I originally thought the same thing, that with the DTCs disabled, the maps wouldn't affect power output. Gunzo stated the theory that even with the DTCs turned off, the maps could still limit power output even without telling you with a code. The way he described everything does make sense, but like you and GST stated, the dyno will show the proof. I agree that if the theory was true, even with the DTCs turned off, you should see differences in the datalog between stock and modified limit tables.

I still think to fully understand this, you'd have to figure out the ECU's logic as to when and why it decides to throw codes based on those airflow limit tables.

I'm also still curious about the ASC light and why the stability control thinks it needs to turn itself off during a WOT pull.

 

GST already proved it. it doesn't limit the GSRs like it does the MRs.

 

The MR has seperate tables for transmission limits. Unless those are modified, the transmission will limit the power output to the wheels. So even the MRs won't be limited by the airflow tables themselves.

So GST has proven that, with the airflow limit DTCs disabled, modifying the airflow limit tables shows zero difference in power output. Now the question is, if all they cause is tuning headaches and don't actually limit anything when turned off, why wouldn't everyone disable their airflow limit DTCs?

 

same reason why people dont set the boost cut to 319...

its a safety feature..

me personally can live without it

 

My simples answer is YES, YES, YES. DO IT and remove these silly limiters. Evo 8/9 owners have done w/o these silly limiters. They are just a PITA.

The only protection that you need is the boost/load cut. Set that about 10 points above the load your hitting per 1000 rpm and you are golden. You have all the protection that you need. If you want more protection, then you can lower the activiation of the load/boost cut from 1000 ms to 500 ms. This way if your car is loading above what is indicated in the load table for 500 ms, boost will be cut.

Evo 8/9s have the boost cut as the main protection and they have been doing fine w/o the silly airflow/torque limiters. Evo X owners have it too. You do NOT need the airflow/torque limiters.

Even if your car is tuned by God and the limiters have been adjusted you will still get the limp mode under certain conditions. No tuner is immune from this.

 

disabled DTCs = happy times

 

so very interesting happened to me today. I (for ****s and giggles) tried adjusting the air and torque tables although my DTC's are turned off and when i did a pull on the free way WOT the asc light came on! so in conclusion, anybody that has their asc light on when at wot and have their dtcs off, put you airflow check and torque tables back to stock to get rid of the problem!!

 

↑↑ That's interesting to hear....although I'm still not convinced the ASC light has anything to do with those airflow tables. My airflow and torque tables are all modified well beyond stock, just because I haven't bothered touching them since disabling the DTCs. I've still never popped the ASC light because of it.

The only time the ASC light ever happened to me was when my fuel pump relay was going bad and I had a few hard hesitations throughout the power band because of it.

 

nope not me. fuel pump is ****, i promise. but that's what happened.

 

I am of the understanding that the limits are there because of the X's fly by wire throttle. hey are meant to protect from a situation where the throttle was stuck or not doing what the ECU wanted it to do. So the ECU checks across everything to be sure that TPS, manifold pressure and air flow are all matching against different tables. If they are not, it cuts off all the fun. I cant think of any other reason that Mitsubishi would have made the result so severe. Kind of like the problems that Toyota is fighting with in their run away cars. They are trying to prevent the lawsuit if you were to plow through a farmers market with a haywire throttle stepper motor.

I have not had to disable any limit codes on Xs that I have tuned so far. Some sure have given me fits getting rid of them. The thing that helps the most is to start going back towards stock numbers (if not all the way stock) at the low rpm area on cars with cams and/or big turbos.

Mike W

 

Toyota fly by wire kills 4 people due to wrong mat:

http://www.cbsnews.com/stories/2009/...n5351341.shtml

Yikes!

Good point Mike, luckily we have big brakes and can turn off the car with the twist of the ignition if need be.

 

well a stuck accelerator pedal isn't something the ECU can fix...

also a misbehaving pedal sensor OR throttle will be picked up by other systems not the airflow/tq tables...

 

I really don't understand the mentality of not turning these off. It doesn't make sense to me given the time it takes to tweak the tables so they are never tripped. There is no benefit I can see for keeping them on.

I remember Ryan trippin these tables mid way through a flyer lap at Redline Time Attack events and being so pissed that something that stupid ruined his lap times.

This is not a safety feature at all in my book. That is what boost error correction and fuel cut is for.

- Bryan

 

+1

 

+1 to that

As far as street driving, I thought I had the codes all tuned out perfectly. I was in the morning rush hour passing a few large trucks at part throttle, got in front of the last one and popped a limp mode with nowhere to pull over. I had to limp it all the way to the next off ramp with everyone flying by like I was standing still.

Definitely not a safety feature in that case either...