Thread: Tach to Pcm
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Old 04-21-2017, 10:48 PM   #16
Liltroy
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Re: Tach to Pcm

Quote:
Originally Posted by davepl View Post
But the video just says "You don't need to know why it is what it is"! I can't live like that! Granted you do give the numbers, which is great.

I think the rough answer is:

Sample values for this calibration:
For 4 pulses, use N= 3 (Note- 8 cylinder tach setting)
For 3 pulses, use N= 4 (Note- 6 cylinder tach setting)
For 2 pulses, use N= 6 (Note- LSx 8 cylinder & 4 cylinder tach setting)

Both cases we're talking about here are eRod or Connect&Cruise, which will usually be run with the factory tune, not a custom tune, so a converter box is actually CHEAPER than an HPtuners VIN license, right? I know I don't have unlimited HPTuners.

You are right, however, in my case I could have done it because I had to change the VSS output tooth count on the transmission anyway, though. But no one seemed to know that back when I asked!
I apologize. I missed the part where you were using the e-rod setup. Of course that also means you're using a 58x reluctor which has different pulses altogether. I only tune the gen 3's so Im afraid I havent really dug into the correct settings for the gen 4(E38) pcms. I own an avalanche that is gen 4 and the tach output is set at 2/2 so thats all I know on that one.
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