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.
Vems is connected as pigyback, so stock ecu manage the 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?
Primary trigger: crank 12+extra pulse
Secondary trigger: Exhaust(4+1) needed for cam sync(working well)
3th trigger: intake(4pulses), needed for campos for intake cam
trigger log of intake cam(for logging is connected to secondary trigger input)
http://www.vems.hu/files/DamirMuha/Honda12Extra/IntakeCamOnCamSynckuglaCivicTypeR-3945.zip
- it's easy to see (from ... what ?) that on idle cam advance is little, but at 2500 WOT is 25-30deg more advanced.
- from this I thought cam position measurement was good.
update 15.8.2011
Car is now running on vems ecu(not mapped).
http://www.vems.hu/files/DamirMuha/Honda12Extra/v3.3_u003945-2011.08.14-22.13.33.vemslog
first ignition coil is connected to vems pin 12, 2nd to 24, 3rd pin 35, 4th to pin 33.
Coils work with logiclevel output 0/5V with stock 510ohm series resistors.
And now tdc is 100% correct.
- first tooth 2
- tdc after trigger 70
- firing 3th cylinder
- bad setting: vvti_measure_tooth is 103 (> 23 ! no such tooth) so cam position always 0deg in log (1.1.96 speed sensor firmware)
- Set in Motorsport/Camshaft angle control/measure at tooth_cnt to 0 or 0..11 (or max 0..23) depending on which tooth you want to measure the cam position. Cam position is measured than.
- according to your triggerlog (that we saved to wav and played back), with measuring at tooth_cnt=10 base position ~23 degree seems OK => also, the following pulse will not interfere even if advanced by 70 crankdegrees (max advance is usually 46..60 deg)
- note the [VT help] for Honda example says "measuring at tooth_cnt = 14" but according to actual triggerlogs that is not recommended: that could result in following tooth too close with your actual sectrigger. Good values are apparently measuring at tooth_cnt = 4,10,16 or 22 but rather 5,11,17 or 23 (+30 deg better clearance, while the following tooth follows > 70 deg later)
- 0 might also work well. It effects the base angle of course.
All three cam sensors are logged good.
http://www.vems.hu/files/DamirMuha/Honda12Extra/v3.3_u003945-2011-08-14-21.57.33.triggerlog
Also for vvti control solenoid needs +12V(it's grounded to engine block). So i added P channel mosfet(irf 9540) with gate pulled to 12V with 10k and gate connected to p259 chip. And diode for protection.
In trigger log i can see that cams are moving, but in log i can't see that(or in vemstune).
http://imageshack.us/photo/my-images/14/camlog.png/
Log:
http://www.vems.hu/files/DamirMuha/Honda12Extra/v3.3_u003945-2011.08.14-22.13.33.vemslog
Car is mapped on dyno, 242@8500rpm. Vtec and VTI are working.
Only start is sometimes hard, like after first successful ignition of mixture spark position is wrong. I'll add trigger logs latter.
http://www.vems.hu/files/DamirMuha/Honda12Extra/v3.3_u003945-2011.08.31-20.13.57.vemslog
There are problems with start and missing spark.
http://www.vems.hu/files/DamirMuha/Honda12Extra/v3.3_u003945-2011-09-26-18.57.34.triggerlog
See at 656ms(also there are 68cam signal, so should be 65+ spark event, but there are 53) , there aren't spark events. So when car start to catching(fast rpm change) vems lost sync.
Here is config:
http://www.vems.hu/files/DamirMuha/Honda12Extra/configk20a2.vemscfg
Can you make a Vemslog while cranking or when the problem seens? The trigger errors can helps a lot.
Suggestion for cranking problem?
- I got a cranking issue as well(MembersPage/FPhil/Install). I guess this may come from the calculation of the angle velocity made by some predictive filter (Kalman filter)which mixed actual values and predicted ones based on passed values. One may needs a specific mix when cranking (multimode filter is quite common)