes out there are nothing more than a glasspack which is what a resonator might be on a car. Or the resonator may be tuned to a specific frequncy to attack a problem frequency, or maybe just a volume in the right place to break up a standing wave/drone or whatever. Put glass packs on it to begin with, they should take out the high frequncy rasp but not do much to lower frequencies. You can call them mufflers or resonators or whatever, it won't change how they work. ;-)
Shouldn't be too hard to find someone with a small block Chevy in any kind of car or truck that you like the sound of and ask them what they have on it!
Resonators are basically glass pack mufflers, very similar construction and theory of operation. High flow Cats and straight pipes are pretty common and on the edge of bearable on a daily commute and pissing off the neighbors. They sound good with a big tip like that. Just straight pipes are going to get old pretty quick for most people. Put the resonators or glass packs in the tail pipes after the axle.
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