10,000uF capacitor for COPs - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 07-04-2008, 11:30 AM   #1
Guest
Thread Starter
iTrader: (6)
 
Join Date: Sep 2007
Location: Vaughan, On, Canada
Posts: 1,092
Total Cats: 0
Default 10,000uF capacitor for COPs

Just found the following capacitor pretty local to me 10,000uf 16VDC. Will this work for the COPs on my 2000 Miata? I really don't know much about the electronic side of things and I believe others were using a 20VDC cap and this one is 16VDC.

No Idea on the price yet probably $5-7 for 1 unit.

Thanks for your help...
M-Tuned is offline   Reply With Quote
Old 07-04-2008, 12:51 PM   #2
Elite Member
iTrader: (22)
 
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,257
Total Cats: 3
Default

Quote:
Originally Posted by mkulak View Post
Just found the following capacitor pretty local to me 10,000uf 16VDC. Will this work for the COPs on my 2000 Miata? I really don't know much about the electronic side of things and I believe others were using a 20VDC cap and this one is 16VDC.

No Idea on the price yet probably $5-7 for 1 unit.

Thanks for your help...

As is your case I have no clue whether that will work but; would you mind buying an extra one for me if it turns out it will work?

I'll paypal you the money.

Thanks,

Rafa
Rafa is offline   Reply With Quote
Old 07-04-2008, 02:15 PM   #3
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

16V should be fine. Does it say 105*C or 85*C? If the latter it won't live very long in the engine bay. It will slowly lose capacitance over time.
JasonC SBB is offline   Reply With Quote
Old 07-04-2008, 02:51 PM   #4
Elite Member
iTrader: (22)
 
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,257
Total Cats: 3
Default

Quote:
Originally Posted by JasonC SBB View Post
16V should be fine. Does it say 105*C or 85*C? If the latter it won't live very long in the engine bay. It will slowly lose capacitance over time.
Jason, are you by any chance running an AEM ems?

Sorry for the threadjacking Marc
Rafa is offline   Reply With Quote
Old 07-05-2008, 03:05 AM   #5
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Yes I am.
JasonC SBB is offline   Reply With Quote
Old 07-05-2008, 10:29 AM   #6
Guest
Thread Starter
iTrader: (6)
 
Join Date: Sep 2007
Location: Vaughan, On, Canada
Posts: 1,092
Total Cats: 0
Default

Quote:
Originally Posted by JasonC SBB View Post
16V should be fine. Does it say 105*C or 85*C? If the latter it won't live very long in the engine bay. It will slowly lose capacitance over time.
I dunno... This is all it mentions..

CEAUF1C103M10 CAP LYT RDL 10000UF 16V 22X35MM Marcon
M-Tuned is offline   Reply With Quote
Old 07-05-2008, 10:33 AM   #7
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

it would be better to start with 20V as they break down over time. a 20V cap will have a longer useful life.
Ben is offline   Reply With Quote
Old 07-08-2008, 03:19 PM   #8
Junior Member
iTrader: (1)
 
Join Date: Jul 2007
Location: Arvada, CO
Posts: 118
Total Cats: 0
Default

Ummm, can I get a quick explanation as to why you're looking into adding a capacitor to your COP setup?

I'm wondering if it's something that might help my 4k, light throttle, hiccup that I get w/ my COPs.
honeydesean is offline   Reply With Quote
Old 07-08-2008, 03:20 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,904
Total Cats: 1,793
Default

what does a large capacitor do? start from there....use the noggin.
Braineack is online now   Reply With Quote
Old 07-08-2008, 04:49 PM   #10
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,328
Total Cats: 1,926
Default

Wire has resistance. The longer the wire, and the narrower the gauge, the higher the resistance.

The voltage drop across a conductor (the difference between the voltage you put in one end and the voltage you get out the other) is directly proportional to the amount of current being drawn down the conductor. As current increases, voltage decreases.

The total length of wire between the ignition harness and the Main Fuse (the primary voltage source, for all intents and purposes) is quite long, and the gauge of the wire is quite thin.

Ignition coils draw a large amount of current for a relatively short period of time, and then no current for a relatively long period of time.

So, when the ignition coils are on (during the dwell period) they are drawing a large amount of current, thus causing the voltage available to them to drop. This reduction in voltage at the coil primaries limits the amount of total power (volts x amps) that they can consume, which has the effect of limiting the total spark energy that they can produce. If a way could be found to increase the voltage available to the coils, then they could produce a stronger spark.

Capacitors are able to store and then deliver large amounts of energy for a short time. They are like miniature batteries.

By placing a large capacitor in close physical proximity to the ignition coils, the voltage drop at the coils is reduced considerably. The mechanism by which this occurs is:

1- At rest, the capacitor steadily takes in current through its positive terminal and stores it until the capacitor becomes saturated. Because it is drawing this current slowly (compared to an ignition coil) and over a longer period of time, it is able to saturate at the maximum possible voltage which the system can deliver.

