dwell reducer circuit for toyota COPs
#41
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Holy ****, why did i just read every post and still have no idea WTF is going on...and i just finished my COP harness.
Hate to sound like Sam, j/k, but seriously, can someone explain this to me in a ESL (English as a Second Language) type of ordeal.
I am running MS standalone on a 94, and my COP harness is a direct PnP into factory harness. Where would i insert this capacitor? Do i need one for each coil, or pair them up, or each on his own? Sorry, but i really do not get this ****, should have stayed on school, i know.
Thanks
Hate to sound like Sam, j/k, but seriously, can someone explain this to me in a ESL (English as a Second Language) type of ordeal.
I am running MS standalone on a 94, and my COP harness is a direct PnP into factory harness. Where would i insert this capacitor? Do i need one for each coil, or pair them up, or each on his own? Sorry, but i really do not get this ****, should have stayed on school, i know.
Thanks
#44
edit: Parallel, and yes. Just FYI, arrows point to ground on those caps.
This is a good read for anyone not savvy on electronics.
http://en.wikipedia.org/wiki/Series_...its#Capacitors
http://sol.sci.uop.edu/~jfalward/ser...lcircuits.html
Last edited by Saml01; 04-24-2008 at 12:14 PM.
#46
Thanks for the info everyone!
Just acquired my TOY COPS and connectors today, and will put the unit together tomorrow.
93 NA 1.6 on EMB stock ECU. Anyone else having problems with their COPS on this set up?
Just checking if the CAPS are installed at the right location on Brianack's schematic?
Just acquired my TOY COPS and connectors today, and will put the unit together tomorrow.
93 NA 1.6 on EMB stock ECU. Anyone else having problems with their COPS on this set up?
Just checking if the CAPS are installed at the right location on Brianack's schematic?
#47
Mini,
I've got an EM-B, and unfortuately it doesn't want to start at this point with the cops in place. I haven't tried to mod the harness with the cap yet.... but basically, if it doesn't start first time with the cops. Jumper over of the ignition wires (removing them from the EM-B) and see if the sucker starts on the just the stock ecu.
Dave,
I've got an EM-B, and unfortuately it doesn't want to start at this point with the cops in place. I haven't tried to mod the harness with the cap yet.... but basically, if it doesn't start first time with the cops. Jumper over of the ignition wires (removing them from the EM-B) and see if the sucker starts on the just the stock ecu.
Dave,
#49
Minime,
There's been a bit of a discussion on this issue with the EMB. Popstoy over on Mnet was able to get the COPs running without issue on a '99 with EMB using Jason's circuit and CAP. My CAP from Ben should be arriving in the next couple of days. I'll try to get it hooked up this weekend and see if the CAP solves the start-up problem. We would still need the dwell reducer to keep the COPs from overheating at high rpm.
There's been a bit of a discussion on this issue with the EMB. Popstoy over on Mnet was able to get the COPs running without issue on a '99 with EMB using Jason's circuit and CAP. My CAP from Ben should be arriving in the next couple of days. I'll try to get it hooked up this weekend and see if the CAP solves the start-up problem. We would still need the dwell reducer to keep the COPs from overheating at high rpm.
#54
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I never saw an answer on the question of the 1.6 dwell, so let me state that on my '92, I measured it at appx. 5ms running last year before I pulled the ECU to go MS.
BTW, a friend has asked if I'd build one of these for his car. Did the group buy on the PCBs ever materialize? If not, I'll host a real one.
BTW, a friend has asked if I'd build one of these for his car. Did the group buy on the PCBs ever materialize? If not, I'll host a real one.
#56
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Well, it seems to me that the only real difference would be the stock ECU dwell. I didn't realize the later cars used a shorter dwell, so this schematic is not one-size-fits all. The board, however, could be.
Looking at side A as an example, the amount of dwell reduction appears to be a simple factor of the RC time constant specified by R as (1/((1/R2)+(1/R15)))+R4 and C as C1. If I'm solving the circuit correctly, assuming Vc must be 2.5, I get t=1.419, which is pretty close to the 1.5ms that Jason claims. It's probably within the tolerances of the various parts, anyway.
One alternative would be to do away with the parallel R2 and R15 combo, and replace them with a single 50k pot.
*or*
We could simply publish a chart of known component values to achieve various amounts of delay. Shouldn't be too hard to figure out.
Looking at side A as an example, the amount of dwell reduction appears to be a simple factor of the RC time constant specified by R as (1/((1/R2)+(1/R15)))+R4 and C as C1. If I'm solving the circuit correctly, assuming Vc must be 2.5, I get t=1.419, which is pretty close to the 1.5ms that Jason claims. It's probably within the tolerances of the various parts, anyway.
One alternative would be to do away with the parallel R2 and R15 combo, and replace them with a single 50k pot.
*or*
We could simply publish a chart of known component values to achieve various amounts of delay. Shouldn't be too hard to figure out.
#57
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Wait, that's not right. R would be 1/((1/R2)+(1/R15)), which is 10.476k, which would make t = 0.726ms. Clearly I'm missing something...
Still, the basic design is universal, just find the right component values to plug in and it'll work with any year.
Still, the basic design is universal, just find the right component values to plug in and it'll work with any year.
#60
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When I get some free time, I'll draw the board so that we can price them.
Before I do that, is everyone happy with the design as it stands? Does anybody feel the need to put potentiometers in so that the dwell can be precisely trimmed? Means you'll need an o-scope to set them up.
Before I do that, is everyone happy with the design as it stands? Does anybody feel the need to put potentiometers in so that the dwell can be precisely trimmed? Means you'll need an o-scope to set them up.