Results 1 to 15 of 825

Thread: DIY LTCC or similar system for LT1s

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #16
    Fuel Injected! spfautsch's Avatar
    Join Date
    Apr 2015
    Location
    Montgomery City, MO
    Age
    52
    Posts
    883
    I revisited the thread tonight to catch up, and finally read the link in the second post pointing to chevythunder. I couldn't help but stumble several times on the description of the degree wheel.

    Quote Originally Posted by (chevythunder page)
    and since the camshaft rotates once per two revolution of the crankshaft, it is in reality seeing 720 pulses.
    Uh, no. Your math is bass ackward. It is true that the camshaft rotates once per two crank revolutions, but if the outer wheel has 360 slots it's only seeing 360 / 2 = 180 per crank revolution. Let's not get caught up on rising and falling edge signals here, but looking past one's interpretation of "pulses" it's getting 360 signals per crank revolution or 720 signals per cam revolution, max.

    Quote Originally Posted by (chevythunder page)
    Like the outer ring, the ecm "sees" 16 pulses for each revolution of the camshaft
    This statement is only correct if you consider "pulses" as both rising and falling edge, but why would we be thinking in terms of camshaft revolutions? As a person who's on the Asperger's spectrum, this drives me batty.

    Unless vilefly beats me to it, I'm thinking my game plan for winter is giving the arduino a shot with the assumption of driving ls1 coil modules with 5v ttl signaling. I think this can be done without looking at the high resolution signal by keeping memory of the current position and calculating rotational speed based on the smaller of the lower resolution signals which the aforementioned page says are signaling 1,4,6 and 7. Another presumption I think can be relied on is where the crank comes to rest at engine shutdown. I've learned from talking to some white haired gentlemen who've seen their share of missing flywheel teeth that chevy v8s tend to come to rest in only about four different spots. In a case of the crank being jogged by a mechanic, if we assume the ECM follows the same logic, worst case the uC will miss the first or second cylinder firing after a power loss but so will the ECM with injection sequencing.

    Am I making any grotesque oversights?

Similar Threads

  1. Which TBI system is better?
    By KeyAir in forum GM EFI Systems
    Replies: 41
    Last Post: 05-13-2019, 09:39 PM
  2. Hard start 93 LT1 with LTCC Ignition Mod
    By beestoys in forum GM EFI Systems
    Replies: 0
    Last Post: 05-18-2015, 08:58 AM
  3. ABS system?
    By K1500ss4x4 in forum Gear Heads
    Replies: 3
    Last Post: 02-06-2014, 06:21 AM
  4. Vortec EGR System?
    By EagleMark in forum OBDII Tuning
    Replies: 40
    Last Post: 06-02-2013, 10:07 PM
  5. Quicker way to do Spark Hook test on the street for LT1s and others?
    By sherlock9c1 in forum Fuel Injection Writeups Articles and How to New and Old
    Replies: 15
    Last Post: 03-03-2013, 01:52 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •