Megasquirt and tacho circuitry

[DaveG]

I have been tuning my 500 for a couple of years now (MS2Extra), but still have not managed to get my Tacho working. The published solutions using "transister/relay" and "multiple diodes" to replace the old coil signal have not worked. Before I start getting more serious and analysing the MS2 signal output, etc, can any MS users advise what their solution has been for driving the standard tacho?

[Pupp]

There's a similar issue between Emerald ECUs and some TVR tachos. Emerald supply an interface box that sorts it, only a few quid so might be worth a try if there's not a MS equivalent (suspect there will be)

[spend]

Try mailing 2monkeys, I cajoled Bruce into having his speedo converted

hope it worked he's been very quiet lately

[dnb]

Make up a circuit using an LM2917 or similar frequency to voltage converter and put this inside the tacho in place of the original circuit board. I think I have a couple of PCBs kicking around that could be populated to do this.

[spitfire4v8]

Speedy cables will convert your tacho for you, or if yours is a later car do what I do and buy a cerbera tacho from one of the breakers / ebay / ph classifieds.

[Ant.]

My emerald Tacho driver works great, cant see why it wouldnt work with the MS outputs...

[spend]

Strangely enough I believe it was the Emerald one that Joo used to use, I know he had some that didn't seem to match up very well...

There are a myriad of permutations of tachos / coils / ecu outputs, at least the newer tachos that accept a digipulse direct from the ecu have less to do as well as simpler wiring? So all in all I guess they have less of a range of possible 'conflicts' to cater for.


Joo BTW

[5.0ltr]

spend said:

Try mailing 2monkeys, I cajoled Bruce into having his speedo converted

hope it worked he's been very quiet lately

Hasn`t he, been thinking about him recent...Bruce, where are you big fella?

[DaveG]

Hi guys, thanks for the input/suggestions.
It gives me a few items to follow through. The car is a 95-500 and the tacho worked fine with the coil. (My speedo was recalibrated for Km's as part of compliance, however the mileometer is still in miles! - explains some of the excess consumption !!)

[daxtojeiro]

Basically some TVR rev counters work on the diode configuration, others don't. V8D and I have come up with a module that works on all the TVRs we have tried so far from the Tacho output I fit on the MS ECU's. So as long as it's one of mine or V8Ds then email me for more details, its £30 inc postage
Phil

[SILICONEKID340HP]

I have one of your megasquirt units,My Tachco bounces can i still send it back to get it sorted cheers.Once the summer is over .

[daxtojeiro]

SILICONEKID340HP said:

I have one of your megasquirt units,My Tachco bounces can i still send it back to get it sorted cheers.Once the summer is over .

Yep, thats fine,
Phil

[neal1980]

So whos has worked with the diodes?? I have 1996 Chim with black /silver clocks Im about to be sent the diode lead to try but looks like this will not work maybe...

[Simon says]

neal1980 said:

So whos has worked with the diodes?? I have 1996 Chim with black /silver clocks Im about to be sent the diode lead to try but looks like this will not work maybe...

I have I have these dials Caerbont ?

[neal1980]

I have these, well ignore the other ones just the speedo and rev counter are standard.

[2Munkys]

5.0ltr said:

spend said:

Try mailing 2monkeys, I cajoled Bruce into having his speedo converted

hope it worked he's been very quiet lately

Hasn`t he, been thinking about him recent...Bruce, where are you big fella?

Yea, I'm still here; just not had the opportunity to pop in so frequently and add my nonsense.

Anyway, yea, Speedy Cables converted my rev' counter. I think it was about £90 inc; took about 6 weeks to turn-around at that time which wasn't brill' but I think they were particularly busy. I think I'd asked Phil to include the signal line with the MS2 (or maybe it's a standard fit; I can't remember tbh). It's a simple hook up anyway and has been trouble free, and that counts for a lot; I'd do it again.

I'll be at the Growl if you wanna check it out.

[spend]

..but once they'd done yours, Tubbs's only took a couple of days if you recall


he was just being a girl & was too scared to go first, otherwise it might have been the other way round service-wise

[2Munkys]

spend said:

..but once they'd done yours, Tubbs's only took a couple of days if you recall


he was just being a girl & was too scared to go first, otherwise it might have been the other way round service-wise

I do remember Dave . . . and your revelling in the fact . It was a good move though; not a half measure.

[spend]

2Munkys said:

and your revelling in the fact .

Wasn't me Bruce! It was the ALMIGHTY FAT ONE that was taking great delight... to the extent that the whole of BOT was probably bored of hearing the story first time & he'll still be telling everyone he meets

[soddy]

Phil at EXTRA EFi does a mod box now that converts the ECU's low voltage output to a coil negative pulse for the rev counter to see and function properly, I use them and up to now have not had a failure.