REAR MUFFLER BYPASS QUESTION
#16
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I didn't notice much of a difference in sound with the RMB on my automatic 87, so I installed an X-Pipe too. No issues with the volume even at WOT, still not loud to my ears. There is a very slight drone in the mid 60's MPH. If I decide to keep this setup I plan to install a resonance pipe and see what that does. Long term I have a set of Devek headers on the shelf that will be going on this car.
On another note, my shop sees dozens of Mustangs & Camaros on the dyno every year, none of them sound like my 928. My 79 with open headers has been compared to the sound of Steve McQueens car in Bullitt, hardly a bad thing.
As for value, is your car an ultra low mileage pristine example? If not, unless the prospective buyer is a 928 expert, they probably won't notice. Most new performance cars are much louder stock than a 928 with an X-Pipe and RMB.
Multiple states have laws going the complete opposite direction on the books or recently passed. You keep talking about this doomsday we all need to be prepared for. A volcano could erupt and wipe out most of us too, why not wax on and on about that?
Yea yea, we all know living in California sucks due to all the draconian laws you are forced to live under. Keep them to yourself, OK? We're sick of hearing about it.
On another note, my shop sees dozens of Mustangs & Camaros on the dyno every year, none of them sound like my 928. My 79 with open headers has been compared to the sound of Steve McQueens car in Bullitt, hardly a bad thing.
As for value, is your car an ultra low mileage pristine example? If not, unless the prospective buyer is a 928 expert, they probably won't notice. Most new performance cars are much louder stock than a 928 with an X-Pipe and RMB.
Yea yea, we all know living in California sucks due to all the draconian laws you are forced to live under. Keep them to yourself, OK? We're sick of hearing about it.
#17
Rennlist Member
Back on topic. I had a RMB on my 89 S4 (still original cats) with the small mid mufflers and it was just loud, didn't have the sound I was looking for. It was kind of just annoying.
I installed a later twin tip rear muffler and now the sound is just right, a touch of rasp and a healthy roar under load. But quieter around town and just cruising. Perfect to me.
The earlier large mid mufflers and rear box make the car extremely quiet which is definitely some people's thing, especially on long drives. Makes the 928 feel more like a GT car if I'm honest.
#18
Rennlist Member
I didn't notice much of a difference in sound with the RMB on my automatic 87, so I installed an X-Pipe too. No issues with the volume even at WOT, still not loud to my ears. There is a very slight drone in the mid 60's MPH. If I decide to keep this setup I plan to install a resonance pipe and see what that does. Long term I have a set of Devek headers on the shelf that will be going on this car.
On another note, my shop sees dozens of Mustangs & Camaros on the dyno every year, none of them sound like my 928. My 79 with open headers has been compared to the sound of Steve McQueens car in Bullitt, hardly a bad thing.
As for value, is your car an ultra low mileage pristine example? If not, unless the prospective buyer is a 928 expert, they probably won't notice. Most new performance cars are much louder stock than a 928 with an X-Pipe and RMB.
Multiple states have laws going the complete opposite direction on the books or recently passed. You keep talking about this doomsday we all need to be prepared for. A volcano could erupt and wipe out most of us too, why not wax on and on about that?
Yea yea, we all know living in California sucks due to all the draconian laws you are forced to live under. Keep them to yourself, OK? We're sick of hearing about it.
On another note, my shop sees dozens of Mustangs & Camaros on the dyno every year, none of them sound like my 928. My 79 with open headers has been compared to the sound of Steve McQueens car in Bullitt, hardly a bad thing.
As for value, is your car an ultra low mileage pristine example? If not, unless the prospective buyer is a 928 expert, they probably won't notice. Most new performance cars are much louder stock than a 928 with an X-Pipe and RMB.
Multiple states have laws going the complete opposite direction on the books or recently passed. You keep talking about this doomsday we all need to be prepared for. A volcano could erupt and wipe out most of us too, why not wax on and on about that?
Yea yea, we all know living in California sucks due to all the draconian laws you are forced to live under. Keep them to yourself, OK? We're sick of hearing about it.
Has nothing to do with CA...why do you think CA has anything to do with it...why is this always your knee-jerk reaction to the topic? The case, South Dakota v. Dole should be what you're upset with in how the constitutional relevance matters to my statement. It's not me...so stop taking it and making it personal. This challenged how the Gov can use $ to enact state laws and behavior.
Im not always smog friendly, but i'm not willingly ignorance if what -is- going to happen someday. If you don't have a stash of cats and smog pumps in storage, you're behind. Im no greenie. Im being practical.
It's the Feds holding onto your highway funds.
You can't say it can't happen because They have done this -3- times to bully states into various levels of "compliance".
Drinking Age
Speed Limits
MC Helmets
(Texting while driving was almost #4)
Existing long-standing 50-state emissions laws are unusually low hanging fruit. It's not even a new law that congress has to pass, it's already there. And WHEN it happens, a few simple percent of the driving public that this would impact, wont be able to raise a candle to it. Nobody cares what the cheaters think (generally)
Being ignorant of this..and that it's highly likely to happen, doesn't mean it should be ignored.
