Billy whats your thoughts on the SA vs FB dizzy differences?

Changing to the FB dizzy sure made a believer out of me.

I would think serious racers would have discovered this a long time ago.

 

I do know that points suck

Never messed with an 80 and 81+ back to back to see a difference.

-billy

 

Just wanted to post back in here that I've been driving the
car some more and it rocks. My Dell stumble is almost gone
which was an unintended side affect.

Things I learned doing this:

1. Always stick to the initial plan. My lack of grounds in the initial
wireup caused me issues that would have been avoided had
I just done what I designed in the first place. DOH!

2. The 7 pin HEIs can be used instead of 4 pin. I ended up using the 4
pins because I bought them while debugging to make sure my
JY 7 pins weren't an issue. I'll use those 7 pins in another
project that I have in mind.

3. The 7 pin HEI do not alter the dizzy timing in anyway unless
the 3 unconnected pins in my drawing are connected to an ECU
that knows how to interface to them. Theres a lot of rumor and
talk out on the internetz about them adding 10 deg advance and
so forth. Thats bunk, the ECU adds the 10 deg advance in limp
home mode NOT the HEI itself.

4. The 80 vs. 81+ dizzy differences are huge. The FB dizzy is a vast
improvement over the 80 for higher RPM reluctor signals.

5. The reluctor signal is reversed for the SA vs FB dizzy. So for the
HEIs if your using the FB dizzy you will have to reverse the dizzy
to HEI connections as show in my previous drawings.

6. Trailing ignition is a just noise and doesn't need to be there,
so its gone. I'd like to plug the plug holes up with something
other than plugs but I guess those can be my spares

If and when I get to a dyno I'll post up the numbers in here for reference.

Thanks to Jeff20B and others before me that have been the pioneers of
alternate Rotary ignitions.

Special thanks to gsl-se addict for listening to my wacky idea in the
beginning and his advice. Thank you to Verneuil for helping to validate
what I was doing, it was immensely helpful to know it worked as
designed for someone else.

I hope this thread helps some others who need a better, more
standard ignition on their rotary.

 

And thank you sir for leading the way! Now please stupidify this setup for those of us who are ignition-tarded and list exactly what we need for this so we can just take a list to the parts store or salvage yard and say I need all this please.

Also please keep us posted as to how well it holds up down the line.

 

You're welcome. Glad you got it working. Glad you see the folly of worrying about trailing ignition. I still can't believe what some do to upgrade trailing, at least for an NA setup (it's supposedly good to keep trailing if boosted).

 

K but what if your running the 2g leading coil is it a good idea to keep the trailing or can I get rid of it?

 

Great work man!

Maybe I'll try rigging this system up before my race on May 8th.
If I do, I'll be sure to post up my results.

I do know for a fact that there are gobs of power to be found in
the ignition systems of these cars. When I was working with Kent
on his system, the power gains were simply amazing. No doubt
I'd still be using it if I hadn't run out of 2nd gen coil packs, which
had the unfortunate habit of burning up on me periodically.



.

 

All I can say is this beats my 2GDFIS hands down and I can now go out
and get HP ignition parts from JEGS or Summit with no problem if
I want to beef it up some.

I built my own version of Kents TT module but I never tried it out. Its still sitting
on my shelf

Its pretty simpe to setup, hardest part is mounting the TFI coils.

 

Tim, not to threadjack, but on the 80's electronic dizzy you have the Red and Green wires
coming out, would you switch that around if you were to change to an FB dizzy? Reason asking
is I wired my MSD up the same way as before when I had the FB dizzy. Dizzy red/green to MSD
Green/purple.

 

Yeah I would expect so. Just look at the reluctor wheel and visualize
how the shape of each would generate a wave form as it passes the
magnetic pickup. They will generate pulses with peaks at opposite
ends. I wish I had a scope to see it because that would really show
the reason why you have to switch the leads.

 

You can keep trailing if you want.

 

I tried a 2GCDFIS on percent's car but it killed the stock leading ignitor after about a month so I replaced the ignitor and put everything back to stock. The performance wasn't really improved from what I could tell going with stock or 2GCDFIS. So it looks like DLIDFIS is in his car's future. It will be interesting to see whether it improves power now that his car has a blow through turbo.

