SI -drive

[Buru]

Man i was wondering that same thing about the SI drive. It would be totally sweet if you could make it like three different Cobb AP v2 maps like

1. Fuel econimy

2. Stage 2 map 93 oct

3. Valet mode

 

you wonder if you could hack an Access port v2 to do that with the SI drive control.

 

aka leave the ap hooked up at all times.

 

I know i would be down for that.

[02BlkRex]

Boost will be lower on i-mode because it is proportionate to throttle.

 

Exactly. IIRC, flooring the gas pedal in I mode only gets you 40% throttle whereas you get 100% in S and S#.

 

Also, there was some talk a while back on why S is 100% and S# is only 98% and some thought it might be because the car was dynoed on S first, then on S# after it was hot, resulting in the lower 98% figure.

[MGV101]

^^ Probably

 

IIRC

 

I - 20% less HP, limited boost. 190hp, 3-4lbs of boost

S - 100% HP, 100% boost, gas pedal movement is equivalent to throttle response

S# - 98%HP, 98% boost, gas pedal movement produces double throttle response

 

And like Richard said, S# will hold gears a little longer and change shift points in an automagic. Probably more helpful in an auto than a manual.

 

I recall a quote from a Subaru exec commenting on S# vs S mode, saying something to the effect of: "In a straight line, the same results can be achieved in either mode, however, one would feel the benefits of S# in twisties where throttle varies more."

 

That's my .02

I am not so sure about the 98% thing in S# unless it is setup differently in USDM compared to JDM.

 

The actual throttle position returned by the ECU when I data log in S and S# are always at 100% when I go WOT.

[BigInALegacy]

Yeah, I remember some thread where they said boost was like .2 PSI less and throttle only went to 98%. Even so, minimal if that. The quote was the more important part of that IMO.

[vicmarsal]

by setting all 3 the same how can there be 3 different maps as you suggest?

 

they are not maps per say but throttle control opening in conjunction with pedal travel.

 

BUT S# does in fact change the shifting behavior on the 5eat.

 

Exactly my point, the OP may be under this impression that theres 3 when in actuality theres one.

[Aquaflight]

In my experience SI-Drive is really great. In slippery conditions, traffic, and low speeds, I mode is really nice. The other modes feel too strong. I don't use S, mainly because I will usually go for S# if I need power. However, at higher altitudes, I feels too weak and S# is too jumpy. I originally thought S was useless, but it does have its applications. S# is really nice and will pick up and go fast. I love it on the hills and curves because I barely have to push the gas pedal. I also like that it holds the current gear after you slow down.

 

In regards to the actual numbers, from what I hear it is about 80% for I and the rest is 100%. However, boost seems to hit 0.5 Bar in I mode and 1.0 Bar in S or S# mode. Here are the videos to prove it (keep in mind that these videos are highlighting the stutter issue so the boost is somewhat inconsistent)

 

[ame=http://www.youtube.com/watch?v=RXjRVPFqGyU]YouTube - Stock 2009 LGT 0-60 Intelligent Mode[/ame]

 

[ame=http://www.youtube.com/watch?v=-ULoZipWK18]YouTube - Stock 2009 LGT 0-60 Sport Sharp Mode[/ame]

 

[ame=http://www.youtube.com/watch?v=CzHJ0wXRNoE]YouTube - Stock 2009 LGT 0-60 Sport Sharp Gauge Close-Up[/ame]

[MGV101]

You only get 0.5 bar in I mode because target boost is governed by RPM and request torque which is governed by pedal input.

 

In I mode, requested torque determined by the pedal angle simply never gets high enough to reach full boost on the target boost table. Try pushing the pedal to about half way in S mode. You will end up at getting around 0.5 bar max too. That is exactly what I mode is trying to do. Limit your throttle input.

[Aquaflight]

You only get 0.5 bar in I mode because target boost is governed by RPM and request torque which is governed by pedal input.

 

In I mode, requested torque determined by the pedal angle simply never gets high enough to reach full boost on the target boost table. Try pushing the pedal to about half way in S mode. You will end up at getting around 0.5 bar max too. That is exactly what I mode is trying to do. Limit your throttle input.

 

Yes! Exactly.

[Richard B.]

fwiw during solid cruising turning the si knob indicates 3 different gas usages.

 

you know that stupid needle that shows how much gas is being used.

 

i is in fact the weakest, s is second and s# is crazy.

 

this is on a rallitek though and im not gonna go stock to verify.

[02BlkRex]

fwiw during solid cruising turning the si knob indicates 3 different gas usages.

 

you know that stupid needle that shows how much gas is being used.

 

i is in fact the weakest, s is second and s# is crazy.

 

this is on a rallitek though and im not gonna go stock to verify.

 

I never really understood how I mode saves gas when cruising. When I'm cruising, I don't usually push the pedal past 40% no matter what mode I'm in. So how does I mode help? S/S# at 40% pedal = I mode. Am I missing something?

[MGV101]

I never really understood how I mode saves gas when cruising. When I'm cruising, I don't usually push the pedal past 40% no matter what mode I'm in. So how does I mode help? S/S# at 40% pedal = I mode. Am I missing something?

It doesn't.

 

 

 

 

 

At least according to the fuel consumption meter (while using cruise control).

[Crawdaddy79]

In city driving it forces you to drive grandma-like, and might save you some fuel if you're not paying attention to how slow you're moving.

[BigInALegacy]

I - mode = Snow mode... nothing else.

 

I think I get better gas mileage in S# than I mode sometimes. I mode requires too much throttle to reach/maintain speeds that I think I waste more gas sometimes in that mode.

[Buru]

could a protuner on this site add some light on this?

