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Turbo Muffler on a 4cyl

In the summer I replaced the splitting muffler on my 4cylinder Ranger with a Thrush Turbo. It was partially as a joke.

I remember Turbos on V8 cars getting gradually louder over time, but on the 4 it seems to have hit a 'loudness limit' of some sort. At first I figured that maybe it was a lesser volume of air, but in all reality my 2.5L 4cyl is about the same as half a 5.0L V8 with dual exhaust.

Something also odd- On V8 cars I remember the Turbo muffler being quiet at low RPMs or a cruise with no load, but then 'opening up' and getting loud when you put your foot into it. The one on my truck is just the opposite- noisy at idle, half as loud at cruise, and when I put the pedal to the floor it is completely silent!

Bizzaro!

-ph

Reply to
phaeton
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My '89 Grand Marquis 5.0L is goofy. A year or so ago the car started making a swooshing sound on acceleration, like something was pumping air through a hose into the atmosphere. Turned out there was a BIG hole in the muffler and the exhaust pipe, and the car was just not one to make a lot of noise. It's definitely quieter with a new pipe and muffler, but even with the holes it was quieter than many stock models of other cars.

Reply to
clifto

It's the rpm difference, the V8 is cruising at the 4's fast idle and the

4 is screaming at highway speed instead of lower rpm roaring.

I put a turbo Dynomax on my straight six Jeep engine and it roars nice under power, but only turns 1750 rpm in top gear at 65 mph.

Just my $0.02,

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:
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Reply to
Mike Romain

Makes sense. So I spose that the turbo muffler is sort of 'tuned' to be resonant in the cruise range of the V8.

There's a guy round the corner from me with a late 80s Cherokee or Wagoneer that sounds something like that- Straight six with a burned- out Turbo or cherry bomb. It's pretty loud, and I'm sure it annoys the hell out of everyone else on my street but I think it sounds pretty cool.

Thenagain, I'm one of those weirdos that sometimes turns off the radio so I can just listen to the vehicle. ;-O

-ph

Reply to
phaeton

I don't think its RPM. Most 4-cylinder cars I've rented recently cruise at about the same RPM or only slightly higher than a v8. The big difference is the firing pattern. When you use a turbo muffler on one bank of a v8, it sees an irregular firing pattern because "90-degree crankshaft" v8s (virtually all production v8 engines) do not alternate between left (L) and right (R) banks, but fire L-R-L-L-R-L-R-R (repeat). That's what causes the typical v8 "burble" exhaust sound even with single exhaust. If you put the same muffler on each bank of a "flat crank" v8 (never used in production cars because they vibrate like a paint shaker) then it would sound like two 4-cylinder engines.

Reply to
Steve

Don't buy the expensive/good turbo's. You want the cheap ones. They're the ones that "burn out"/get a deeper/throatier sound with age. The good ones are made to hold up longer and not change their tune. Years ago I was buying Walker Universal Turbos for $15/$20 each and they "burned out" nicely. Stocked the common sizes. (2", 2 1/4", 2 1/2", center inlet/oulet, offset inlet/outlet) Turbos, not glass packs. Glass packs don't burn out as much/any, and are a totally different sound. (never cared for glass packs) Had a pipe bender and did alot of dual exhaust.

Reply to
dahpater

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