Open Loop EBC + no variable TPS = Fail
 

I just installed the DIYautotune EBC today and started tuning it. I was really excited, but that soon turned into disappointment. My target boost is 12PSI. If I actually tune for it in near steady state with 4th gear pulls, I will overboost like crazy in transients in lower gears. It's worse than an MBC, IMHO.

*sigh* When is MS going to get closed loop boost control? :vash:

you need to tune the cells better, you need to use 4th or 5th gear pulls to determine the RPM you need to start opening the valve at.

Problems solved.

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I struggled with EBC for a year and a half. Switched 2 weeks ago to an MBC and I'm never looking back.

Sav, I am with you. I cannot seem to make it work either. I tried again this weekend to tune it to no avail. I did some 4th gear pulls from 2k, and the turbo actually spools slower with the EBC than with the MBC. I would change the spring in the waste gate, but I don't think that will solve the issue.

I built the EBC circuit and bought the solenoid, but after two years I've never gotten around to installing it. My TurboXS MBC works just beautifully.

Here's a brief fifth gear pull, going up the sunshine skyway bridge. The log starts at fully closed throttle, as I wanted a good look at the boost threshold in my particular setup.

http://img02.picoodle.com/img/img02/...pm_289bb06.gif

I want a smaller turbo, I am convinced of that. I reach 188kpa at 4200.

I have a 42/.48 T3 that I can rebuild or I can get smaller 60/.48 T3. The one I have now is 60/.48 T3/4, and it is huge compared to the other T3's.

We're running open loop on our red test car without a variable TPS, and it works fairly well other than that it doesn't compensate for altitude. Keith G is working on an easier to tune closed loop code that we plan to test out when it's ready.

I dont have any problems....

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How do you get yours to show up in Vac/PSI and not KPA?

Pick the option in MLV...

And BTW his shows MAP and Boost

Hmm... maybe OL EBC + no variable TPS + me = fail.

Where are you guys getting your EBC boost signal? Mine's plumbed at the vacuum nipple just after the throttle plate. Maybe that's too noisy a signal?

EBC sucks and everybody knows it. Get a MBC and dial it in and you'll be happy. T off your FPR line and use that to feed the MS it's vacuum supply and to feed the MBC.

Oh, never noticed it before. Good call.

Yeah, as much as I thought I'd hate it early on, the TD04H-15G has proved to be a very nice little unit. Insta-spool at low RPMs, and yet it still works ok at higher RPMs, putting about ~13psi without making so much heat that the intercooler melts. The exhaust system has a lot to do with it, I expect.

Well, I have a .42/.48 Garrett T3 that I need to find a turbine housing for. The housing is cracked in multiple places on the exhaust side. I would like to stay with the T3 since my manifold is obviously set up for the T3. The T3 flange will need to be redone though as the current T3/4 5 bolt pattern is larger than the T3 I am thinking of installing.

The exhaust is restrictive. I don't run a cat, but I can image that 2.33 or whatever the size racing beat exhaust is doesn't help at all.

And.....I am still bummed about the EBC not helping the spool.

http://www.boostedmiata.com/logs/ebc_vs_mbc_spool.jpg

it helped mine with a T3....


The biggest help with spool was my 3" exhaust and headwork however....


I almost never drive the miata without my laptop with me anymore, it's easy enough for me to change a few cells if the weather happens to be too cold and I overboost. In the least I have a switch to cut the EBC off and fail to wastegate, if one wanted, they could wire a MBC to fail to.

For the $5 I've invested into my EBC it works well enough for me. I maintain a perfectly flat boost level to redline, with my MBC it always spiked then tapered off a touch as seen above...

My MBC doesn't spike at all. It is a Turbonetics MBC if that means anything, probably not though. Once the MBC level is met then it is nice and flat, only fluctuating from 188-189 kpa. The EBC does work, don't get me wrong. I have fiddled with it enough to know that it is working as it should when I set the parameters to limit boost to wastegate level. It is just that the EBC hasn't increased my spool like I was hoping it would. Once I get the new exhaust I will revisit the EBC again to see if it helps.

It's final, EBC is out, just ordered my MBC.

I just finished the mods to my MS board and didn't even bother with EBC.

Just got my mbc... tried my best at tuning the ebc, but I can either get great spool in a high gear pull, but I will overboost/spike pretty hard from high rpm shifts where the turbo is already on boil. Can't get best of both worlds, and messing with the ambient temperature changes are too annoying.

I tried the closed loop ebc algorithm in Megatune. It actually works, just not well. I couldn't get it to respond quickly enough to changes in boost buildup. Nothing but overboost and me shitting my pants, although I admit I wasn't patient enough to try giving a good tune with gains. I played with derivative a fair amount to no success, but left gain as-is.

I bought the nxs mbc off ebay for 20 bucks. Pretty simple. It has a SS ball with a fair bit of heft. Mcmaster sells ceramic balls for pretty cheap, so I might order one up to see how that might affect the boost response of the mbc if there are boost spikes.

I had my MBC in, the finally mounted my 15 PSI actuator (11-17 adjustable) from BEGI and left the EBC out.

I set it to around 17 psi it appears. I am at 14 psi < 3400rpm in 4th gear. Is there gain to be had by reinstalling MBC?

That's about what I make with my 2560 but I have a crappy 7psi actuator. I'm gonna test out the 11-17 adjustable one I ordered for my other car on it and see what it does.

@paul: I had a 7psi before and was thinking high rpm boost drop off was caused by it. It think the 17psi has much better spoolup. I will probably refit the MBC to see what it does some day.

Well that certainly gets me excited. The near $100 cost for it with bracket from BEGi better give me something. Actually I bought it for my daily driver because I just swapped out the 2554 for a 2560 and the stock actuator can't be used if I clock the turbo. So I am getting one of those brackets BEGi makes that attaches to the exhaust housing so the compressor can be clocked in any direction. So if I throw this actuator on the Machine and like it it means I will need another for the daily. Damn it.

Another strong vote for KISS: no EBC, no MBC, just a wastegate can that is up to it's job. I run a BEGI 12-17psi piece (probably from APT too) that results in near constant 1 bar boost.

I am going to source it postIC/preTB too maybe.

EDIT: You may see full boost 100-200rpm later, but it comes in a lot smoother and that is something my drive line will like, as do I on the track coming out of a tight corner.

I love posting replies to the wrong thread and getting a reply ;) I was to say that I prefer wastegate actuator only now to MBC. With MBC boost climbs much more aggressively (and thus spools 100-200rpm sooner), but I prefer actuator only for now.