Failing to understand history is a great way to get caught unaware of it happening to you later. It's not even a political argument, it's how the highway fund has been used, and will almost absolutely for sure in the future. The tip of the spear is the EPA chasing down Diesel mod shops and tuner boxes.
Last edited by Speedtoys; 06-07-2023 at 02:21 AM.
#19
RL Community Team
Rennlist Member
Rennlist Member
I have a different engine (16v) on both my 928s. One is a 79 with 83 4.7L in it and the other an 84 Euro S twin dizzy. Both have the same exhaust setup, which is the later stainless round tube headers into a catless Y-pipe to a Borla cat-bacj system. The 84 is my daily driver and sounds great when you get on it but has zero drone at any rpm. The system on it previously was a Magnaflow setup that droned like crazy below 2,200 rpm. Got that replaced as soon as possible after buying the car.
#20
Drifting
My car is the loudest and best sounding and it is also the cleanest! ZERO NOX! Functioning SS Hi-Flow round cats are part of my system. Proof that clean and loud and enjoyable can be part of the same package.
Last edited by Petza914; 06-07-2023 at 10:50 AM. Reason: Deleted political rhetoric and left pertinent 928 info.
#23
Drifting
(This is auto related so mods should lay off the starbucks and chill) NO legislation is needed to get EV's to take over the market for everyday driving! I was in ON the Tesla IPO way back when because I believed in the tech when everyone else thought Tesla was a joke that wouldn't survive. EV's are good for all commuting and general travel. Nothing more pointless than having engines running in traffic jams. That could be alleviated with flex hours, better traffic patterns,no tolls................
Sportscars are a TINY segment of the car market, TINY! No need to make these cars go EV. The amount of pollution from such a tiny number of these cars is negligible. The ONLY reason they might be in trouble is the marxist personalities in 1 segment of the ploitical spectrum! NOTHING TO DO WITH POLLUTION, ALL to do with CONTROL! We are actually low on CO2
and this
Last edited by tv; 06-07-2023 at 02:54 PM.
#24
Rennlist Member
Join Date: Oct 2010
Location: Memphis, TN 1987 S4
Posts: 1,078
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15 Posts
I had an 87 w/ X pipe and RMB. It was a perfect sound even when on it. Not nearly as loud as a mustang and no drone at highway speeds. I tried the same with my 89. Intrusively loud. I had to remove the RMB. The 89 was a German mustang
#26
I have ran my 87 for 10 years with an h-pipe, no cats and an RMB. As others have said it’s only loud when you stand on the loud petal.
Everyone loves how my car sounds.
Now I have been getting tired of the stink so I just put on 200cel flow master spun cats. My sound is down slightly, but the overall sound at cruise is pretty much the same.
Definitely do the RMB, it’s easily removed and sold if you don’t like it.
Everyone loves how my car sounds.
Now I have been getting tired of the stink so I just put on 200cel flow master spun cats. My sound is down slightly, but the overall sound at cruise is pretty much the same.
Definitely do the RMB, it’s easily removed and sold if you don’t like it.
#27
Rennlist Member
Thread Starter
Thanks EVERYONE for the great information and observations. I listened toa lot of video's on you tube last night, and the different configurations definitely influenced results. My wife was a little concerned about cabin noise since the 87 is our long distance cruiser 70 percent of the time. I do not think it will be that much of an issue with my set up so I am taking the plunge. A reenlist member has offered me a nice RMB set up and I will do before and after videos for the forum.
My son and his B 52 crew agree too!
Thanks again for all the valuable insight. Can't wait to "get er done"
Lon
My son and his B 52 crew agree too!
Thanks again for all the valuable insight. Can't wait to "get er done"
Lon
#28
Rennlist Member
I've tried them all. From straight pipes, RMB, gutted cats etc.
I believe I have the perfect balance of not being a bad neighbor but still enjoying a decent sound. Along with headers, I have 2 cats from a low mileage GT (OEM) along with a Magnaflow muffler at the rear with two exhaust tips.
No issues with CA smog
I believe I have the perfect balance of not being a bad neighbor but still enjoying a decent sound. Along with headers, I have 2 cats from a low mileage GT (OEM) along with a Magnaflow muffler at the rear with two exhaust tips.
No issues with CA smog
#29
Rennlist Member
texas....i gutted my cat and replaced the rear resonator (84) with one of these....... far better performance now...the flowfx kills a lot of noise but basically performs like a straight through. i don't know what's up with the resonators but i did comparisons before and after and the resonator basically does nothing. the flowfx kills enough noise keep me from being embarrassed, but still has some grumble. and it's priced right. replacing the stock resonator was easy...i cut and bent an elbow on the front side and welded it up. i'm guessing that a decent muffler shop would cut out the old one and install the new one for $125ish
#30
Drifting
David Clark headphones. I worked there summers in HS. Interesting company. They also made space suits for early NASA missions, shuttle, and SR-71. On lunch break I would peek into the space area and saw Helmets and suits at various stages.