Break in tuning

[DMC7492]

Hi guys I'm getting close to fire up. My 2005 wrx engine was overhauled and I am looking to base tune to break in. It ran great before with a 3" MAF tube EXT wastegate and 3" exhaust other then that it was stock.
During the build I kept the MAF tube but changed the turbo inlet from stock up to 3" from the MAF tube to the turbo. I put in 750 injectors and a td05-18 txt turbo. My boost map max was at 19. On a stock turbo.
I want to lower WGDC to 0 and run the wastegate spring pressure.
The timing will be pulled back 5 degrees across the entire range.
The wastegate was sent in for overhaul and they put in a 20 psi spring.
1. What size spring would I need to run 20 psi with a three port Wastgate solenoid?
2. Would I need to calibrate the MAF?

What else should I be looking for with a breakin MAP?

[ssssly]

I would suggest larger injectors than that for that build. You are going to be at the far end of duty cycle at 450 CHP with 750cc injectors. I would generally put 800cc injectors in a 18 G build. But with the current injectors on the market, it is easier to just get a set of ID1000s. Since the off the shelf tunes for them are pretty on point.

There is also no need for 3" MAF or turbo inlets at that power level. The stock MAF and turbo inlet will flow enough for ~500hp. If you already have it on might as well leave it, but it makes it much more difficult to tune.

The wastegate will not open at all until the spring pressure is exceeded. So when you put a 20psi spring it it, that is the least amount of boost you can maintain at a steady state.

A 20psi spring on an 18G turbo is pretty excessive. That is very close to the max the turbo can put out. And pretty much makes having a boost controller moot if the wastegate won't open until it hits 20psi. An 18G should be a 22-25 psi turbo so you probably want around a 16 psi, 18 max, spring on it. Unless all you want to do is drag race.

For the initial few hundred miles run 0 WGDC and pull the timing 15 degrees, at least, across the map.

Change the oil after the first 100 miles or so, then again at ~500 miles.

Then put your regular map on it and have fun.

If the tune was already for a 3" MAF, you shouldn't have to mess around with the MAF tuning too much. If you think you will have to, you want to use whatever injectors were in it on the previous tune until you get the MAF dialed in. Because unless you are going to speed density, you do not want to try to tune your MAF and injectors at the same time.

[DMC7492]

Thanks for the tips. I pulled the Tial wastegate off this morning two springs both green a 7 psi and a 13 psi spring. Total 20.
Running at the break in with the 7 seems like a better idea.
Blouche recommended the 18XT and the 750 injectors, for the 818 application.

[Hindsight]

Out of curiosity, why is MAF tuning easier than Speed Density?

[ssssly]

Speed density tuning is much more difficult than MAF tuning to set up. Is actually easier to deal with afterword.

However, it is even more difficult to tune both non-stock injectors and non-stock MAF at the same time in a MAF tune than in a SD tune.

So if he was planning on going SD anyway, it wouldn't represent a large increase in complexity to do them both.

If you are planning on sticking with a MAF tune, you want to make sure you use stock injectors to get the MAF tuned dead on, then put the non-stock injectors in and tune them (or vice versa).

[DMC7492]

If you are planning on sticking with a MAF tune, you want to make sure you use stock injectors to get the MAF tuned dead on, then put the non-stock injectors in and tune them (or vice versa).

That might be an issue I sent the old injectors to DW. If I set the fuel injector scale to 748-750 and then proceed to the MAF since it was tuned with the Larger MAF. It should be close right?
I do have the original plastic turbo inlet from the 3" MAF tube, which it was tuned with, I could install it set the injector tune and then put the custom pipe on and correct for that.

[STiPWRD]

That might be an issue I sent the old injectors to DW. If I set the fuel injector scale to 748-750 and then proceed to the MAF since it was tuned with the Larger MAF. It should be close right?
Be careful setting the injector scaling too high off the bat. For whatever reason, the ECU likes to see slightly lower injector scaling than what the injectors actually flow at. For example, I'm running modded wrx injectors with measured flow rates from 822-824cc. If I scale the ECU to 820cc, the engine will run very lean. Through some trial and error, I found that scaling the ECU to 760cc provides a good starting point - the car idles at 14.7 AFR and drives great (when not in boost). I still have to tune while in boost but have to wait until the car is registered. Of coarse, you will need a wideband to properly measure AFR and figure out your injector scaling.

[ssssly]

For the scaler, take the average flow of all four injectors and set the scale at 85-90% of that.

For idle the latency is what will be important for smooth running.

Same for closed loop.

You need to get the latency tuned in for whatever scaler you set. You can be way off on the scaler and still get it to run right with proper scaler and air corrections. You obviously don't want to be making those huge corrections, so getting the scaler close is The best way to go about it. But how much fuel is actually delivered is far more dependent on the dead time calculations.

This is also why you don't want to try to tune a MAF at the same time. If you don't know exactly how much air is being introduced you can't calculate injector dead time for proper fueling no matter how close the scaler is.

[DMC7492]

"For the initial few hundred miles run 0 WGDC and pull the timing 15 degrees, at least, across the map. "
That Sounds good but where would I pull 15 degrees from ?
In the 1.2-2.14load area? Or down at the low load side?
I'm trying to post my Base Map.However cannot get it loaded. I could email to any one if they would like to review and make suggestions.

48416

[ssssly]

If you aren't familiar with EFI tuning, it might just be easier to scale the whole table down at once. Take 25-30% of of it.

Select the entire table. Then, on the tool bar, there is an empty block to the right of the up and dow arrows. Type .25-.30 in the empty block and hit the Mul button tot the right.

[DMC7492]

Hi guys engine started right up. Total ECU dissection. Front fuel tank and complete overhaul. Fire up and ran for about twenty minutes up to temp and then dropped oil. It runs rough at idle to keep running to break in I had to jack the fuel pressure up to about 80 then it ran a lot better than in this video. So I believe some tuning will be happening soon to get the fuel pressure back to 45 psi.

https://m.youtube.com/watch?feature=youtu.be&v=fpk1khlZCZM

[ssssly]

What are you using for tuning and logging?

[DMC7492]

Im using Romraider,logger and ECUFlash, I have been reading and studying the NASIOC complete guide to tuning and the COBB instructional guides.
https://cobbtuning.zendesk.com/hc/en-us/articles/200025064-Subaru-Tuning-Guides-and-Worksheets
And this one.
https://26fd2796-a-62cb3a1a-s-sites.googlegroups.com/site/asubienewbietuningguide/ver-1-0/ASubieNewbieTuningGuide1_0.pdf?attachauth=ANoY7cpk nXUzmAtSdY4lU-bp6XphSr9t3gJGym8jTG2obj4dIhFwjzAAuUeU2o8qww7gcUfq 02YiRGgHYrhkUMJJz2D-2l-mCS2r9KrN-ckCDi7lV3ErYXTo3kQMG3Kz2A6676va1sB_A0y6w_gE-FfYTXYAiYqWq1kJ8fjL25aQWMVNRilzj-8f_cLBX63wpgUWS8dBmvXeI4Gfmg_FH1cnQ8gDOmgIYUAgi771 Rk11SVlcoLC8oKml3QDyv2dusXIxuyhYoON-&attredirects=0&d=1

[ssssly]

I very strongly suggest putting a stock MAF on it to tune the injectors. And then tune the MAF to the injectors.

Particularly if you are following that guide and don't already have a decent amount of EFI experience.

And doubly so if yo are gong to try to road tune it, since you won't be able to watch the logs and with untuned injectors and a 3" MAF you can blow the car up in seconds.