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Discussion Starter · #1 ·
Advice and opinions please.

My 124 Abarth is two and a half years old, although I've only owned it for the last three months. I've read the forum posts as well as watched all the relevant YouTube clips regarding the known valve issues. Consequently I took the time yesterday to free off and anti-seize grease the valve workings and spring. It was fairly easy for me to free off and so I was quite pleased that things would operate as normal. As with others though I noted that the spring is, in my opinion also, far too strong for exhaust pressure alone to allow activation of the valve.

As a result I concocted a test that my son, my neighbour and myself carried out earlier today.

At idle we noted gasses coming from all four pipes. When I manually activated the valve none of us could detect any difference to either the sound or the amount of exhaust coming from each pipe.

We then tried the same exercise at a constant 2000rpm and then repeated the exercise again at a constant 3500rpm. None of us could detect any difference whatsoever either in the noise or the proportion of gasses emitted.

I am at a loss to explain these findings. It suggests to me that either the valve is totally inoperative, broken internally, or even non-existent. I would be surprised if it were broken internally as the car has a low mileage and freeing off the valve didn't require great force in the first place.

Am I missing something obvious? I would love to get to the bottom of this because it clearly manifests itself in the 500 based Abarths with Record Monzas as well. Did Fiat/Abarth sell us duds here?

Please let me know your thoughts.

Regards,

Stan
 

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1st. This will only work with engine load. Just revs in neutral will not produce a lot of exhaust pressure. Maybe someone can film a valve while car is on a dyno.
2nd. I have the same feeling about the spring. It’s to strong.
 

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This thread and video may be informative.

 

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Discussion Starter · #4 ·
Thanks for your responses Robbert and Jack.

Firstly Robbert, yes of course I agree about the engine load issue, but perhaps I made my point badly. What I was trying to convey was that even with revs and me operating the valve, not the exhaust pressure, there wasn't even a slight change to the tone. Nothing. Blow lightly through a trumpet and operate a valve and you will hear the difference just as if you were blowing very hard through the trumpet. I hope you get my point. The valve was being operated, it should surely have had an audible effect certainly when we were up in the rev range. My neighbour by the way is a car technician and felt the test was valid.

Secondly Jack. The best YouTube clip available and I'd already seen it several times whilst doing my initial research, but once again it doesn't show the valve operating. A 595 Abarth guy had a GoPro on his, just like Robbert rightly suggests, and nothing happened even under full load out on the road.

So none the wiser really. I thin k a lot of owners are greasing up the valve and thinking all is good, but I'm not convinced.

Does anyone else have any thoughts?

Thanks again for the responses guys. The quest continues.....
 

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When I bought mine the RM wasn't on the menu as they were reserved for the"Monza Edition" (a limited release at the time, $5000 extra). I can get it now as a $2000 spare part!

Anyway, I thought that the valve was closed at low revs, directing all the output through the muffler. As the revs increase the valve was pushed open allowing the some of the output (including noise) to bypass the muffler and directly exit. This seemed to make sense.

Greg's video has shown that the output is from all pipes which must mean that the valve opens at low revs, maybe not all the way though. Only opening fully at higher revs.

I'd like to know for sure as well as I'd like to get one. My car is fully loaded apart from the RM but can't justify the 2 big ones, especially if it only makes a difference at high revs. The stock muffler is loud enough at the moment with some people here saying it's too quiet (maybe the stock Oz version is louder than in other markets! Unlikely but who knows?).
 

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When I bought mine the RM wasn't on the menu as they were reserved for the"Monza Edition" (a limited release at the time, $5000 extra). I can get it now as a $2000 spare part!

Anyway, I thought that the valve was closed at low revs, directing all the output through the muffler. As the revs increase the valve was pushed open allowing the some of the output (including noise) to bypass the muffler and directly exit. This seemed to make sense.

Greg's video has shown that the output is from all pipes which must mean that the valve opens at low revs, maybe not all the way though. Only opening fully at higher revs.

I'd like to know for sure as well as I'd like to get one. My car is fully loaded apart from the RM but can't justify the 2 big ones, especially if it only makes a difference at high revs. The stock muffler is loud enough at the moment with some people here saying it's too quiet (maybe the stock Oz version is louder than in other markets! Unlikely but who knows?).
The RM on my car is definitely louder at idle than stock exhaust, specially when cold, lol.
 

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I think the valve is designed to leak a considerable amount of exhaust gasses through as a way to tune the sound of the exhaust. At idle, it likely leaks all the exhaust gasses through. Without any load on it, there is probably not enough exhaust flow to change the sound, even when you rev the engine and open the valve manually.

When you get on it under load, the sound of the exhaust definitely changes.
 
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