Transistor Trick Circuit Boards *Interest*
11-19-05, 08:44 AM
#1
Transistor Trick Circuit Boards *Interest*
This thread is to gage interest in the professionally built circuit board for the 2GCDFIS w/ TT (a.k.a. ‘transistor trick’). This will be available in either a kit form or as a pre-built unit. The kit will include all needed parts with the exception of possibly wire and connectors. More details will come soon.
You can read more about the transistor trick:
https://www.rx7club.com/1st-generation-specific-1979-1985-18/transistor-trick-2gcdfis-411312/
or
https://www.rx7club.com/1st-generation-specific-1979-1985-18/2gdfis-transistor-trick-installed-438878/
Those threads can be hard to follow, so a basic description of the circuit is:
The kits will likely run about $30 shipped and the pre-built units being about $45. The actual pricing will depend on the number of people ordering. The more we can get the cheaper the price will be. There may be a deposit required for people interested. Deposits will be taken once the Group Buy is approved. The remaining balance would then be paid once shipping begins. Paypal as well as check or money orders would be accepted.
People who have already contacted me expressing possible interest are:
List is growing fast.
1. Dan_s_young
2. Wodihor
3. smurfy RX3 (possibly 2 or 3 units)
4. aussiemg
5. Mazdo (2 assembled)
6. Unsupa
7. candyassmiller
8. teejs
9. mpetersrx7
10. kgray (1 assembled)
11. grease (1 assembled)
13. Anex 570 (1 kit)
14. EonBlue (1 kit)
15. JDGJr85GSLSE (2 assembled)
16. RX7Rox (1 kit)
17. nakedfzone (1 assembled)
18. Dom (1 kit)
19. onslaught_81 (1 assembled)
20. Slammed_GSL (1 assembled)
If you are listed and have changed your mind, please let me know. For those interested in getting in on a kit or assembled unit, please let me know. List if you are interested in a kit or an assembled unit and the quantity you would like if you want more than one.
Thank you.
Kent
You can read more about the transistor trick:
https://www.rx7club.com/1st-generation-specific-1979-1985-18/transistor-trick-2gcdfis-411312/
or
https://www.rx7club.com/1st-generation-specific-1979-1985-18/2gdfis-transistor-trick-installed-438878/
Those threads can be hard to follow, so a basic description of the circuit is:
Originally Posted by gsl-se addict
What is it?
The 2GCDFIS w/ TT (2nd Gen Coil Direct Fire Ignition System with Transistor Trick) is an ignition system that allows the use of the 2nd generation RX-7 coil and ignitor to work with the 1st generation ignition system. The goal is to gain the direct connection between the coil and the leading spark plugs (spark doesn’t need to go through the distributor cap/rotor). An additional benefit is the gain of a “late leading” spark. Both leading plugs fire every 180* of engine revolution instead of once every 360* as with the stock ignition. This creates an additional spark just before the exhaust phase of the combustion cycle. This helps to burn up left over fuel resulting in cleaner exhaust as well as possibly a bit more power and fuel economy.
As you see in the regular 2GCDFIS threads (sans TT), the 2nd gen ignitor is removed and the coil is fired from the 1st generation ignitor. People have done this because the 2nd gen coil in normally fired from a 5v square wave produced by the 2nd gen ECU. The 1st generation ignitor is triggered by the VR sensor in the dizzy.
This circuit (TT) acts to interface between the 1st gen ignitor and the 2nd gen coil/ignitor pack. This lets the 1st gen ignitor receive its signal as it normally does. Instead of firing the coil directly, it triggers the TT circuit which converts the signal to what the 2nd gen ignitor needs. The 2nd gen ignitor then fires the coil.
There are several advantages to this. First, the 2nd gen ignitor is much larger so it can handle higher currents than the J-109 (name of the 1st generation ignitor). It has also been shown to keep firing strong until much higher RPMs than the J-109. I have tested the 2nd gen coil on the bench to the equivalent of over 14,000 rpm and was still firing strong. The third thing is that since the 2nd gen ignitor is doing all the work, the load is taken off the J-109. This means that the 1st gen leading ignitor should last much longer.
The 2GCDFIS w/ TT (2nd Gen Coil Direct Fire Ignition System with Transistor Trick) is an ignition system that allows the use of the 2nd generation RX-7 coil and ignitor to work with the 1st generation ignition system. The goal is to gain the direct connection between the coil and the leading spark plugs (spark doesn’t need to go through the distributor cap/rotor). An additional benefit is the gain of a “late leading” spark. Both leading plugs fire every 180* of engine revolution instead of once every 360* as with the stock ignition. This creates an additional spark just before the exhaust phase of the combustion cycle. This helps to burn up left over fuel resulting in cleaner exhaust as well as possibly a bit more power and fuel economy.
