SI -drive

"a new feature for 2007: SI-Drive (Subaru Intelligent Drive). "It's like having three engines in one," says Subaru. Marketing-speak translated, SI-Drive is a bit of software that alters the engine's throttle sensitivity and responsiveness depending on which of its three modes (Intelligent, Sport and Sport Sharp) the driver selects. On automatic-equipped GT models, it also affects the transmission's shift points..."

Hi all... this is my first post (i tried the 'search' function with little luck). this is a GREAT forum to learn about the Legacy! Thank you.

I understand that the 05-06 2.5 GT model is 'rated' a bit higher in HP and Torque. And i realize that the #'s were changed in 07 due to the engine mapping SI-Drive function... that the motor is really exactly the same.

For those of you with SI-Drive - do you actually need to keep it in Sport Sharp or Sport to get all the boost out of the motor? Is there anyway to choose SS as the default mode upon start up?

I'm looking at 07 models but don't want to shy away from the 05's & '06's if the SI-Drive is a pain-in-the-ass. thanks for your input.

The HP numbers changed due to the way the industry is calculating it. Engine is the same and it had nothing to do with SI-Drive as far as i know.

Si-Drive is kind of gimmicky. The car will start in either I or S mode depending on where you last had it. Once the car warms up it can be placed into S# mode. S and S# aren't all that different. The only usefulness I see is that it might be easier to cruise around in the winter on bad roads in I mode.

I've also read that S# restricts the throttle to 98% open for some odd reason. S# also requires you to watch the red line if your going wot in 1st and 2nd.

Other that that i like it.

The HP numbers changed due to the way the industry is calculating it. Engine is the same and it had nothing to do with SI-Drive as far as i know.

 

Si-Drive is kind of gimmicky. The car will start in either I or S mode depending on where you last had it. Once the car warms up it can be placed into S# mode. S and S# aren't all that different. The only usefulness I see is that it might be easier to cruise around in the winter on bad roads in I mode.

And when you get dyno tuned, you can have 3 different maps using the SI drive

And when you get dyno tuned, you can have 3 different maps using the SI drive

and I must say SI drive after a tune is amazing!....if I'm getting on it in in Intelligent I stay at around 2 or 3lbs...then if I kick it to sport sharp it jumps to around 14lbs or so...

interesting information...

does anyone have specific boost numbers available for each mode?

From what I've read and memorized, the boost, and HP are the same for S and S#... just S# will give you more throttle with less pedal.

Also from what I remember, I puts out about 20% less HP than S and S#.

Someone posted a dyno map of all three modes on here a long time ago, and that's what I remember... I should have bookmarked it because it seems impossible to find.

Of course, all of this goes out the window with a custom tune.

Ask Men FTW!

http://www.askmen.com/top_10/cars/top-10-useful-car-gadgets_4.html

top-10-useful-car-gadgets

"No.4 - SI-Drive - Subaru

There’s good, and then there’s better. Subaru already has overachieving all-wheel drive standard on its models, but this system lets you set distinct response patterns for your throttle and transmission. So, no, this is not Subaru’s answer to BMW’s iDrive. It’s a multimode system for six-cylinder and turbocharged Legacy and Outback models. Based on conditions, your driving environment or even your mood; you can opt for smoother, more fuel-efficient operation or let it all hang out with WRX STI-like sharpness. That’s minus the WRX’s polarizing looks, of course."

I've got two Subarus with SI drive, one an automatic and one a manual. After having played with the different settings, I've settled on leaving both in S-mode all the time.

I-mode is probably a bit of a gas-saver, but it seems to limit the car's responsiveness when you really want to get on it (expressway on-ramps, for example). And, IMO, S#-mode is just a gimmick to make the car feel like the various American cars that have twitchy throttle pedals. You can get just as much response in S-mode if you simply push harder on the pedal. What that means is that you really have more overall control in S-mode than in S#.

I'm of the opinion that the whole SI-Drive thing is just for marketing hype. That "askmen" quote exemplifies this. I can see having two settings (for economy purposes when your grandmother is driving the car), but having three is silly.

Not all of Subaru's "innovations" qualify as hype, though: what I'd really like in my Legacys is the STI DCCD. That -- which I had in an 05 STi and used a lot -- is truly a great feature. HPH

From what I've read and memorized, the boost, and HP are the same for S and S#... just S# will give you more throttle with less pedal.

 

Also from what I remember, I puts out about 20% less HP than S and S#.

 

Someone posted a dyno map of all three modes on here a long time ago, and that's what I remember... I should have bookmarked it because it seems impossible to find.

