legacycentral bbs

The stock ECU uses the MAP sensor for fuel cut.

With the configuration of the PP, you'd really be much better using a separate FCD wired in between the ECU & PP.

The PP has an analog deflection which typically hooks up to the MAF sensor to allow modifcation of fuel. I wouldn't recommend altering that. The other wires that are intercepted are for timing, which I wouldn't alter as well.

Everything else just taps into the sensor signals, and doesn't interupt it.

Right on, I guess I'll have to put in a seperate FCD.

Speaking hypothetically, what is the factory ECU using the map sensor for? Since we have a turbo car that retards timing via ECU, I was thinking why not avoid using the PP to modify timing and instead use it to alter the MAP and MAF settings. I don't understand what you mean by "analog" deflection, do you mean 2 dimensional in terms of the mapping?

Next questions:

Can the PP show injector pulse width?

Thanks by the way for calling me back that day. We are street tuning this car on Saturday so if you can....leave your phone on, I've learned more reading here on what you guys have done compared to the Rallitech forum...

Thanks, Keith

I'd suggest checking out Vikash's FCD.

I think the ECU is mainly using it for fuel cut. THere may be other functions, but I'm not 100% sure. Vikash would probably know for sure.

I'm just not sure you could use the timing map to modify the MAP signal because it was setup for timing. The PP gets its rpm signal from the ignition leads.

Analog deflection is just the MAP that typically modifies the MAF signal.

No the PP can not show injector pulse width.

Vikash's scan tool can show injector pulse timing though.

No prob, I'll be having the dent guy pull the dents out of the car on saturday, so I should be around.

In some of what I read, I thought that you could add a MAP sensor to your manifold and wire this in, the PP could be configured to use this signal to modify fuel. So in this type of arrangement, the MAF voltage would be utilized off boost and idle, however when needed the PP would monitor the added MAP sensor and adjust fuel. I guess that could be funky with big oll injectors making it very rich at idle and cruise.

It's been challenging learning about this piggyback and not seeing too much support or experience with Subaru's.

mr soul wrote:In some of what I read, I thought that you could add a MAP sensor to your manifold and wire this in, the PP could be configured to use this signal to modify fuel. So in this type of arrangement, the MAF voltage would be utilized off boost and idle, however when needed the PP would monitor the added MAP sensor and adjust fuel. I guess that could be funky with big oll injectors making it very rich at idle and cruise.

It's been challenging learning about this piggyback and not seeing too much support or experience with Subaru's.

not quite. The PP can run a seperate set of injectors. These injectors can be controlled by a MAP sensor. The reguular fuel map that modifies the MAF signal can be tuned (deflected) by whatever input you choose to wire to it (MAP, MAF, TPS). Ignition can be modified based on MAP. all of these modifications have a Y axis of engine speed. You'd get all of that simply by reading the instructions from the PP. When reading, keep two things in mid that are not intuitivly obvious.
In PP language, Deflection is the input on the brown (I think it's brown) wire. This is selectable per the way you want to tune. See my response to Legacy777's thread on the PP SMT6 forum for more info on which signal to use per your situation. Also, AMP = MAP PP just calls it Absolute Manifold Pressure. This was confusing to me at first as I wasn't sure what the hell they ment by AMP.



on a side note. to get rid of fuel cut on a turbo car, why not just place a pressure regulator in the line going to the MAP sensor. You set it just below the max boost for FC and it won't know the difference. You've got the PP to deal with timing.

Yes Mr soul if the factory ecu fuels off of the map sensor yu should be able to wire the PP to that. THe perfect power will have a built in voltage clamp under global setting, just set the max analog voltage lower. THe same would go if you used the MAF signal. I am using and aftermarket 3 bar map sensor for the deflection on my car.


I was going to email you guys about some dohc turbo heads and such....

oh and welcome to the "party" hope you have better luck than we are.

Tyler,

That's not really going to work. The legacies use MAF for fueling needs. If you wire the MAP sensor into the analog deflection setup (which normally is setup up to the MAF sensor) then yes you can set a voltage clamp, but you will have absolutely zero control of the stock injectors.

You could drive an additional injector and if you use the MAP sensor as your deflection (brown wire) that would probably work, but to me that's sort of a waste of the PP IMO.....just my thoughts.

what is the point of the MAP sensor on the legacy turbo than?


sorry didnt need to spread misinformation.

I guess another option would be switching to the jecs MAF which reads higher. I am at 16 PSI now and havent seemed to have maxed it out yet.

I'd say the main point of the MAP sensor is boost cut.

Tyler,

Did you get everything worked out? I just skimmed the thread since it is so long.

The extra MAP sensor is so the PP6 can understand boost levels. This is critical for timing. As boost rises, timing must fall. The MAP sensor is also very useful for allowing the PP6 to underdstand engine load.

