Perfect power tuning and stuff thread

[Legacy777]

Continued from here
http://bbs.legacycentral.org/viewtopic. ... 739#147739


PM from Tyler (bmxpunk)

Ok Josh,

I have (as you know) the ej22t motor in my impreza.

I am running the wrx turbo Td04 for the time being. It has been ported,polished and ceramic coated. Definately looking for a 16G to upgrade to.

I am also running a wrx intercooler, with the metal STI Y-pipe, mug mod.

Right now I have the stock injectors, but I want to find something a little bigger. I think 440s would be perfect but 550's are probably tops. I think i can do this with my old 1.8L NA fuel rails and the newer sti injectors.

So far I have been working really hard on the fueling maps. They are the biggest pain. I also have pulled a degree of timing onceI hit boost and on top I pulled 2-3 degrees depending on rpm and boost level. i am not wuite sure if this is enough or too much. I am looking for reliability (which I just got-damn headgaskets!) but decent power.

My big problem is with the MAF sensor. I am maxing it out at 3500-4500 rpm, where is is reading 4.3+volts so my ecu will not read it. This is where I am having my biggest problem. I have been asking for advice on what to replace my MAF with and not getting any answers other than "with a new bigger one." What fits? how much bigger? Why? i AM JUST NOW STARTING TO UNDERSTAND ELECTRONICSbut not nearly enough. Its not mechanical enough for me

Once I get some things set and in place as far as boost I will email you the maps. I am now kinda bypassing Rallitek and talking straight with Perfect Power, though he doesnt know subaru much, he understands his product. Give him some voltages and he's got answers. He has something for me and we are gonna see if it helps my car out at all. I will keep you posted and you do the same. Good luck, cant wait to see yours, its gonna be so much more refined than mine!!!

Tyler

[Legacy777]

My reply

Hey Tyler,

What ECU are you running? The stock ej18 ECU?

What MAF sensor are you running? The black plastic bodied one, or the aluminum one? If you are running the aluminum one, you should be able to use the black plastic bodied one, and get more range out of the MAF. The only problem is you'll have to scale the MAF sensor signal in the PP.

That is what I plan to do. I had sort of wanted to get the PP before I upgrade turbo or injectors, so I can play with the MAF sensor isssue. My only concern is that if I tune the PP to use the black MAF sensor, will I have re adjust the maps when I put larger injectors in?

So I definitely have some questions/issues I'd like resolved, however I think the best way is to just get the PP, and start playing. There's a "new-to-houston" tuner in town. They have an AWD dyno, and experience tuning, etc. Some of the impreza guys are doing a dyno day this saturday. I may try to stop by, and leave the perfect power manuals with him, and see if it's something he's familar with, or if it's something he could help with when I come to the time to tune.

Keep me posted.

Thanks

[Subtle]

Check out sdsefi.com

The SDS doesn't use s maf

[Legacy777]

I don't want stand alone

[bmxpunk]

Just saw this.

Here is what i was sent from neil at Perfect power:


Hello Tyler.

We are having this same problem on our side as well. The Subaru we are working on will only be coming in on Monday, but we think we know what the problem is. The boost clamp on this car is variable. This means that the standard boost voltage clamp is not sufficient because it varies. What you need to do is clamp the voltage by putting negative values on the analogue map and add the extra fuel needed on the extra injector.

Will keep you posted as soon as I get get more info

Neil

[Legacy777]

Tyler,

Just curious....what was the question you asked Neil?

[bmxpunk]

Josh:


"Thanks as I did not recieve this(installation guide) when I purchased my smt6 but that doesnt exactly help. I already have the unit wired and installed. Tuning is where I am having the problem.

I have enclosed the wiring diagram from which I installed my smt6. This is the one that rallitek supplies. The differences I have as per the recomendation of Sean at Rallitek are:

1: My analog in and out are wired into the MAF signal as I dont have a stock MAP sensor. (different model year car)
2: My analog deflection is wired to an aftermarket 3bar MAP sensor that has no other bearing on my engine control systems. It is wired directly to the perfect power smt6 for the sole purpose of reading analog deflection as per Reccomendation form Sean at Rallitek.

