Quick ?

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 1:18 am

Thats what I washoping you werent going to say. Remember when I said " thats a long story that I dont want to get into now"

Yeah......

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 1:45 am

...yeah...

If all you need is ghetto fuel control, maybe you could put in a super strong fuel pump, a rising rate fuel pressure regulator, and leave everything else stock?

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 1:58 am

Well I want it to be reliable. I have a bigger fuel pump- walbro. I would like to be decent. i havent got a response from sean in a long time.

i really want to get every thing "right"

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 2:17 am

Hmm. So an EJ22T ECU then? You probably won't get much more reliable than that. And it is the right ECU for the EJ22T, no?

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 2:40 am

NO I said earlier. I am using the 1.8 IMpreza ecu with the perect power becasue I believed sean when he said that I would be fine and wouldn't need to rewire my car. That the perfect power would take care of everything. I sold my harness and ecu to Natoe.

So know when I start my car it sounds like I have antilag but sure as hell doesnt work like it.

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 2:56 am

I'm sorry if it seems like I'm being unhelpful. I was just responding to your saying that you wanted reliability and to get everything "right." Installing an EJ22T ECU is honestly the best solution I can think of.

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 3:09 am

I assumed that. I would like to get some better heads. some dohc turbo heads and wire my car for those.

I had planned on wiring my car. Then I was promised ALOT, and so far not much has been delivered.

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 4:01 am

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 5:05 am

I do appreciate your help. I kinda feel taken advantage of by vendors thinking they are talking to a kid. which sucks cause I havent had any (physical) help yet. Everything on my own.

Natoe · Post by **Natoe** » Thu Nov 10, 2005 5:11 am

hmm it sucks that rallitek is bein that way... i could run up to portland and give them a spank or somethin for you. ever thought about megasquirt? i dont know, just an idea.

Natoe · Post by **Natoe** » Thu Nov 10, 2005 5:13 am

also bmxpunk, if you want to trade MAF's.. id be willing to do that if you think you need the 1.8 one again, since i do need a leg turbo one

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 5:31 am

Are the stock EJ18 injectors really only 180cc/min? That seems tiny... I guess it could support the EJ18's 110 hp, but just barely. I wouldn't expect FHI to cut it so close.

That might be too small, but if they're actually bigger than that, maybe you should seriously consider swapping your EJ18 injectors and the EJ18 MAF sensor back in, and putting on an RRFPR. It should run much better than an EJ18 ECU with an EJ22T MAF and EJ22T injectors with an untuned Perfect Power.

Natoe · Post by **Natoe** » Thu Nov 10, 2005 6:03 am

but it cant be left that way for long... especially with his turbo running 8 psi at wastegate.... i dont know, all i know is though it sucks, i scared a couple by making my car backfire at idle haha

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 6:49 am

Can't be left what way for long?

An RRFPR is an adequate, if crude, way to deal with fueling a turbo. And if he added something to retard spark on boost -- say, one of the newer MSD DIS-2 units, or a J&S SafeGuard -- he'd probably be able to boost it all day long. Output and economy would be suboptimal, of course, but that's a different concern.

douglas vincent · Post by **douglas vincent** » Thu Nov 10, 2005 7:48 am

Not questioning anyone here, just throwing this out.

OK, if the ECU can't supposedly compensate for the high MAF readings when on boost, then why am I seemingly running without problems at 8-10 psi on the 1990 NA ECU? My fuel adaptation is the 370 cc injectors, Walbro pump and the wierd MSD adapted Bosch rrrpr that may or may not do anything.

My theory is that the ECU DOES calculate the MAF reading. The reason I think this is because the ECU is programmed to read the MAF signle when off boost which is from .0 to around2.75- 3.0 (on my car at least). So why would the ECU programmers just level off the fuel to MAF reading. Makes no sense. All the programmers would have to do is just do the minor calculations on up and leave it at that.

I suspect that fueling to MAF reading for the 1990 NA ECU is going to be VERY similar to the turbo ECU, but I don't know how to compare for sure.

Natoe · Post by **Natoe** » Thu Nov 10, 2005 8:25 am

vrg3 wrote:Can't be left what way for long?

