Any of you guys know if the factory tach will work straight from the msd's tach signal output wihout a tach adapter?

 

You are using it on the trailing coil?

The OEM/factory tach is coming off the trailing coil.

 

I got two blaster two coils and dual msd 6a's with an early distributor ( I went turbo/carbureted in my 87). I just want to know if I can connect the tach signal wire to the msd 6A's tach signal plug. My car is working fine but no tach. The wire is yellow with blue stripe right?

 

Took the chance and it works great!!!!!!

 

Cool, thanks for posting your results!

 

No problem!

 

Please, recommend trouble shooting in getting tach signal back to tachometer. My 91 N/A's tachometer went dead after installing Mollory HyFire 6a which has the exact same wiring as MSA 6a. I had Mallory Hyfire 6a hook up to T1 and 2nd HyFire 6a hooked up T2, the car started and ran fine, very smooth ... just no tach movement at all!

I beleived the engine code flashed for 01, trailing ignition coil.

Any input would be greatly appreciated.

Thank you

Dow

 

How did you install the Hyfire's?
Why are you running them on your trailings?
Are you making over 500hp???


-Ted

 

Ted,
The idea of amplifing an electrical current to the coil T1 and T2 excited me enough to spend $$$ and hook them up. The Mallory HyFire 6a are designed to work in the same manner as MSD 6a. My 91 FC N/A only has basic modifications of intake, headers, high flow exhaust and MSD superconductor plug wires, so I was hoping to have efficient burning and extract that one last horse power as a by products. The Mallory HyFire 6a was installed using white wire, - signal to coil for tirggerring
HyFire 6a box. Box setting on 4 cylinder.
The PCM , check engine code shown Trailing signal was interupted. My 12 volt inline fused from battery to Hyfire 6a boxes may have a bad connection, because I put everything back and my tachometer worked just fine and no more code 01 after clearing it off.
Would you recommend hooking up HyFire 6a, on the Leading coil insted of having on Trailing ; one on T1 and
another T2 ?

 

Installing a CDI box on the leadings usually produce better power and performance than trailings.

Trailings produce like maybe 20% max of the power output of the engine.


-Ted

 

Ted,

My HyFire 6a has been installed on the leading coil,
L1 & L2. Hyfire 6a ihas been functioning well, tested and varified by the light tester which blinked from idle speed to constant bright light when the light tester hooked up to the L1/L2 coil's positive terminal.
Do you have any idea how trailing signal can be hook up to Hyfire / MSD 6a, yet retain the tach operation?
I could not be so sure if one HyFire 6a hooke up to leading has more gain than each HyFire 6a on T1 and T2.

Thanks

Dow

 

If you're still using the trailing stock wiring and ignitor, the stock tach should still be working.

If you were cutting wires before the ignitor, that would explain why the stock tach isn't working.


-Ted

 

I had a + signal wires to coil T1 hooked up to red wire, + input on Mallory HyFire 6a and black wire, - signal to coil hooked up to white, - input. All these were done after ignitor output going to coil T1, same set up for T2 on 2nd HyFire 6a. All wiring was done in according to Mallory's instruction for import vehicles. The car wil not registered any tach signal after HyFire 6a was hooked up to T1 coil.

It's okay, perhaps I could not explain very well why I want to have 2 HyFire 6a amplified Trailing coil, one on T1 and another T2. Currently, I have one HyfFire 6a hoked up to Leading coil and I have my tachometer in operation. ...

I just wonder if HyFire 6a / MSD 6a could be hooked on Trailing coil T1 & T2 as well as on Leading coil, if so will tach adaptor be required?

Thanks for your time

Dow

 

The reason the stock system gets its tach signal off of the trailing is that the trailing coils are neither advanced or delayed by the engine computer (unlike the leading).

I think both Ted and I were wondering if you hooked directly up to the trailing coil, or between the ignitor and the trailing coil or before the ignitor and trailing coil combo. Sounds like you do have it correct there...

If you hooked up between the ignitor and coil then the ignitor should still report the tach signal on the Yellow/Blue.

*edit<
Now as I remember the Hifire6A tends to be confusing to install as there are two black wires, one labled 18 awg and one called 14awg in their instructions, however you must look very close to actually read the 18 AWG on the correct black wire as it externally appears to be the larger of the two wires.

So... if you have those two backwards the unit would not work, but since the car would run anyway you might not notice.

Does the indicator light on the Hifire6A flash (fast) while the engine is running it should... if it does not, it is indicating that the 18 AWG black wire is on the wrong lead.

And finally are you getting any tach signal on the yellow wire from the Hifire 6A. You will need to use a multi-meter that reads tach to see.

 

Mr. Ice Mark,

What an honor to have you taken your precious time responding to my question.
When I had 2 of Mallory HyFire 6a hooked up to each of Trailing coil, the HyFire 6a 's diagnostic led stay constant ON/RED, indicating everything was working fine? I disconnected 2 HyFire 6a that were hooked up to each of Trailing Coil and installed only one of HyFire 6a on to Leading Coil. All the wring was done exactly the same, I was rewarded with very responsive throttle input and a working tach. A heavy 14 gauge, black wire has always been hoked up to the negative side of battery terminal and smaller black, 18 gauge was hooked up to coil's negative terminal. If HyFire 6a could ampified ignition out put to Trailing coil, would there be any gain or just less pollution coming out of exhaust? When you get aroung to read this reply, PLEASE ..... please, share your comments on hardcaore-performance turbo kit on FC N/A.

Thank you

dow

 

The led should stay on, but blink during cranking
This might help you out...
https://www.rx7club.com/forum/showthread.php?t=252522
Something funky happens to the trailing signal when a CDI box is installed on it..
Brave guys running a mallory hyfire on a rotary, its actually quite a good ignition, buts its a 50/50 chance when you first turn the key...Max

 

Maxthe7man,

HyFire 6a on my 1991 RX-7 has led; red light on ,while the engine is running and everything works just fine.

 

I know this is an old thread I was just given (free) a Mallory 6a in the box and i;m looking into installing it in my 13b 1974 repu. has anyone done it on a carbureted engine.

 

Yes I have. What are your questions?

We run it on our 13B race engine, which has a 51IDA Weber Carb, an old school distributor, and some Blaster 2 coils. We actually run 2 Mallory Boxes - one for leading and one for trailing on that car.

The process involves: Hacking the ignitor on the distributor and reinstalling it (Directions here: MSD 6A direct fire Ignition for Mazda RX-7 Rotary Engine - Dr. Scott M. Baker)

We did ours a little differently as we don't go direct fire - Modified Ignitor > Mallory Box > Coil > Distributor > Plug. We tried direct fire and it was cranky, so we went the other way with it.

 

Awesome thank you for responding, a little info on my set up I have a 1974 Repu with stock engine 13b 4port. I have a RB header and a IDF 40 weber system, 2 MSD coils and a 83 ignition. can run just 1 Mallory box in my set up since is a bone stock engine? Also how would I hook it up do you have a schematic available.

thank you again

 

I'd run the Mallory box on the Leading side. It would only require one modified ignitor, and you can run the trailing through the conventional ignitor/coil/distributor system. I'll see what I can do to document this later - I'm at work right now.

 

Great I really appreciate it thank you again!!!!

 

Hi ToySport any word on that Mallory diagram. thank you in advance