E-Bodies.org Cuda Challenger Forum

Technical Shop => Engine, Transmission & Rear End => Modern Hemi Swaps => Topic started by: anlauto on February 11, 2021, 01:41:42 PM

Title: Tach Signal ???
Post by: anlauto on February 11, 2021, 01:41:42 PM
Okay....thinking in advance here, but....Where the heck would I find a tach signal on a crate 392 Hemi ? :looney:
I'm using Dakota Digital gauges if that makes a difference.
Title: Re: Tach Signal ???
Post by: dodj on February 11, 2021, 01:56:24 PM
Don't you buy a harness and cpu to go with those crate motors? Must have an output from the cpu I would think for the RPM? Just guessing here. :dunno:
Title: Re: Tach Signal ???
Post by: anlauto on February 11, 2021, 02:09:35 PM
Quote from: dodj on February 11, 2021, 01:56:24 PM
Don't you buy a harness and cpu to go with those crate motors? Must have an output from the cpu I would think for the RPM? Just guessing here. :dunno:

YES...I bought everything....read the instructions several times, no mention of a tach... :headbang:
Title: Re: Tach Signal ???
Post by: Skdmark on February 11, 2021, 06:38:51 PM
Not sure if this helps.
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2490654/re-using-factory-tach-in-e-body-with-gen-3-swap.html

MSD tach signal pickup mentioned in moparts
https://www.holley.com/products/accessories/gauges_and_gauge_accessories/tach_adapters/parts/8918
Title: Re: Tach Signal ???
Post by: anlauto on February 11, 2021, 06:57:47 PM
Thanks for the link...sounds weird :looney:

@GoodysGotaCuda (https://forum.e-bodies.org/mlist/goodysgotacuda_66) @303 Mopar (https://forum.e-bodies.org/mlist/303-mopar_7)  What have you guys done ?
Title: Re: Tach Signal ???
Post by: SRT392 on February 11, 2021, 08:10:13 PM
Alan,   i'm trying to figure that one out also. if someone chime in let me know.  also the pwrr steering pump (modified 15% less) says it needs a cooler..  anybody have a part number or pic??
Title: Re: Tach Signal ???
Post by: GoodysGotaCuda on February 12, 2021, 03:46:06 AM
Quote from: anlauto on February 11, 2021, 06:57:47 PM
Thanks for the link...sounds weird :looney:

@GoodysGotaCuda (https://forum.e-bodies.org/mlist/goodysgotacuda_66) @303 Mopar (https://forum.e-bodies.org/mlist/303-mopar_7)  What have you guys done ?
Sorry I have a megasquirt ecu, it has its own tach output. I can't speak for any Mopar harnessing or ecu.


Sent from my iPhone using Tapatalk
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 03:49:15 AM
Okay, thanks for chiming in  :drinkingbud:
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 04:43:26 PM
Post up the instructions for that CBID module....  I'm thinking (and hoping since I want to use a Hellcrate) that will allow you to use the BIM-01 module from Dakota Digital to pull ALL of those signals right off the CANBUS by hardwiring in or using a DLC Y cable.  Tach, ECT, EOP, etc....  The only thing I am uncertain of is how you send the A/C request and VSS signals back to the ECM.  Hopefully those are wired to the CBID.

Edit:  To be clear, most of the signals other the vehicle speed and fuel level could potentially be broadcast and pulled off of the CANBUS so you won't have to install a bunch of redundant 2nd sensors and wiring for the gauges.  Just one cable between the gauge and BIM-01, and another between the BIM-01 and DLC.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 05:11:17 PM
WOW....I wish I had the slightest clue of what you were talking about....I'm way to old to understand even half of those acronyms mean :('
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 05:18:05 PM
CBID - CANBUS Interface Device.  It comes with the Mopar Controls pack.  Post up the instructions and we can decipher it more.

ECT - Engine Coolant Temp

EOP - Engine Oil Pressure

DLC - Diagnostic Link Connector (19 pin where you plug a scan tool into)

CANBUS - Controller Area Network bus.  Think of it like an ethernet cable for car computer modules.

The BIM-01 is a Dakota Digital expansion module that listens to messages being broadcast on the CANBUS.  It literally plugs into the DLC connector.  It'll pick up all of the signals needed to drive the gauges and sends them directly to the gauge module without needing a bunch of dedicated gauge sensors and wiring mess.

Again, how you get vehicle speed and A/C request back to the ECM is unclear; the main Hellcrate manual doesn't cover that.  I ASSume the CBID one will.  If you wire it to that, then the BIM-01 will pull that signal too.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 05:26:54 PM
There's only two areas in the instructions CANbus is mentioned.
First in the Body Harness description where it says (not used in this application)
and a page talking about a Star connector
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 05:31:30 PM
There are no other instructions with that module itself in a separate bag?
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 05:39:04 PM
No...no other instructions...
But I guess this is what you're talking about ? https://www.dakotadigital.com/index.cfm?ptype=product&product_id=752&category_id=646&mode=prod
I watched the video...

