You can easily get around over running the maf by passing air around it. No need to rescale at all. You can bypass 10% and you can bypass 50%. You can also compensate for larger injectors by the size of your bypass. This was how early 90s mas sensors where moddified to achieve high airflow without over running the maf. Al Blaha went 10.50 using a modified mas 8-10 years ago.

 

Type R blow off valve makes a very nice bypass. Only opens with boost. Flow is substantial.

 

I think when considering all of this it comes down to a few things, which make me feel better about what I recommend.

Fact is if you have an EVO that is modified up through our Stages 1-4 you are best off with the stock reflashed ECU. I already said that. They work perfectly, no need for all the datalogging at that point, just have it tuned and enjoy the car.

Once you go beyond that many of you guys are coming up with ways to rescale, use other MAF sensors, trick this, bypass that, manipulate that over there etc., etc. I have to say that when you get to having to do all that is it worth it to just say "I run the stock ECU and make 500 whp". Who cares. Put some real fuel management on the car, tune it like it should be and make 550 whp without the fuss and messing around.

I have a car here on our dyno now we just finished. On our low reading MD AWD dyno it just made 515 whp at 22 psi of boost on straight 93 octane. Why mess around, do it right.

This is enough WHP to easily exceed 130 mph trap speeds on straight 93 octane.

 

Exactly. That is why trying to explain the limit of a MAF in terms of boost just doesn't work.

That certainly makes sense. A stock 2G DSM MAF is good up to about 50lb/min or so with the stock bypass. And Evo MAFs are good for even more flow.

Note that this is how you measure the limit of a MAF.

However, the MAP sensor on an Evo (and a 2G DSM) isn't actually used to index into the tables. Stock "MAP" sensors are actually "MDP" (Manifold Differential Pressure) sensors. They only measure vacuum and are used by the ECU to figure out if the EGR is working properly.

Instead, the ECU calculates the amount of mass airflow that is flowing into the engine per revolution of the crank. This is the amount of air (in grams) that makes it into the cylinder. It is roughly analagous to the manifold pressure if you give it a simple conversion factor, assuming that VE is 100% (it isn't always, of course. It varies with RPM).

 

I am moving this thread to the Advanced Engine Management and Tuning Forum. The advanced forums were created exactly for this type of thread. Please take note of the stricter posting requirements.

https://www.evolutionm.net/forums/sh...d.php?t=197554


Great discussion and information!



Speedlimit...

 

I don't think there's really any disagreement on which way to go when things get complicated, I think the issue boils down to most of these cars are still street driven, and still need to pass an inspection of some form. Some states are safety only, Some have more restrictive requirements, all will eventually have OBD-II tests.

I do understand that everyone that produces parts are for "Off Road Use Only" but We really don't have a really powerful solution that will do the job and still pass at least that portion of the test. At least until some sort of emulator comes along, many of us can't use an AEM or any other standalone. Well, thats not true, we can, but then we have to maintain enough compatibility with the ECU that it can somehow pass once a year (or two years) and we all know that once you get to that point, its alot more difficult to go back.

Aside from Legalities.. The ONLY addon I am running on my car that is altering the MAF sensor signal, is an aftermarket MAF.. Otherwise my car is tuned entirely on the ECU at the moment (To clarify I have an ECU+ on the car, but its not doing anything but logging data at the moment) And the connector I'm using plugs right into the stock wiring harness for both components.

Now, I do understand where Al is coming from when he's talking about the AFR Target values as opposed to Injector Duty.. There is a table for those things, I have found an additional half dozen tables, some were very large and appeared to be related to those functions (I have not confirmed it yet) And its only a matter of time before those are figured out. Only the AFR targets are based on VE at the moment, and therefore are pretty predictable to adjust even if they are massaging numbers that no longer represent the actual target AFR.

The duty cycles for the injectors are pretty static based on those tables, injector scale and latency alter those values pretty predictably, and the MAF calibration table additionally alters that value..

Is it complex? Well, yeah it is kinda, but only because we're still learning what the stock ECU is capable of.

