Has anyone tried this iPhone app for belt tensioning?

Different engine positions result in different camshaft loading. This is a repeatable pattern over 2 revolutions of the engine.
Imagine instead of looking at engine revolution you made a mark on the belt instead. This would have no relation to camshaft varying load, at least not until after many engine revolutions.
But the point is, the belt tension is dependent only on engine position, not on where the mark on the belt is.

 

Hi all,
old thread, I know.
But for me relevant, as I am starting with the XLmajor on my 550.
I downloaded the Gates Carbon app, to check the present tension on my old belts.
The waterpump belt only saw 56 Hz on the app (???), but the long strand can be twisted over 180 degrees easily.
From my experience with belts, too low a tension, but so much off?
I measured like 10 times, values 55-56Hz all the time...looks like the app is correct...

As it should be 120 -130HZ, something obviously is not correct , most likely adjusted wrongly by the indy that did the last maintenance 4-5 years ago.
I guess there were no apps in 2016..
I tensioned it further to 124Hz, but it now appears to me as a really high value for this type of belt with such a long upper side.
It even sings a bit now when plucked.
I get a consistent 124-125 Hz , but should this belt really be feeling this tight?
( I do not mean the 124Hz, I know that the value is correct, but the very tight appearance of the belt)

Because all belts measure very, very low, (timing belts to 45 HZ ) I am questioning the measurements I took a bit , even if I could replicate those values all the time.
I hope somebody remembers how their freshly and correctly tightened belt felt...

 

I used this along with a proper belt tension gauge and the iPhone app read low
I can not remember exactly but it was very consistent
Did you put in the correct length and use it as described
If you did I found it close but low
Can not remember how much I am guessing here but I thought about 10%

 

Can someone post a link to this Gates app, (Android) please?

 

Thanks, 10% too low would sound logical to me, as the present timing belts are 84 HZ at the most when put under tension by rotating the engine by hand, and I assume that they have not been set tighter than the spring allows by itself.
So around 95 real Hz sounds right in that case. (The 575 WSM 126Hz on the long side of the timing belt can only be reached by helping the tensioner a bit)
The maintenance was done by an indy that has a very good name regarding Porsche and BMW, but apparently did know sh*t about ferraris.

I have removed the v-belts (and steering pump) again, and I will set the tension when I am done with the major, at 110 for the waterpump (still twice what it was...)
At the moment I am shamelessly copying the aluminium bridges MSW developed to help safely removing the cams, so it will be some weeks before I will tighten the belts again.

About the Gates app for Android, it is called Carbon Drive. Very easy to use.

 

Robbe- The 575M WSM cambelt frequencies were superseded by those in the 612 WSM, just so you know.


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Yes, I seem to remember to have read that somewhere ( I read a lot of threads on the 550 service, like 10 hours of postings, just to educate myself for this endeavour), but thanks for showing the info!!
Just a question about it that I can't find answered so far, about that the total sum of frequencies should be 335 to 360 Hz.
Is the sum of the tension measured at the same time for both long and short side , or is it the sum of the highest tensions one can set any side to, by turning the engine Clock wise or a bit counter clockwise? I assume at the same time, but I like to be sure...

 

Robbe,

Got it.

Thanx.

 

As of today, the Gates Carbon Drive app states it’s for bicycles, motorcycles and scooters. That’s the only one I can find.
is this the one that everyone is using for their cars?

Thanks

 

Try 'Carltune'
'Belt Tension meter'
'Spectroid'

I preferred Carltune the best, but all 3 gave consistent results