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-   -   ultra conservative above 15psi (https://www.miataturbo.net/megasquirt-18/ultra-conservative-above-15psi-50146/)

miatauser884 07-29-2010 09:35 PM

ultra conservative above 15psi
 
Would you guys that are running high boost give me some very conservative timing and fuel (with req fuel so I can scale it) numbers? I'm trying to schedule some dyno time. I only have numbers I trust up to 15 psi. I'm not real sure what I should put above that for safety in case of spikes while tuning at home this weekend. Unfortunately diy was booked on Aug 10 when I will be in Atlanta :(

Up to 22psi would be great. Thanks

rbluemx6 07-29-2010 09:39 PM

I have my top row of timing at 300kpa 5 degrees. 250 kpa at 8 degrees. That's on my FE3 mx6 with a TEC2.

hustler 07-29-2010 09:49 PM

I could show you mine but it would probably blow your motor. Just find detonation or MBT, then start pulling spark. I pulled 6* I think from MBT because I basically race this car and I wanted to compensate for timing belt stretch. You can also tune on lower octane than you typically run and use fuel as head-room. I hear the rule is 2-octane points = 3* spark according to the guy who does custom Chevy and Ford tunes.

Its going to be different for each turbo, manifold, DP, head, and whatever else so no example is really going to help.

miatauser884 07-29-2010 11:41 PM

Thanks. I plan on tuning this weekend, but the few pulls I've done went straight to 20psi. I'm not even sure my fuel and spark is safe in this range. I'd hate to blow my motor with under 500 miles on it.

hustler 07-30-2010 07:38 AM


Originally Posted by djp0623 (Post 609469)
Thanks. I plan on tuning this weekend, but the few pulls I've done went straight to 20psi. I'm not even sure my fuel and spark is safe in this range. I'd hate to blow my motor with under 500 miles on it.

Start with 5* advance accross the board and work your
way up.

shlammed 07-30-2010 08:54 AM

did your WG even open? one of my friends had that issue and wasted an entire dyno day.

what WG spring do you have?

Braineack 07-30-2010 09:16 AM

give it around 13-14°

miatauser884 07-30-2010 09:53 AM

Thanks everyone. I feel a bit better about the situation with these numbers, and talking to brain about the boost settings.

It turns out that I misunderstood wg open/closed duty. with normal and inverted selection. It was over boosting because I had my duty table set to 100% boost everywhere as opposed to 0%. I was set to normal instead of inverted. Now it is keeping boost at or near zero. Cars in the shop for transmission swap as I'm typing this.

Turbobarber 07-31-2010 02:02 PM


Originally Posted by djp0623 (Post 609631)
Thanks everyone. I feel a bit better about the situation with these numbers, and talking to brain about the boost settings.

It turns out that I misunderstood wg open/closed duty. with normal and inverted selection. It was over boosting because I had my duty table set to 100% boost everywhere as opposed to 0%. I was set to normal instead of inverted. Now it is keeping boost at or near zero. Cars in the shop for transmission swap as I'm typing this.

So - I am having a similar problemish... ish I say because I don't think the waste gate can control my boost.

I have the GT2554r and the tube header from BEGi. With the wastegate adjustment set to virtually no preload(just enough to have the WG stiff).

I still push 12-14 psi. I don't think it's stuck or sticking... It moves freely when disconnected and moves properly with some effort when attached.

This is with no EBC in line.... My only purpose for the EBC was to help bring on the boost sooner.... I'm sure the WG is fully opened by the time I'm seeing 4 psi as is. My hope was to stop the WG from opening until I hit 7-10 psi and then let her fly open and try to hold it down around 12~14psi.

Any more than 14-15 psi and I'm sure to be in trouble.

Anyway, this situation has made tuning the EBC very confusing. It's hard to tell if its working or not because no matter what I do, the boost seems to come on slow till about 7 psi then it shoots to 10-11 and then climbs to 14.

My boost duty on closed loop bounces all over the place trying to control the boost like a frantic monkey.

using open loop so I can control the duty cycles directly and this seems to be working best... So I believe the EBC to be working properly, the PID code just can't handle not being able to control the boost...

Any ideas? Am I flat wrong?

Is there a reason that boost duty cannot be controlled by kpa vs rpm?
In the stead of TP% vs rpm of course.

This in my case would be PERFECT... Ben? lol

miatauser884 04-12-2011 12:30 PM

My new Map sensor is in and I'm turning the boost up to 25psi. I believe that this is about the max for efficiency in this churbo. Then again, how reliable is this data.....

I just want to verify that my timing numbers at 250kpa should be ok to run up to 300kpa where I have just set my boost overshoot. My EBC is set to 270kpa.

Preluding 04-12-2011 01:04 PM

I have the same problem with my Churbo and custom seperated DP.

But my wastegate flapper is hitting the downpipe and not opening....

Undo your wastegate arm and check to see if everything moves freely on yours

miatauser884 04-12-2011 01:26 PM


Originally Posted by Preluding (Post 713448)
I have the same problem with my Churbo and custom seperated DP.

But my wastegate flapper is hitting the downpipe and not opening....

Undo your wastegate arm and check to see if everything moves freely on yours

What kind of advance are you running at 25psi?

Braineack 04-12-2011 01:31 PM

so the map sensor worked out for you?

miatauser884 04-12-2011 01:36 PM


Originally Posted by Braineack (Post 713465)
so the map sensor worked out for you?

Yes, thank you very much for spoon feeding me that sensor. I had a little issue at first calibrating it. I didn't realize that it was ok to put a negative kpa value for the 0 volt reference.

I even got a nice placebo effect the first drive after the sensor install. Car felt smoother all around. :)


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