i tried posting this in the general foum, but no one seems tomtalk there, so i thought you first gen people migh know.





ok i have aftermarket 60,000 volt coils in my 2nd gen drag car, running a carb.(coils from Sumitt racing)

I have had the ignition setup in the DLDFIS, or what ever you call it (the Dual Leading Direct Fire Igntion System) and i have had it in stock configuration. (for a first gen)

(first one with 3 coils, and second one obviously with 2 coils)

my question is, has anyone had any problems with coils not intended for a rotary, (is there such a thing).

the reason I ask, is because my new engine does not seem to run very well, mostly at high RPM's, i am wondering if this might have somehting to do with aftermarket coils not keeping up with the high RPM's of a rotary.

another reason i ask is when i am at higher RPM's (like 6-7k) the tach starts to freak out, (pegs 10 - 12,000)

does anyone have experiance with this?

thanks!

 

speed,
I have experience with different direct fire set-up such as DLIDFIS, MSD 6 series with 2 coils and MSD 6 series with FC coil. I never seen that problem. How did you wire it to the distributor. If you wired it backwards, then it can cause a problem.

With my RX-3, I have pegged my 10,000 tach with no problem. Thats using the 6A with no rev limiter nor venturies in my 48 IDA.

 

right now i am running stock, i decided to go back to stock so that the DLIDFIS setup is out of the question.

could a faulty igniter cause this problem, bad cap and rotor, maybe a bad coil. or does it sound like i have another issue some ware else.

Myself and my dad have been working on this for a few days now, and we are just out of ideas, we are not the dumbest guys in the world either. (my dad is a big V8 guy, but extremely new to the rotary world)

now what is interesting is that my last engine (that i built) did the same thing..........



ok here is the VERY long story made short.

I had a perfect running second gen street car. I turned it into a "race car" by completely removing everything, and starting over. all injection crap was removed, and a Holley carb setup was installed. due to the lack of a computer, a first gen coil was installed. the engine was a 6 port "street port" engine built by me. and yes it was my first engine.

when the car was taken to the track for it's first time, it was discovered that the car was running very poor. it did not rev past 6k and it lack some serious power on it's way to 6k. in fact i ran the 1/4 mile in 20 seconds.

We tried everything we could think of. we have had 8 different carbs on that car, including the one built by racing beat specially made for rotarys. two different ignition systems were installed one being stock, and the other DLIDFIS.

didn't seem to matter what we did, the car just ran like crap. I came to the conclusion that the engine I built was to blame, and decided to have someone else build my engine for me.

The new engine is a bridged 4 port, and some of the internals are asked to be a secret. I can tell you though that they are 3mm 2 piece seals.

The new engine had 60 PSI while cranking and required push starting to get it fired up. the engine now has about an hour or so of running on it. (by running i mean idle, driving up and down the driveway, and even around the block.) this car is not a street car by any means so diving it to put miles on is virtually impossible. after running it for the hour it has, the compression is now at 75 PSI. (yes this is taken from a piston tester with the check valve removed)

the problem is that this new engine is doing the same thing the last engine was doing. since we have discovered the problem I have gone back to a stock ignition system, and tried 3 more carbs, and changed some settings.

we are at a loss, we are out of ideas, and can't believe the problem is still here. when i have asked members of this forum (in the past with the last engine... almost a year ago) no one has EVER heard of a problem with not revving, and an extreme loss of power. I seriously doubt that i am the only one that has had a problem like this. I am hoping some of you rotor heads out there that know these "old school" systems can help.

Thanks to anyone that has ANY ideas.


please keep in mind that a lot was left out so it was not WAY WAY WAY to long, but you get the jist of it. :p

 

exactly what coils have you tried? all these carbs you tried.... did you go thru and actually tune them? the holleys especially, you may have been way out of sync on the secondary jetting. would cause this problem.

 

The only coils i have tried are the aftermarket coils i am running now. kinda the reason for me asking if the coils could be breaking up at high RPM's. didnt know if this was common or if i should look elseware.


the carbs have been tuned, or at leastwhat we could. we even used one that came from racing beat that is setup for the rotary. but yeah we have played with jets, squirters, acc pumps, and acc pump cams. it all seems to make a differance A LITTLE, but nothing even remotly close to something that would be drivable/racable.

and timing.... timing is stock, although we have advanced it, and retarded it, this seems to realy make no differance. only major differance that we noticed is starting. (by stock i mean, the dot lines up with the slash, i am sure it's not dead on, but even off the little it could be will not cause this big of a problem)

 

As long as your fuel pump and filter are up to snuff, I would start looking for poor grounding. It might be worthwhile to run a few extra ground wires to make sure that all of your juice is flowing properly. Good luck with it.

 

what kind of aftermarket coils tho. my msd blaster 2's died of very fast. now i run the accel SUPER coil. ****** huuuuge and very looow resistance.