2- When the ignition primary begins to charge, it draws a large amount of current down the harness, causing the aforementioned voltage drop. However, since the capacitor holds a large amount of stored energy at a voltage higher than what the harness voltage would be were it allowed to drop, the capacitor begins to discharge, feeding power out into the ignition coils. Because the coils are being supplied with additional power from the capacitor, they charge at a higher voltage than they otherwise would, allowing them to generate a larger spark.

3- When the coil primary shuts off, the now depleted capacitor once again begins to charge itself, and the process repeats.
Joe Perez is offline   Reply With Quote
Old 07-10-2008, 04:08 PM   #11
Junior Member
iTrader: (1)
 
Join Date: Jul 2007
Location: Arvada, CO
Posts: 118
Total Cats: 0
Default

thanks for answering me like a tool braineak.

and an honest thanks to joe perez, however I do understand what a capacitor is and I also understand how the capacitor will work in the car. My question was more along the lines of what problem is this aimed at solving.

I've had a diy COP ignition for about a year now(back when the wiring diagrams for the 1.6/1.8 was credited to lazzer) with no noticeable problems other than the 4k, light throttle, instant stumble I get now and then. I was trying to figure out if this additional mod would help rectify that. It doesn't seem like it would since the car's basically cruising when it happens, so its not drawing as much power to the COPs as it would be during WOT(during which I experience no problems).

I read a lot of the other thread about the 'dwell reducer circuit' for the COPs, and in there people were saying for a 1.6 (as my 92 is), it wasn't necessary.

In all, it seems like a pretty good mod to do, but I like to actually know the reason/purpose of a mod for my car instead of blindly spicing in capacitors.
Thanks again to Joe Perez. EDIT: I read the 1.6 AFM removal of yours. Very neat stuff and very well written.

Last edited by honeydesean; 07-10-2008 at 04:23 PM.
honeydesean is offline   Reply With Quote
Old 07-10-2008, 04:24 PM   #12
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,904
Total Cats: 1,793
Default

Quote:
Originally Posted by honeydesean View Post
thanks for answering me like a tool braineak.

you're welcomes.
Braineack is online now   Reply With Quote
Old 07-14-2008, 03:05 PM   #13
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,328
Total Cats: 1,926
Default

Quote:
Originally Posted by honeydesean View Post
I've had a diy COP ignition for about a year now(back when the wiring diagrams for the 1.6/1.8 was credited to lazzer) with no noticeable problems other than the 4k, light throttle, instant stumble I get now and then. I was trying to figure out if this additional mod would help rectify that. It doesn't seem like it would since the car's basically cruising when it happens, so its not drawing as much power to the COPs as it would be during WOT(during which I experience no problems).
Well, technically the coils draw the same amount of power on the primary side no matter what the load is. The difference is on the secondary side- as load (basically MAP) increases, the resistance on the plug gap increases. So the likelihood of a misfire increases with load because the secondary has to come up to a higher voltage in order to produce a spark.


Quote:
I read a lot of the other thread about the 'dwell reducer circuit' for the COPs, and in there people were saying for a 1.6 (as my 92 is), it wasn't necessary.
Well, depends on your definition of "necessary."

The dwell time of the factory ECU on the 1.6 cars is ~5.5 milliseconds under normal operation conditions. I verified this myself by using an oscilloscope with an inductive DC ammeter on the primry side of my stock coils back when I was running an EMU.

Others have made a similar observation on the Toyota COP, and determined the optimal dwell time to be in the neighborhood of 2.5 milliseconds @ 12v.

The "problem" that the dwell reducer sets out to address is that if you leave the coil primaries energized for longer than is necessary (after they have reached saturation and the primary current has leveled) you are just creating additional heat in the coil primary without any benefit.

It is said that the 1.8 factory ECUs have a shorter dwell time, although I've not actually measured it myself. If this is the case, then in theory, the dwell reducer circuit would be more necessary on the 1.6 ECU.
Joe Perez is offline   Reply With Quote
Old 07-15-2008, 02:53 AM   #14
Junior Member
iTrader: (1)
 
Join Date: Jul 2007
Location: Arvada, CO
Posts: 118
Total Cats: 0
Default

Dang, I was hoping I didn't have to decipher that electrical diagram.

But thanks for the help Joe, I'mma get on buying/wiring all the necessary business.
honeydesean is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
91 1.6l turbo complete part out. Tony the Tiger Miata parts for sale/trade 63 12-29-2016 03:23 AM
Toyota COP Erat Miata parts for sale/trade 17 02-17-2016 05:22 PM
01-05 Fab9 PNP COPs (used) FrankB Miata parts for sale/trade 6 09-30-2015 12:48 PM
Sold fail wagon Miata parts for sale/trade 2 09-07-2015 09:51 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:08 AM.