MoTeC Global Forum

Trying to see if I can use the stock sensors in an LS1 engine with my M8 ECU.

Thanks in advance!

I would say yes.

However, whether the M8 is able to decode that terrible 24x crank wheel is another matter.

But the actual sensors should be fine.

Just use multy tooth mode with failling edge on the crank. This edge is evenly spaced.

You may however suffer at high RPM with the sync crossing over the crank edge due to cam belt streach and causing a missfire

SprinterTRD wrote:Just use multy tooth mode with failling edge on the crank. This edge is evenly spaced.

You may however suffer at high RPM with the sync crossing over the crank edge due to cam belt streach and causing a missfire

LS1 uses a weird 24x trigger, the teeth are not evenly spaced.

LS1 is an old pushrod V8, there is no cambelt.

Some visuals and info on the crank trigger. Cam trigger is easy though

http://www.vems.hu/wiki/index.php?page= ... wentyFourX

be as handy just to stick a 36-1 onto it.

stevieturbo wrote:LS1 uses a weird 24x trigger, the teeth are not evenly spaced.

Sprinter TRD specifically said Falling edge which are in fact all evenly spaced on the LS1.

stevieturbo wrote:LS1 is an old pushrod V8, there is no cambelt.

But they still have a timing chain and distributor gears all with stretch and backlash which causes the same problem. In multi tooth mode if your sync position moves too close or especially crosses over the ref trigger edge you can get trigger errors.

AdamW wrote:

stevieturbo wrote:LS1 uses a weird 24x trigger, the teeth are not evenly spaced.

Sprinter TRD specifically said Falling edge which are in fact all evenly spaced on the LS1.

stevieturbo wrote:LS1 is an old pushrod V8, there is no cambelt.

But they still have a timing chain and distributor gears all with stretch and backlash which causes the same problem. In multi tooth mode if your sync position moves too close or especially crosses over the ref trigger edge you can get trigger errors.

Didnt realise that. I just see the 24x as the trigger from hell. Even with the OEM ecu, it seems to cause many problems especially at high rpm.

Wheels dont run true, the wheel splits apart etc. They just seem to be very poor.

Got an Answer from Simon at Motec West the other day on this one.

He is a super great guy and I sure appreciate his kindness and expertise!


He said the M8 never has had a 24 tooth setting available for the terrible signals it produces.

He also said He could upgrade it to an M8-High Speed for a minimal fee and it will work with the new 58X Gen IV LS trigger wheels, so that is useful!

Yes, but if you have an engine with the 24x wheel, it's a crankshaft out job to swap the wheel to 58x.


It would be a lot easier all round just to mount a new wheel, 36-1 or otherwise on the crank pulley.

Turbofreak wrote:...
He said the M8 never has had a 24 tooth setting available for the terrible signals it produces.
...

Do you have a capture of that signal?
Or what is the nature making it terrible?

Turbofreak wrote:Got an Answer from Simon at Motec West the other day on this one.
He is a super great guy and I sure appreciate his kindness and expertise!
He said the M8 never has had a 24 tooth setting available for the terrible signals it produces.
He also said He could upgrade it to an M8-High Speed for a minimal fee and it will work with the new 58X Gen IV LS trigger wheels, so that is useful!

I don't see why mode 11-14 wont work - the max recommended teeth is 16 for this mode but that is only because it gives you a small "window" where the sync edge must occur.
You could also just cut some teeth off the original wheel to make it into a 4, 8 or 12 tooth wheel.

Holmz wrote:Do you have a capture of that signal?
Or what is the nature making it terrible?

There is some captures shown on the link that Stevieturbo posted earlier in this thread.