What if I told you that its likely an entirely new rom would be written that would/could have all of the standalone features you wanted? There are quite a few unused input/outputs on the stock ECU, Half dozen at least, There is already a similar ECU Rewrite out there (DSMLink), and there is enough motivation and technical knowhow out there that we will likely see something in the near future.

I think the essence of the entire debate seems to keep coming back to the MAF, and I agree, the stock MAF has its limits, and you do end up hacking it, adjusting it, farting on it whatever it takes to get it to work.. But in my case, I have removed my MAF sensor for a sensor that is calibrated to read airflow to 80lbs (65 was stock I think was mentioned) The output of my unit can go as high as 4000hz, and the ECU is indeed capable of understanding a value over 3000hz, its deceptive because its logging output (Mut protocol) only says 1609hz when you pin the value, but it is actually able to handle way over that.


I think what it all comes down to is what our needs are, I am a car enthusiast, and I care about the environment (I run a cat) and LEgality (I HAVE to run OBD-II) but I like to push the limits. Additionally I built my setup to be able to run E85 when it becomes available, so my injectors are larger than they need to be for that reason.

Let me point out a few things since nobody really knows too much about my car..

I have Buschur components through stage 4, I run 280 Cams, 1000cc injectors, a Buschur GT35r turbo kit, a CATALYTIC CONVERTER (Catco aftermarket 3"), Apexi AVC-R (the best closed loop boost control unit available right now, and ugliest), I have an ECU+ I use only for logging, HKS-DLI2 (and even COP setup with it), I have a multi-output RPM activated switch for my shift light, I am logging an amazing amount of data, and able to tune the car with very little difficulty. It idles nearly stock, runs smooth, doesn't have drivability problems, *PASSES AN INSPECTION* and retains all the emissions controls.

My car makes power, how much I'm not sure yet, I just started tuning the car and pushing the limits a bit further as I learn more about ECUFlash and the ECU, I have specifically stuck to the ECU to see if it can be done but also to stay at least legal in spirit..

You know what makes it better? Everything is mounted into two plug and play harnesses (One for the ECU, One for the MAF) that can be removed in 10 minutes, I can run entirely off the stock ECU and MAF only if I wanted to.

My entire point isnt to argue what is better, the AEM is still a better solution for a no compromise high horsepower car, unfortunately Life, and the street is full of compromises, the Federal laws, and local laws get more strict every day. And we all need to be aware of this, and ready to accept that there may be a time where its necessary to work within boundries we're given (and bend the rules while doing it of course)

When I bought my Turbo kit from Buschur, I was so excited, I got it and started mocking everything up, then I noticed something, it didn't have an O2 bung in exhaust turndown from the turbo that goes to the downpipe. I wrote him an e-mail and said that it was inadvertantly omitted. THe reply to me was, It actually is intentional, the AEM doesn't require it. I was a bit shocked, but not upset (I had to weld my own bung in) I run the stock ECU and had to make that compromise.

I think in reality, I probably have done MANY things different than the majority of you guys, and many things the same way. But innovation and education don't come with doing it the way everyone else does, sometimes you break the rules to make them. I'm just surprised this eagerness isn't being shown for the stock ECU.

Its obvious that limits are only there to be broken.. I'm glad to be one of the people doing it. Who knows, this time next year I may be trying something completely different and new.. Heck, This time last year I was pushing the limits of the stock turbo, ultimately I made my goal and moved on... I just didn't talk much about it because I was disappointed with some of my results.

 

Good points malibu and don't think I don't respect you guys for what you are doing with the stock ECU. Believe me, I spend a lot of time lurking and just reading what it going on.

I also must admit that being out here where we have no emission testing I forget that the OBDII port isn't just there for extra weight in the center of the car! That is a huge issue and shouldn't be over looked.

 

Remember what you did on the stock ECU in your 1G RWD, Dave. 9.4 in the 1/4, right?

That car is running again this weekend at the NDRA race at New England Dragway, btw... Josh Mowery did a great job putting it back together. I can't wait to see it run. It is one of my favorite cars to watch.

I was there when you did your first burnout with it behind the autocross at the shootout years ago. I was there when you ran your first 10, and ran I back behind the stands to congratulate you when you came driving back afterwards! Good times.

