Hi, Engdahl here.
A customer of mine wants to run a VIPER V10 with VEMS and we therefore have some questions.
What do we need to do to run this engine?
Please specify the trigger. See MembersPage/PeepPaadam/BMWwithViperEngine
and take notes (eg. copy relevant info here and edit) what is applicable, how it differs, ...
We assume wasted spark ignition: 5 ignouts for 10 cyls
exact positions (angles) of these TDC events:
- ...
- ...
- ...
- ...
- ...
Considering every 2nd crankpulse, evenly spaced, every 72 crankdeg:
- e = [0 :9 ] *72
- 0 72 144 216 288 360 432 504 576 648
- Alternating 0,18 crankdeg:
- o=[0,18,0,18,0,18,0,18,0,18]
- e+o = 0 90 144 234 288 378 432 522 576 666
- As you see the result is 90, 54 crankdeg timing ... (because of 72+18, 72-18). Please confirm: does this match the Viper engine ?.
If VVTI (camshaft angle control) will be used, check actuator authority range: if there is a "race-condition" between sectrig pulse and primtrig pulse.
First: Will Vems allow for ODD fire V10 config? Yes!
- we have investigated the needs and implemented some minor required firmware work, [firmware 1.2.33 ] supports your odd-fire viper v10, make sure to also update ini files from web in VT.
- we have created a configlet for easy setup, in VT-> primary trigger settings select configlet "Chrysler_Viper_V10_10+1_Camsync" this takes care of most of the basic settings
- some calibrations still remain, strobing (and calibrating) tdc after the trigger
- verifying the correct order of the 18 degree alternating delay; the configlet default now is 18 degree delay applied to the odd cylinder numbers, if the 18 deg delay on the even cylinder numbers is needed edit the configlet file "Chrysler_Viper_V10_10+1_Camsync.txt" (in your VT_install_dir/configlets/trigger), comment the line: "h[3]=00 48 00 48 00 48 00 48" and uncomment the line "h[3]=48 00 48 00 48 00 48 00"
Proof of concept triggerlog output (note the double amount of ign0/ign1 falling is normal because of the 'and 0x07' reported cylinder number)
I have tried to change Engine setup in VEMSTUNE to oddfire, but it seems to do nothing.
- the key to set up is trigger type, ignchmax, reftooth and per cyl spark delay (odd fire config bit only has effect if RPM is fluctuating because of uneven tooth; Not needed for many setups, eg. if every 2nd tooth neglected by using auditrigger divby 2)
How do we go about setting upp the odd fire sequence? My first option is to mess with Trigger reference tooth table. (TRTT)
The Viper V10 is a 90 degree 10 cyl engine. 720 degrees / 10 = 72 degrees. And on a 90 degree engine that means 18 degree Odd fire on right-bank cylinders. Correct?
If i change TRTT tooths will it still sync the tooth correct after the missing gap?
- If i change the order, VEMSTUNE sets a warning.
- for this trigger setup it is very likely that VT will show warning we will have to neglect: there are some special (rarely used) cases the firmware handles but outside "normal-range" for VT
What is the other options? The separated cylinder spark delay does allow for more than 3 degree delay.
- VT sets a warning for >3 that can be safely neglected if one knows what he is doing (which usually implies the steps of specifying, asking help with benchtesting).
Question 2:
Is he want to run full sequential in the future, is there any possibility to get a custom firmware to run 10 inj outputs?
- 10 injectors, with 2 injectors on each (5 injector outputs)