SkillOBskilled

iTrader: (1)

So I got my CLS6 a month ago and until now I have been just reading and researching within the forum.

I ve decided to get thermoblock spacers, XS headers (maybe comptech if they get their act together), pull the intake resonator and drop in a K&N filter, oh and a UR pulley.

Most of these items are on their way and I will likely install all or most of them over a weekend.

Is the ECU gonna work itself out and reach optimum setting after a few days that include changes for ALL of the mods? Or should I do each mod a week apart and let the car adjust each time?

nbennettksu

iTrader: (2)

I've read on here that the ecu takes a couple of days to get used to things, but i've also read the opposite. I'm no help whatsoever. Mr.Steve has a pretty strong opinion about it, maybe him and or some other heavy hitters will help you out more.
But from my personal experience, my ass dyno has noticed most of the gains right after putting the items on...

fuzzy02CLS

iTrader: (2)

Yes. You should do the idle re-learn procedure after you install everything. The instructions are in the FAQ.

After that the ECU will get a baseline & take a day or so to adjust to the increase air with more fuel. The stock ECU does have some adjustment built in.

SkillOBskilled

iTrader: (1)

What about a unichip upgrade?

Thats something I havent understood very well from reading the archives. If the ECU is capable of adjusting to all of the mods, whats the point of getting a UNICHIP with say just HEADERS programming? I understand its purpose for an SC, but not for anything below that.

After these mods and letting the ECU adjust, is a UNICHIP going to give me any more then a 5 hp?

CLsuperhero

probably not more than 5 hp the stock ecu is good at adjusting to bolt ons the unichip will just correct some slight errors in the ecu. SC or turbo, ECU tinkering is a must!

BigLizard

UniChips aren't made for the 6 speed...only AUTOs.

mrsteve

iTrader: (1)

Why do you think the idle re-learn procedure is required if the ECU isn't disconnected or has a power interruption (i.e., disconnected battery)?

Also, why do you think there will be an increase in air based on the mods he is installing? The headers and air intake modifications will increase efficiency but they can not increase the volume of air because the cylinders remain the same size.

The ECU is constantly changing variables based on driving style and other atmospheric conditions so yes it will adapt to your change in driving style (you'll be putting the pedal to the floor more frequently). But there aren't any changes to the air/fuel mixture based on the addition of headers and an intake on a naturally aspirated motor. The cylinders still have the same volume and the air is not being compressed (i.e., boost). Less restriction = more efficiency = more horsepower.

mrsteve

iTrader: (1)

The UniChip has the ability to alter fuel tables and ignition timing. For a naturally aspirated J32A2 you can lean the mixture out by adjusting fuel trim. Best results are around 13.2:1 AFR whereas the stock mixture is around 12.1-12.5:1 AFR. While the UniChip can adjust ignition timing I found no tangible benefit to increasing spark timing while tuning on the dyno.

The UniChip is not a good tool for a supercharged or turbocharged application because it does not have control over injector pulse width and in order to achieve a desirable increase in power the MAP input voltage needs to be manipulated which presents a very violate operating condition because of heavy reliance upon the rising rate FPR.

Welcome to the forum; these topics have been discussed many times and there is an amazing amount of knowledge available on these forums.

fuzzy02CLS

iTrader: (2)

The manual says to do it anytime the battery is disconnected. I've had strange idle problems after disconnecting the battery when I didn't do the idle re-learn. Like stalling at a light, or the rpm surging & then throwing a TPS failure code. Happened with the headers, & spacers I installed.

For the ECU I've read that any amount of increased airflow needs to have an = amount of fuel added to perform & avoid lean conditions. The stock ECU will have to adapt to this new air/fuel requirement. Or is that with only FI cars? Is the CLS different?

mrsteve

iTrader: (1)

Correct. If you disconnect the battery you should perform the idle relearn procedure. It's easy and quick; but the battery may or may not need to be disconnected for his planned mods which is why I raised the question.

As for "increased airflow;" yes if you increase air you will need to increase fuel. However, I fail to see how adding a cold air intake and/or headers will increase the volume of air within the cylinders. It's physically impossible to increase the amount of air entering the cylinders without increasing the volume of the cylinders. The engine pumps air in and then pumps air out. If you increase the efficiency (i.e., allow the engine to more easily pump the air it requires at any given rpm) you increase the power. That's all a cold-air intake and headers do: increase efficiency. A cold-air intake also funnels colder air (which is typically just slightly more oxygen rich based on the temperature differences we're talking about) which in turn will produce a slight increase in power but the volume of air stays the same.

This is also why most people claim to achieve greater fuel efficiency when installing a cold air intake and/or headers. If the engine is operating more efficient it requires less fuel. If there was an increase in the amount of air the engine was drawing in there would be a corresponding increase in the amount of fuel it requires; that surely wouldn't increase fuel economy.

Also, the ECU will adapt to an increase in airflow or atmospheric pressure immediately; that's what the MAP sensor is for.

Let's say for the sake of argument that I'm wrong. That adding a cold air intake and headers increases the amount of air the engine consumes at any given rpm. Let's also say that the ECU will take a few hours or a few days to notice the change and adjust for it.

The first time you fire your car up and take it for a spirited drive with the new mods (which for the sake of argument are introducing more air to the cylinders) and (for the sake of argument) the ECU slowly begins to "reprogram" itself to adjust. Well while during that first time you pressed the gas to the floor and put the ECU into open-loop you'd start throwing P0171 and/or P0174 LEAN codes and your CEL would illuminate. Since we're claiming the ECU doesn't immediately recognize the theoretical increase in air this would have to be the result.

And we all know that simply isn't the case.

Excelerate

iTrader: (1)

This is a good thread. A lot of good information here.

Forced induction though would increase the amount of air in the cylinder, so it isn't an impossibility.