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-   -   Looking for 10psi EBC table for T25 (https://www.miataturbo.net/megasquirt-18/looking-10psi-ebc-table-t25-15858/)

samnavy 01-17-2008 10:39 PM

Looking for 10psi EBC table for T25
 
Since I fully expect the EBC insulation to work and I'll be able to start tuning tomorrow, I'd like to not have to start from the beginning. I've got the MAP of Brains T3s60 running 14psi and it's gonna be a shit-ton of trial and error to flex from that to get me where I want to go.

Anybody want to help me out.

I'd like not to start from scratch. OF COURSE I KNOW EVERY SYSTEM IS A LITTLE DIFFERENT AND I'LL STILL HAVE TO DO SOME ADJUSTING OF MY OWN... but if you've already done some work, it'd save me a lot of time.

If you're in the 8psi-10psi range w/EBC and a T25 and it's working pretty good, just take a screenshot of your target table or email me the file.

Thanks all!!!

Al Hounos 01-17-2008 11:23 PM

just try 30 across the board. check your logs, correct, repeat. at around 5000 mine likes to start creeping so i run it about 4 points lower after that for a flat boost line.

but each car is really very different, it even varies from day to day depending on temperature.

has anyone got closed loop boost targets working well? it sucks when my dialed in boost map starts hitting boost cut because it's 30 degrees outside all the sudden.

krayzrac3r 01-17-2008 11:42 PM

dude before you even mess around with it...set your over boost setting just in case you boost too much and lose your motor

Savington 01-18-2008 12:29 AM

Sam, gimme a few minutes. I'll go find the logs from when I dialed my EBC in with the small T25 and get the DCs for you.

Edit: Start at 55 across the board and see where that gets you. Should be close.

Braineack 01-18-2008 12:39 AM

I say, make the cells 100 2000 3000 4000 5000 7000

make the first three column 100. turn your over boost on and be very careful.

then log a short 3rd gear pull of your spool up, pull over and see the RPM point you hit your target.

then tune the 2nd column about 300-400RPM below that, and the 3rd column the exact RPM you hit the boost target.

in the 3rd column to redline, turn the % number down to 20....work your way up until you achieve the boost level. turn the remain column retain a flat boost curve as needed.

should take about 5-8 3rd gear pulls.

deliverator 01-18-2008 01:11 AM

When tuning with the wastegate duty cycle on my WRX I put an MBC in parallel with the EBC. The MBC is sort of a hardware failsafe.

Ok, to be honest I run the MBC in parallel all the time, a la http://forums.nasioc.com/forums/showthread.php?t=602674 :-D

samnavy 01-18-2008 09:42 AM

Is that in case the EBC fails closed?

It looks like a decent idea if you're extra paranoid... should I be?
The overboost feature works perfectly (ask me how I know), but I also thought that MBC's still (just like a wastegate spring) open gradually as the boost ramps up... that's why EBC's are fractionally better for spool, keeping the signal line fully closed to ensure maximum spool.

I'd think once you removed the MBC, you'd spool quicker as there had to be some air leaking past it and would have to readjust your numbers? Am I correct?

Thanks for all the other advice... this is gonna be easier than I thought. I don't suppose there's a "HOW TO TUNE YOUR EBC" thread I missed that discusses this in depth. Maybe somebody can write up a quick description of how to set up a base target table for a few of the more common turbo sizes. A small T25 spools off idle, but a bigger T3 would need dramatically different numbers to make sure it didn't hit out of control around 4k.

Too bad it's supposed to snow here tomorrow. I suppose if I had all season tires and 10k posts, I'd feel safe testing... but maybe I'll wait until it's a little warmer next week. Tomorrow it gets a bath and a wax... in the garage with both space heaters on blast!!!

deliverator 01-18-2008 07:18 PM

Quote:

Originally Posted by samnavy (Post 201187)
Is that in case the EBC fails closed?

It would help for that, but my reasoning is that it'll guard against too-aggressive wastegate gain rates.