As you see in the regular 2GCDFIS threads (sans TT), the 2nd gen ignitor is removed and the coil is fired from the 1st generation ignitor. People have done this because the 2nd gen coil in normally fired from a 5v square wave produced by the 2nd gen ECU. The 1st generation ignitor is triggered by the VR sensor in the dizzy.
This circuit (TT) acts to interface between the 1st gen ignitor and the 2nd gen coil/ignitor pack. This lets the 1st gen ignitor receive its signal as it normally does. Instead of firing the coil directly, it triggers the TT circuit which converts the signal to what the 2nd gen ignitor needs. The 2nd gen ignitor then fires the coil.
There are several advantages to this. First, the 2nd gen ignitor is much larger so it can handle higher currents than the J-109 (name of the 1st generation ignitor). It has also been shown to keep firing strong until much higher RPMs than the J-109. I have tested the 2nd gen coil on the bench to the equivalent of over 14,000 rpm and was still firing strong. The third thing is that since the 2nd gen ignitor is doing all the work, the load is taken off the J-109. This means that the 1st gen leading ignitor should last much longer.
People who have already contacted me expressing possible interest are:
List is growing fast.
1. Dan_s_young
2. Wodihor
3. smurfy RX3 (possibly 2 or 3 units)
4. aussiemg
5. Mazdo (2 assembled)
6. Unsupa
7. candyassmiller
8. teejs
9. mpetersrx7
10. kgray (1 assembled)
11. grease (1 assembled)
13. Anex 570 (1 kit)
14. EonBlue (1 kit)
15. JDGJr85GSLSE (2 assembled)
16. RX7Rox (1 kit)
17. nakedfzone (1 assembled)
18. Dom (1 kit)
19. onslaught_81 (1 assembled)
20. Slammed_GSL (1 assembled)
If you are listed and have changed your mind, please let me know. For those interested in getting in on a kit or assembled unit, please let me know. List if you are interested in a kit or an assembled unit and the quantity you would like if you want more than one.
Thank you.
Kent
Last edited by vipernicus42; 11-19-05 at 12:30 PM.
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11-19-05, 11:18 AM
#8
The assembled unit would only require a 2nd gen leading coil with spark plug wires. You would also need to provide connectors for wiring it up. The only question right now is the ignitor connector. They are hard to find new. I used connectors from a wrecking yard last time. It is hard to get the old terminals out and does require a special crimper for the new terminals. You may have to just get a spare connector (they are used in many places within the car) and just splice the new wires on that connector.
11-19-05, 06:12 PM
#15
JDGJr
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Originally Posted by gsl-se addict
The assembled unit would only require a 2nd gen leading coil with spark plug wires. You would also need to provide connectors for wiring it up. The only question right now is the ignitor connector. They are hard to find new. I used connectors from a wrecking yard last time. It is hard to get the old terminals out and does require a special crimper for the new terminals. You may have to just get a spare connector (they are used in many places within the car) and just splice the new wires on that connector.
11-19-05, 11:46 PM
#20
Certified Old Fart
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Yup, I've been waiting for this one too. Just bought a 2nd gen coil, and now I'll make sure not to pull the ignitor!
One question - I want the ability to return the car to EXACT factory stock in case I ever sell it. Will I be able to do this?
Other than that - put me down for one unit - assembled.
Thanks!
Rob
One question - I want the ability to return the car to EXACT factory stock in case I ever sell it. Will I be able to do this?
Other than that - put me down for one unit - assembled.
Thanks!
Rob
11-20-05, 12:13 AM
#21
Lives on the Forum
As long as you keep all of your original ignition equipment installed, switching back would only take a minute. If I remember right; 1. You switch the hot wire from the new coil back to the old one. 2. Switch the plug wires back to the Cap. 3. Plug the original ignitor wire back into the 1st gen ignitor. I believe that should do it...
11-20-05, 03:35 AM
#22
Yep. Just as Kentetsu said. You can swap back to stock real easy. Just get the ignitor plug from another car, so you don't have to cut your harness. I even left the stock coil powered (it does fire since it isn't getting a signal). This way I can switch back to stock in probably less than 2 minutes.
11-20-05, 01:27 PM
#25
Put me down for 1 kit.
I bought one of the original TT boxes and after several months - I'm still loving it! Every 1st gen owner should do this to their car. And to answer someones question above - I just wrapped my old wiring up in with the new wiring and left the old coil in place. If my 2nd gen ignitor/coil pack went out I could return my car to stock ignition in 5 minutes (I kept the old distributor cap --> coil plug wire).
I bought one of the original TT boxes and after several months - I'm still loving it! Every 1st gen owner should do this to their car. And to answer someones question above - I just wrapped my old wiring up in with the new wiring and left the old coil in place. If my 2nd gen ignitor/coil pack went out I could return my car to stock ignition in 5 minutes (I kept the old distributor cap --> coil plug wire).