These recomendations are based form the fact that I am using a turbocharged engine with a stock ECU that was Naturally aspirated. The perfect power I was told could correct the ecu's short comings.

Most of the time the car runs fine. The exception is (and it sometimes varies) a huge buck or dead spot at either 3500rpm or4500 rpm. It only does this when the accelerator is pressed 50%+ and not "eased into." The analog in voltage goes to 4.3-4.7 when this happens and my stock ecu is supposed to read up to 4.5 volts being max. Is there a scale for the analog in/out that can be adjusted? What are my other possibilities.

Thank you,
Tyler"

[bmxpunk]

If you ave a tuner in town and a dyno, you are already way ahead of me. The clostest of either is 4 hours away. Ft collins, CO

[Legacy777]

Damn....that sucks man. Hopefully you can get things figured out.

[bmxpunk]

SO i am trying to sort this out in my head.

If i get a lean spot because the MAF is Maxed out, my ecu reads that as a high injector duty cycle correct. So if I upgrade the maf sensor first so it reads a broader range, then I will upgrade the injectors. With bigger injectors, It will be far richer with my stock ecu, so in turn, I will end up putting negative numbers in the perfect power for most of the map. Wit hthe negative numbers, and the broader MAF sensor, my stock ecu should never see the 4.5 voltage that causes the fuel cut.

Does that sound right?

[Legacy777]

If you get a lean spot, that's not necessarily caused by the MAF. If the MAF is maxed out, the ECU will probably also be maxing out the duty cycle of the injectors. So the cause of the lean condition would be lack of fuel flow capacity.

Yes, if you put larger injectors, the engine will run richer, and you'll need to scale things back with the PP.

The MAF sensor replacement will just allow accurate reading of air flow across a larger range of air flows.

[bmxpunk]

Who is happy, I am. thats right. I finally started playing with scaling the sensors in the perfect power and gusess what-----minimal buckicng. and I am getting the fuel maps close. but tomarrow is my birthday so if I get money I am going to buy a new MAF sensor and if there is any left over after rent and the phone bill, I am gonna find new injectors. It is time for more boost baby!!

Suggestions on injectors that will eventually mate with a td05-16G? hopefully pushing 16-18psi.

[Legacy777]

Is your MAF sensor bad, or are you looking to get one of the JECS ones?

[BAC5.2]

Josh -

Why not use the Black MAF, scale accordingly, and when you go to larger injectors, simply scale them down?

I know the UTEC has this option. You have new injectors that flow X fuel at X pressure compared to stock. (flow test new injectors vs OEM at the same rate and compare).

Then you simply plug in the value of the new injectors (800cc for example), and it scales MAF voltage to attain the proper injector pulse width for the correct amount of fuel per voltage reading on the maf.

This is good and bad, in my eyes.

Good, because you also increase the range of the MAF (so to speak, you scale the signal down. You basically "trick" the car into running how you want. You tell it less fuel is coming in, so it decreases pulse width. With stock injectors, this would starve the engine of fuel. With bigger injectors, it runs just right. This is tuned with wideband, of course). From what I've witnessed, this is pretty good for on-boost tuning. One step to rich is better than one step to lean.

The bad thing is the resoloution. For every millisecond longer that the injector is open, it flows roughly 50% more fuel than the millisecond before.

So if at 1ms you flow 100cc's, at 1.1ms, you'll flow 150cc's. At 1.2ms, you'll flow 225cc's. It's easy to have TO much fuel or TO little fuel.

This can kind of be countered with dual injectors. Both stock. Then you can simply turn on the other injectors to meter (in stock fashion) the proper fuel. The tuner (whatever medium you choose), would simply send two different pulse widths. One set to primary injectors, and one set to secondary injectors. Tune the secondary injectors for whatever fine control you would like.

You have two sets of matched flow injectors.

