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Silber 850 knock sensor

TWARD700

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Nov 26, 2007
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Seattle WA
Full throttle pull for 20 seconds 4' of powder stated to fall on its face and blinked a knock sensor on the gauge. Anyone have this happen??


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T

TheRedrooster

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Nov 5, 2012
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Sled turbo sputtering

No that’s not the problem it’s a lack of fuel not gearing your afr are to high if you keep running it like that you’ll fix it for sure it will go boom
 

TWARD700

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Nov 26, 2007
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Seattle WA
I have the 26 tooth to gear from TKI
To go to 2.4 gearing running 2.52 now
Running SHR weights 6 gram screw 2 gram on bolt clicker 3
Pulls 8000 ever time I look down but the recall says 8440


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F
Nov 27, 2007
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medicine hat
Ya this pdrive is defiantly I think leaving something on the table, my stock 850 is also showing 8400 max rpm, but only shows 8-8100 on a big pull when looking

I looked at my stock primary after the last few days of hard 100 second pulls and the belt is up less than 1/2 inch from top of primary... thee is no way in hell that it can’t over rev with a turbo added making another 50 hp..

Why Sibler needs to add some gearing, my other two turbo xm sleds run 2.03 and 2.10 gearing and belt goes one inch from top of primary on a good pull at 7000’
 
F
Nov 27, 2007
2,495
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medicine hat
Talking with a tech tonight, he says after 8300rpm ecm starts pulling fuel, this would also lean out and hit knock much easier, possible det plug damage you seen

Gearing up was on the top of his list of things to remedy problem
 

winter brew

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I believe these digital tach's are slow reacting. It can easily flash to more than indicated when the track is briefly unloaded.
I would load it up to never see more than 7900, try gearing up as Fred suggested.
Curious to hear if that addresses the issue.
 
F
Nov 27, 2007
2,495
712
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medicine hat
I sure would like someone to verify the tacks are slow.. it would solve some mysteries for sure.. I was thinking of putting a digatron on with playback to find the rpm surge area.. I have went up slow on rpm to find where it Max’s out but no luck, only seams to be on wot stabs where it happens, maybe belt slip on secondary

I believe these digital tach's are slow reacting. It can easily flash to more than indicated when the track is briefly unloaded.
I would load it up to never see more than 7900, try gearing up as Fred suggested.
Curious to hear if that addresses the issue.
 
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