 

 

Of course, all of this goes out the window with a custom tune.

I know I was one of the people posting the dyno of the SI- drive on a Stock car.

Heres my post from my thread. http://legacygt.com/forums/showpost.php?p=1608067&postcount=1

Just got back from dyno the results kinda surprised me is it normal? Best run 222.24HP and 251.12TQ Thats like 0% drive train loss.

 

Run was done on S# mode for the highest reading one. the other runs on this img is from car getting heatsoaked. we did 5 runs on they dyno testing all modes.

Run 1: S# Colder Engine 222.24HP and 251.12TQ

Run 2: S# Warm Engine 219.99HP and 247.16TQ

Run 3: I 181.83HP and 194.82TQ

Run 4: S 214.06HP and 238.22TQ

Run 5: S# last run Hot 213.87HP and 238.46TQ

 

1st pic shows the S# cold, S and S# hot.

2nd pic shows all the runs on 1 sheet

3rd pic shows all 3 SI Drive modes.

 

http://img.photobucket.com/albums/v97/Bbc84/Legacy%20GT/5b420ed4.jpg

http://img.photobucket.com/albums/v97/Bbc84/Legacy%20GT/59a9795c.jpg

http://img.photobucket.com/albums/v97/Bbc84/Legacy%20GT/159389a7.jpg

And like everyone says, after you get tuned, SI drive doesnt really work the same. Heres my stg 2 dyno tune from a few weeks ago.

http://img.photobucket.com/albums/v97/Bbc84/Legacy%20GT/Stg2DynoTuned.jpg

And like everyone says, after you get tuned, SI drive doesnt really work the same. Heres my stg 2 dyno tune from a few weeks ago.

 

If your tuner knows what he is doing, SI-drive will work just like it does on a stock tune.

From what I've read and memorized, the boost, and HP are the same for S and S#... just S# will give you more throttle with less pedal.

 

Also from what I remember, I puts out about 20% less HP than S and S#.

 

Someone posted a dyno map of all three modes on here a long time ago, and that's what I remember... I should have bookmarked it because it seems impossible to find.

 

 

Of course, all of this goes out the window with a custom tune.

Yeah what he says is mostly true and also if you get the car protuned then yes, it gives the tuner the ability to put 3 different maps on the car thats instantly accessed with the SI Drive switched, each of my I, S, S# modes are tweaked a little differently from each other after the standard base map was adjusted.

I know someone who had I or S instead of S# mode tuned as their most aggressive map so it would always be available on startup.

And like everyone says, after you get tuned, SI drive doesnt really work the same. Heres my stg 2 dyno tune from a few weeks ago.

 

Sorry but that's incorrect, my SI drive functions pretty much the same, just with different maps, even w a stg 3 tune.

Yeah what he says is mostly true and also if you get the car protuned then yes, it gives the tuner the ability to put 3 different maps on the car thats instantly accessed with the SI Drive switched, each of my I, S, S# modes are tweaked a little differently from each other after the standard base map was adjusted.

 

I know someone who had I or S instead of S# mode tuned as their most aggressive map so it would always be available on startup.

 

 

 

Sorry but that's incorrect, my SI drive functions pretty much the same, just with different maps, even w a stg 3 tune.

I guess what I meant to say is it doesnt work the same way as stock, where it just limits the throttle, and techincally its the same map on all 3 modes stock, but w/ throttle limited. But when tuned it can behave completely different in each mode, not just throttle limited.

I guess what I meant to say is it doesnt work the same way as stock, where it just limits the throttle, and techincally its the same map on all 3 modes stock, but w/ throttle limited. But when tuned it can behave completely different in each mode, not just throttle limited.

SI Drive can only limit throttle whether it is custom tuned or not. Maybe your tuner set I mode to 10% throttle, S mode to 80% throttle, and S# to 100% or something similar?

SI Drive can only limit throttle whether it is custom tuned or not. Maybe your tuner set I mode to 10% throttle, S mode to 80% throttle, and S# to 100% or something similar?

I've been wondering about these claims, as well. SI-Drive has nothing to do with ECU maps, and AFAIK there isn't anything a tuner can do to change that--it's just the nature of the system. So far I've only heard one or two people actually claim their tuner set up their SI-Drive for different "maps." I strongly suspect it's just confusion.

SI Drive can only limit throttle whether it is custom tuned or not. Maybe your tuner set I mode to 10% throttle, S mode to 80% throttle, and S# to 100% or something similar?

...so SI drive only offers different throttle sensitivity - the turbo boost is always available at 100% to the driver - no matter what 'drive' is selected... is that right?

