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Re: S80

Posted: Sat Jan 12, 2019 1:16 pm
by iceman_n
jpr.racing07 wrote:Hi its not when i remove plug leads its when i remove the Plugs (ie no compression ) so engine turns faster then it synchronises
have you try it with just no leads to see how it performs ?

Re: S80

Posted: Sat Jan 12, 2019 2:10 pm
by jpr.racing07
Its a 6.2 all aluminium sbc red lining at 9000 rpm,S80 waisted spark
Crank trigger ford sensor 36 tooth 1 missing in a single seater a Gould Gr 37

Re: S80

Posted: Sun Jan 13, 2019 4:15 am
by Rob Stevens
You forgot to mention that the thing sounds like the Devil himself created it :)

Crank trigger wires the wrong way round?
Gap tooth factor wrong?

Re: S80

Posted: Sun Jan 13, 2019 4:27 am
by jpr.racing07
Hi Rob its just had a big upgrade new heads you can walk down the ports
All titanium valve gear. Gap at sensor .8 of a mm ,checked wires at sensor all correct even tried other way around no different. Is there a minimum cranking rpm for the S 80 too synchronise.

Re: S80

Posted: Sun Jan 13, 2019 5:11 am
by stevieturbo
And still no scope trace ?

Any rpm to start, would only really be governed by strength of crank signal...which will relate to speed to a degree with a VR sensor, but also sensor type, wheel setup etc etc.

Hence a scope trace of the signal should tell you everything you need. ( as well as diagnostic display and crank errors etc )

Re: S80

Posted: Sun Jan 13, 2019 5:53 am
by stevieturbo
FWIW, my LS cranks at around 145rpm. I've used the same Ford VR sensor and DTA 36-1 trigger wheel I've had since I first started with my P8 back in 2002 or so. ( well I have replaced both over that time, but still same type of wheel and sensor )
So have used identical setups with RV8 TT on P8 and LS with P8 and S80, and currently same trigger setup with my Syvecs.
Why change something when it works perfectly.

Actual voltage of the sensor is pretty low at cranking speeds though.

This log should give some indication. Ignore the voltage scaling on the crank AN15, it's just because it's logged as a raw input which has an internal pullup, 2.5v there would be considered the zero volt line.
But as you see, on initial cranking voltage is very low, rising with rpm and eventually very high once started.

Top graph is rpm, although even here it takes a few teeth before a speed is indicated.

Bottom graph is a pressure sensor in cylinder 1 ( so it is starting and running on 7 cylinders )
So each peak there is TDC on cylinder 1. And although not critical, my missing tooth on DTA would be seen as 67deg in DTA's general engine settings, again you can see the relationship between the two clearly here.
There is lots of other info available, but I've removed it for ease of viewing
Pressure sensor in cyl1 was just playing with a compression test with engine starting and running.
syvecs comp test start.jpg

Re: S80

Posted: Sun Jan 13, 2019 6:35 am
by jpr.racing07
Thanks steve its booked in to be remapped by Sandy Brown in Feb so least i have it running.i will try and upload photos of crank oscilloscope

Re: S80

Posted: Sun Jan 13, 2019 7:11 am
by Rob Stevens
What's this set at?

Re: S80

Posted: Sun Jan 13, 2019 7:29 am
by jpr.racing07
Hi Rob its set at 1500

Re: S80

Posted: Sun Jan 13, 2019 12:29 pm
by Rob Stevens
And its definitely a 2 wire crank sensor (inductive) connected to pin 12 and a sensor ground?

Does it run fine once it is running?

Oh and I hope you have the traction all configured as you will need it.

and switches
Traction on/off
wet/dry
Launch momentary button
Launch RPM knob
Traction aggression knob


And use the random cut patterns, very effective at containing RPM