I've owned my Evo sincle last fall and I've finally lost the battle over whether or not to mod it. I plan to do an HKS intake, HKS 264 cams, HKS downpipe, and HKS exhaust. The question is, do I _need_ to do an ECU reflash to support these mods, or is that only to maximize them and get th emost power.

I plan to do a flash, but don't know when I want to take the car out of commission for a couple of days to do so.

Thanks in advance for any tips.

 

It would be a gigantic mistake to do those mods without a flash (or some type of tune). The Evo in stock form is very poorly-tuned. If you go and add an intake AND cams, you'd have a total POS, honestly. Don't mess around with mods like that, especially internals like cams without doing a flash. You also would need several other supporting mods to complete your list. Please do some research and homework. The search button is at the top right of the screen. Use the advanced version...

 

+1..... a true Evo owner would have already know that even if you throw on an exhaust system you will need a flash. Let alone you want internals and the other stuff u mentioned ..... SEARCH!!

 

Well since you asked in the Newbie/FAQ I'll try and answer some questions.

Yes you will need a flash, I believe what Warrtalon is mentioning for supporting mods would be a boost controller of some sort and since your doing cams, some aftermarket head studs wouldn't hurt.....

Possibly also the injectors, however I would talk to one of the tuners that do flashes. You can search but I think calling a reputable tuner would be even better. I would hate for you to come across the wrong thread where people are just typing "what they heard". Depending on what your goals are, the tuner may influence you on how to achieve your goals in a different way, you never know....

Hope this helps!!!

 

WTF?! How is your response helpful? I posted to the newbie forum to not annoy people like you that expect everyone to already know everything because they spend every waking moment on the boards. I guess I'm not a true Evo owner because I'm not afraid to ask for advice.

 

This is what I assumed after what I found on the boards, thanks for confirming.

Can you (or Warrtalon?) help me understand what the issues are with the factory ECU that makes it have an issue with an intake/exhaust. Maybe I've been spoiled, but coming from BMW tuning the ECU actually does a fantastic job of adapting to the better breathing. You eventually max out the injectors and will run lean at high revs with the Bimmers, but the brain supports you making improvements to the motor. I've read that fuel is also an issue with the Evo.

This is exactly what I was trying to avoid by asking the question. I've reached out to a couple of tuners to see what their recommendations are and to get an idea of supporting mods by level of tune. Hopefully I'll get some clear answers.

Just to clarify, I never said I did not plan on doing some sort of tune. I just wanted to see if I could get away with spreading out the install of the parts and the flash of the ECU.

Thanks again.

 

That's just how it is. This is not a BMW. The factory tune is already rich as hell. When you throw in an intake, it causes lean spots and throws off the MAF readings with turbulent airflow that the MAF wasn't designed to read - this is why we have an enclosed, sealed airbox.

With cams, that completely throws of all the fuel and timing, so you make a bad situation worse. The ECU has no idea how to adjust for such mods, because it is not programmed to optimize itself. It is programmed to run very rich, so you need a flash (or other tuning device) to get the AFRs and timing optimum through the entire powerband for whatever mods you get.

 

Thanks for the heads up. I knew the cams would throw things off, but I wasn't expecting the same reaction from the intake and exhaust. I guess I've been spoiled to date with the Seimens ECU in the M3.

Now I know that I just need to plan to have the car out of commission for a couple of days to deal with all of the mods at once.

 

Notice how he didn't mention anything wrong with the exhaust though. Hell, even dealerships for the most part don't mind at least a catback exhaust. But if you plan on warranty work...which i doubt since your planning on cams and flash, etc..... may want to check in person with your local servicer.

 

Nope, no warranty for me. Once I bolt this stuff up I'm assuming that I'm giving up my right to warranty service on the motor.

I may or may not put the exhaust on before I pull the ECU and install everything else. It actually may be easier to leave the car at a friend's shop and have him do it all at once instead of me doing the job piecemeal.

 

Good deal...let us know the progress!!!

 

I will. I was actually planning to do some before and after dyno time as well, so I'll be sure to post the results.