How does a “stage 1” remap work?

[Basil]

I am pretty inexperienced with modern cars most of my knowledge is with classics (despite being 19). I drive a 1989 Austin Mini, the engine has very few standard components remaining it has: Larger hif44 carb (idle speed and mixture can be adjusted with a couple of screws or a new needle) with K&N cone filter, alloy ported inlet manifold, LCB exhaust manifold to straight though exhaust, gas flowed fully ported and polished cylinder head with larger valves and double valve springs with unleaded valve seats, high lift roller rockers, blocked bored to take 73.5mm pistons giving 1380cc (from 1275), new cam (yes just one, which is deep in the engine) has 297 degrees duration (chugs on idle), modified distributor for race curve (rotating it adjusts advance and retard, changing weights and springs inside adjusts ignition curve), up rated clutch (pretty much on or off), lightened flywheel, balanced bottom end all on a short ratio gearbox with a 4 pin diff I could go on but that is most of it, gives just over 100bhp in a car that weighs about 650kg, so about 160bhp / ton.

Now this is my daily driver and it’s getting a bit much, lumpy cam and clutch are a pain in traffic and is a bit thirsty so I am looking for a replacement, I think a mk4 golf gti (1.8 turbo) would be a nice replacement. Now my question is how do stage 1 remaps work, how do they give better performance but use no more fuel? Practically all the mods to the mini give better performance work by allowing the engine to take in more air and more fuel. So how do remaps work, do they alter the ignition timing to give more or less advanced? If so does that not lean out the mixture or is it just a case of upping the boost a bit and checking the fuelling isn’t too lean. Out of curiosity I would love to know how they work, feel free to be as technical as you like in your response I need to learn the lyngo sooner or later.

[AlanD]

Not my words but taken from another forum which sums it up pretty well.

The engine ecu controls various factors to make as much power as it does, such as turbo boost pressure, fuel injection parameters (start of injection, duration, number of injection cycles per stroke etc.) and ignition timing. What happens when the car is remapped is that the tuner downloads the mapping data from the ecu, optimises and modifies it, then re uploads it to the ecu again. The new map is designed to give a different characteristic to the engine depending on the owners requirements, the tuners mapping, the cars capabilities etc. and each tuning company usually has their own idea of what is best. Their "best" may not be what you want.

[Basil]

Thanks that is a start, but how exactly do they "optimise and modify" it to make more power on the same amount of fuel.

[AlanD]

If you put your foot down in a car that has been remapped you will use MORE fuel and not the same.

Forum sponsor R-Tech (who did my remap) will no doubt stick their head in here and be able to give you a much better answer than me.

[Basil]

If you put your foot down in a car that has been remapped you will use MORE fuel and not the same.

Do they only affect the car at high revs and/or when under heavy load? I guess that would explain it.

[recci]

As far as I understand it the ECU is like the brains of the engine. VW will have programmed it to provide a balanced amount of power Vs engine life and fuel economy. But generally not using the engines full potential. When you get it remapped your changing the way the engine thinks and using the engine to its full potential.

[xxpenxx]

As far as I understand it the ECU is like the brains of the engine. VW will have programmed it to provide a balanced amount of power Vs engine life and fuel economy. But generally not using the engines full potential. When you get it remapped your changing the way the engine thinks and using the engine to its full potential.

+1

[Basil]

So higher rev limits and more boost?

[Khare]

From what I know, stage 1 is just a remap without changing any bits. Stage 2 is a more aggressive remap with change of chamshafts and some head work (I think), and stage 3 + is used for street race/track use.

[AlanD]

Stage 2 usually entails having a full turbo exhaust and some form of induction + a more aggressive map to take into account the mechanical changes.