I believe I used a tick over 3.0" to compensate for bends without a mandrel. It was more of a mental exercise, but my numbers looked unworkable that soon.
I agree and added reiteration of what you'd already said beginning with "Doesn't hold water."
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08-24-2016
I believe I used a tick over 3.0" to compensate for bends without a mandrel. It was more of a mental exercise, but my numbers looked unworkable that soon.
I agree and added reiteration of what you'd already said beginning with "Doesn't hold water."
08-25-2016
It certainly does hold water. I'm not saying that the only thing you need to do to get a 3800 to sound decent is make both secondaries the same length. There is obviously more to it than that. But it just seems as if 999 out of 1,000 exhaust threads here revolve around cat or no cat, resonator or no resonator, muffler or no muffler, which muffler to use, which cat to use, blah blah, etc. etc. and almost no one addresses the giant elephant in the garage, which is the front bank travels significantly farther before it joins the rear bank. As you've said, because of it's funky firing order and split journal issues, these engines are already behind the eight ball trying to make them not sound like crap, and the grossly unequal secondaries just makes it harder. So it does matter. It is a piece of the puzzle. That's all I'm saying.
A V8 is a V8. It's always going to have certain basic sound charecteristics, no matter how you exhaust it. But listen to sound clips of the same V8, one with equal length secondaries and one with a FWD, crossover type setup, and you will hear a difference. The unequal length crossover enhances the undesirable half-octave tones and some rasp.
When I said turbo 3800's sound better than non turbo cars, I was referring to the "newer" series 2 and 3 3800 kits that have closer to equal length inlets, as opposed to the old Grand National turbo setup, which has very unequal length inlets. The Grand Nationals still have the accentuated half-octave tone, but it's masked somewhat by a different cam than we have and of course, the turbo.
The closer to equal length your exhaust secondaries are, the better the pulses "line up" to exit the pipes, and the "cleaner" your sound is likely to be.
08-25-2016
Listen to my car. Or YouTube true dual 3800 Camaro, Firebird, or Holden Commodore and you tell me they don't sound significantly different and better than most every other FWD 3800 running around. Better yet, YouTube supercharged Commodore hill climb and tell me you wouldn't trade your cars sound for that. Ask yourself what the basic common denominator is with their setups.
As a car geek, all I'm trying to do is make my cars run, look, drive and sound as good as I reasonably can. I think that's all many of us are trying to do.👍
08-25-2016
I'll listen to it when I get a chance later tonight. I am actually on some of the FB groups for the L67's down under and have listened to enough of their sound clips to know that while they sound a little deeper they STILL have the staccato idle and rasp that we have here. I have watched their "Skids" videos, idle clip and revving of the engines. They don't sound significantly different than the cars in the States. I have listened to straight piped Camaros and they sound like a 3.8. I have a coworker with an 05' Bonneville GXP and it sounds like a V8 there isn't any rasp and there is nothing doing with the unequal length from one bank to the other. He has had the car a while I have driven it many times and I always hear him when he leaves for the day.
Again have you ever seen the Edelbrock TES system? It's basically a set of mid length headers where the Drivers side crosses over under the engine and then meets up with the passenger side header and merges, not unlike a set of SD headers into a flanged collector. I described the rest of the system previously. The primary tubes are all unequal length with the 2 and 1 primary tubes being shorter and progressively getting longer going to the rear of the engine. The car sounded like any other V8 with headers and dual exhaust. I used to always ask how I got dual 3" exhaust under there and would just tell them it's single exhaust, just all 3". Most dual exhaust systems on GM G-bodies when done dual would have the driver side swing over to the passenger side and through the transmission mount since there wasn't a reduced area for the pipe to run and it would sit too low. This made the pipes about 3' longer on the drivers side. So the length plays no real part in he raspyness of our engines. As an audio guy that was really big into frequency cancellation, which in fact I had made a noise cancellation system while I was in school for electronics for a project (I wish now I had patented it) I studied all types of enclosure design and built literally hundreds of enclosures and I know a thing or two about how to cancel or boost a sound.
