Autosport Labs

Here's something that neatly solves a nagging problem for nearly all Megajolt installations: interfacing existing Tachometers to multiple coil packs.

http://www.autosportlabs.org/blog/?p=1618

Available now in our online store: http://www.autosportlabs.com/tach-adapter-p-65.html

Looks good

(now it's time for some cheaper shipment options )

Thanks!

Set up a group buy!

Just in time for my new project!
Thanks Brent!

just got mine and it looks good, i really underestimated just how small it would be.

2 questions:

1. Will the solder used for the components melt at the temperatures used to shrink heat-shrink tube?

2. What gauge of wire would be suitable for hook-up?

cheers

Ian B.

Brent, will this resolve the 4AGE tach signal problem?

Ian,

The solder won't melt at the temperatures used to shrink heat shrink tubing.

Not a lot of current flows through here - small gauge wire is fine and makes it more convenient.


A similar circuit works for my AW11 tach, so it should work for the AE86 tach as well.

Note, this board is not a cure-all for *all* tachometers out there. it has the addition of 100K resistors across each diode which helps make certain tachometers compatible - such as the 914 tach we're using in our race car: that tachometer wouldn't work with just diodes.

If your tacho works, but has a hissy fit bouncing around at higher rpms.
Would this adapter help ?

Toenee,

Can't say for sure. How is it wired now? More info would be helpful.

Sorry yes more info needed, it's wired to the megajolt as per the diagram

toenee, it would probably work- especially if the tach was connected to the (-) of the original single coil.

Ian,

Did you get the adapter board installed? How is it working?

brentp wrote:toenee, it would probably work- especially if the tach was connected to the (-) of the original single coil.

Yep it's a RVC tacho from a MGB, just put my order in cheers.

Hi Brent

Feel a bit guilty 'cos it's not fitted to my megajolt. I am about 2 weeks away from start up on my Zetec Caterham 7 conversion and have fitted a DTA ecu as i want to go injection in the near future. The DTA has simillar issues driving Tacho's so i will let you know how i get on. I used raychem solder splices to join the wires near the ecu by baring a short section of the driver wire and then bonding a 18awg wire from here to the board. It's then all heat-shrinked into the loom.

The first batch flew out the door- we now have plenty of the tach adapters in stock: http://www.autosportlabs.com/tach-adapter-p-65.html

Thank to those who've been patiently waiting!

My tach is not giving the correct readings at times. It's reading too low. Is this supposed to be a better option and replace the home made "diode circuit"?

Car is a BMW 2002 4cylinder M10 engine. Thank you