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Is there much of a benefit from this...Is it a different diameter....on the V8s I have seen the gain is mostly from just turning the accessories slower..,less parasitic loss...
 

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Discussion Starter #4
Confirmed pulley does fit, with no issue, there must have been a running change since my 500 was a 2013 and it had the timing marker pulley, but the 124 does not. I weighed the pulley factory is 44.10 oz, RRM is 30.10 oz.


Pulley is exactly the same diameter so there is no effect on the speed of the rotation on the accessories. I noticed the difference on the 500, and noticed the difference on the 124, I'll take the 14oz drop in rotating mass(every bit helps with a 1.4l), and I already had the part.
 

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Confirmed pulley does fit, with no issue, there must have been a running change since my 500 was a 2013 and it had the timing marker pulley, but the 124 does not. I weighed the pulley factory is 44.10 oz, RRM is 30.10 oz.


Pulley is exactly the same diameter so there is no effect on the speed of the rotation on the accessories. I noticed the difference on the 500, and noticed the difference on the 124, I'll take the 14oz drop in rotating mass(every bit helps with a 1.4l), and I already had the part.
RRM claims a weight difference of 2 pounds on their website. "-Only weighs a bit over 1.5 lb compared to stock 3.5 lb" Are you sure it's only 14oz?
 

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Correct me if I am wrong but doesn't the OEM crank pulley have a torsional vibration damper in it??...and the lightweight does not have one...how does that workout on these small engines??...does it create an issue??...on the high horsepower late model General Motor cars i have had that is a definite no no...
 

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Correct me if I am wrong but doesn't the OEM crank pulley have a torsional vibration damper in it??...and the lightweight does not have one...how does that workout on these small engines??...does it create an issue??...on the high horsepower late model General Motor cars i have had that is a definite no no...
That's a good point, and you are correct in that the original pulley has a damper. When these products first showed up on the 500 Abarth scene in 2012, this exact issue was a very hot discussion point. Time has proven the naysayers wrong. There are hundreds of these engines running with lightweight pulleys with no dampers, and I haven't heard of a single issue.

I am not sure what the difference is in the late model GM engines. It's probably a difference in ballancing. Historically Fiat engines don't have a damper from the factory, I was surprised when I saw that this one did.

Greg
 

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That's a good point, and you are correct in that the original pulley has a damper. When these products first showed up on the 500 Abarth scene in 2012, this exact issue was a very hot discussion point. Time has proven the naysayers wrong. There are hundreds of these engines running with lightweight pulleys with no dampers, and I haven't heard of a single issue.

I am not sure what the difference is in the late model GM engines. It's probably a difference in ballancing. Historically Fiat engines don't have a damper from the factory, I was surprised when I saw that this one did.

Greg
Greg,

Could there be a difference because the drive train is in direct line with the engine and crank therefore introducing harmonics from the rear differential on up...since this is the first application where the engine has been oriented this way...just a thought...
 

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Greg,

Could there be a difference because the drive train is in direct line with the engine and crank therefore introducing harmonics from the rear differential on up...since this is the first application where the engine has been oriented this way...just a thought...
Maybe, but there have been many older rear drive Fiats that didn't have a damper.

Greg
 
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