Building my own ignition....

Buggy · 10-26-2010, 09:06 AM

I've gotten kind of sick of the serious mess that DLIDFIS has created under the hood of my Rx-4 so I'm playing around with the idea of building my own ignition system using LS series coils and possibly a CAS to trigger the whole thing. I know people have done similar setups before using haltech, motec, etc ecus to controll it all, but I'm just building a simple ignition system. No need for an expensive ECU on a carbed engine. Does anyone have any insight on this? I can't see why you couldn't use the stock CAS to trigger the coils themselves. Each individual coil has its own ignition module built in so it should be as simple as just wiring it all up. I'm no electronics expert though so I thought I'd ask before I start breaking things.

t_g_farrell · 10-26-2010, 09:46 AM

I think you need a computer to interpret the CAS signal and trigger the coils.

Remove the trailing and it will help clean up a lot of the mess.

Buggy · 10-26-2010, 01:53 PM

That's what I was thinking. I know the CAS creates an analog signal and I'm almost positive the LS coils require a digital signal and the voltages of both will probably be different as well. I'll have to do some more research. I was hoping someone else would have possibly tackled this already.

2gslse · 10-26-2010, 03:11 PM

if you were able to make the system work that easy you would also lose your vac. and mech advance that your distributor has built in already

RETed · 10-26-2010, 03:23 PM

+1

How do you dial in your ignition advance or any custom ignition timing curve?
This is why aftermarket computers are used in between everything.

-Ted

Buggy · 10-26-2010, 04:21 PM

That thought never crossed my mind either. Right now I don't run vacuum advance, but mechanical advance is being used. It would be like using a completely locked distributor. Seeing as it is going on a bridgeport the ignition could be left way advanced all the time. Some adjustment through the rpm range would be much more ideal though.

I could modify a distributor and just use it strictly for a trigger device. I have to go look at some parts and come up with ideas. This will work one way or another........

Buggy · 10-26-2010, 04:27 PM

Also another reason I want to get rid of the current ignition system is the fact that I do run into some ignition breakup at high rpms ( like about 8k). I may have to go full electronic with some sort of ECU.

t_g_farrell · 10-27-2010, 07:53 AM

What are you using for ignitors in your current DLIDFIS?

What dizzy are you running?

Buggy · 10-27-2010, 08:12 AM

I'm running a distributor from a GSL-SE and igniters as well. Good old J109's.

t_g_farrell · 10-27-2010, 09:45 AM

I'm no expert but I think an MSD might fix your >8k ignition issue.

No ECU needed either.

FC Zach · 10-27-2010, 11:05 AM

Thats a big 10-4 on the MSDs, but you will either need to modify or bypass the igniters for that set up.

Buggy · 10-27-2010, 11:38 AM

If I'm going to spend cash, I'm not going to waste it on an MSD box. I'll go all out and get an ECU that I can tune an ignition map in to suit my needs and I can run the coils I want. I can always add fuel injection then later if I choose to do so. You can pick up some pretty good and cheap used stand alones these days. I had a megasquirt I sold for next to nothing. Should have kept it...... Oh well, hindsight is 20/20 as they say.

Buggy · 10-27-2010, 11:42 AM

My whole idea here was to build something on the cheap as my recent TII purchase has left me slightly broke. I already have the LS coils (got them dirt cheap) and i have tons of CAS gears and distributors and crap. Keep throwing thoughts and ideas at me though. This thread is helping me think about this and I like hearing everyone else's thoughts.

NoDOHC · 10-27-2010, 05:28 PM

I would install the aftermarket ECU, your engine will thank you. The fuel is much easier to tune using an aftermarket ECU than a carb.

Your engine has a lot more than 156 WHp in it, given the mod list.

I made 155 WHp with a stock 6 port and Haltech e6x.

Buggy · 10-27-2010, 05:48 PM

This is all very true. To be honest though the car is making more power than that. We stopped the dyno pulls at 7000rpm because the dyno was overloading the car and it was getting hot. They hp curve was still increasing at 7000rpm and this was on a mustang load dyno. I'm sure its closer to 170whp, but I do agree it has way more and FI with a standalone would tap into that. I like the weber carb though. It keeps with the old school feel. It's a tough decision.

