That is interesting. The PCM looks for a 24x signal from the crank sensor.... ans a 2x IIRC from the cam sensor.

 

so basically another pickup needs to be added and the current wheel needs to be changed out for one with 2 teeth. I guess the LS1 PCM wants to see both 180* and 360*?

one question though... (I'm not familiar enough on the LS1 stuff) does the LS1 have a crank trigger reading the crankshaft itself, and a different sensor for the camshaft reading the cam itself? I ask because if thats the way it is we can run a 48 tooth wheel for the crankshaft off of the camshaft itself since it turns at half the crankshaft speed. Or you can do what most people do and run an MSD flying crank trigger mounted to the balancer, or supercharger pulley.

 

Probably.. i will check this out entirely...

the wheel can be adapted like the fast wheel in front of the crank balancer?

 

yes, I have seen it in front and behind the balancer.
in front of it you can run a bigger wheel for better resolution.

 

Would you still be willing to do that 48x teeth thing??

the pcm needs the 180 and 360.

I was thinking that if you can modify the relutor wheel on the 97lt1 system it could be so... do you have the resources to make a reluctor wheel 24x for the crank off of a lt1 97?

With your setup and that crank reluctor ring, one could adapt the ls1 pcm entirely... and i think i need one desperately now :S

 

Yes, that would work, and can be done... the relucter ring would need to be added to the crank on the outside of the timing cover, or you could just double the teeth it is now and run it off the cam as well, but the whole design would have to change to make room for two sensors since the shaft can't be any longer due to not being able to get a cover over the unit since the water pump is in the way.

It will be way more acurate at the crank since you need exact TDC unlike the cam sensor reference that just needs to be in the ballpark so that it knows which cylinder is number one during initial startup. If its done at the cam you will have some variances due to the chain and stretch over time.

Now for the bad news...
I don't have either engine to mock this up on anymore, since I sold my entire project. You should be able to find a decent performance shop that can do this for you if you are not capable of doing it yourself.
Feel free to use my idea, I would like to see it actually put to good use!!!

 

Well... 2 things.... the lt1 does use the cam as a reference for firing and i see no issues with them on higher mileage engines.. Then again that is why they moved to the crank referenced signal???

Anyways.... Its a really interesting idea. You could add 2 sensors there because the water pumo will not cover everything from the opti....

The 97obd2 lt1 has a crank reluctor ring, all we have to do is use that sensor and front cover but machine a ring that gives a 24x pulse. It may be a bit less accurate and the pulse will be obvioulsy shorter as the ls1's reluctor is pressed on the carank and its on the rear... and its huge

What do you think?

 

Actually I believe the reason the sensor was added to the actual crankshaft was so it could detect misfires by reading fluctuation in the crankshaft itself.

Your right though, I forgot about them doing this on the later LT1/4s.
Still, I would need to see this in order to work it all out.

Are you sure there arn't any other sensors or emission devices that the 98 up LS1s are using that the LT1/4s don't have before going through all this?
Plus what about the A/C, tranny, instrument cluster, etc.?

 

The tranny is the same... so it works even better with all the torque management ****...
8 coil packs and such...
CCP is still there
EGR is still there
A/C is the same.... instrument cluster can be changed since you can scale the tacho output... all in all... it can be done.... problem is crank sensor.