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-   -   MSPNP Boost Control? (https://www.miataturbo.net/megasquirt-18/mspnp-boost-control-11199/)

hazimwood 07-12-2007 12:15 PM

MSPNP Boost Control?
 
How does one setup the MSPNP for boost control. I imagine there is a solenoid that needs to be purchased for this to occur. How accurate is it? IS getting an electronic boost controller from greddy,hks etc.,going to work out better?

richard_ha 07-12-2007 12:25 PM

http://forums.turbobricks.com/showthread.php?t=80599
95% of your answers are there.

Splitime 07-12-2007 12:58 PM

He has the MSPNP though... no proto area and might have different board layout.

I'd suggest waiting for Foundsoul or Matt Cramer to speak up on this.

FoundSoul 07-12-2007 01:00 PM

We've just recently gotten the valves in stock, and just today got the connectors in stock for them as well... so we'll have this better documented/illustrated very soon for you. In short though, you wire the 12v wire of the valve to a switched 12v source, and the ground pin of the valve to the MSPNP's EBC output. The shiny port on the EBC solenoid goes to the turbo/intake plumbing (INPUT) and the black port goes to the Wastegate (OUTPUT).

The EBC settings in the MSPNP MM9093 base map are a good starting point for open loop control and you really should only need to tune the DC Target map. First, take a baseline datalog of your boost curve with wastegate pressure. Then take a second datalog with the EBC at the base settings (20%). Gradually raise the DC% for all cells until you see if making a difference (30%, 40%, 50% untill you see it raising your boost a bit) datalogging at each step and watching for the difference. Then you can start adjusting the RPM columns and the values in those columns to increase/decrease the DC% to increase/decrease boost at specific RPM ranges. Goal being a nice smooth boost curve, maybe letting it taper off just slightly as RPMs climb. It takes a little time to tune and is best tuned on the dyno as you'd be making alot of more than likely dangerous high speed runs to do this anywhere else (starting at very low RPM in 3rd or 4th and running to redline).

Note-- on the MM9093 with the 90-93 Miata you don't have a variable TPS, so this 8x8 table you see has been essentially reduced to a 1x8 table since you can't adjust boost based on throttle position. We've basically locked throttle position at 50%. I'd recommend adjusting all cells in a column to the same value each time you make a change anyways... So that all values in the 2300rpm fields for example are the same, and all in the 2900rpm column are the same, etc.

Tuning note-- If you want boost to come on a bit sooner, you may end up with 100% DC in the low RPM points. Careful with this though, as you'll more than likely need to pull back on that DC% at or just before where your turbo normally spools or it may spool to the moon. So you might have 0% at the first column, then 100%, 100%, 95%, 85%, 85%, 90%, 95%, 95% when you're finished tuning for example. That would be for a car that needed a little help spooling early, then came on strong and you wanted to keep it from spooling too high so you pulled some DC% out (down to 85%) but then as RPMs climbed maybe you saw it tapering off too fast so you gradually added some DC% back as it rev'd out to keep it from tapering too much.

Don't just plug the example numbers above in there though. Tune it from the bottom up or you may just accidentally see 30psi for a split second, and then be posting a thread on the forums on how to run a compression test ;).

FoundSoul 01-02-2008 09:50 PM

A while back we updated the MSPNP manuals with more thorough info on tuning EBC-- here's a direct link to the tuning section heading, scroll down just a bit for the EBC section.

MM9093

MM9495

paul 01-02-2008 10:05 PM

great timing but in the 94/95 manual you need to remove this line "Since there is no TPS unless you have modified the unit for potentiometer TPS, you will want to set all the bins for a given RPM level to the same percentage."

FoundSoul 01-02-2008 10:13 PM

DOH! Thought I fixed that when I first put it up-- it's fixed now, thanks....


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