I'm already getting my list together of what I want to do to the FC when summer comes, and so far I have emissions removal, new vacuum lines all around, and of course looking into a re-vamped ignition system.

I haven't played around with ignition-related systems in my cars before, so I just had a couple of questions, and I did read FC3S.org's write-up on his HI-6 install.

My goal is to get my GXL to run smoother, increase efficiency, and I wouldn't mind an increase in power as well.

The current things I have done this season are as follows:

- Gutted cats, HKS clone exhaust (system still uses the stock 2.5 diameter pipe), Racing beat y-pipe.
- HKS cone intake
- Cleaned and balanced injectors
- New battery
- New rear calipers, pads all around, brake system flush
- Chassis and ECU re-ground (still sorta in progress)

It doesn't seem I've gained a whole lot of power, but response is much better and my mileage has gone up a small amount. I can also feel a bit more of a "kick" when I floor it on the freeway.

1. With the HI-6 system, are the power gains noticable, or is it a small increase? I'm not sure if these systems would make much of a difference on the N/A platform. It seems to me that's it's mostly turbo people using them right now.

2. Will I be required to buy two of the HI-6, since the FC3s.org tutorial only shows the HI-6 being installed on the leading ignition? I'm assuming the leading is the most important because the trailing is really kind of a clean-up step in the cycle, right?

3. Until I can get a hold of the HI-6 system (if I go with it based on your recommendations), can the stock ignition be re-grounded from the white connector (I haven't pulled the wiring schematic yet, but I assume the black w/yellow strip is the ground)?

4. A quick one really, what's a good type and a good place to get a hold of nice vacuum lines? I would go with the cheap-o NAPA stuff, but I want to make sure it will resist the temperatures and other conditions in that crazy engine bay.

Thanks for any advice bros!

 

1 - the gains are very minor. Just a bit smoother.
2 - I just used one unit on the leadings. If you want to hook up the trailings, then you will need an additional 2. Making 3 total.
3 - ?
4 - I got mine from bakerpreformance.
-a

 

almost imperceivable. No low RPM power gains at all. In fact to anyone who claims any low RPM gains after adding a CDI/ignition controller, I call BS and suggest that their car was in the need of a good tune up. Replacing the SP cables and spark plugs would have given them the same gain.
a single unit for leading is all you will need, however if you wanted to do the trailing coils, you would need a total of three (one for the leading, one each for the trailing. However there is no real need for the two additional units for the trailing coils unless you are expecting to hit 10K rpm.
The coils get ground from the ECU. They can not be "re-grounded". Black/Yellow is ignition 12volts + at the coils.
Ebay

 

Ah, so the professional opinion would be that I should save my money and buy cooler stuff.

I've been doing more reading, and it seems the stock ignition system is actually pretty bad-***, but when would it be advantagous to upgrade? Would slapping a new ignition module on top of the controller begin to make a noticable difference?

As far as the ECU grounds go, which ones would you suggest grounding out? I originally made four grounds, but a couple of people were telling me that some of those grounds will distort sensor readings if they don't run through the stock wiring.

Vacuum hose related: Is silicone really worth it if you don't care at all what it looks like? I'd rather have just straight black vacuum hose, anything else is rice IMO unless oyu have removed emissions and a shiny new looking bay. Mine is clean, but hardly shiny. I know that silicone can also be disolved by petro-chems, and I'd rather not deal with that headache.

Thanks again for filling my head with answers.

 

This reply is based on my experience only. Some will disagree (Hi Ted! ).


None whatsoever. Waste of money. No mileage increase, no power increase, and no change in the idle. Of course, my car was running properly before the CDI install, which is probably a factor.

You only need to install on the leading. The trailings just fire as a "clean up" operation. If you're very ****, then also do the trailing with either a dual channel or two boxes. But so not worth it...

Ground the stock ignition at the ignitor only.

Silicone lines from any performance shop.

 

Mazda saw a gain of 4 HP on there race cars by switching to CDI,.. of course these are 300 HP beasts so the gain on an FC would probably be like 2 HP.

