rwiii

What is a flash and what does it do? What does it cost? Thanks

ivangene

this outta sum it up for ya

I know what it does for me, but alas I cannot afford it even though I keep trying - its pretty expensive

Divot

Ed, you need a lesson in framing the subject.

ivangene

LOL

Pac996

It's the redoing of the firmware of the engine control unit (ECU).
You can change a few things that effect performance. Do an internet search for the places that do that sort of thing.
If you have a great guy like scott that works on my car he does it just to make you happy.
Went back to him for an oil change last time around.

losdeanos

It just reprograms the computer, normally they just mess with the boost and timing, I think. You can make a lot more power on turbos with an ECU flash but on an NA engine i don't think it does much.

Pac996

If there is mapping of fuel you can dyno for best power when altering exhaust and intake. It can be an engine life save since some changes can cause lean spots which flashing can take care of since p cars don't have PC3 usb power commanders available for them.

rwiii

Ed's explanation is the easiest for me to understand.
Why doesn't it come from the factory optimized? Is it like a "reset" or do they have a program they are putting on the chip or a change in the program? Is there some super secret insider code? Anyone do a RWHP on the Dyno before and after? What do most shops charge for this?

redridge

To maximize the flash.... one must make the intake and exhaust more free flowing.... these however, tend to cost $4k+

Pac996

Look at all those cows saying "Mom!"

chsu74

+1

Awesomo996

Sometimes they don't optimize the ECU software for max HP because that degrades the mileage. I did the ECU update on my '08 passat turbo and got an extra 40HP, but my mileage dropped by almost 10 MPG. The software updrade I got has a cool feature where it also reprogrammed one of the stalk buttons to be a on/off button for the extra HP / lower MPG.

I think the BMW M6 has the same thing built into it's I-drive software. You don't get the full 500 HP unless you go into the menu system and select it.

Shark Attack

It's the dealers was of billing you 600$ to tighten your gas cap when they find that your cel light was caused by your own stupid stunt.

BruceP

At any given throttle position, your ECU is trimming fuel/air mixture and timing. Additional parameters are there for operating temperature and whether the knock sensors think there is any pre-detonation going on. The factory settings have something to do with performance, but also have to take other things into account, such as fuel economy, emissions, and the octane rating of 'typical' fuel for the market the car is sold in.

In a normally aspirated car, ECU flashes usually pick two pieces of low hanging fruit: Fuel quality, and emissions. The EPA urban drive cycle in particular demands some settings that diminish performance slightly from what the engine might naturally prefer for efficiency. Basically, by flashing, you get more aggressive timing and mixture parameters on the assumption that the car will be fuelled and operated at a level better than the manufacturer's assumptions.

Some flashes also move the redline up slightly, 200 rpm being common. The benefit of this is purely and simply so that trackies can delay their 2/3 shifts For the rest of us, not much use.

The difference between good ones and cheap ones has to do with how granular the programmer got with tweaking those timing and mixture settings, and whether they bothered testing their work. Some custom tune for the stuff your car has on it and the exact fuel you plan to use. I think there are even some that your tuner can tweak with your car on a dyno. Generally speaking, though, if you see double digit HP gains claimed for flashing a normally aspirated car, you should be skeptical of the product because the programmer went for an impressive peak number rather than better drivability.

The benefits are pretty minimal, seat-of-the-pants wise. Of all the stuff I did to my car, the flash was the most subtle. The exception is for turbos, where eliminating the huge amount of engine protection margin the manufacturer put in results in pretty big gains. Basically, most of what you read online about ECU flashes is nonsense either way. They don't do nothing, and they don't transform your car either. It's tuning, at the margins. Even car companies - including Porsche - do it when they introduce 'special' models with intake and exhaust revisions. Up to you to decide if it's worth it on your own car, but it is 'real'.

My .02