2jzGTE 12 tooth crank + 1 cam wheel decoder setup

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shaodome
Master MS/Extra'er
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Joined: Thu Aug 26, 2004 1:58 pm

2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by shaodome »

So a buddy of mine is building a car for the 24 hours of Lemons race next week and we are using a MK3 Supra Shell with a 2jzgte engine laying around in the shop.

The MS is actually a spectre unit, but it does have dual VR decoding circuits on board as well as some later varient of MS1Extra. My question is in regards to the wheel decoder setup for Generic wheel.

The crank has a 12 tooth evenly spaced wheel and there are two separate (G1 and G2) cam signals triggered off a notch in the cam (none of which are adjustable). G1 triggers when piston 6 is at TDC and G2 triggers when piston 1 is at TDC. On MS2 extra I run off NE and G2 with the tooth offset angle set at 0 and the car runs great.

I have no idea what to set the Trigger A, B C and their returns to for this though...same with the trigger angle. Any advice?
shaodome
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by shaodome »

I haven't found too much in the 7m threads either yet....

I was figuring for MS1, that this would have to be set as a 24 tooth wheel since it is spinning at crank speed + 1 cam.
jsmcortina
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by jsmcortina »

Six cylinder ? Wasted spark ?

If yes, then you need to combine the two G sensors and specify 12 teeth. I don't know on the triggers except they will be 4 teeth apart.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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shaodome
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by shaodome »

jsmcortina wrote:Six cylinder ? Wasted spark ?

If yes, then you need to combine the two G sensors and specify 12 teeth. I don't know on the triggers except they will be 4 teeth apart.

James
Correct, it is an inline 6 in wasted spark. Why couldn't I set it as 24 teeth and just use the single G2 signal?
jsmcortina
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by jsmcortina »

Because it won't work?

MS1 is too "dumb" to support that configuration.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
shaodome
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by shaodome »

jsmcortina wrote:Because it won't work?

MS1 is too "dumb" to support that configuration.

James
wait...something must be getting lost in translation here. I know MS1 can do this, I've run 6+1 on my Mazda KL setups for years now. On the v6 with firing order 1,2,3,4,5,6 I was able to set it as follows:

Trigger angle = 60
Trig a = 1
trig return a = 2
trig b = 3, etc etc

Kinda like how this shows in the manual: http://msextra.com/doc/ms1extra/MS_Extr ... 2nd_VR.GIF

I'm not running COP, just 3 spark outputs.

The problem i'm wondering about is either the G1 or G2 in regards to the trigger angle?
Matt Cramer
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by Matt Cramer »

shaodome wrote:
jsmcortina wrote:Because it won't work?

MS1 is too "dumb" to support that configuration.

James
wait...something must be getting lost in translation here. I know MS1 can do this, I've run 6+1 on my Mazda KL setups for years now. On the v6 with firing order 1,2,3,4,5,6 I was able to set it as follows:

Trigger angle = 60
Trig a = 1
trig return a = 2
trig b = 3, etc etc

Kinda like how this shows in the manual: http://msextra.com/doc/ms1extra/MS_Extr ... 2nd_VR.GIF

I'm not running COP, just 3 spark outputs.

The problem i'm wondering about is either the G1 or G2 in regards to the trigger angle?
That's because a KL can use "rising and falling" mode and trigger on both ends of the cam sensor. The equivalent here is tying both G sensors together.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
pimp4lyphe
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by pimp4lyphe »

I'm also trying to set up a toyota 24+1 distributor with MS1Extra, i need to know where to send the 2nd trigger input?

Thanks.
jsmcortina
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by jsmcortina »

Did you read the MS1/Extra manual for second trigger ?

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
pimp4lyphe
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Re: 2jzGTE 12 tooth crank + 1 cam wheel decoder setup

Post by pimp4lyphe »

jsmcortina wrote:Did you read the MS1/Extra manual for second trigger ?

James
can't find it
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