 

Yeah I was checking my spark plugs this morning and noticed some corrosion on the + post on my trailing coil so I think I may have been running without a trailing coil. I cleaned it up the best I could but haven't had a chance to test it but I'll probably spray some contact cleaner or somethin on it and hit it with a wire brush again later.

 

Just wanted to relate another way this mod improved driving my 7.

When I start my car cold with the choke on, it now cranks up within
the first turn of the crank. I basically just flick the key and its on.
Its pretty amazing.

The other thing is when I back out of my garage with the choke on,
I used to have to be very careful feathering the throttle to keep it
from stalling out as I turned and backup the small rise in my
driveway. Now I just let the high idle (when the choke is on)
roll me out, don't even have to touch the gas. I had noticed that
the car was pulling a lot better down low but this was actually
pretty cool when I noticed it. If the choke is not on, I just need
to barely lay my foot on the gas and thats enough to roll me
out and up the drive and its very stable, no missing or sputtering.

I used to have manifold vacuum hooked up to the dizzy vacuum
advanced but since this mod I have it un hooked and it pulls as
good or better from idle. Good bye vacuum advance

 

I get a pretty big performance kick from the vacuum advance, but I don't run it off manifold vacuum (which makes it work in reverse in my opinion). I've got mine hooked into the nipple farthest forward at the base of the carb. You might want to give it a try before throwing it out the window.

 

He runs a Dell, not the Nikki

 

Ah, no ported vacuum on a Dellorto. Anyway with the new ignition I don't feel a need
for it. Its really that much better.

I'd like to hear Verneuil input on his experience since getting it working.

 

So which port is this on the nikki? And im havin trouble timing this thing. I got a shitty *** timing light that work for nothing. So im having to time this by trial and error and its not workin at all. So she not runnin at tip top and i still think this carb is a pos, Dont think the guy who rebuilt it knew wtf he was doing at all.

 

Sorry to hear that. If I was closer I'd bring mine over. Its an old SunTune light.

 

Its all good. So i took out the trailing. Pretty sure it was giving me problems lol. Well she runs good, But i was looking through some threads found i have my vacum advance on the wrong nipple. So ill correct that and see if theres a jump in performance.

 

So was the last diagram the correct one after you changed to a FB dizzy?

 

The last diagram is the most accurate but in my implementation I didn't do the
trailing at all. So its even simpler and right now I'm using the 4 pin HEI and not the
7 pin. Both worked but when I was doing the final debug on it, I replaced the
junkyard 7 pins with new 4 pins in a mistaken attempt to fix a poor dizzy signal
from the SA dizzy. Thats when I discovered the difference in the FB dizzy and
started using that. Just never went back to the 7 pin modules but I've kept them
for my next project.

Its very important to ground the HEI on the screw hole with the extra metal collar
around it. The grounds have to be there. Ask me how I know

 

Alright. Seem simple enough. I'll let you know how it goes.

 

I went ahead and did this setup and I'm only having a couple of bugs to work out. I too am getting the breakup/misfire at 5k... I'll try reversing the pickup leads. (Did this change your base timing?)

Also:
... I have a 82+ distributor and a couple of strange things are occuring. The first of which is that the rotor was beating against the cap at 4.5k+ (Yes, everything was attatched correctly.) The second, which is more puzzling than ate-up bearings... Is that the mechanical advance will advance with engine speed just fine, but take its sweet-*** time getting back to 0. You can take your hand off the throttle and watch the timing mark on the pully slowly (eh... 10 or 15 seconds) draw itself back to 0. Yes, the vac. advance is disabled for that diagnostic.

I'm using the MSD Blaster 2 can-coils, which have slightly different specs than the MSD Blaster 2 Ford TFI coils. New wires, BUR9EQ, no trailing (yet.)

 

Yeah try reversing the signal from the dizzy. When I was playing with it, the SA
dizzy signal was the reverse of the FB dizzy signal. It didn't change my base
timing at all. Really never had to touch the timing.

I would check out that dizzy, sounds like maybe a bent shaft or maybe the upper
part is on crooked. I've never taken an RX7 dizzy completely apart but I think
theres a top half that attaches to the shaft. That may be why the mechanical
is slow. Also it may need a good cleaning. The mechanical is just some weights
and springs so gunk in the works could make it slow.

Oh and skip the trailing, you won't notice it missing at all.