If your MAF is still reading under 5v then there should be no need for larger MAF.

-Sean S.
www.RalliTEK.com

Whoa its sean, howdy!!

I have things mostly worked out.

Cold start Idle still sucks but the 550 injectors helped out immensly.

I was wondering what the stock legacy Ecu used the MAP sensor for sorry, I understand why the SMT6 uses one.

I do get this wierd thing where it just dies when I am in first though. still working on it.

bmxpunk wrote: I have things mostly worked out.
.

You should run my car after i install the standalone and get it tuned for 20psi with the wrx heads. We could videotape it.

bmxpunk wrote:Whoa its sean, howdy!!

I have things mostly worked out.

Cold start Idle still sucks but the 550 injectors helped out immensly.

I was wondering what the stock legacy E

cu used the MAP sensor for sorry, I understand why the SMT6 uses one.

I do get this wierd thing where it just dies when I am in first though. still working on it.

What conditions in 1st gear? Wide open throttle? Cruise? Off throttle... I forgot, what year is your car?

-Sean S.
www.RalliTEK.com

PS are you using the AEngineTemp Map for cold start adjustment?

-SS

Rallitek.com wrote:

bmxpunk wrote:Whoa its sean, howdy!!

I have things mostly worked out.

Cold start Idle still sucks but the 550 injectors helped out immensly.

I was wondering what the stock legacy E

cu used the MAP sensor for sorry, I understand why the SMT6 uses one.

I do get this wierd thing where it just dies when I am in first though. still working on it.

What conditions in 1st gear? Wide open throttle? Cruise? Off throttle... I forgot, what year is your car?

-Sean S.
www.RalliTEK.com

No specifics in first I just start going can be any throttle position under 3/4 throttle and it just stops.

It also has a horrible buck when you let off and coast like up to a stop light, nothing seems to affect that though. A/F ratios aer 14.7 where they should be an my grounds have all been redone. so ecerything should be reading fine.

My Car is the 95impreza & ecu with a 93 22t motor.

Do you guys have a Perfect POwer IN Kelly's car yet?

Rallitek.com wrote:PS are you using the AEngineTemp Map for cold start adjustment?

-SS

you know, this makes no sence to me. Why does the PP have a cold start adjustment? It's not a stand-alone system. The stock ECU will adjust for cold starts. Just because you have a PP installed, doesn't mean it won't do that anymore. Tell you the truth, I don't see how this could help at all, especialy since you can't add fuel using the function. The largest number you can put in is 1... so if it follows the algorythm in the documentation, ANALOG OUTPUT = ANALOG INPUT +- OFFSET +- (FUEL MAP VALUE * A_ENGT) then all you'll be able to do is lean out the mixture with the A_ENGT value anyway.

When you are using larger fuel injectors the factory ecu cold compensation can be too much fuel. The AEngTemp map allows you to cut back the warm up enrichment.

-Sean S.
www.RalliTEK.com

I have used the temp adj. a bit, I will play with it a little more

Well my friend who is running a similar setup (same ECU/ wiring, chassis, but 2.5-T) just got the Greddy emanage ultimate, so I will have something to compare the perfect power to.

SO far I see pluses and minuses to both but I will do a full write up as I get more time with the emanage

Yeah, definitely let me know.

I haven't had any issues lately with bucking/hesitation, so I'm pretty convinced it's an interference issue....but with what...I don't know.

I still don't have the analog signal hooked up though.

I did get some bucking yesterday morning in third gear.

partial-to-full throttle.

disheartening, but hasnt happened since

HEY EVERYBODY THE BUCK IS COMING BACK!!!!!!!!!


We should throw a friggin party.


EEEEEEEEERRRRRRRRRRRRRR!!!!!!!!! I am gettting so pissed.

Ever been in a situation on the highway where you have to punch it to get out of the way or something like a general safety/self preservation concern? yeah it was one of those times where you are cruising on the highway...

4th gear driving at like 3500, pushed WOT and it started bucking. What the fuck seriously when it is a question of my safety or my passengers.....

not a happy camper.

Did I mention the emanage can delay the rev limit.......

told ya......wish I was wrong, but I just can't see running the PP with these issues. It's competely 100% unacceptable.

Sean, or anyone from rallitek, if you're reading this, it'd be nice to get some feedback/comments, since these were purchased through you guys.

Yeah it sucks......

I really really HAVE TO 100% use it when on boost, but having the bucking problem be so sporadic really really sucks.

I still suspect that everyone is having problems that may not be caused by the same base issues, but thats my own conspiracy.

It really sucks that you guys are having these problems. I had high hopes for the PP, but it doesn't look like it's a worthwhile setup.

Guess I'll have to end up going standalone :\