Is it as simple as it sounds ? I can simply plug it into the DLC port and a way I go ?
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 05:44:07 PM
Yup...  Those are all basic signals present on any CANBUS.  There are likely a ton of others too: oil temp, boost, oxygen sensor values, fuel trims, throttle position, intake air temp, probably hundreds if not more that can be read by devices like that.

I'm still puzzled how you feed vehicle speed and A/C request to the Mopar ECM though....  I guess maybe it doesn't NEED vehicle speed the way they programmed it, but something has to tell the ECM when to turn on the A/C compressor and there are no wiring instructions in the manual.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 05:48:21 PM
What is this: CBID - CANBUS Interface Device?
Do I have one ? Do I need one ?

I'm still a little confused.. :drunk:
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 05:51:31 PM
LOL, it's supposed to come in that controls pack kit!  I'm pretty sure it's that small black module in the top left corner of the kit contents pic on the first page of the manual.

P/N 77072456.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 05:57:35 PM
You mean this thing ? It's just a fuse box
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 06:02:15 PM
No, the Hellcrate must come with an extra module then.  I wonder why that would need an extra module and the 392 doesn't.

Do you at least have a 19 pin scan tool plug (DLC) in that kit?  As long as you have that it's going to be plug and play for that BIM-01 module.

If not, you'd need to splice into the CAN wiring going to that STAR connector (long rectangular bar with multiple plugs)
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 06:05:49 PM
YES....it does have the DLC plug and even a nice bracket to mount it ...LoL
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 06:09:39 PM
You're golden then.  You won't even have to wire power or ground to the BIM-01 if you go that route; it gets that through the 19 pin.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 06:21:20 PM
Sounds "TOO" simple now :thinking:
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 06:52:20 PM
So theoretically, with this BIM-01 from Dakota Digital, I could plug my new E Body dash into my DLC on my 2017 RAM and the dash should work ? 
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 06:57:42 PM
Yes, actually.  Or a 2010 Camaro.  Or a 2015 Honda Civic.  It's a standardized communication protocol.  Call them up if you think I'm crazy!
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 07:01:36 PM
That's pretty cool I'm still wondering what this is and if I need one "CANBUS Interface Device"...In the pictures I posted on the instructions it mentions "not used in this application"  Will that matter, when it comes to the DLC outputs ? Or did you just mention that to confuse me  :looney:
Title: Re: Tach Signal ???
Post by: Dmod1974 on February 12, 2021, 07:08:52 PM
No, you don't need the CBID to make the gauges work.  I confused you; it's part of the Hellcrate engine controls only I guess.  That in and of itself is just another device reading and sending information just like the BIM-01.

The CAN wiring is already in the 19 pin connector, otherwise a scan tool would be unable to "talk" to the ECM which would prevent it from being programmed, diagnosed, or tuned for that matter.  It will be plug and play.
Title: Re: Tach Signal ???
Post by: anlauto on February 12, 2021, 07:15:33 PM
That's cool  :bigthumb:

FUNNY STORY:.....My customer is the one who ordered the Dash from Dakota back in December. He had phoned them and talked directly to their tech line....I just went back and read his email to me, dated 12/03/20, and he ordered the dash along with the BIM-01  :headbang: :headbang: :headbang: :headbang:



If I had of just stopped thinking in advance, and waited for the dash to arrive.....my endless questions would have likely been answered  :console:

I certainly do appreciate our conversation tonight...THANK YOU for your time :drinkingbud: good night  :worship:
Title: Re: Tach Signal ???
Post by: SRT392 on February 12, 2021, 07:35:42 PM
Alan. So it's my turn to be confused. Could you throw up a pic of the BIM-01 so I can see if I got that with my Dakota Digital? I may need some help making sure I plug this stuff in correctly. Take care
Title: Re: Tach Signal ???
Post by: anlauto on February 13, 2021, 04:57:58 AM
i don't have mine yet, but here's a link....take a minute and watch the video...


https://www.dakotadigital.com/index.cfm?ptype=product&product_id=752&category_id=646&mode=prod


Title: Re: Tach Signal ???
Post by: SRT392 on February 21, 2021, 08:04:45 PM
now that i have pwr again and can get on line  thanks Alan i'll call Dakota and see if that will work....thanks
Title: Re: Tach Signal ???
Post by: Blake@diyhemi.com on April 27, 2021, 04:16:54 AM
There are two ways to get a tach signal