Hello everyone. I'm hoping that you can help me out on a tuning question I have.

Does the timing trend stay consitent all the way up to 30psi+ ? Between each 4 psi column there is a 3.5 deg difference. Is it safe to say that this pattern/trend will continue to 30 psi? I just don't want to start out with timing too advanced once I turn up the boost to the next column. The timing between each 4 psi column is retarded 3.5 deg and appears as if it will continue that trend.


Tuning would be easy if boost was dead on in each column. What method
do you use to tune timing in each column appropriately?
Example...right now my 16 psi column is perfectly tuned but now that
I'm going higher I want to tune for 18-19 psi. Do I only adjust the 22
psi column since its extrapolated? Do I highlight all columns to the
right of that as well or only the 22psi column until I end up to the
right of 22 psi? Tuning boost in these tables is hard because its
typically slightly to the left or right of the boost column you are
trying to tune.

The reason why I highlight everything to the right is so I keep the timing up/consistant and not
too retarded once I get to the next column. I just want to make sure
this method is fine. Ideally, if I can run boost to exactly what the
column is then all I have to do is tune that single column of boost.

This is honestly the ONLY issue I have with tuning
right now because when you run a datalog, it always shows those 4
boxes scrolling through the map but ALWAYS highlighting two columns at
once! If I see that the box is dark red, it tells me that the column
its in is what I need to adjust.


Thanks for any help you can provide!

Anthony

 

 

1 degree of retard per pound of boost seems to be a fairly typical response. It's a good place to start, but as with any tuning changes, you need to do a lot of data logging to make sure the changes are safe. When tuning, I try to make every cell in the map valid, even those I don't expect to ever hit. That way, if the car ever over boosts or does something a bit off, I may not be completely screwed.

Tim

 

I was only unsure of my abilities because I have never tuned an S2K @26-27 psi making 700hp. I rented a dyno and tuned my car on E85 and ended up making 696hp / 471tq. I answered all my own questions once I started doing runs on the dyno and all my knowledge came together and made sense. Thanks for the reply. For the E85 setup, it wanted roughly .75 deg per lb but at higher boost was more like .5 deg per.

My biggest worry was cranking up boost to a value I've never hit and just making sure that the timing was low enough to start with. She's a monster now haha.

 

Congrats on your #'s..! Very brave for tuning it yourself at that level.! So what values you ended with at that psi levels? 10-12? My car at low 12psi is running at 18 deg max on pump 91 do you think 15psi and 15 degrees would be too low?