does anyone know the offset in degrees of the 4x reluctor wheel vs the no. 1 cylinder at tdc?

reason i ask, im using this sensor to trigger my megasquirt ecu, and i need to know the offset so that i can accuratly set the timing, our timing covers have no provisions for a tab for use of a timing light, so i cannot cross reference to that reading, anyone have any ideas?

 

I didnt know 95 Fbodies had a CPS. You must have converted to OBD2. What timing chain are you using on that twin turbo setup? Most heavy duty timing sets require that the CPS reluctor be removed.

Steve

 

He didn't convert to OBD2, he has the timing cover and reluctor wheel from my car and I have his because I converted to OBD1 and he needed something with provision for a crank sensor for his aftermarket computer. So he is using a 96-97 timing cover and reluctor wheel, but not the OBD2.

 

what he said...haha, and stock timing set, for this reason

im hoping the opti will still output its timing to the stock computer even though it is not controlling ignition, its still powered so it can run my stock tach, and im still throwing spark through the opti, so im hopeing my scanning software for the stock lt1 computer will show the timing that the megasquirt is controlling...hmm if not ill have to make some sort of timing marker for the timing cover, and mount it on the water pump since the opti is in the way

that is, unless someone knows this phasing...please

 

Wish I could tell ya man BTW, you might wanna check out the Cloyes C3039 timing set, It works like stock like you need it to, but is much stouter than the factory cam sprocket, and not too expensive (~$100) You can pick one up at any O'Reillys

 

o really? man i wish ide have known that when i was building the motor...its in the car now...lol, well if i have problems i guess thats what ill replace it with

 

I'd like to keep an eye on this project. I thought long ago that a OBD2 crank posistion sensor woudl be the way to go on a swap like this.

I like megasquirt, its pretty cool stuff. I like the open development of it too.

 

According to megasquirt you can use the tach signal and I quote.

"Input triggering for injection events is derived from an existing ignition system - either by connection to a conventional Kettering ignition coil (- terminal) or by using the TACH signal available from virtually any OEM or aftermarket ignition system. MegaSquirt uses an on-board opto-isolator to prevent damage due to inductive kickbacks present on ignition coils. Remember, MegaSquirt only controls fuel, not ignition."

The tach signal is on the Red PCM connector, 13th pin using the only solid white wire.

I don't see the need for an additional sensor.

I saw this also

"Start-Up - Cranking RPM: This is the rpm at which MegaSquirt-II switches from the cranking pulse width injected at every ignition event to the pulse width calculated from the fueling equations (MAP, IAT, RPM, etc.). 300 rpm is good for most automotive engines, but a higher value may be needed for motorcycle engine or other specialized uses."

As Alvin said, interesting maybe worth watching.

 

you cannot use the stock tach signal as it works off of the low res opti signal, which has 4 slots of UNEQUAL length, since it is actually a cam sensor, it would need 8 slots, of all equal length...some people have tried to write code to compensate for this, but as far as i know, nobody has made it work properly. i believe one guy got one running like this, but his rpms were half of what they should have been in megatune software

 

You lost me on that one... While the Opti low res pulse pattern is made up of 8 slots, 4 of which are unique widths, I wouldn't think the low res pulse pattern would be replicated in the tach signal output from terminal A13.

 

ohh...well im not quite sure about the slots, i didnt mess with the opti at all, i just went straight to the crank position sensor cause the megasquirt will only operate off that tach signal if the stock computer is controlling the opti, and the megasquirt is controlling fuel only, the megasquirt is controlling fuel and spark on my car.

 

So how many teeth are on the reluctor wheel for the CKP your using and how will you reference the CKP signal to the position of the pistons?

 

I thought I had already given you this info.... but why not use the 60-tooth crank wheel wheel and sensor that Electromotive made to use with their short-lived SDI/Opti-Eliminator kit? The wheel bolted directly to the stock damper and the magnetic pickup went on two of the water pump bolts. That will give you a crank position signal, suitable for bank-to-bank injection. I had one more than 6 years ago.

 

did you read the post? that was my original question...

anyway...the car runs, so this sensor works fine, i just have no idea of its relation to tdc

 

WTF, you didn't need the offset anyway?

You should have used the high res signal in the first place