So a thought occured to me with these wacky learn down computers our cars have. Is it possible for a short period of time, to totally fool it for some signifigant short term gains?

I think of this in terms of something like running on a dyno or drag racing.

This is my thought about how it might work...

Lets say I want to go to the drag strip and am looking to put down the best time possible. Before I drive to the track, I place a VERY restrictive filter in place of the current air filter or something which dramatically reduces the air flow into the engine.

Given the learn down feature of our cars, it wants to make 260 hp...By going heavy on the throttle on the trip to the track, in a fairly short time it will learn that it needs a lot more boost to make the 260hp with all the restriction it now has.

Now at the track, all the restriction is removed and in theory the car should be making a fair amount more hp since it has not yet learned that it can reduce the boost and make the 260hp. Possibly enough time for 1 or 2 runs at a higher boost setting.

So is there any reason to think this would not work? I defer to those who understand these ECU's better then myself, but in the short term event such as a dyno run or 1/4, it seems to me that this could work.

 

Confusing, maybe for a short time, but after a few minutes of driving the ECU will see that you have modded the car and then "Learn-Down"

 

In theory that should work, but here's something easier. Simply adjust the wastegate rod so its as short as possible, this will bump the boost up a couple psi until the ecm re-adjusts. This works, but not for long.

 

Well thats expected but a few minutes is all thats needed....primarily for the duration of a 1/4 mile drag race

Have you tried it? What sort of gain? Is there a "how to" on that?

 

Simply find the turbo and adjust the wastegate rod so it looks something like this.
From what i remember there was around 2-3 psi more boost with the before and after datalogs.

Before


After

 

It's funny this came up because of something I thought I had noticed. After doing a road trip on regular unleaded, it turns up the use of the turbo a bit to compensate (I can hear it more and sooner in the rev/pedal range), and then when I put in premium back in again, it seems much quicker... but then when I start it again later it's back to "normal" and the turbo's a little quieter again.

I think these ECUs "learn down" on a key-turn basis, analyzing changes needed and then making its tweaks the next time you start up. So if you can make it learn up over an engine start or two, you should have it pushing above normal for at least one engine start. Just maybe don't shut down the engine or you're back to square one.

That's sure playing mind games with it, but it's worth a shot if there are performance benefits to be had. On that note, maybe people that are interested in tweaking the wastegate should actually adjust the wastegate open first, say on the way to the strip so it will learn the new position during the drive there, and then close it to that position you all are talking about once you're there so when you turn on the ECU/engine again it adapts to the drive-to-the-strip position until it logs something's off and readjusts next time you cycle the ECU. It may amplify the benefits that you are seeing.

 

Yeah...that was my thought about that concept as well.

I think I will try tommorow with a VERY restricted filter setup and see if there is any change.

If anybody else has ways of fooling the cpu, lets hear them.

Free Horsepower is always fun.

 

The wastegate rod itself will always "rest" at the same place when the engine is off. It's just a dumb canister with a spring inside of it. So unless I'm totally misunderstanding what you guys are suggesting, that method of adjustment will net you nothing.

What would be key is finding out if there is some operational parameter (ie: a temperature, pressure.. whatever) that denys the ECU the ability to enter "learn down" mode. However, unless some of us start hacking the ECU ourselves OR a GM Engineer decides to key us in ... we'll never find it. I don't think such a mode exists honestly, but who knows. There are tons of GM employees/engineers on the Solstice forums and they all run the stage kit flash. You'd think if there was some quick fix, they'd be using it.

My biggest complaint is how inconsistent my car feels. Sometimes it feels QUICK, other times I'm like..... where the hell did the power go? I know a lot of people say a flash fixes that. I'm just not willing to trash my powertrain warranty just yet.

 

im with you, on that at the track even i ran a 14.5 @101
the next run i missed 3rd and ran 14.6 @ 104 (if i didnt miss woulda been my best run ever)

 

So what will that do to people with tuned cars LOL

 

works..... for a lil like 30 min max...... but it def works and you can feel the dif........ btw my "very RESTRICTIVE air filter" was the sock one and i just ran with no filter for planned races

 

It is not going to help much at all or for very long. The ECM will adjust really fast. Just get it tuned.

 

The spring is under more tension now when you shorten then rod, it'll take more pressure to open it. Once the ecm figures out your boost is too high it'll force the boost solenoid to bypass more air to the actuator and it'll open like stock.

Give you a bit more boost for a couple of pulls, then goes back to normal.

 

hmmm this is interesting

 

But it's still learning down.... BOOST doesn't equal HP in all cases!

 

a tune just seems sooo much easier. why not just do that?

 

Airflow went up too, around 15-20grams/sec.

Its free? But ya a tune is so much better.

 

I'm sure it did... but was any power truely gained....