Quote:

It looks like a decent idea if you're extra paranoid... should I be?
The overboost feature works perfectly (ask me how I know), but I also thought that MBC's still (just like a wastegate spring) open gradually as the boost ramps up... that's why EBC's are fractionally better for spool, keeping the signal line fully closed to ensure maximum spool.
Quality MBC's are on/off only. There's no gradual opening. MBC's > EBC's when it comes to spool.

There are two different kinds of EBC's, though- blocking and bleeding. Blocking can spool almost as well as an MBC while bleeding can never spool as well.

Quote:

I'd think once you removed the MBC, you'd spool quicker as there had to be some air leaking past it and would have to readjust your numbers? Am I correct?
Nope. An EBC's spool can never be better than a quality MBC's boost.

Quote:

Thanks for all the other advice... this is gonna be easier than I thought. I don't suppose there's a "HOW TO TUNE YOUR EBC" thread I missed that discusses this in depth.
Tuning EBC's is a royal pain. I haven't messed with an MS yet, but tuning my WRX's boost tables the real trick isn't setting the max WGDC's but the fine and coarse gain rates for the EBC.


The real reason I use the MBC is because I cheat- above 90% throttle I set the EBC to 100% which means boost builds as fast as it possibly can- which would overboost, 'cept the MBC keeps it capped to where I have it set (just a wee bit higher than the ECU's max boost and a wee bit lower than the ecu's boost cut threshold.

Braineack 01-18-2008 07:22 PM

YOU FAIL DELIVERATOR. please refrain from helping sam.

deliverator 01-18-2008 07:26 PM

Quote:

Originally Posted by Braineack (Post 201589)
YOU FAIL DELIVERATOR. please refrain from helping sam.

Interesting. Perhaps there's a difference in vocabulary?

EBC spool is inferior to a good MBC.

That's the logic among WRX tuning enthusiasts, anyway.

Don't agree?

Really polite, btw.

Braineack 01-18-2008 07:37 PM

I dont agree.

How can a ball & spring spool better than an a controlled solenoid.

Sam's solenoid can stay 100% fully closed within a few RPM of his boost target.

A $1000 MBC or $10 DIY MBC will always slowly creep some boost into the actuator as the boost pressure increases. It's a spring. there isn't some magic point where x psi of boost makes spring contract fully, but never at x - 1 psi of boost.

Since Sam can keep any and all boost from entering his actuator until whatever rpm he wants, the solenoid will spool the turbo faster.

I have plenty of logs to prove this point however I killed the HDD on my tuning laptop so I am unable to do so.

deliverator 01-18-2008 07:56 PM

Interesting...

My experience with an MBC is either there's enough pressure on the spring to break the ball's seal or there's not. It'd let little tiny 'puffs' through, huge gusts, somewhere between, or nothing at all.

I'll start a fresh thread about this so we don't totally derail this one. Very interested in pursuing this discussion.


Quote:

Originally Posted by Braineack (Post 201593)
I dont agree.

How can a ball & spring spool better than an a controlled solenoid.

Sam's solenoid can stay 100% fully closed within a few RPM of his boost target.

A $1000 MBC or $10 DIY MBC will always slowly creep some boost into the actuator as the boost pressure increases. It's a spring. there isn't some magic point where x psi of boost makes spring contract fully, but never at x - 1 psi of boost.

Since Sam can keep any and all boost from entering his actuator until whatever rpm he wants, the solenoid will spool the turbo faster.

I have plenty of logs to prove this point however I killed the HDD on my tuning laptop so I am unable to do so.


Al Hounos 01-18-2008 08:05 PM

we've had this thread before.

EBC > MBC

Braineack 01-18-2008 09:02 PM

here...i don't have the boost log that corresponds with this dyno, but it's pretty clear.

http://www.boostedmiata.com/dynos/mbc_vs_ebc.jpg
green = EBC Blue = MBC

m2cupcar 01-18-2008 09:29 PM

IMO if an EBC is outperformed by a MBC, then it's not tuned (set up) well. That's the clear advantage of the EBC, it can be tuned to fit the system.


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