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View Full Version : Thoughts on my ms tables.


e30gangsta
12-13-2020, 09:52 PM
Looking for any insight/help on my MS tune.

Sr20det redtop
mx8270
s4hl cams
built head and usual bolt ons on 93.

https://i.ibb.co/xhtp2RS/1.png (https://ibb.co/319DTLy)
https://i.ibb.co/XtP9F4Q/Capture.png (https://ibb.co/89wJPBC)
https://i.ibb.co/wwrQq3L/Capture2.png (https://ibb.co/hZ1dNhM)
https://i.ibb.co/FHWBnG9/Capture3.png (https://imgbb.com/)

NukeKS14
12-14-2020, 08:39 PM
You've neglected to provide a ton of info that anyone would need to begin to evaluate your tables but I'll wade in...

Your boost control table... no one is going to be able to help you with that. You need to go out and tune it in yourself because it's dependent on SO many variables. I would DRASTICALLY lower your values from 3500 RPM to redline in the 100 and 95 cells. Start more conservatively with somewhere around 10-15 and raise it little by little. You're going to hit boost cut as soon as it spools with that table IMO. I have no idea what a plotted compressor map for your engine/turbo/hotside combo looks like so I don't know where to begin rescaling it but you're wasting a lot of resolution here. you don't need 3 columns for 100%. Megasquirt extrapolates the values between cells. You're just sacraficing a column to nothing here. Need to know when your turbo hits peak boost on wastegate, then you can work off of that to add spool and shape your table.

Fuel table likewise depends on a lot of variables. we're not going to be able to help you with that much either in terms of values but as far as shape goes, right off the bat I don't like how your fuel VE table looks. If you're using auto-tune, that tells me you're only actually reaching just under 175 kPA which means a huge amount of wasted resolution. If that isn't partially tuned map it doesn't make sense to me then. There's no reason that your cells at 175 kpa 5800-6200 should be a higher value than the 200 kpa row above it. Fuel demand goes UP with higher flow, potentially stays the same into runover if you allocate a row for that but... not down. Not that much.

The ONLY thing you're really going to get help with is the ignition table... and I'd be VERY wary of advice given with that. I don't have experience tuning SRs or have one of my own so I'll stay out save to say I'd recommend rescaling it to align with psi-equivalent values so you can use a rule of thumb to flesh out a base map to start with (more on that in a sec) You're also wasting resolution going down to 10kPa. where does the engine idle at? with fat cams it's probably going to be closer to 40kPa-ish I'd wager.

My advice to you is this; Ask the forums for feedback on your base settings for the tune (required fuel, deadtimes for your injectors, dwell, idle, etc... ) In order to do that we need injector info and the base fuel pressure you're running at as well as coils and some other minor stuff. Build your ignition map off of rescaling a base map for an SR20 from here; http://www.megasquirtpnp.com/mspnp2_maps.php, extrapolate it to what your target is for boost and take 1-1.5 degrees out per psi at the 100 kPA row and above for starters.

Go to an experienced tuner or rent some dyno time and conservatively dial in the fuel ignition and boost duty tables because no two engines are going to be the same here.

I wouldn't advocate scaling the tables the way you did; I tend to align mine more in terms of psi since that makes more sense to me for ignition timing (taking out 1 - 1.5 degrees of timing per psi of boost to begin timing the ignition map for example.) For a street driven car I also use a 60:40 rule for 60% of the cells 100kpA and below and 40% or less above 100kPa. Most of your driving is going to be transient out of boost in a street car. WOT boosted is fairly linear and easier for MS to extrapolate. your more dynamic use in ignition and fuel is going to be below 100kPa so it's going to run smoother that way.

Here's a good link for helping you convert between kPa and Psia for maps;
https://forums.holley.com/showthread.php?9178-MAP-kPa-to-Boost-PSI-Equivalents.

and I'd edit your MAT air density table. I wrote a post about it in my build thread so I'm not going to retype it all but here (scroll to the bottom of that post)
https://forums.nicoclub.com/nukeks14-s-grip-zenki-build-t626307.html#p6810091

best of luck.

e30gangsta
12-14-2020, 10:01 PM
So first things first I appreciate your time and help writing that post.

Dead times are solid, I inputted them straight from Injector dynamics site. The car is running on id1300s with a base fuel pressure of 43.5.

The timing map I took it from martin rs enthalpys website. He has a base timing map listed there and I pulled 2-3 degrees out of the entire mp to make it even more conservative. And this was just a rough map that we knocked out in an hour on an actual dyno. As for the boost duty cycle table I left it at 100 up to 3500rpm because I want the wastegate completely shut until then, to help the turbo come online aa quickly as possible. I appreciate the links and I will definitely try what you suggested. Thank you.

NukeKS14
12-14-2020, 10:06 PM
. As for the boost duty cycle table I left it at 100 up to 3500rpm because I want the wastegate completely shut until then, to help the turbo come online aa quickly as possible. I appreciate the links and I will definitely try what you suggested. Thank you.

Why do you want 3 columns to do that when you can do it with 2?

e30gangsta
12-14-2020, 11:19 PM
Why do you want 3 columns to do that when you can do it with 2?

Honestly because I did it in less than an hour. And I just took the stock ms breakpoints and just used that. I will rescale them like you suggested.

Kingtal0n
12-21-2020, 01:34 PM
That has to be an E85 ignition map.

On pump 93, max timing is 9 to 12* around 15-18psi of boost, whether we are talking an LS engine or a SR20 or 2jZ

Be careful what you are doing