[BigInALegacy]

there's a ton of information on it from when the COBB AP was released. At least 3-4 pages JUST talking about this issue. Cobb reps started the thread to get feedback from 07-08 users.

 

Find that thread and search, you'll find a slew of stuff.

[dudeondacouch]

I think if the si-drive worked the way it COULD, it would be great. As it stands now, it's a gimmick.

[rtbrjason]

I - mode = Snow mode... nothing else.

 

I agree. I'm thinking I mode could come in handy on some dicier road conditions. Outside of that I use S and usually switch to S# whenever I think about it.

[Zed 2.0]

^^ I would use I mode when I had to sit in traffic around Chicago for hours on end. It makes constantly modulating the clutch and throttle a bit easier.

[urs1ne]

It may be chincey but I like it a lot. When I want to drive fast I jump from S to S#, when I want to get economy and not let meself go fast I go to I, and for everything else it stays on S. True this feature is better geared to grandma who might buy a Legacy but I still like it.

[Richard B.]

I never really understood how I mode saves gas when cruising. When I'm cruising, I don't usually push the pedal past 40% no matter what mode I'm in. So how does I mode help? S/S# at 40% pedal = I mode. Am I missing something?

 

 

dunno. i am no longer stock. on steady state cruising i can flip the knobs and watch the gauge move. i could check the mpg though to see if that changes.

[Backlash]

dunno. i am no longer stock. on steady state cruising i can flip the knobs and watch the gauge move. i could check the mpg though to see if that changes.

 

i finally got my car yesterday. (now i need to get my camera back...)

 

ok, i have been watching this thread and was very curious myself. so... driving back last night over the 120 miles i decided to play with SI-Drive and see whats what.

 

had cruise set to 60mph, and in S#. noted the MGP on the display. (flat ground)

switched to I mode. MPG did go up a bit. .5-.7ish. it jumped a few times all over the place, like up to 111mpg... I figure i hit a small downhill slop enough to back off the throttle. i only switched over for maybe a minute at a time, so the .5+ gain could be more over time.

 

Remember I was completely stock during this. only "performance" mod i had was the Short throw shifter...

Just put in my Drop in filter tonight, and going to put the CBE on this weekend.

 

as far as power goes, I mode definitely has less power than S#.

[02BlkRex]

dunno. i am no longer stock. on steady state cruising i can flip the knobs and watch the gauge move. i could check the mpg though to see if that changes.

 

you have an auto, right? maybe it is different in an auto since SI Drive has a hand in shift points and revs? i have to agree with it being a gimmick on a manual though.

[DrCloud]

I'm not persuaded, despite the "authoritative" claims made here, that the SI-Drive has control over the 5EAT's shift points.

 

Because the SI-Drive does alter the behavior of the DBW throttle settings, and the throttle has some control over shift points (drive like a Grandma and it'll shift like one; get on it in any SI-Drive setting and it'll hold gears longer), there's no doubt that the transmission feels different in the different SI-Drive settings.

 

But to suggest, as has been done here, that the SI-Drive somehow alters the TCU's behavior needs verification before I'll believe it. HPH

[BigInALegacy]

http://www.worldcarfans.com/2060418.003/subaru-intelligent-drive-si-drive

 

SI-Drive: Three Engines in One

 

 

The new SI-Drive system allows the driver to maximize engine performance, control and efficiency by choosing from among three selectable modes – “Intelligent”, “Sport” and “Sport Sharp” – using a rotary dial on the center console.

 

The SI-Drive controls the electronic throttle system’s response and fuel and ignition curves to modify engine torque characteristics, changing the performance character of the car in each mode. With "Intelligent" mode selected, the system reduces engine torque and maximum power and switches to a more relaxed throttle response curve. Intelligent mode is an ideal choice for smoother response while commuting in traffic, for example, where it can also help boost fuel efficiency by up to 10 percent. In addition, "Intelligent" mode’s more relaxed responses and lower torque output make it an ideal complement to the low-traction surface driving safety provided by the Subaru Symmetrical All-Wheel Drive System.

 

In “Sport” mode, the performance of the 2.5 GT spec.B (and other 2007 turbo Legacy and Outback models) is similar to the 2006 model, with quick throttle responses and powerful, linear acceleration. The linear acceleration characteristic of this versatile mode makes it ideal for driving on freeways and suburban streets or for climbing mountain roads.

 

In “Sport Sharp” mode, SI-Drive modifies the engine’s electronic throttle mapping to deliver lightning quick throttle response and more power sooner. Delivering maximum driving enjoyment, this mode is ideal for tackling twisty roads and for merging or overtaking other vehicles on the highway with confidence.

On 2007 Legacy and Outback models equipped with the 5-speed automatic transmission (not available on Legacy 2.5 GT spec.B), SI-Drive also changes the transmission’s shift patterns. It will hold each gear longer through the rpm range and downshift more quickly under hard acceleration, depending on the mode selected.

 

The SI-Drive system includes instrument panel displays that allow the driver to monitor performance. The multi-information display located in the tachometer face – in addition to providing trip computer functions – denotes the selected SI-Drive mode and provides an active torque curve display.

When “Intelligent” mode is selected in vehicles with a manual transmission, a shift-up indicator blinks to signal the optimal shift point for maximum fuel efficiency.

[BigInALegacy]

Another article for people to mull over. From the Subaru Drive magazine.

 

http://www.drive.subaru.com/Summer07_whatmakes.htm

 

http://www.drive.subaru.com/Sum07/si_drive_diagram.jpg

 

That article has alot of good technical information in it too. Also, see here it does effect the TCU:

http://www.drive.subaru.com/Sum07/csidrive_diagram.gif