Cruise control and the SI drive

[Boxer]

More and more I discover what a crock the standard programming for SI drive is. Its marketed as being a change in ECU programming making it change from economical to sporty to sharp.

Well we all know the S# is just S with a more sensisitve throttle map making full throttle at about 3/4 pedal.

Now I have noticed that I mode is merely a throttle shortening too I used to think that I mode limited boost to 0.4bar, but now I think its a function of partial throttle opening and no change in boost map
Has anyone noticed what happens when you have cruise control activated and you are in I mode? You can press the accelerator all you like but you will get no more than 0.4bar boost. EXCEPT if driving under cruise and it wants to accelereate up a hill or such - full 1.1bar boost is available to the cruise!!

Obviously cruise bypasses the SI drive - but it also demonstrates that the SI drive is not really changing ECU mapping - otherwise boost maps and ignition maps would be affected under cruise as well.

Just and observation and disappointing the SI drive could have been so much more. (and can be in aftermarket tunes from what I've seen)

[WhiteGTB]

Can't say that I have noticed Boxer.. but yeah alot of others have said it is just a gimmick.

I am unsure of what the actual detailed differences are between all the modes.

Does anyone know here on the forum at all?

[coyote]

I, S and S# all share exactly the same maps and boost targets - as you said, only the throttle mapping is different.

Boost is controlled via the maximum boost target for any given throttle position.

For example, in S# at 50% throttle you may get a max of .4 bar and 1.1 bar at 100% throttle. If having your foot flat on the floor in I gives you 50% throttle, then you'll get the same .4 bar as S# even though there's no more to give.

Kind of makes sense that cruise must only pick one mode to control throttle, otherwise you'd need three completely different cruise programs.

[Arith]

Do people really drive in S and I? Why? Don't wanna go that fast, just don't stomp on the pedal too hard. Don't think my car's even been outside of S# since I got it (except during the slow, agonising with for the engine to warm up and it's stuck in S).

[Boxer]

Do people really drive in S and I? Why? Don't wanna go that fast, just don't stomp on the pedal too hard. Don't think my car's even been outside of S# since I got it (except during the slow, agonising with for the engine to warm up and it's stuck in S).

I never use S# its a bullshit map too. Why do you want 100% throttle at 3/4pedal?? There is no more power under S# so as you said - why not just use S all the time and regulate power with the right foot eh

But yeah - the fact you only use one mode is furtehr evidence the Subaru SI is not what it should have been

S# makes heel and toe a chore as you cant come off the accelerator far enough when braking and your over do the blips on the down changes.

Also when driven in anger its to easy to get rev 'flares' between gears as again if you dont come off the accelerator fast enough as you depress the clutch.

Maybe different in the auto.

The beef I have is the marketing surrounding SI suggests it changes economy, and performance - which in fact it doesn't.

I like to try I mode for greater economy once in a while and always thought it had a different boost target which it doesn't. I had hoped it had a different boost, and maybe ignition map.
The 'intelligent shift light' is worthless too - it always has a static setting where it tells you to change gear - there is no intelligence at all - it takes no account of engine load (i.e. road incline) Otherwise it would tell you to shift up at 2000rpm on downhills and 3500-4000 on up hills, but they are all 2500rpm.

Always knew the S & S# thing was an illusion to make the car 'feel' more powerful to the unwitting by making full torque without having to press the pedal all the way.
Now I've found the others as well its just disappointing to have such a cheap gimick on a respected vehicle

All SI does is change the accelerator/requested torque relationship across all settings.

[senator]

SI drive is purely a way to control throttle % nothign to do with boost controll, for that you need an aftermarket controller.

when using cruise control i tend to switch to I mode, no point in using more throttle to maintain a steady cruising speed....... its also makes a difference with fuel too.

[coyote]

SI drive is purely a way to control throttle % nothign to do with boost controll, for that you need an aftermarket controller.

when using cruise control i tend to switch to I mode, no point in using more throttle to maintain a steady cruising speed....... its also makes a difference with fuel too.

There are boost targets for certain rpm and throttle position. If a certain mode does not access 100% throttle, then it also doesn't access the boost target assigned to 100% throttle.

Boxer's point is that cruise in I mode is no different to cruise in any other mode.

[Boxer]

SI drive is purely a way to control throttle % nothign to do with boost controll, for that you need an aftermarket controller.

when using cruise control i tend to switch to I mode, no point in using more throttle to maintain a steady cruising speed....... its also makes a difference with fuel too.

True SI does only control throttle % (or more correctly - 'requested torque', as the throttle butterfly will not neccessarily be fully open at maximum requested torque - but thats another discussion)

How ever you dont need an after market boost controller to chnge boost characteristcs - its all there in the stock ECU - Subaru just chose not to use it in SI drive. Aftermarket tunes can change boost targets which as coyote said are variable according to rpm and throttle (requested torque).

Finally not point using I mode for cruise - cruise is the same in any mode - the catalyst for this thread I started - this is what I found this week.