Tacho output SMC

[BEE-J]

I'm wanting to hook my tacho up to my SMC as it seems to be a bit out. Is it as simple as running the tach wire to a certain ecu wire or is there more to it than that?

[MRMRacing]

SMC do not have tacho output, you have to connect it thru your ignition system.

What ignition system do you have?

[BEE-J]

MSD 6AL, thats what its connected to now but seems to be out unless i have another problem and the tacho is right. I had a launch limiter set to 4500 but it was limiting to approx 3000rpm. It could be that i have set something up wrong perhaps

[BEE-J]

Could it be that having a 4500 rpm limit with a 500rpm window makes it limit the engine on the lower side because its off boost and because the tach flickers it may well be around 4000rpm and i'm just seeing 3ish because its jumping between 3-4000rpm?

[Ian]

What RPM does the laptop screen show?

Don't forget that the 6AL tacho output responds to input trigger signals from the ECU. So if the ECU limiter is using Ignition cut the signals to the 6AL will be cut and so will the tacho pulses.

[Chris]

6AL is a 6A with revlimit. What is the rev limit in the 6AL set to?

Chris

[BEE-J]

What RPM does the laptop screen show?

Don't forget that the 6AL tacho output responds to input trigger signals from the ECU. So if the ECU limiter is using Ignition cut the signals to the 6AL will be cut and so will the tacho pulses.
That makes perfect sense i understand now what is happening. I have not taken notice what the laptop tacho was showing but i'm sure it will be all in line and i infact don't have a problem. Thankyou

[BEE-J]

6AL is a 6A with revlimit. What is the rev limit in the 6AL set to?

Chris
8000 pill in the MSD just to get around it, all limiting done in the ECU

[BEE-J]

Okay so i don't need to alter the way the tacho is wired. I had a launch limiter set and i was getting confused because i was seeing the tach around 3000rpm when it should have been about 4500, but now i know its just the tacho being cut. I was also confused because it wasn't on boost where i thought it should have been.

Another question, can i pull timing before boost but leave it as tuned once boost comes on. Like pull timing between 1-4000rpm or wherever the cut off is?

[Ian]

Is the Serial number after 5700 or, if earlier, do you know if a switch input has been fitted? If it has a switch input you could use the retard component of the ALS function.

[BEE-J]

Serial is L6958T2A4. Would you mind explaining to me more about the ALS and how i would set it up, thanks