Good thinking man...I'm happy you responded in this thread because before I started it, I was very impressed when I read your numbers. Im looking for a used MR myself and am impressed...

Now Ive read with tuning the CAI can get you 7-10 hp max. Do you just feel its not worth the $$$ and hassle? I am tieing it into no "sound/bling" characteristics when I ask you about it, just the performance gains. And theres no other acceptable means of replacing the stock DV besides the JDM MR version?

 

What are you going to do with the car?

There are millions of different ways to tune these cars and get power out of them.

 

Tuning wise, I believe S-AFC through street tuning. Ive been told that with good street tuning you can gain more power than custom dyno tuning. My cousin has been street tuning S-AFC for awhile now and we would do it together...

 

you've been told wrong.

sorry, but you don't strike me as the type who can tune your own car. First, you aren't gonna make any power without getting your ECU flashed to ATLEAST remove fuel cut, second...not much way to street tune an afc without first having it dynotuned to be dialed in, then making MINOR adjustments on the street...either way you need a custom tune first.

Not to mention, you don't need to be touching anything that controls your a/f ratio like that without a wideband....thats playing with fire.

If you want a fast EVO you can have it done right for not that much money. Hell, even if you only get a flash with a full exhaust.

My advice is to have it custom flashed AFTER you buy some parts(full exhaust, ect)

Don't trust your cousin to street tune your 35k dollar car with a fuggin afc....thats just retarded

 

Evolvd what is your name on nasioc?

Being a former high HP subaru owner, and current evo owner(still have a swapped 2.5rs for my DD) You need to go over your over all goals for the car.. How far do you plan to go? The cars are very similar in many ways, and totally different in others.. The evo is very brainless to mod, there is a very fine line of what is done.. Intake, exhaust, cams, EM, etc if you wnat more turbo kit of some sort.. The Sti has a bit more variety of set-ups to choose from since there are a million bolt on turbos, rotated kits, etc..

What is the car mainly going to be used for? And why the MR over the gsr?

ALso take into consideration what you feel more comfortable working on.

 

Well, I'd love to get 7-10whp from any intake, but I don't expect it. Maybe 4-5, but that's pushing it. A CAI sucks in hot engine air while the stock intake sucksin cold, external air. The CAI also sends in turbulent air that throws off the MAF, while the stock box doesn't. A CAI can work with a tune, so it's not all bad, but I just can't justify the cost. There are some really nice units (ARC) that involve a custom airbox that attaches to the stock intake snorkel and stock MAF pipe, but that's $$$$.

As for BOVs, there are plenty of nice ones that recirculate, so you don't have to just get the MR DV, but it's the only one that costs $120.

 

Jeff, I have always regarded you as quite knowledgable, but what's up with the flash whoring? Why do you think you need an ECU flash to make ANY power? There's 2 of us with just exhaust and S-AFC (I have an MBC; he does not) who are running 12.2@111-112 in 05s, and we don't hit fuel cut, because the S-AFC causes fuel cut to happen at much higher air flows than stock due to the negative settings.

Why would you need a dyno first before street tuning an S-AFC? You can get the info you need when logging, and a dyno doesn't mimic street conditions, so it's only useful as a general reference. It is also not true that you can only make MINOR adjustments on the street. I went from 0% across the board in stock form when I started my tuning all the way to -12% at 7500rpm with a gradually declining step starting at 5000rpm. This resulted in low 11 AFRs with a beautiful timing curve. Why would you say I need a custom tune/flash in order to accomplish this?

 

I meant minor adjustments from the dynotuned settings. What are you logging with?

And you obviously aren't most people, you seem to have your **** together. Anyone who is on here wondering what some of this stuff is isn't probably capable of tuning their own car onthe street from scratch.

How do you know what your a/f's are? How much boost you running on pump fuel with that stock timing you are running?

And im far from a flash *****, i hate flashes and have never ahd one(other than to bump rev limit and eliminate fuel cut)....i like to be able to adjust my settings and switch maps, but its not for everyone and i give advice based on the knowledge that people radiate in their posts.

 

And FWIW, i did forget that the MR actually has a higher boost limit before fuel cut than the 03/04 models do when i was talking about the flash.

And those are pretty quick ETs for your trap speeds, you must be a good driver....but there is more power to be had.

Have you considered a cutout off of your downpipe? If you are running the stock cat, you will see huge gains in both spool time and power.

 

I was about 2 ask the same question. Im running 12.5 @ 108 with a S AFC that is has setting from another car. Plus I have made the tuning less aggressive. I have a slow *** 03 though.

 

i was trapping 108 with a manual boost controller and full exhaust....

 

I put your last 2 together in here...

I log with a narrowband pocketlogger, so I don't have the luxury of wideband AFRs at this point. I tune based off my timing, but I keep an eye on O2s to know where my AFR is. I used to tune just for the AFR, but I found that timing didn't always follow the optimal AFR, so I switched over to the timing method, but while keeping a keen eye on the O2s to ensure I don't go too lean. I run 21psi on pump (93) and ran 22-23 at the track with 104 mixed in.

I don't think fuel cut is higher because of the MR...I thought it was based off air flow. People tend to hit fuel cut at certain karman readings, but that max air flow can be raised by deceiving the ECU, which is what the S-AFC does. It doesn't remove fuel cut, but removing fuel at higher rpms allows for more air flow before fuel cut. I'm currently hitting a peak of 1860hz without hitting fuel cut.

Don't be fooled by my 12.2@109. Because of the 6spd, 4th gear maxes out at 111, and I kept hitting the rev limiter before crossing the line, which was slowing me down at the end, so I got to the top of 4th on that run and let off the throttle slightly to stay off the limiter. The result was my best ET, despite an average 60' (1.75), but a lower mph. On the next run, I got a better 60' but hit the limiter en route to a 12.24@110.62 (slips in my sig hyperlink). I haven't considered a cutout in the DP nor removing the stock cat, because I want to stay as stock appearing and emissions legal as possible for both legal and warranty reasons. Even if I threw in a test pipe for the track and ran C16, I wouldn't be able to overcome the 4th gear rev limit problem. Also, even at 7800, other MRs haven't gone much over 111, so a flash wouldn't be worth the cost.

 

Well, im sure you know this but the AFC doesn't pull fuel, it tricks the computer to thinking there is less air passing through the MAF thus making the ecu pull fuel.

Now, how are you changing your ignition timing with an afc? or did i misread somewhere?

And, adding a cutout to your downpipe would allow you to pass emissions with no problems at all....only thing that the warranty would be voided on is your downpipe also....if your dealer tells you otherwise, find another dealer....there are good ones out there.

 

I control timing indirectly with the S-AFC. It really works, but you just have to know what you're doing. You can detect knock based on the timing curve and then adjust fuel (+/-) accordingly. If I have a dip in timing at a certain rpm, then I adjust the fuel either up or down depending on the O2 reading until I get a linearly increasing timing advance that maxes at 20-21 at the top of 4th.

Well, I may have to look into the cutout more closely, but I did not want to make any modifications to my dp/cat, nor do I want to be loud, which I assume is the case when the cutout is open. I could only open it at the track, but I don't plan on dragging anymore, so I don't know. Maybe if it's easy enough, I'll do it.

 

Man you might have to teach me!