I was at the track this weekend and noticed something happening at the top of 1st gear. Didn't know what it was till watching an in car video and I think the #2 rev limiter is cutting in. I have it enabled and set to 6,050 / 6,000 rpm spark only, then pin mapped to a ground input for my line lock. Basically the same way rev limiter #1 is hooked to my trans brake which is working good. Any ideas as to what I'm missing? Also upon searching I realize "Spark - High Only" may be recommended for rev limiters. When should I use |Spark Only" vs "Spark - High Only".

 

What do you have your main rev limit set to? You posted #1 and #2 but not Main Over-Rev.

 

7050 / 7000 Spark Only

 

That is indeed odd, I would guess you would have other issues showing if one of the buttons was grounding during the run somehow. Edit: You aren't somehow hitting button #2 during the run are you?

 

No definitely not hitting the line lock button. But it certainly could be something else and just a coincidence it's happening right at 6,000. Easy enough to disable and see if it goes away. But what about question #2. When to use Spark only vs Spark High Only?

 

I haven't used the "Spark, High Only" setting but it looks like it was implemented to keep the target rpm from swinging. Before the update some were reporting a 400rpm swing while against the limiter. There is a long thread on the topic On yellowbullet
Rev Limiter Updates V4 – A new rev limiter type has been added called “Spark, High Only”. This type has a single high side value. It is recommended to use this for a 2-step rev limiter and as a high side rev limiter. Other rev limiter types have had updates to them and can be adjusted to the users desired needs.

 

Ok yes I see, lots of discussions on that one Thank you! I do notice quite a variance when I'm on the rev limiter on spark only. I will look over the datalog closer (still learning) but if I remember right it went rich right then too, which I though would also indicate a cutting ignition? But perhaps I've got something happening in the fueling coincidentally right at 6,000.

 

Here is a datalog (hoping it works). I'd really like some advice on how I can improve or hear what is seen? The dip at 6,000 may be fueling, target afr I see changes, looking at the lean spike when I go wot etc.