 

I talk to you guys often enough to realize that its a reason of practicality. You have no idea how much I wish I was living in your area where I didn't have to worry about this (I work for a company that is now largely based out of Ohio, and there may be a time I end up in the area)

I can't get over how much I've learned about the ECU in a short time. And I haven't even full disassembled the Rom (Specifically for my car) But I can already see there's plenty of room in there for improvement, and place to make it if I can find the tools to write it. The stock ECU really does work alot like any other standalone, just one nobody gave us documentation for..

 

I agree with your points on the stock ecu

In April of 2003 I went 11.8 with the stock ecu and safc with stock turbo cams, etc - the first to go 11's in a usdm evo 8.

Back in October 2003 Modified Magzine my car my car was featured after running a 11.65 (Dan Cokic driving) with a works basic reflash and a emanage doing the fine tuning - details are available in that article. BTW that was at 20 psi as we had no idea how much the evo motor would take back in those days. The car came in 2nd place at the 12th DSM shootout the first year to have a evo class and was the fastest evo there.

Two weeks later with some more adjustment I went 11.1 at 25 psi of boost with the same reflash and emanage.

It was at that time that I bought the tech tom equipment and started trying to make big power with the stock ecu

At some point I came to the conclusion that the stock ecu COULD be used to go very fast and make big power - but that the limitations in doing so would proove to be more and more difficult the more power you made

The max whp I made on the Dyno Flash was 575 whp on a 100% stock bottom end with hks 272 cams and my old gt30 r turbo

I used the stock ecu until I installed my first built motor with JUN 272 cams and discovered it was almost impossible to get it to idle decently

Now, I know more tricks in reflashing and could prob have gotten the idle decent with my current level of skill but I still feel like a race car should have a stand alone ecu

I guess since my car is a full race 100% unlimited machine it makes sense to have a stand alone ecu

Frankly - the hasssel of working around a stock ecu to get the car tuned becomes a real nusiance when you are making big power

Boost comp tuning is a function opf the aem which really makes tuning a race car very easy and hassel free

After all - I am still running the base tune - untuned from the Black Buschur race car in my car and I went 9.7 @150 mph

 

Jack


Lets hope that Cobb goes through with its plans for the access port on the evo

Speaking as someone who is a pro tuner of wrx's and also ecutek the stock ecu has become in many cases BETTER than the aem with better data logging and features

What Cobb has done is to totally unlock all the festures of the subaru ecu and present it in a very useable fashion with real time map trace and amazing data logging features

The sad reality is while ecu flash is cheap to obtain I do not see much motivation for the developer to enhance the features and work on new functions

With a product like ecutek much of the extra cost associated gets channeled back into R & D so while it does cost more, in the case of the subaru product you get much more features

The Cobb product would have been nothing short of a total revolution of evo tuning and it would be a shame if that product is put on the back burner becuse of the advent of free flashing tools

Despite the amazing features that ecutek and cobb have developed for stock ecu tuning - the fact remains that for really fast high whp racing evos a stand alone is the best path

At all the NHRA events and NOPI and IDRC no one runs stock ecus anymore

I think David Buschur was the last racer to go really fast on stock ecus

 

What about the Evo IX's? Does the added resolution of the ECU add anything to the table in terms of Tuning and WHP? Is it able to achieve higher WHP goals over the VIII?

 

It's coming sooner then you think.. *wink*

 

I can only hope that it does. It has been a long time comming and i just hope that its not the case of cinderalla showing up at the ball when its already over !

Cobb access port for subaru is a really top notch product and if it were avilable for evos I would prob be recomending it to all my tuning customers

 

The Accessport is something I've been eagerly waiting for, for quite some time... It will be nice to see what they ultimately come up with.

the OpenECU stuff is great, and the development is initially being done by one person, but it is supposed to be Open Source, which means over time, more of us will directly participate in the development. Also, the Definitions for the ECU, and the reflash tool, are independent efforts, much of the definitions that allow us do the mapping were contributed by members. It would be nice to see some sort of realtime tuning and logging, and that may happen with ECUFlash at some point..

Time will certainly tell, I'm just glad to be involved in this..