...so SI drive only offers different throttle sensitivity - the turbo boost is always available at 100% to the driver - no matter what 'drive' is selected... is that right?

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

SI Drive can only limit throttle whether it is custom tuned or not. Maybe your tuner set I mode to 10% throttle, S mode to 80% throttle, and S# to 100% or something similar?

I dont know then, but if you look @ my stock dyno above, you can definatly see a big break between I and (S/S#) modes.

But in the stg 2 dyno tune, they all pretty much end up @ same HP near redline, so doesnt that mean all SI modes are @ 100% throttle?

sooo much misguided information being spewed in this post.

me? i have an auto and si drive.

si drive is still intact even with rallitek maps.

i mode is the weakest

s is good

s# feels nuts.

s and s# are the same after the initial take off from a standstill. the increase throttle input from less travel on S# makes it feel more powerful leaving the line. i said "feel" for you non reading ignorant people out there. def FEEL the same after the midrange.

i and s shift the exact same way.

I def limits throttle even with my rallitek. the only difference from stock to rallitek is that now at least in manu mode I will go to redline stock always shifted at 5500rpms no matter what.

dont tell me tcu this tcu that. i own it and use it i (me) KNOW what i am talking about.

S# on the auto is in fact a different shifting "system". s# will hold a gear for 3 seconds at least once you start getting on it. if you do not move the throttle for 3+ seconds it will shift to the higher gears. if you tap the throttle again within that 3 second window you will notice no shifting delays or anything...it just goes because it is still in that one gear. s or i would have already gone to 5th.

seriously S# feels crazy especially with a power upgrade.

si drive doesn't mean as much to a manual tranny as it does to the auto.

there you have it. stock and tuned impressions and experience.

i would NOT get an 08+ auto leg gt. why? they dropped in longer gears. it's easier to do a vb upgrade on the 05-07's to get that decreased shift times than the 08+ received. it is much harder to swap out gears.

dont worry about the paddle shifter. the buttons on the steering wheel do the exact same thing.

do i see si drive as a gimmick? nope. it has it's uses. do not let anyone say it is a dog. i would put money on a race with a gt using i mode vs a n/a 2.5i anyday.

I think where people are getting the impression that there is a different map for each is that the tuner may have overridden the the si drive and set all 3 I,S and S# to 100% essentially creating one map but making it seem like 3?? I dunno just offering a solution to the confusion.

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.

^^ 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 found this article... still more to digest:

http://www.edmunds.com/insideline/do/Drives/FirstDrives/articleId=115529

My finger is on the button

Also new for 2007 is a drive-mode feature called SI-DRIVE in Subaru-speak (not to be confused with BMW's infernal iDrive). Standard on all Legacy 2.5 GT models, SI-DRIVE manifests itself as a console knob with which the driver can select from one of three pre-programmed engine maps — called Intelligent, Sport and Sport Sharp modes. Each mode is intended to impart a different driving character through alterations of throttle response and boost levels of the 2.5-liter turbo flat-four engine (and revisions to the shift strategy of autobox-equipped Limited models).

Fiddling with the SI-DRIVE knob during our driving stint confirmed a noticeable difference in drivability among the three modes. Intelligent mode, which Subaru reckons will improve real-world fuel economy by about 10 percent, took the legs out from under the car when squirting around in traffic.

We figure any fuel savings garnered in Intelligent mode will be the result of simply taking fewer chances in traffic — the reduced boost and too-soft throttle response make it more likely to be caught with its pants down. Alas, fuel economy in steady-state driving (as on a freeway) is unaffected since SI-DRIVE only enters the picture when the driver rolls into the throttle to stir the boxer engine.

Commendably smooth, one mill powers all 2.5 GT variants, generating 243 horsepower at 6,000 rpm and 241 pound-feet of torque at 3,600 rpm with a characteristic muted chuffle. Don't fret over the apparent drop in power and torque compared to 2006 models — it is an illusion caused by revisions to the SAE's testing protocol. In reality the engine is identical to last year's 250-hp rating. The full helping of power and torque are available in Sport and Sport Sharp modes, while Intelligent mode knocks about 20 percent off those values.

To be frank, SI-DRIVE appears to be the answer to a question no one asked. Sport Sharp mode is all that's really needed — with solid midrange torque, passing power is a flex of the ankle away, and it's never too abrupt or jumpy. Too bad, then, that of the three modes Sport Sharp is the only one that cannot be selected as the default upon startup. We predict that drivers will play with SI-DRIVE for a day or two, then pick one mode and stick with it. It won't be Intelligent mode.