An RRFPR is an adequate, if crude, way to deal with fueling a turbo. And if he added something to retard spark on boost -- say, one of the newer MSD DIS-2 units, or a J&S SafeGuard -- he'd probably be able to boost it all day long. Output and economy would be suboptimal, of course, but that's a different concern.

you cant leave it like that for long with those injectors because they 180lph cannot support 8 psi of boost... maybe if you kept the revs waaay down, but it would run lean if you took it up at all

Natoe · Post by **Natoe** » Thu Nov 10, 2005 9:38 am

what doug is saying makes me think that something else has been going wrong besides MAF readings anyways... starting rewiring on friday

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 2:51 pm

Doug - What do you mean by compensating for high MAF readings when on boost? I don't understand.

The MAF sensor on your car is identical to that on my car and on other turbo models. And your ECU is very similar, though its tuning differs of course.

The ECU always uses the MAF sensor signal to determine fueling. It's the primary input into the fuel computation.

Your MSD FPR isn't raising differential pressure on boost, but depending how you have it set it could be raising static fuel pressure, effectively making your injectors bigger.

Natoe - Well, I did qualify it by saying 180cc/min injectors are probably too small... But remember that as the RRFPR increases pressure it also increases injector flow.

Do EJ18 injectors really only flow 180cc/min?!

Post by **Legacy777** » Thu Nov 10, 2005 3:22 pm

I really doubt they only flow 180cc/min.

There was some discussion on NASIOC about it, and I'm pretty sure they're around what the n/a ej22 is.

douglas vincent · Post by **douglas vincent** » Thu Nov 10, 2005 5:37 pm

What I am saying is that if the MAF reading is reading 4.2 because I am pushing 8 psi through it, the NA ECU doesnt care if it is boost or atmosperic pressure thats causing the MAF to read 4.2. The ECU just dumps enough fuel in correct correlation.

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 6:06 pm

exactly douglas!!! but on what ever boost I am running now Max boost at least, I am running like 4.2 volts from the maf and the diagrams for my ecu say it maxes out at 4.5. so I am getting close to that 4.5 and cant make much correction wit hthe PP. so I was hopoing a different ecu would read more more gram/sec per volt than my current MAF. That should lean out the bottom and give me room up top to make correction.

Post by **Legacy777** » Thu Nov 10, 2005 6:28 pm

You need to swap MAF sensors and rescale the MAF, which can be done with the PP.

vrg3 · Post by **vrg3** » Thu Nov 10, 2005 6:46 pm

Doug - Yes. The ECU fuels based on airflow. It measures MAF voltage, converts that to a measured flow, divides by engine speed, divides by the desired air/fuel ratio, and pulses the injector accordingly.

The catch is that a motor on boost needs to run a lower air/fuel ratio than a naturally aspirated motor. The turbo ECU is programmed to deliver this richer mixture.

bmxpunk - Realize that the transfer functions of our MAF sensors are nonlinear. They're quadratic with a positive second derivative. The two Subaru sensors actually read about the same at low airflows; it's only at high airflows that the signal differs significantly.

If you think you can figure out how to make that work out for you, I wish you good luck.

But what do you think of my RRFPR suggestion? Consider -- you could have the exact right air/fuel ratios when off boost, and when on boost the mixture would just get richer and richer as manifold pressure gets higher and higher.

If I were in your shoes that's what I'd do. Heck, that is what I'm doing right now -- a Vortech FMU is ensuring I get enough fuel even when I'm flowing more air than the stock fuel system can deal with.

Wait -- you're actually able to tune with the Perfect Power?

bmxpunk · Post by **bmxpunk** » Thu Nov 10, 2005 9:05 pm

Oh yeah fueling and timing (supposedly) so far I pulled 1 degree of timing when I get on boost, which seemed to smooth the car out. THe perfect power also will do fueling but when I reach the upper end of the MAF, It has no headroom to adjust through.

Thanks for explaining the functions behind the ecu's computation of the MAF. I like math, but that might be a just little ahead of my two semesters of college calculus.

Post by **Legacy777** » Thu Nov 10, 2005 9:40 pm

vrg3 wrote:Wait -- you're actually able to tune with the Perfect Power?

The perfect power will all me or anyone to slap on a bigger turbo, injectors, and swap to the JECS MAF sensor. It'd probably be a bit of tuning, but yes you can do all that and have it work correctly.

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