Tuning vortec to run on as little sensors as possible

[454cid]

If MAF is more accurate than MAP for fuel/air anyway, then is MAP technically necessary? Also would there be any cons to tuning out the cam and crank sensors, since those weren’t listed as an absolutely necessary sensor to make the car run?

I understand these are dumb questions but I’m trying to learn more about tuning and efi systems

The cam and crank sensors are how the pcm knows what position the engine is in, at all times. I'm pretty sure the pcm would be completely lost without them.

 

[Vikingdude]

Cam and crank sensors are how your engine knows where it is in rotation and delivers fuel and spark.
What do you hope to achieve by eliminating sensors? They all perform a job, so you will need to replace it with something, or pay the price (reduced performance, decreased reliability, poor fuel economy, etc.)

 

[Scooterwrench]

GM put the parts on there for a reason. I'm just now starting to understand what the individual sensors do and how they affect the performance of the power train. Delete crank and cam sensors and your stuck in your driveway.
No crank sensor,no spark or fuel. No cam sensor and spark and fuel at the wrong times.
You may want to consider a Model A Ford!

 

[L31MaxExpress]

The L31 does not need a cam sensor to run, it serves very little purpose actually. Not that I would go and delete any of my sensors just because I felt like it. The only sensor I tend to delete is the knock sensor. On more performance oriented stuff the knock sensor can actually cause detonation.

 

[454cid]

The L31 does not need a cam sensor to run, it serves very little purpose actually. Not that I would go and delete any of my sensors just because I felt like it. The only sensor I tend to delete is the knock sensor. On more performance oriented stuff the knock sensor can actually cause detonation.

I'd like to hear more about both if you have the time. I'd think the cam sensor allows for better control of the ignition timing. My Saturn didnt have a cam sensor but that was a waste spark ignition which I understand has it's own peculiarities. Supposedly a value was calculated by the pcm.

Also a knock sensor causing detonation seems counterintuitive.

 

[Hipster]

You may want to consider a Model A Ford!

Maybe he's prepping for an EMP, One's gots to know how to get around in the apocalypse. lol

 

[Komet]

Cam and crank sensors are only needed for sequential fuel injection. If you're down with the batch fire, you don't need them.

 

[L31MaxExpress]

I'd like to hear more about both if you have the time. I'd think the cam sensor allows for better control of the ignition timing. My Saturn didnt have a cam sensor but that was a waste spark ignition which I understand has it's own peculiarities. Supposedly a value was calculated by the pcm.

Also a knock sensor causing detonation seems counterintuitive.

The L31 with the low-res 4 pulse crank sensor does not even use the cam sensor for anything related to the ignition timing. The only thing it does is help the PCM determine when to fire the injectors.

As for the knock sensor causing detonation, it absolutely can and that is the reason why it is disabled on my 383. Retarding the timing can actually cause detonation from excess heat. I did not believe others that had stated that before, until I ran into it myself. Knock sensor was picking up noise from the forged pistons and valvetrain. Retarded the timing, then it went to the low-octane spark table. Once on the low-octane timing map, it was still going to maximum retard as soon as it turned on. My ~30* of total timing became 10-15* of timing, the chambers started heating up, before long I actually heard light amounts of spark knock aka pinging.

 

[L31MaxExpress]

Cam and crank sensors are only needed for sequential fuel injection. If you're down with the batch fire, you don't need them.

As I understand it the P01 and P59 are not even down to batch fire with a failed cam sensor. I am not sure if this is only with a 24x reluctor or if it is true of the 4x reluctor on the L31 as well.

 

[454cid]

The L31 with the low-res 4 pulse crank sensor does not even use the cam sensor for anything related to the ignition timing. The only thing it does is help the PCM determine when to fire the injectors.

Doesn't the off set between the cam and crank sensors effect timing?.....or is that why the offset can be so far out of spec before setting a code? Spec is +/- 2, but a code isn't set until something like 22 degrees out.

As for the knock sensor causing detonation, it absolutely can and that is the reason why it is disabled on my 383. Retarding the timing can actually cause detonation from excess heat. I did not believe others that had stated that before, until I ran into it myself. Knock sensor was picking up noise from the forged pistons and valvetrain. Retarded the timing, then it went to the low-octane spark table. Once on the low-octane timing map, it was still going to maximum retard as soon as it turned on. My ~30* of total timing became 10-15* of timing, the chambers started heating up, before long I actually heard light amounts of spark knock aka pinging.

Ok that makes sense, to me.