 

I ran 3 blaster 2's for years with an MSD 6A on the leading with my old carbed engines.Never any problems.
Ive heard the stock FC coils are very stout and powerful for factory coils.Plus the dual tower leading coil is perfect for a direct fire system.Most FC guys dont bother to upgrade them,even when pushing 400-500hp.Ive been running the stock FC coils and the same 6A on my TII transplant for almost 5 years with no issues.Coils have about 110,000 total miles on them,got em' from the junkyard for next to nothing.

 

Coils are from Sumitt Racing. they are their 60,000 volt coils part number SUM-G5220 from http://store.summitracing.com/



all grounds are good. besides the solid engine mount, i have a 4 gauge cable from chasis to engine. and 4 gauge from battery to chasis.


fuel pump is also from summit. part number SUM-G3136K (both the pump and regulator)

the filter is a Fram, i dont remember the part number, but it is the $60 replacable filter. (inside is replacable)

 

steve, i wish i had the same luck. when i ran my msd to the 2nd gen coil it was pretty crappy i dunno why. i had to back timing out sooooo much and it seemed to run real rich on that setup. like it wasn't burning the fuel as good as before. it's possible the coilpack i had was junk.

 

Speed,
What about the spark plug wires? If its magnecor, I had problems with them in the past. Try running stock NGK, they are fine for direct fire.

 

funny you say that, i just took off the accell 8 mm wires, and put on the stock NGK wires on sunday.

 

Huh,I must be lucky.Ive been running the same 10.5MM Magnacores for about 6 years with no problems on various engines with the same MSD 6A box.Stock plugs,stock timing,stock FC coils and CAS.Its never broken up or missed or anything.Ive also heard the FC ignitors dont suffer from failures like the FB units.

 

yea they're much stronger. i am using 8.8 mm accel wires with great success. wish i could use the damn fc coilpack

 

how do you use the FC coils, i have some of those laying around, maybe i can try those.... although i am getting the drift that no one has heard of the problem i am talking about, so it sounds like i should look elseware.

 

no it does sound like you are having possible iginition break-up. try running an msd 6a to the stock distributor with a good set of coils. that's what i'm using on my turbo 12a. works beautifully. i used to have break up around 5500rpms bad before this setup.

 

.... crap..... I dont have an MSD just laying around.
what about trying the FC coil thing? how do you use the FC coils, does it require any modifacation of the coils?

 

this was in the archives...

https://www.rx7club.com/1st-gen-archive-71/electrical-easy-2nd-gen-direct-fire-install-20-minutes-398818/

 

thanks man, ill see if i can find my old FC coils. Hope i didnt toss them with all the other "extra" parts removed.

 

Have you actually verified the trailing ignition is working?

 

yes it works, verified by pulling the wire and checking for spark, and also checked by hooking up the timming light to both trailing wires.

i never did bother to look and see what the light does at high rpms though........ HMMMMMM...... i will have to do that, maybe the light startes to flake out like the tach does at high RPM's. if thats the case, then It sounds like i have a problem with the ignition breaking upi like i thought. if the light is still smooth whent he car "stops reving" then i would susspect the trailing ignition is good.

hmmmm?????

 

I really don't think that your trailing ignition would have any noticeable effect on your performance, even if it was completely dead.

 

speed,
Run a new wire from the battery to the coil's + terminal (but disconnect the factory wires). if that helps then you may wanna try running a new line to the coil's positive terminal (fog lights relay and toggle switch). If that doesnt help, then at least you know its not in the harness (process of elimination).

 

in this car, every wire has been removed. there is not one factory wire in the car. the only wires in the car are the ones i ran to power the stuff that needs to be powered. in fact everything that i need is on a switch inside the car, the switches are ignition, fan, alternator, fuel pump, NOS, and starter. the only other wire in the car is for a brake light. were talking a total of 10 wires or so.

you really should see the car Wacky, i think you would like it. did you see it at seven stock? i wasnt very far from your green and white car. to bad I never got o meet up with you.

anyways, for NOW i have a couple things i want to try.

1 i want to put some bigger jets back in it, leaning it out seemed to have made it worse. we will see what happens when she runs FAT.

2 replace cap and rotor..... you never know.

3 hook up a light on the secondary coils, and see what it's doing at high rpms

4 try running the FC coils in the car.

5........ ok so i am out of ideas again. maybe start replacing the coils with differant ones, i would hate to start buying more stuff that i dont need.



hey here is a question for you guys. the car has BRAND new plugs in it, we got the car to start, and ran it for about an hour. (like i said before) after that hour i pulled the plugs and they were BLACK!!!! not wet and gooey black, but dry and black. i have never seen my plugs look like that before, what does this mean.

 

your idle mix may be way too fat, which carb is currently on the car? if it's a holley, take the primary metering plate off and blast compressed air thru the main channels. sometimes they can get dirt in them and will make the fuel just bleed out other orifices and you will have no control over idle fuel mix. same thing happened to me, blasted it, worked fine. do you have a wideband? this would help greatly in tuning