Fire the primarys at 1ms and flow 100cc's. Fire the secondaries at the same time at 1ms, and total fuel flow would be 200cc's. So what? Well, if you were to fire the primaries at 1.1ms you are at 150cc's of flow. Fire them at 1.2ms, and you are at 225cc's of flow. It would give you better resoloution, but it's more to fuck with and more to fuck up.

Does Perfect Power have the ability to control two sets of injectors? Does Perfect Power have the ability to control two sets of injectors INDEPENDENTLY of one another? Does Perfect Power have the ability to scale injectors?

[bmxpunk]

Josh -

Why not use the Black MAF, scale accordingly, and when you go to larger injectors, simply scale them down?


Does Perfect Power have the ability to control two sets of injectors? Does Perfect Power have the ability to control two sets of injectors INDEPENDENTLY of one another? Does Perfect Power have the ability to scale injectors?

First part: that is exactly what I plan to do.

Second part: no, no, and no.




You are too damned smart for my own good.

[bmxpunk]

Anybody made there way over to the perfectpower forum yet? They keep telling me to get another smt6 on top of my current one.

"oh its bucking 2 PP's will fix that. Bad fuel milage, oh you can only fix that wit h2 PP's"

I am stoked though. My car is running way better. I rescaled EVERYTHING. adjuted a built in voltage clamp. turned up the boost and kept going!!!

Douglass just got his so hopefully things will go much better sooner for him.

Now i need new injectors. Anybody in COlorado have some bigger ones for either the 22t rails or old na rails? I will be down friday and that would make life great.

[Matt Monson]

Tyler,
You only asked me about injectors. I've got NA Ej22 rails for you...

[bmxpunk]

oh i already have the rails from my old 1.8. sorry should have been more clear.

[Legacy777]

Phil,

I'm not 100% sure what the PP is capable of. I'm still reading up on it. I picked one up yesterday when I was in Portland.

As I mentioned in Doug's other thread, there seems to be some options as to how you hook up the PP, whether you use the throttle sensor or the MAF sensor for engine load. I need to do some more reading and figure out what setup will allow me to control what I want.

Because technically, I could swap to larger injectors, swap maf's and use the MAF sensor as the engine load, and just scale the MAF sensor to the new injectors. I think that would work....and I believe I'd still have a separate fuel/injector map I could fine tune.

[bmxpunk]

Or you can use an aftermarket MAP sensor for load and connect the PP to the MAF sensor to control fueling. That is how sean told me to do mine.

[Legacy777]

I guess it depends on what you're starting with. Your stock ECU didn't have a MAP sensor. I think I recall reading that the MAP sensor on the turbo legacy doesn't affect timing/fuel (except for fuel cut) but I'd have to verify that.

Need to do more homework.

Here's some pics of the perfect power
http://www.main.experiencetherave.com:8 ... rfectpower

[bmxpunk]

Yeah it does depend. There are a bunch of ways to set this thing up. My 1.8L ecu that I am using, doesnt have any form of a manifold pressure sensor, so I added one(3bar MSD) that is strictly for the perfect power.


Just went to the J-yard and am installing the Jecs MAF sensor. I will take it out so a little tuning and datat logging and let you know what I come up with.

[Legacy777]

Cool.

[BAC5.2]

Josh, in your searching, find out if the PP can control 2 sets of 4 injectors (independent of eachother).

That'd be great if you could. You could just do what I said above, and have much more fine fuel control.

Also, what is the resoloution of the fuel/timing maps? I think I recall stock being 12x12?

It would be nice to be able to control fuel/timing in 250RPM incriments. Espically if you are running to 8k or something ridiculous like that.

I'd love a PP to fool around with, but I think I'll still end up using a UTEC.

[bmxpunk]

Bac: As far as resolution goes, all maps are 8x16.


The different maf sensor did a huge amount of good. I still kinda get the fuel cut/ bucking but I am pushing almost 12 psi now.
Everything from startup to full throttle is much smoother.