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Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 6:29 am
by hellosubaru
I would like to know if I can run these injectors and MAF together without an EMS/piggyback temporarily and safely on an EJ22t. I was told the injectors are gray top 440cc's, and the MAF is a JECS/AUTECS MAF.
Here are the injectors:
And here is the MAF:
Thanks,
-Jason
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 4:56 pm
by mike-tracy
Your ECU will learn to run the injectors better over time (but will always run much richer than necessary), but won't be able to take advantage of the MAF at all. The MAF requires you to cut and splice and ground the wiring harness to be able to start the car with it.
These upgrades are a good fit if you want to run an ej20g ecu with one of Rob's ecu conversion cables, however.
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 5:34 pm
by Legacy777
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 6:37 pm
by hellosubaru
Yes, I'm familiar with the Robtune ECU, I just wanted to know if I could run this combo temporarily without harming the engine. I'd like to pick up one of Rob's ECUs before Christmas, but until then I was hoping I could run this combo safely.
Thank you.
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 7:20 pm
by wtdash
Hi,
Just to clarify...the JECS/AUTECS MAF shouldn't be used even w/the wiring mod noted above (no offense Mike!). It'll make the car run lean. Running the 440's won't properly compensate for this - I tried it when I had my Legacy and 440's - and AFR's were scary lean.
EDIT: No MAF wiring changes are needed w/the Rob Tune - just swap in the JECS/AUTECS MAF and w/the EJ20G ECU it'll work as is.
Since you don't have a mod list in your Sig, I don't know what you've done past stock, but suggest getting the upgraded turbo, an IC, boost gauge and MBC installed - all of which can be run on the stock injectors/MAF.
Save the 440's 'til you have the Rob Tuned EJ20G ECU installed, and aren't wasting gas 'til then.
GL,
Td
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 8:08 pm
by hellosubaru
wtdash wrote:Hi,
Just to clarify...the JECS/AUTECS MAF shouldn't be used even w/the wiring mod noted above (no offense Mike!). It'll make the car run lean. Running the 440's won't properly compensate for this - I tried it when I had my Legacy and 440's - and AFR's were scary lean.
Since you don't have a mod list in your Sig, I don't know what you've done past stock, but suggest getting the upgraded turbo, an IC, boost gauge and MBC installed - all of which can be run on the stock injectors/MAF.
Save the 440's 'til you have the Rob Tuned EJ20G ECU installed, and aren't wasting gas 'til then.
GL,
Td
Thank you, this helps. I don't have a mod list, because I'm doing everything at once basically. I'm planning on installing a td04, wrx TMIC, and MBC (basically everything you listed), plus the 440s and MAF. I already have a boost gauge installed.
I'll just wait until I can afford the Robtune like you suggested.
-Jason
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 8:28 pm
by wtdash
hellosubaru wrote:...... I'm doing everything at once basically. I'm planning on installing a td04, wrx TMIC, and MBC (basically everything you listed), plus the 440s and MAF. I already have a boost gauge installed.
I'll just wait until I can afford the Robtune like you suggested.
-Jason
Jason,
That all sounds good. I'd install in increments for the stuff you can. Why? So you can troubleshoot upgrades independently as you go.
You can do as others have done (not naming names) - throwing it all under the hood @ once, and the car may not even start. Not cool and it makes finding the cause 10X harder as the # of variables are compounded by each mod.
Plus the fact that the TD04 + WRX IC ('06-07, correct?) plumbing can be a challenge just by itself.
You can install the MBC along w/the other goodies now and 'CAREFULLY' play w/turning up the boost a bit. Fuel cut is @ 12.7PSI, and according to the
Legacy FAQ you can run up to that if your car is currently running top-notch. Do some research on here of what others are running w/just the TD04 and IC.
TD
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 9:11 pm
by hellosubaru
wtdash wrote:
Jason,
That all sounds good. I'd install in increments for the stuff you can. Why? So you can troubleshoot upgrades independently as you go.
You can do as others have done (not naming names) - throwing it all under the hood @ once, and the car may not even start. Not cool and it makes finding the cause 10X harder as the # of variables are compounded by each mod.
Plus the fact that the TD04 + WRX IC ('06-07, correct?) plumbing can be a challenge just by itself.
You can install the MBC along w/the other goodies now and 'CAREFULLY' play w/turning up the boost a bit. Fuel cut is @ 12.7PSI, and according to the
Legacy FAQ you can run up to that if your car is currently running top-notch. Do some research on here of what others are running w/just the TD04 and IC.
TD
I'm hoping the engine will be in top-notch shape, because it's currently getting a full rebuild.

That's why I was going to do this all at once. I've done some research on the td04/WRX TMIC (namely, this thread:
http://bbs.legacycentral.org/viewtopic.php?t=38598), so figured I'd do that while the engine was out. Maybe I'll wait for the turbo/TMIC upgrade until I have the Robtune.
Or, I may do the turbo/TMIC, drive it a while, then do the 440s/MAF/Robtune.
Also, is there a MBC you recommend, or should I just do a EBC?
Thanks for your guidance, it's much appreciated.
-Jason
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 9:34 pm
by wtdash
Jason,
A full rebuild? Awesome....I'd throw some forged pistons in there if you're going to the trouble/expense.
I just updated my EJ20G thread
HERE w/the MBC I used w/my Legacy (scroll down).
And Rob doesn't recommend the BCS or EBC (AFAIK) - just go w/an MBC and be done w/it.
You're welcome,
Td
Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 9:59 pm
by mike-tracy
Todd, keep em coming, I hate giving out bunk info.

Re: Is EMS needed for 440cc injectors and
Posted: Mon Aug 27, 2012 10:09 pm
by wtdash
mike-tracy wrote:Todd, keep em coming, I hate giving out bunk info.

You and me both, sir....you and me both......
Also, there are
no MAF wiring changes needed w/the Rob Tune - just swap in the JECS/AUTECS MAF and w/the EJ20G ECU it'll work as is. But you'll still need to address the other wiring changes as noted in Rob's threads.
TD
Re: Is EMS needed for 440cc injectors and
Posted: Fri Aug 31, 2012 2:54 pm
by legacymax
wtdash wrote:hellosubaru wrote:...... I'm doing everything at once basically. I'm planning on installing a td04, wrx TMIC, and MBC (basically everything you listed), plus the 440s and MAF. I already have a boost gauge installed.
I'll just wait until I can afford the Robtune like you suggested.
-Jason
Jason,
That all sounds good. I'd install in increments for the stuff you can. Why? So you can troubleshoot upgrades independently as you go.
You can do as others have done (not naming names) - throwing it all under the hood @ once, and the car may not even start. Not cool and it makes finding the cause 10X harder as the # of variables are compounded by each mod.
TD
Listen to this, I have done the "throw everything at it at once" approach and it is not a good one. I would run that engine through its paces first to work out any bugs. Also, if something is wrong with the rebuild, then the builder can't come back to you and say it was your mods that screwed the engine.
-Max