Any downsides to anti reversion mufflers/devices?
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Re: Any downsides to anti reversion mufflers/devices?
The existing bullet is after the cat about 20in, the bullet is there because I had it on hand- no other reason- I am running a proper muffler as well.
Re: Any downsides to anti reversion mufflers/devices?
How many mufflers total?
A cat + a bullet muffler + a "proper muffler" ?
Excessive restriction creates more ex reversion on cammed engines.
A cat + a bullet muffler + a "proper muffler" ?
Excessive restriction creates more ex reversion on cammed engines.
Re: Any downsides to anti reversion mufflers/devices?
As it is, as a DD- it is barely tolerable noise wise. If I was to do it again- I would likely use a aerochamber. Existing muffler is Donaldson.
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Re: Any downsides to anti reversion mufflers/devices?
Sorry for dragging up an old thread, I just thought I would comment my experience with a Dynatech torque booster/ anti reversion chamber...
I installed one yesterday on my 350hp inline 6 running a 252/260@50 cam and a big port cylinder head designed for high rpm.
No dyno data but I can definitely say part throttle torque has increased from 2500 onwards. When feathering the throttle around a bend the car feels much more responsive and pulls easier onto the cam. A definite improvement.
I have not noticed much change with full throttle hp. On a street or circuit car I would not hesitate to install these. I can see pulling out of a corner would be improved for circuit work. You could hold the taller gear where without the booster I would probably drop back another gear.
I did not really notice any real difference to sound.
Just thought I would share!
I installed one yesterday on my 350hp inline 6 running a 252/260@50 cam and a big port cylinder head designed for high rpm.
No dyno data but I can definitely say part throttle torque has increased from 2500 onwards. When feathering the throttle around a bend the car feels much more responsive and pulls easier onto the cam. A definite improvement.
I have not noticed much change with full throttle hp. On a street or circuit car I would not hesitate to install these. I can see pulling out of a corner would be improved for circuit work. You could hold the taller gear where without the booster I would probably drop back another gear.
I did not really notice any real difference to sound.
Just thought I would share!
Fumbling around in the shed...
Re: Any downsides to anti reversion mufflers/devices?
A pair of anti reversion "mufflers" placed directly after the header collectors filled in a 90 lb ft hole in torque curve of a 424 CID SB2.2 dirt late model engine @ 2500-ish RPM with no significant difference in power everywhere else in the curve.
Very helpful on slow restarts.
Very helpful on slow restarts.
Re: Any downsides to anti reversion mufflers/devices?
food for thought. thats a lot of overlap for a tiny cam.
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Re: Any downsides to anti reversion mufflers/devices?
It's in the only spot that fits really, which was about 15 inches from the start of the collector.
Can't say I would call my cam tiny, and not sure how you worked out the overlap without knowing where the centres are, unless you are referring to another cam?
Fumbling around in the shed...
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Re: Any downsides to anti reversion mufflers/devices?
@lc-gtr-1969
You got any video of that motor of yours. I would love to see it (and hear it) if you do. I love inline sixes.
You got any video of that motor of yours. I would love to see it (and hear it) if you do. I love inline sixes.
High quality metal, body and paint work
http://www.spiuserforum.com/index.php?t ... inia.9030/
http://www.spiuserforum.com/index.php?t ... inia.9030/
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Re: Any downsides to anti reversion mufflers/devices?
https://www.youtube.com/watch?v=N-U61tWYaDUChris_Hamilton wrote: ↑Sat Dec 11, 2021 3:23 am @lc-gtr-1969
You got any video of that motor of yours. I would love to see it (and hear it) if you do. I love inline sixes.
Fumbling around in the shed...
Re: Any downsides to anti reversion mufflers/devices?
sorry about tiny cam. Was looking at mopar numbers.
Re: Any downsides to anti reversion mufflers/devices?
This may have been touched already but this appears to me to be much the same principle as the exhaust termination boxes used to simulate an open header. Those however depend on volume to create the reflected pulse as well as a similar placement of the collector entering the chamber.
Is this to say the anti-reversion chambers from crateinsider.com are accomplishing the same thing with a much smaller package? If I'm not mistaken I believe the conventional termination box has to be equal in volume to the CID of the engine. Or half that if two are employed.
Kevin
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Re: Any downsides to anti reversion mufflers/devices?
I thought that may be the case, no problems, cheers bud!
Fumbling around in the shed...
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Re: Any downsides to anti reversion mufflers/devices?
I do not think these AR Chambers are quite the same as termination boxes, both may help minimise reversion for obvious reasons, but as you suggest, I am not sure the AR chambers have the volume or dramatic change in area that a termination box will have to induce the engine thinking it has open headers.skinny z wrote: ↑Sat Dec 11, 2021 11:08 amThis may have been touched already but this appears to me to be much the same principle as the exhaust termination boxes used to simulate an open header. Those however depend on volume to create the reflected pulse as well as a similar placement of the collector entering the chamber.
Is this to say the anti-reversion chambers from crateinsider.com are accomplishing the same thing with a much smaller package? If I'm not mistaken I believe the conventional termination box has to be equal in volume to the CID of the engine. Or half that if two are employed.
If I could fit a termination box I would run one but room is quite tight under there...
Fumbling around in the shed...