Honda F20
From the S2000, this is now a popular engine conversion into older cars and Lotus 7 replicas as it is an RWD engine.
There are 12 equally spaced teeth 30 degrees apart, with an additional tooth positioned ~20degrees after one (~10degrees before the next).
The engine turns clockwise (apparently this is the only Honda VTEC engine that does) so the trigger pattern is:
..., 30, 30, 10, 20, 30, 30, ...
Suggesting that this trigger cannot be used with InputTrigger/ShortGapTrigger (See below). Missing tooth with advanced filtering, setting missing tooth threshold between 1.5 (30/20) and 2.0 (20/10) could work, if it starts with 1.75 it will run too (the wildest relative acceleration happens during cranking, because of the low RPM).
Maybe the trigger could be turned over and refitted which would give the pattern: ..., 30, 30, 20, 10, 30, 30, ...
- Which could make the missing tooth setup work correctly, at least in 1.0.x (without advanced filter, or with advanced filtering and ~200% threshold ?). In 1.1.x (<= 1.1.95) the timing from last pulse could interfere with the extrapulse in certain situation so would require careful benchtest.... or rather:
Now the proper 30, 30, 10,20, 30 ... setup is implemented (along with any similar "extrapulse setup"), also with camsync in 1.1.96. Now under testing.
did you try with missing tooth setup
- if gaps are 30,20,10,30 (in this order)
- try a simple missing tooth setup
- since 10=>30 is more than 1.5 x even multitooth advanced filtering is not needed
- another_trigger_tooth=06 (if 4 cyl)
If gaps are 30,10,20,30 than a variation of InputTrigger/ShortGapTrigger that is not yet supported, I think (because it would also require shortgap at the next event to be fired, 180 degrees later in a 4cyl)
TODO: Configlets should be made for:
- ...30, 30, 10,20, 30, 30... 12+"extrapulse" crankshaft wheel
- 180, 180, 30,150, 180
- 4+extrapulse like the [Honda K20A] cam
- 120, 120, 40,80, 120, 120, 120
- highly suitable 6+extrapulse trigger on truck camshaft (eg. in producer-gas 1500/1800 constant RPM applications where timing-from crank has marginal advantage - especially that cam is gear-driven (no sloppy belt).
- Faster starting can still be achieved with the help from a good crankwheel trigger (like 36-4 rover k4 MembersPage/YasecElise), but these powerplant engines run all the time, and startup rarely anyway.
- 0(30), 120(90), 240(90), 360(90), 480(90), 600(90) rising-edge-absolute-position(pulsewidth) both-edge sensing HALL-only !
- given that homemade setups are reasonably HALL-type, 6 pulse with one lengthened or shortened pulse also makes sense for custom-machined wheels.
- this needs firmware mod for sure.
- Obviously the 6+extrapulse is better option when made from bolts.
In factory applications the missing tooth wheels are better choices (and actually mostly used: better timing and diagnostics can be achieved without stricter wheel-precision requirement), but for home-made setups the low toothcount (often bolts) are usually appealing.
Bench test results
- Fw 1.1.96 supports as extrapulse trigger
- without camsync use configlet 4cyl_12+extra_Honda_Nocamsync (configure as 12 tooth coil-type + extra pulse trigger enable, ref tooth table 0, 6, 0, 6)
- with camsync use configlet 4cyl_12+extra_Honda_Camsync (configure as 12 tooth coil-type + extra pulse trigger enable + maximum edges between secondary edges = 2, ref tooth table 0, 18, 12, 6)
- VemsTune trigger play support ( from VT newer then 2011-07-28 ) as h124 ( h: Honda 12 : 12+1 primary trigger 4: 4+1 secondary trigger)
- Tested [Benchconfig]
'Test on real car
Car is honda type R ep3, 2.0 vtec(also vvti) k20a2 engine.
Primary trigger:12+1(extra pulse)
Sec: exhaust cam(4+1)
Log and trigger log:
http://www.vems.hu/files/DamirMuha/Honda12Extra/ExhaustCamonCamSynckuglaCivicTypeR-3945.zip
Rpms are good and stable(tested till 8000rpm) only at cranking rpms aren't 100% stable
And for TDC settings are:
TDC after (60deg, not 100% sure, but error is max +-5deg)
first trigger tooth:3
but firing 3. cylinder, not first
Then i connect intake cam to secondary trigger:
log:
http://www.vems.hu/files/DamirMuha/Honda12Extra/IntakeCamOnCamSynckuglaCivicTypeR-3945.zip
It's clear form logs that intake cams move 30deg max with stock ecu.
Didn't test connect all two cams sensor to vems(sec and third input). It's that option sported for intake cam VVTI?