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-   -   how to run dual boost maps (https://www.miataturbo.net/megasquirt-18/how-run-dual-boost-maps-20965/)

cardriverx 05-14-2008 04:57 PM

how to run dual boost maps
 
Now I know it uses the JS1 pin, but do I need to ground it to activate the 2ed table? Like a switch going from the JS1-switch-ground wire?

Joe Perez 05-14-2008 05:04 PM

On a 3.0 PCA, it's JS9, which is logically equivalent to pin 6 of JP1 on a R2.2 PCA.

Here:
http://www.msextra.com/manuals/MS_Ex....htm#mapswitch

MikeRiv87 05-14-2008 05:16 PM

if your just looking for a low/high switch and ur using an EBC u can always just run a toggle on the signal wire from your ms to the ebc. This will give you a low (gate pressure) and a high which will correspond to the ebc duty table in your ms. Don't make things more complicated than they have to be.

Braineack 05-14-2008 05:25 PM


Originally Posted by MikeRiv87 (Post 256912)
if your just looking for a low/high switch and ur using an EBC u can always just run a toggle on the signal wire from your ms to the ebc. This will give you a low (gate pressure) and a high which will correspond to the ebc duty table in your ms. Don't make things more complicated than they have to be.

I think this is the best way since I don't like using closed loop boost control.

cardriverx 05-14-2008 06:17 PM


Originally Posted by MikeRiv87 (Post 256912)
if your just looking for a low/high switch and ur using an EBC u can always just run a toggle on the signal wire from your ms to the ebc. This will give you a low (gate pressure) and a high which will correspond to the ebc duty table in your ms. Don't make things more complicated than they have to be.


Gate pressure on my car is very low, like 5 psi. I do not wanna run that haha.

Ill have to take a look at the diagrams, thanks joe.

TonyV 05-14-2008 06:35 PM

I was interested in this as well, but after some driving at 5psi, I can finally see what Scott meant by "your not gonna wanna go back to low boost" lol...

But for shit's sake, IF one wanted to do the above (wg pressure OR ebc map via toggle switch), wouldnt you have to:

A-tune 2 diff msq's (one for wg boost, one for high boost)
B-have to still find a way to switch between the 2 msq's/maps???

I mean I guess you could just plug in the laptop and load the appropriate table for the correct boost situation, but that kinda defeats the purpose of a "switch"..no?

Or is possible to tune 1 table well enough to handle both high/low boost properly?

Joe Perez 05-14-2008 06:38 PM


Originally Posted by tvalenziano (Post 256958)
IIF one wanted to do the above (wg pressure OR ebc map via toggle switch), wouldnt you have to:

A-tune 2 diff msq's (one for wg boost, one for high boost)
B-have to still find a way to switch between the 2 msq's/maps???

A- No, of course not. Think about it- if you push the pedal down part-way and go to 5PSI, then push it all the way and go to 13 PSI, did you need two maps to accomplish that? No. You simply have one map which is tuned for all MAP conditions- from vacuum all the way to max boost, and everything in-between.

B- No, of course not. If you do the switching by using a toggle to interrupt the line to the EBC, then no MS-related fanciness will be necessary. The MS will simply fault out of closed-loop boost when it realizes its not hitting its targets and revert to the DC table, which will of course accomplish nothing since the EBC is disconnected.


Or is possible to tune 1 table well enough to handle both high/low boost properly?
You really don't understand how any of this works, do you?

Savington 05-14-2008 06:46 PM


Originally Posted by Joe Perez (Post 256959)

You really don't understand how any of this works, do you?


pwnd

TonyV 05-14-2008 07:24 PM

lol, no but trying to...and think I'm grasping this concept a lil better now...

Braineack 05-14-2008 10:00 PM

You really dont need to tune different fuel maps. it can handle all boost levels, just as it can handle all vacuum conditions.

Since you have TPS you can make your boost map go low boost at 95% throttle and full boost at 100% throttle. That's easy enough.

or you can add a MBC into the wastegate line for your low boost setting. So when you switch the solenoid off, the MBC will keep the boost above 5psi, but below your "high" boost.

You can do dual boost control maps, its an easy mod, however it require closed loop boost maps. when the switch is toggled, you have the option to change to a new fuel map and spark map, none of which you need to do.

kotomile 05-14-2008 10:07 PM

shorten the WG arm and the 'EBC off' psi won't be 5 psi anymore ;)

simple.

ZX-Tex 05-14-2008 10:15 PM


Originally Posted by kotomile (Post 257046)
shorten the WG arm and the 'EBC off' psi won't be 5 psi anymore ;)

simple.

Yep. I did this with a GT2560 and it works great. I went from 5 psi to 7.5 psi just by tightening the arm.

FWIW after the intercooler and clutch install I will be raising the boost and doing it with the method described by MikRiv. Use the wastegate for low boost, use the MS and EBC for high boost, switch the signal to the EBC to change modes.

cardriverx 05-14-2008 10:56 PM

Guys, I still want the use of the EBC at both the low and high boost.

Now would a active low input work? The way I see is that I need a 5v source, splice that into the line that goes to one side of the switch and js9 using 2 diodes, Then the other end of the switch goes to a ground.

Is that right?

Im just going to use the MS's abilty to switch between 2 EBC maps.

Also, has anyone found the closed loop system to work ok, since I have to use it?

Joe Perez 05-15-2008 12:17 AM


Originally Posted by cardriverx (Post 257064)
Now would a active low input work?

Again: http://www.msextra.com/manuals/MS_Ex....htm#mapswitch

Note that there are two different circuits, one for active-high, one for active-low.

cardriverx 05-15-2008 07:36 AM


Originally Posted by Joe Perez (Post 257100)
Again: http://www.msextra.com/manuals/MS_Ex....htm#mapswitch

Note that there are two different circuits, one for active-high, one for active-low.

Could you explain the differences for me?


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