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-   -   Hydra EBC tuning issues (https://www.miataturbo.net/diy-turbo-discussion-14/hydra-ebc-tuning-issues-25638/)

posidon42 09-03-2008 04:29 PM

Hydra EBC tuning issues
 
There is something strange going on with the car and I want to know what you guys think I need to do to fix it. I am trying to do some road tuning of my EBC and have a pretty good map right now. The problem is the results keep changing even though the settings don't.

I was adjusting some settings this morning and doing some road tuning on the way to work. Apparently there is a discrepency between my boost gauge and the Hydra as the gauge was indicating a sustained 13 psi but the Hydra log was only saying 11. No big deal, but the difference is important. So closer to work (not logging this time), I tried some more WOT runs and the gauge was only getting up to 10 psi. So somewhere I lost 3 psi worth of boost with the same settings.

Any ideas? I was thinking it might be a heat soak issue, but I am driving highway speeds NOT in boost 99% of the time. I am going to get some more data on the way home and post my settings and a log when I get home.

paul 09-03-2008 05:22 PM

Same gear?
Same load? as in flat road, incline, or decline.
Up to same RPM?

posidon42 09-03-2008 06:08 PM

Road was flat, but you got me thinking about the gears. I think the higher psi run was in third and I was doing the others in fifth and just flooring it. I guess I didn't think this would make a difference. I am going to have to try this on the way home.

paul 09-03-2008 06:15 PM

That's interesting. If the rpm range where you went WOT was the same I would think you make more boost in the higher gears. more load + more time = more boost

m2cupcar 09-03-2008 10:05 PM

I tuned closed loop running the same stretch of road in the same gear (4th). It'll make your life a lot easier. As stated, you should see higher boost at a given rpm in the higher gear.

posidon42 09-04-2008 01:19 AM

2 Attachment(s)
So here is my best data log run. I started in second and was going uphill.

The second chart is my current PWM settings. I can't seem to figure out an empirical relationship between the duty cycle and the pwm settings. I called FM and they said I just have to have someone watch to see which zone is active... Seems like I should be able to read the duty cycle area off this chart and adjust the zones that are too high or low. But it does't seem to work that way.

posidon42 09-04-2008 01:30 AM

1 Attachment(s)
Also, I was noticing that my AFR gets REALLY lean on deceleration. According to the logs, it is getting up to 20 whenever I take my foot off the gas. Where would I adjust this in the Hydra settings?

m2cupcar 09-04-2008 09:22 AM

I'm going to assume your target is ~10psi. The spikes you're getting at the start of each gear needs to be controlled by another parameter. I don't know the hydra, but all (AFAIK) ebcs have overshoot and droop control. Think of it as the ecu anticipating the target just ahead so it starts to bleed boost off before it reaches the target in order to hit the target. THEN knows that right after bleeding some boost off it will need close down the gate just a bit to compensate for the droop. This scenario is more so with journal bearing turbos. And I know with the LINK it's very hard to eliminate the spike w/o totally rounding off the transition to target. BUT you should be able to reduce the spike to <1psi over your target- considering that's what I've done with the LINK. btw- notice the how much more dramatic boost activity is in the higher gear- that giant spike is directly related to the increase in load from 2nd to 4th.

Why bother with open loop boost control vs. closed loop? For the time invested you would have a more robust boost control with the latter... I can't imagine the hydra not doing a better job at it than the LINK.

y8s 09-04-2008 09:59 AM

This is useful:
http://www.mrcontrols.com/installs/n.../boostctrl.htm

and the boost control duty cycle is not DC%. That's fuel. You want Wastegate PID (%) on the graphs. And for god sake dont put 3 lines of the same color up at once. DLL will let you change the colors. And get rid of everything but RPM, Boost, and Wastegate PID.

your AFR is lean at lift because it should be. double check that your "fuel cut on decel" setting under the Injection tab of the settings dialog is checked. it probably is. which is fine.

posidon42 09-04-2008 11:50 AM

Thanks y8s. I will adjust the graphs when I get home to make them more readable. I was trying to find where I could adjust the colors and was unsuccessful.

The fuel cut on decel is enabled.

m2cupcar - the boost target in the Hydra tables is set to 10.5 right now, but I would like to have a solid 12psi through the range. That is my goal anyway.

y8s 09-04-2008 12:02 PM

I dont have DLL on this computer but I believe it's up under customize graphs.

I just use MegaLogViewer. :)

posidon42 09-04-2008 11:27 PM

better graph posted :)

y8s 09-05-2008 09:44 AM

you can set min and max values for the variables in MLV too. might help scale the numbers some and give you a clearer picture.

for example: set wastegate to go from 0-100, boost from 0-20, AFR from 9-20.4 (this will put 14.7 on the horiz line).

and one last thing? put a new calculated variable in. Call it "MAP (kPa)"

and paste this into the value box:
[vacuum (mmHg)] > 0 ? (760-[vacuum (mmHg)]*0.13332239) : ([boost (psi)]+14.696)*6.89475728

then you will have awesome.


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