As far as all the exhaust threads that talk about what mufflers, cat or no, and all that, well none of that is going to change the firing order, so the fundamental frequencies are still going to be the same. The guy I referenced earlier with the 4.3 in the Blazer well he basically created a resonator and with dumb luck ended up with something that sounded a little better. I asked him why he ran that and he said he just guessed that would help but he had no understanding as to why. The GN's have a transverse crossflow muffler stock (like all other A/G-bodies) with "dual" exhaust. And again the reason that the turbo sounds better is because the pulses hit the turbine wheel and are slowed which makes them quieter than without it and most people still have mufflers after that as well. Equal length or not it won't really make a difference. You could make the car straight piped headers that stick straight out of the hood and go to the moon and all you would get is the Mooninites *****ing about how raspy it sounds.
Equal length or not the sound is the same the only difference is the scavenging effect by the cross sectional area and length it only changes where the scavenging is most effective. The longer the tube the lower in the rpm band that the engine will make torque the shorter the higher in the rpm band the make more torque. Just like a long port will have a lower tuning frequency than a shorter port in an enclosure. It doesn't change how it sounds it only changes where it peaks.
I hear what you are trying to do (pun intended), but without changing the firing order and re-engineering the crank you really aren't going to change much without cancellation of the offending pulses which is why everyone already says use the stock mufflers since they are large and dampen the sound pretty well. The Supercoupe had dual cats and into a resonator which was a dual in single out muffler with the inlets running the length of the resonator and the outlet ran all the way to the front of the resonator so that the gasses and sound had to pas through the perforated tubes and a smaller amount going from the rear of the resonator back to the front and back through it to the outlet. It was super restrictive and chocked down the power by 25 hp. It was the single largest restriction in that system and people always said it was put there so that the SC wouldn't make more power than the Mustang, well that may have had an ounce of truth to it but the real reason was to quell the raspyness of the engine along with 2 BBQ size mufflers. And that is the crux of the biscuit... cancellation and muffling.
Jeff
Like I said I will listen to it when I get home and see what you have going on there.
08-25-2016
Originally Posted by NSTGP1
Ok ok I did as you asked and listened to the suggestions and the ones in this thread and the Holden hill climb. No idea which one is yours. The Holden in the first link sounds a little deeper, but the rasp is there. They only have slight differences in sound with that white one sounding like someone was running over a flock of geese or something.
08-25-2016
My car is the red McLaren tribute car, which I believe is the second link at the top of this thread. Hey, I hear you (pun intended) about there still being some measure of V6 rasp in all of these clips. Especially the white one, although I don't like downing the guy for going out on his own and trying something unconventional with his ride. It's a hobby, and trial and error in the name of innovation is part of the territory, right? That's how I look at it anyway so kudos to him for taking one for the team so we all know another way not to run 3800 exhaust. Seriously though, cheers to you white car owner dude.👍
Listen, few things sound better to my ears than a healthy American V8. I own one myself. With my Grand Prix I'm just trying to get the best sound out of it that I reasonably can, on a working guy hobby car budget. I guess I've just resigned myself to accept that I'm dealing with a 6 cylinder engine here and no matter how much I breath on it it's still going to retain some of it's "six-ness". When I start it up and listen to it idle, it could easily be mistaken for a small V8. But as the revs climb the staccato comes out and it sounds like a cross between a Japanese sport bike and an Indy car. Not a V8, but 100 times better than any other 3800 I've personally heard. It brings a smile to my face and that's what I built it for, so i'm happy.
I appreciate your arguments dude. I get what you're saying. It's good to have healthy debate. Have a good night, cheers.
08-26-2016
I think people open the exhaust up too much and the makes them sound bad. I have tog headers 3" dp, no cat, 3" resonator, 2.5" resonator both stainless works, then into two 2.5" borla mufflers. I have no raspy sound at all and pretty much no drone. I use to have a just one resonator a 2.5" magnaflow and it was complete crap. High quality resonators and mufflers seem to be only way to make them sound ok, other than turbo.
Id like to hear a GP and Regal with all the same exhaust, but the one muffler vs two
'
08-26-2016
Ebk231 post a clip of the car I'd like to hear that...
08-27-2016
^^^ Agreed. Dual resonators crossed my mind.
08-28-2016
I will get a vid, might not be for a week though
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