Flow Rate of the Sub SPFI Fuel Injector

[rojai1]

Does any one know what the spec flow rate is for the SPFI throttle body fuel injector used on the 90's EA82? Or know where a person can find that spec?

 

I am converting my EA81 to a Megasquirt SPFI using the intake and throttle body from an EA82. I will probaby also use the sub MAF sensor along with the Megasquirt MAP sensor so I am looking for the voltage to flow spec for the 90's EA82 MAF also so that I can set up the tables in Megasquirt....

[GeneralDisorder]

You'll probably have to test it. I don't know that those figures were widely published if at all.

 

I understand the desire for MS, but why not just use the Subaru ECM? It's cheaper, and actually has quite a bit of headroom built into it's simple design. It's already setup for a 90 HP, higher compression engine, and can handle a bit on top of that. Should easily be good to 100 HP, and that's not an easily obtainable figure on the EA81 anyway - not with the stock heads, which is the only thing the SPFI intake will fit on.

 

GD

[rojai1]

You'll probably have to test it. I don't know that those figures were widely published if at all.

 

I understand the desire for MS, but why not just use the Subaru ECM? It's cheaper, and actually has quite a bit of headroom built into it's simple design. It's already setup for a 90 HP, higher compression engine, and can handle a bit on top of that. Should easily be good to 100 HP, and that's not an easily obtainable figure on the EA81 anyway - not with the stock heads, which is the only thing the SPFI intake will fit on.

 

GD

 

There are a bunch of reasons to megasquirt.

 

1) I use a wideband O2 sensor. That would be a waste with the OEM Sub ECM which can only use a narrowband one.

 

2) I have total control of all the tuning and spark advance with megasquirt. Why fuel inject if you do not have the cabability to play with the tuning? The stock ECM is no fun and has no appeal to me. I would rather use a carb than the stock ECM. I can access the megasquirt code. Can not do that with the stock ECM.

 

3) A laptop in the front seat hooked to megasquirt is way cool. You can see everthing that is going on. Other output and monitoring options are available including data logging.

 

4) I can use both a MAF and MAP sensor.

 

5) Megasquirt is fun to build if you have the skill. The stock ECM is a black box set up for the EA82. I am using megasquirt on an EA81 with the EA82 manifold and throttle body.

 

6) Megasquirt rules if you want to learn about FI and tuning.

[GeneralDisorder]

But at the end of the day it's still a 75 HP engine. Not worth the effort when the stock ECM is nearly free by comparison.

 

I understand the desire - I was a software engineer.

 

But the effort is mis-directed. Drop the stock stuff on the SPFI system and use the MS for something it can really play with. EJ22T for example. Something that HAS the potential that MS offers. The potential of the EA81 is maybe a few HP. All the work will be for naught when it's really not any fun to tune it. You know how the adage goes - "polish that turd too much and it will melt"

 

If you want to do it, get some EA81T heads, a turbo, and run MPFI. At least that would have some potential with forced induction.

 

Also - without seperate cam and crank signals, or at least code to understand the CAS distributor used by the stock SPFI ECM (which I've considered writing, but again with the effort thing...) the tuning abilities of MS are severely hampered. The CAS distributor has a weird slot pattern that is not understood by MS - at least not as of the last time I looked into it.

 

GD

[[HTi]Johnson]

...You know how the adage goes - "polish that turd too much and it will melt"...

There is another one "To all their own." As for megasquirt, I built a megaview unit for mine. I can for you, if you're interested.

 

Also, he can get the basics down, with a cheap engine, cheap parts and no EJ conversion. Then, if he wants more power, he can step up to the EJ side.

[rojai1]

But at the end of the day it's still a 75 HP engine. Not worth the effort when the stock ECM is nearly free by comparison.

 

I understand the desire - I was a software engineer.

 

But the effort is mis-directed. Drop the stock stuff on the SPFI system and use the MS for something it can really play with. EJ22T for example. Something that HAS the potential that MS offers. The potential of the EA81 is maybe a few HP. All the work will be for naught when it's really not any fun to tune it. You know how the adage goes - "polish that turd too much and it will melt"

 

If you want to do it, get some EA81T heads, a turbo, and run MPFI. At least that would have some potential with forced induction.

 

Also - without seperate cam and crank signals, or at least code to understand the CAS distributor used by the stock SPFI ECM (which I've considered writing, but again with the effort thing...) the tuning abilities of MS are severely hampered. The CAS distributor has a weird slot pattern that is not understood by MS - at least not as of the last time I looked into it.

 

 

You are correct of course.....But you do no understand my motivation.

 

My EA81 runs fine with the stock carb. But my little project has never been about cranking out significantly more HP with the EA81. I would be happy with a 10% increase in HP or even none at all. It has been more about the challenge of just doing it and learning something that I can carry over to other vehicles. I also am a software person and an electronic tech.

 

I obtained most of the EA82 SPFI parts for free. MS2 kit with the stim cost $300 plus my time. $200 for the O2 sensor and controller. Yes, I will have $500 plus change in the thing. That is probably more than the vehicle is worth.

 

I am not using the stock SPFI distributor. I am feeding MS2 with the square wave from the VR module in a locked EA81 disty with no advance. I could also use the wave directly off of the VR. MS2 can use either and I can enter the advance curve that I want.

 

This project is mostly about dinking around with something for the pure fun of it. The MS2 box can be used on any vehicle. I can not do that with the stock box from the SPFI system.

 

At some point I will probably use the MS2 elsewhere. Or I could always sell it on ebay for a couple bills and recoup some of the expense.

[JWX]

GD, The MS can read EA82 CAS and obviously the EA81 dizzy.

 

 

rojai1, Why use the MAF? The MAP sensor alone will work just fine. The MS needs a 0-5v maf, which I don't think the SPFI MAF is, as the turbo one is 0-10v. You could retrofit a Ford, or other 5v MAF I just don't see a point.

[GeneralDisorder]

GD, The MS can read EA82 CAS and obviously the EA81 dizzy.

 

Since when? There were problems with it last I checked...

 

GD

[JWX]

Since the MS2 was out, I am also using an MS1 on my car, and gets an RPM. It hasn't ran yet for other reasons though.

 

Now, does it do a good job? idk yet, but it isn't that different from a KA "CAS" and those run fine.

 

http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_subaru_rx_turbo.htm

[rojai1]

I did get my EA81 in my 84 wagon to run well with my MegaSquirt controller.

 

I did not use the sub MAF sensor, only the Megasquirt MAP unit on board the unit.

 

I was able to measure the flow of the throttle body injector using the Megasquirt. The one I am using tested at 540 cc/min on my home set up. I only inject twice per engine cyle which seems to work OK. My pulse width is quite low at idle.

 

I am still doing some tuning and when I think it is all dialed in then I will post my setup file and a few hints for anyone else that would like to try to run an efi setup on an EA81 using a MegaSquirt box.....

[GeneralDisorder]

Right on - glad you got it running. Was it worth doing?

 

Your setup file would be most appreciated. I may install MS on my SPFI powered Brat prior to doing an EJ22 swap to it since the SPFI is already in place and I can do the MS install and wireing before swapping the motor out.

 

GD