PDXTuning

Nice post TDC, very informative, but I wanted to add a couple things to this.

Long term fuel trims will actually change the open loop fueling. So some of the effects of the intake will diminish as the long term fueling adjusts.

As TDC stated the larger MAF housing will increase timing. The ECU is primarily run off the load calculated from the MAF voltage. Anytime you decrease the MAF voltage you are making the ECU calculate the load incorrectly. Since as a general rule less timing is run for more load, you get more timing with the leaning out effect. This is what is so dangerous about running intakes on our cars. The entire architecture of the ECU requires the load to be properly calculated.

Most intakes can be tuned for, but you really should only run an intake when required. The timing changes and fueling changes should be accomplished through proper tuning, not with a global alteration of the calculated air flow into the motor.

Jarrad

99% of intakes WILL LEAN THE CAR OUT

and most will affect the timing a bit

 

 

Some of you guys are QUITE mislead about ahow the ECU "adjusts"

 

ill go into a bit about it:

.........

When you removed your friends AP from your car you likely got a new map on your ECU. The AP puts a stock map back on, not necessarily the same map your car had on it. The map they put back on may not have the stutter problem.

You know what I noticed:

I tried out my friends AP for the weekend back during Thanksgiving, and it was cold. When I did that the stutter was gone. I know that the ECU is effectively reset when putting a map on, so I figured that was why it was gone, and eventually it will come back.

 

The weekend comes to a close and I take the AP off, and go on my merry way. The thing is, its like a month and a half later, and I still don't have the stutter. I have driven at least another 1000 miles on the car, so it should have showed up.

 

Now here is my theory..I don't know if it holds water, but here goes.

I bought my car in July, and at the time, I didn't feel too much stutter..at least enough for me to complain about it. So I am driving it for like 3-4k miles and then Fall hits and things start to cool down. Then I start getting the stutter, so I am like..oh it is because of the cold weather that it is getting more apparent.

 

I then do that AP stuff mentioned earlier Thanksgiving weekend, effectively resetting my ECU. But when the ECU was reset, it was COLD outside, like 35-40 degrees, and the weather has been like that ever since then. Is it possible that the COLD brings on the stutter, and that by reflashing in the cold, and having the ECU relearn in the cold, it has learned to control or reduce the stutter?

Depending on the tune, either can happen. If the map is too aggressive you will loose power over time. If the map is not setup quite right it will learn to get stronger over a couple hundred miles. If the tune is perfect it will be strong after just a couple pulls.

Jarrad

For you the end user the biggest difference between the two maps is a base map takes much longer to load into the ECU than a real time map. With street tuner you can make changes to a real time map, and those changes instantly take effect. A base map requires the changes to be flashed, severl minutes time, into the ECU before they will take effect.

Jarrad

I have been reading alot on the AP before I buy one. But could some one explain to me the difference between BASE MAP/REAlTIME MAP. If you want to take the time I'd appreciate it. I am bit of a noob at the MOD game, but i got the itch and want to know what im doing....

This is actually a bit of a touchy subject, since in some manners PDXTuning and Cobb are competitors. Both companies are well respected, and both are putting out what they believe to be the best balance of safety and performance. When choosing one over the other you should look at all the information available to you, and choose what you like the best.

The simple truth is this: there is no absolute best base map. So long as both maps produce good results and longevity of the motor/car over a broad spectrum of cars, they are both good base maps. Judging that one car made more power than the other does not mean that it has a better base map, nor does it mean that it is less safe. Due to that fact PDXTuning would never compare the power output of our maps to anyone’s map and claim PDXTuning’s map was better.

I hope this helps people understand a bit,

Jarrad

Why not? PDX charges a premium for their AP with custom maps. People will want to know what they're getting for the additional expense. If the differences are significant I'm sure it would generate a lot of business for PDX from current AP owners. I'm really interested in seeing how their AP maps compare to their ECUTek maps posted a while back.

 

Sure you can, but not from different dynos. PDX could easily dyno the base AP map then reflash/dyno with their custom map and publish the results.

We are doing AP's with custom maps.

They will be the same basic map as our EcuTek map. The AP and the EcuTek are two different approaches to accomplish the same thing, both load new ROM data into your stock ECU. Right now we are working on converting our maps, which takes a bit of time. Once we have a complete selection we will make a more public announcement.

For a LGT or STi the price will be the same as an EcuTek reflash, $799 for the AP and our map.

Jarrad

No, he means AP.

I didn't know PDXtuning did Cobb AP's. Do you mean ECUTek map?