ECU/Piggyback, Injector, and MAF questions

[hellosubaru]

Hi,

I'm hoping someone can explain some tuning paths and terms to me. I've been searching and reading for the past few days about engine management, injectors, and MAFs, but it's still a bit fuzzy to me.

I am currently running an EJ22t motor with the stock turbo (VF11?) turbo. I have been slowly collecting parts to upgrade to a TD05 w/ 06-07 WRX TMIC. What I would like to know is:

1. What are people using for engine management for a TD05/TMIC setup? I've seen some people say this setup is ok on the stock ECU up to 11PSI, but others say you need engine management. I've seen a lot of people point to the robtune chipped ECU, but it appears its only for the EJ20g, not the 22t. What are people using for engine management on the EJ22t? I'd prefer a piggyback to avoid full standalone costs. I'll only run 11 PSI daily, 15 PSI max.

2. Will larger injectors be needed for the larger turbo? Common sense tells me yes, but I'm not sure which to get. I've seen posts about gray and yellow top 440cc injectors, is this the correct way to go? What is the difference between gray and yellow top injectors? Should I be looking for one color over the other?

3. MAF. Assuming I don't go with an engine management solution that uses MAP, what are people doing for an upgraded MAF? What is the JECS MAF (I see this referenced a lot)? Are there any other MAFs recommended for higher air flow / tuning?

Thanks for helping me understand all this stuff.

-Jason

[Legacy777]

Jason,

The TD05 & TMIC will work fine with the stock engine management. As noted if you push more boost, that's where you start to run out of the range of the stock MAF and injectors can handle. At that point is where you will need some form of engine management. I ran a TD05 with the stock ECU and stock boost for a while without any issues. The point at where you start to max out your injectors and MAF will vary depending on your other supporting mods. If you have a free flowing exhaust intake, etc. you tend to hit that point at a lower boost level.

The rob-tuned ECU can be made to work with the ej22t.

If you stick with the stock boost, you shouldn't need injectors. If you push the boost, you'll need larger injectors and MAF. The yellow sti injectors are 550's. The black JECS MAF sensor is a good replacement if going with the Robtune or other engine management. I would recommend the robtune ecu if you decide to push more boost through the engine.

[hellosubaru]

Is the black JECS MAF sensor an aftermarket piece, or is it a MAF from another Subaru? If it's aftermarket, where can I get one?

Is the robtuned ECU plug and play, or is wiring involved? I'm assuming I plug the EJ20 robtuned ECU, and not use a EJ22t robtuned ECU correct? It sounded like rob hadn't gotten to chipping a 22t ECU yet.

Also, what is the stock ECU good up to? I know every engine / tune / components are different, but is there an estimate? What is stock EJ22t fuel cut, 12.5 PSI?

Thanks again,

-Jason

[sqc151]

subscribed.

[Legacy777]

Is the black JECS MAF sensor an aftermarket piece, or is it a MAF from another Subaru? If it's aftermarket, where can I get one?

It's a stock Subaru MAF from the non-turbo 90-94 Legacies. In 90-91 it was found on the AT cars, in 92-94 it was found on both the AT & MT cars. This MAF was also on some of the newer 95-99 Legacies & Imprezas.

Is the robtuned ECU plug and play, or is wiring involved? I'm assuming I plug the EJ20 robtuned ECU, and not use a EJ22t robtuned ECU correct? It sounded like rob hadn't gotten to chipping a 22t ECU yet.

I'm pretty sure it's mostly plug & play, with the exception of the ignition. Rob also has a 4-to-2 ignition converter that allows using the ej22t's coil pack setup. I'd suggest checking out the two threads in the electrical forum for more details about each option.

Also, what is the stock ECU good up to? I know every engine / tune / components are different, but is there an estimate? What is stock EJ22t fuel cut, 12.5 PSI?

Thanks again,

-Jason

It really depends on the mods. I made about 150 hp/tq to the wheels on the stock ECU. That's probably just around 200 crank hp/tq. With my mods I was pretty much at the limit of the stock MAF. Fuel cut is around 12 - 13 I think. Someone else can confirm.

http://main.experiencetherave.com/subar ... gdyno1.jpg
http://main.experiencetherave.com/subar ... gdyno2.jpg

[ghia nut]

What are the benefits to running a td-05 over a stock vf11 on a stock car? I'm assuming higher boost when you can afford injectors tune and maf but something like sooner boost or quicker response etc?

[Legacy777]

If you stick with stock boost levels, there's really not much benefit with going to a TD05. The benefit comes with higher boost and more power delivery at higher boost levels.