10-26-2010, 09:06 AM	#1
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	Building my own ignition.... I've gotten kind of sick of the serious mess that DLIDFIS has created under the hood of my Rx-4 so I'm playing around with the idea of building my own ignition system using LS series coils and possibly a CAS to trigger the whole thing. I know people have done similar setups before using haltech, motec, etc ecus to controll it all, but I'm just building a simple ignition system. No need for an expensive ECU on a carbed engine. Does anyone have any insight on this? I can't see why you couldn't use the stock CAS to trigger the coils themselves. Each individual coil has its own ignition module built in so it should be as simple as just wiring it all up. I'm no electronics expert though so I thought I'd ask before I start breaking things. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-26-2010, 09:46 AM	#2
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC Posts: 757 Rep Power: 0	I think you need a computer to interpret the CAS signal and trigger the coils. Remove the trailing and it will help clean up a lot of the mess. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

10-26-2010, 01:53 PM	#3
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	That's what I was thinking. I know the CAS creates an analog signal and I'm almost positive the LS coils require a digital signal and the voltages of both will probably be different as well. I'll have to do some more research. I was hoping someone else would have possibly tackled this already. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-26-2010, 04:21 PM	#6
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	That thought never crossed my mind either. Right now I don't run vacuum advance, but mechanical advance is being used. It would be like using a completely locked distributor. Seeing as it is going on a bridgeport the ignition could be left way advanced all the time. Some adjustment through the rpm range would be much more ideal though. I could modify a distributor and just use it strictly for a trigger device. I have to go look at some parts and come up with ideas. This will work one way or another........ __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place Last edited by Buggy; 10-26-2010 at 04:24 PM.

10-26-2010, 04:27 PM	#7
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	Also another reason I want to get rid of the current ignition system is the fact that I do run into some ignition breakup at high rpms ( like about 8k). I may have to go full electronic with some sort of ECU. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-26-2010, 03:11 PM	#4
2gslse Rotary Fanatic Join Date: Apr 2008 Location: front royal va Posts: 440 Rep Power: 18	if you were able to make the system work that easy you would also lose your vac. and mech advance that your distributor has built in already

10-27-2010, 07:53 AM	#8
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC Posts: 757 Rep Power: 0	What are you using for ignitors in your current DLIDFIS? What dizzy are you running? __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

10-27-2010, 08:12 AM	#9
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	I'm running a distributor from a GSL-SE and igniters as well. Good old J109's. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-27-2010, 09:45 AM	#10
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC Posts: 757 Rep Power: 0	I'm no expert but I think an MSD might fix your >8k ignition issue. No ECU needed either. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

10-27-2010, 11:05 AM	#11
FC Zach RCC Loves Me Not You Join Date: Mar 2008 Location: Eagleville, TN Posts: 2,267 Rep Power: 20	Thats a big 10-4 on the MSDs, but you will either need to modify or bypass the igniters for that set up. __________________ 1993 Yamaha GTS1000 1992 Celica Turbo AllTrac 1987 RX7 Sport 1979 Yamaha G1, KM24 powered 1975 Dolmar KMS4

10-27-2010, 11:38 AM	#12
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	If I'm going to spend cash, I'm not going to waste it on an MSD box. I'll go all out and get an ECU that I can tune an ignition map in to suit my needs and I can run the coils I want. I can always add fuel injection then later if I choose to do so. You can pick up some pretty good and cheap used stand alones these days. I had a megasquirt I sold for next to nothing. Should have kept it...... Oh well, hindsight is 20/20 as they say. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-27-2010, 11:42 AM	#13
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	My whole idea here was to build something on the cheap as my recent TII purchase has left me slightly broke. I already have the LS coils (got them dirt cheap) and i have tons of CAS gears and distributors and crap. Keep throwing thoughts and ideas at me though. This thread is helping me think about this and I like hearing everyone else's thoughts. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-27-2010, 05:28 PM	#14
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	I would install the aftermarket ECU, your engine will thank you. The fuel is much easier to tune using an aftermarket ECU than a carb. Your engine has a lot more than 156 WHp in it, given the mod list. I made 155 WHp with a stock 6 port and Haltech e6x. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

10-27-2010, 05:48 PM	#15
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	This is all very true. To be honest though the car is making more power than that. We stopped the dyno pulls at 7000rpm because the dyno was overloading the car and it was getting hot. They hp curve was still increasing at 7000rpm and this was on a mustang load dyno. I'm sure its closer to 170whp, but I do agree it has way more and FI with a standalone would tap into that. I like the weber carb though. It keeps with the old school feel. It's a tough decision. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place