Unknown piggy back identification help?
#50
Boost Czar
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
The crank signal goes in the opto circuit (U3, not visible) and the cam signal goes directly to JS10 with a 470ohm pull up to 5v. It's running the 4G63 trigger wheel decoder
why do you need to see them?
#51
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,023
Total Cats: 6,591
My own preference is to use either a MAX9926 chip or a circuit based on a dual-comparator such as a TL082 or LM393, derived from work done several years ago by AbeFM, JasonC and myself. Such typologies afford the best opportunities for noise filtration, proper implementation of adjustable hysteresis, etc.
Historically, it has been common within the MS1 / 4G63 community to use the stock opto circuit (with a pullup) to handle the CKP signal, and to apply the CMP signal, with a pullup but without any isolation, to pin 11 of the CPU. Again, this is not my preferred method, but it is the one historically practiced by the community and endorsed by DIYAutoTune: https://www.diyautotune.com/tech_art...azda_miata.htm
So that's what you've got here. It's an ancient design which lacks proper isolation and input filtration, but it seems to work for about 90% of users.
#52
Thanks joe. Im not the best when it comes to inputs just yet so new concepts like that are helpful when explained.
I spent 2 days trying to get the stock 3.0 vr circut to read my honda missing tooth distributor setup without any luck... so any information I find on the subject helps better my understanding. I will be setting it up with an aem epm trigger now to delete the distributor and go cop.... my current plan is to use stock 3.0 opto input and another add on using a similar opto isolator to read the 1x wheel... are you suggesting I can use the output from the 1x wheel unfiltered?
I spent 2 days trying to get the stock 3.0 vr circut to read my honda missing tooth distributor setup without any luck... so any information I find on the subject helps better my understanding. I will be setting it up with an aem epm trigger now to delete the distributor and go cop.... my current plan is to use stock 3.0 opto input and another add on using a similar opto isolator to read the 1x wheel... are you suggesting I can use the output from the 1x wheel unfiltered?
#53
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,023
Total Cats: 6,591
Yes, that much is obvious.
1: You don't need an AEM EPM trigger (or any other aftermarket device) to go COP.
2: Your car does not have a distributor. It has two ignition coils wired in a wasted-spark configuration. EDIT: Oh, wait, are you talking about the Honda here?
I'm not exactly sure what you mean by "1x wheel."
And, as someone who has spent a lot of time working with input circuits on the MS in a Miata context, don't waste your time duplicating the stock opto circuit for a second input. If you're gonna build a non-stock input circuit, do it right: https://www.miataturbo.net/megasquir...ircuits-25789/ EDIT: I assume we shafted back to talking about the Mazda again.
2: Your car does not have a distributor. It has two ignition coils wired in a wasted-spark configuration. EDIT: Oh, wait, are you talking about the Honda here?
And, as someone who has spent a lot of time working with input circuits on the MS in a Miata context, don't waste your time duplicating the stock opto circuit for a second input. If you're gonna build a non-stock input circuit, do it right: https://www.miataturbo.net/megasquir...ircuits-25789/ EDIT: I assume we shafted back to talking about the Mazda again.
#54
Sorry I wasnt clear enough but I totally switched gears to talk about my honda.... I have a megasquirted miata already lololol. ")
Thanks for the help on this though I really do appreciate it. The reason for the distributor delete was mostly due to the fact I cant make it stop leaking oil :(
Thanks for the help on this though I really do appreciate it. The reason for the distributor delete was mostly due to the fact I cant make it stop leaking oil :(
#57
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,023
Total Cats: 6,591
I gotcha.
I'd remove the distributor from a B engine just on general principle- they offend my sense of style.
And yeah, that AEM unit will work fine on any MS using the generic toothed-wheel decoder setup page, for any combination of batch / sequential injection or ignition you can come up with. 24T is kind of a weird one, but the Wheel Decoder Spreadsheet will give you everything you need, once you determine the angular alignment of CMP relative to the crankshaft.
I'd remove the distributor from a B engine just on general principle- they offend my sense of style.
And yeah, that AEM unit will work fine on any MS using the generic toothed-wheel decoder setup page, for any combination of batch / sequential injection or ignition you can come up with. 24T is kind of a weird one, but the Wheel Decoder Spreadsheet will give you everything you need, once you determine the angular alignment of CMP relative to the crankshaft.
#60
I know this is an old thread but I stumbled across it with some random browsing and felt compelled to reply.
For the record, I never cheated in auto-x. I came up with the wiring scheme, and took Brain's help in wiring this ECU originally to be legal in the old STS class (I think). I quickly realized that getting around the "stock AFM rule" was going to be very difficult if not impossible with my electronics skills at the time. So I turbo'd it and had a hell of a good time after that in one of the prepared classes (I forget which exactly, maybe AMT). Won several events and legitimately beat the crap out of much more expensive and well prepared STi's, EVOs, Corvettes and one time, even an Elise.
It looks like this car changed a few hands after I sold it in 2011 or so, but I'm happy to see that it's still running well after all these years. It figures, I spent a shitload of time tuning it and tried to account for every possible scenario with the fuel and idle control maps, with the exception of altitude (not many hills in MI).
Oh and just as hindsight, my total budget for the turbo project was $1k and I came out slightly behind, at $813.89 for the turbo parts and ~400 for the ECU.
Anyway, good to see you all again. Back to my cave. Ciao!
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM
stoves
Suspension, Brakes, Drivetrain
5
04-21-2016 03:00 PM