Okay, so i have a EVO VIII on wich the former owner installed a Invidia TBE & Injen intake, and he also had the car have an ECUtek tune.

I am now looking into installing a new header, O2 housing, downpipe, high flow cat & another IC in the near future.

I've done searching but cant find a satisfying answer.

I know you need a remap when you upgrade new parts like a TBE & intake from stock, that's already been done. But the question i cant find the answer to is:

When i install the extra parts as mentioned will i need to have another tune/re-tune/upgrade tune? or will the ECU "learn" to properly deal with the changes?

A extra question being a total Noob on ECU tuning and unable to find the answer in one of the thousands of topics about ECU! If you have a ECU tune and the car is without power during maintenance wich requires the battery to be disconnected is the tune erased? I've read the ECU is reset when the battery is disconnected but does that mean that the tune is gone to and the ECU is back to "standard".

thanks in advance

 

In my opinion the best is if you retune your car according to your new mods, these will provide more gas flow. It would be a good idea to also get an AFR gauge, it's also helpful when tuning and logging.
No, your tune is not gone after disconnecting the battery, only the stored errors (if the cause disappeared).

 

Evos use MAF sensor to read airflow. When you add mods that make more power, they make more power by letting the engine breathe more air. The MAF adjusts for the additional air and is safe but by no means ideal.

I would retune after those parts regardless but especially because the car was purchased modified you have no idea what kind of map is on the car.

Boltz

 

BTW I would skip the header and 02 housing. They have neglible gains, will crack much more easily than stock and are a pain in the *** to install.

 

I saw a lean spike from 5000 to 5500 or so after adding a cat-back to my car tuned for a DP only. This was with the stock cat.

So, exhaust mods can affect the tune in a negative way. It would be best to at least have the tune checked.

 

I agree on a tubelar header being more prone to cracking part, but seeing that i'm not putting much mileage on the car and I tend to take care to let things cool down after pushing it, I should be okay, and i intend to do it as proper as possible and that would include not to go for the show and shine under the hood but just wrap it in heat insulation (though i know that's no gaurantee, but still).

But on the contrary of what i have been reading so far, you say that installing a Header, O2 housing & downpipe would not gain me much?? Or do you mean it would not gain me much/have ill effect when installing those parts and neglect to have the ECU remapped/retuned/flashed????

 

Get a re-tune after everything is installed if you wanna go that route. The headers, yes, are more prone to crack like the other's above have stated.

You can never go wrong with a re-tune. Better be safe, than sorry.

 

Done more reading & searching here, and abandoned the header, O2 housing for the moment.

The smart way I think to go first is to start to log what the car is doing atm. Just need to figure out what to get. I wont be tuning myself I only want to log and be able to see when something is wrong and then have somebody who does know what he is doing adjust things accordingly. All suggestions for what to get for that purpose (apart from: Sell the car and get a bycicle NOOB ) are welcome

 

If the parts significantly change the flow characteristics of the engine then it should be retuned.