 

And Mazda probably switched from a distributer setup. Our cars already come with an excellant and thoroughly modern ignition system.

 

The only gains I have seen using a CDI (I actually use the crane on my vert) on the leading col is less spark break up at higher RPMs.

If you look at most dyno sheets for a 84+ non turbo 13B; the spark starts misfiring around 6-6.5k RPM. A CDI unit will help prevent that. They also tend to help misfiring at idle.

But as Arron said, the stock system is pretty damm good, and unless you are planning on using that upper RPM power; a CDI will not help any real additional power.

 

That is my finding too.
High RPM breakup is far less.
I use to have breakup at around 6.5k - 7k RPM.
But with the Crane, it's all gone. It'll pull right to 8200 rpm.
HOWEVER, it eats plugs like crazy.

I had the NGK iridium plugs in there thinking they will withstand the CDI. Well, I was partially right. The iridium electrode didn't wear out at all. But the hook that it fires too (don't know what that's call) got eaten off pretty bad...

 

Use the Denzo Iriduims instead. At $35 each, so far they actualy have lasted 10K miles without any problems or noticeable wear for me. As a plus side, I did see a slight HP gain useing the Densos.

The NGK Iridiums suck and die early even on a non rotary engine.

 

What if I were to pull the ignition and put an MSD ignition unit combined with the CDI? It's not something I actually plan to do now, but my curiousty has been perked a bit.

 

I don't think I would bother w/ CDI on NA or low boost TII until I had bought all the other cool stuff.

I saw no idle or low rpm gains when I went w/ 2 crane Hi-6 and LX-92 coils for the leading plugs.

I had a TON of gain in the upper midrange and high rpm (4-8,000rpm), but ~20psi boost and richer than 10:1 AF ratio is probably the only reason the stock ignition was breaking up. It can spark it off reliably richer than 8:1 AF now, but you gotta be rich to run that rich- lol.

I use $7 NGK Iridium plugs since the hot ignition EATS plugs fast. NGK BR10EIX- they come in many heat ranges- they are for 2 stroke snowmobile. You need a thinwall socket to put them in.

 

http://fc3spro.com/TECH/MODS/IGN/cdi.htm

SAE papers showed Mazda got an 8hp increase, and I don't think it was changing from a distributor.


-Ted

 

Oops, "8ps" increase...
It was "HEI" versus "CDI".

http://www.thecarricos.com/ACRE/Recent-tech84-7-11.pdf


-Ted

 

Page cannot be found.

 

ahh sorry it was 8 hp, been awhile since i looked at that prt,.. ive got them all printed out let me post up a pic of it...

 

asdf

 

what replace the ECU with a Dizzy and MSD ignitor???

Or are you thinking that a MSD 6A is not a CDI/ignition amp?

 

again only an increase above 6k RPM

 

would i care about it being anywhere else?

 

60% of automotive drivers almost never exceed 5000 RPM.

Since the torque curve on a stock S4 13B dies around 6K... well most people don't use the engine to its fullest.

 

Crap, they changed the directories a little...

http://www.thecarricos.com/ACRE/Docu...ech84-7-11.pdf

You can peruse the entire directory here:

http://www.thecarricos.com/ACRE/


-Ted

 

power keeps going up until 6.5k on s4's and 7k on s5's

and i dont know about most drivers but im aware of the fact i drive a rotary,.. if i need power the car is not staying under 5k for very long.. and any extra HP right aroung the HP peak will be welcomed with open arms.

 

Interesting read. I'm still not convinced (based on my own experience) that an ignition upgrade is worthwhile on a properly running street car...Around here, those CDI boxes go for roughly $400. Maybe they're a dime a dozen in the states, but paying that kind of cash for a 0-2HP gain just doesn't seem worthwhile.

What's also interesting is that they increased gap at the same time. Obviously, this will result in better ignition. And then you would need a higher voltage to fire those larger gaps...

Yeah, but then I would have to download each PDF and manually read each one to find the one you were referring to...