'07 Subaru Legacy SI-Drive Explanation

[Joel Gat]

I don't think Cobb has the resources to modify this ECU, from what little I know, the knob and mappings will increase the complexity of ECU mappings by orders of magnitude.

Hello,

 

Doubtful - it's probably a set of flags that determine which map to use, kind of like the high and low detonation maps work right now. Given conditions X, Y, and Z, use the low det map, otherwise, use the high det map. Given switch position 1, use fuel/timing/ignition maps 1(a, b, and c), otherwise use 2, otherwise use 3.

 

Should be simple to implement. I'm guessing Trey will need, as soon as possible after he gets his hands on an ECU, a Spec.B to be dropped off at his shop for a week of R&D, after which he'll announce new APs.

 

Joel, being optimistic, knowing how slow the Cobb time-line is

[kenzo]

There's been no indication that the new BlingKnobWithLameFixedNotReallyAGraph SI-Drive provides increased power or torque ratings over the '05 or '06 LGTs, so why should we expect better performance? Isn't the "Intelligent" setting really just an artificial -reduction- of hp/tq?

 

Yep, that's really intelligent. Maybe in '08 we'll get the "Genius" mode with further performance reductions.

[f1anatic]

What makes you guys think that the 3 modes...intelligent, sport and sport sharp are something more complicated than a real-time map. Afterall, you can do this on the fly...and apparently you are able to do this with an Accessport already. i do not know really...cause I do not have such a tool...but from what I have read...it all seems to me that instead of a base map and a real time map...you'd now be loading 1 base map and 3 real-time maps into the ECU. Doesn't seem all that complicated to me. Just a smarter ECU with more RAM memory and ability to flip between them. Which would require the Accessport to identify that ...and since the Accessport units can already store a number of maps...you will just transfer a few of them to the car.

 

I don't know the current stocker Legacy serves my purposes so I never bought into Cobb's , TDC's and other folks tuning solutions. I am being raped at the pump with 3:15 gas so ...tuning for performance is out of my mind and pocket right now.

 

PS: I can do away with the graph. Since the car also has DCCD, what is the use of that with an open front diff ?

[axis008]

The car does not have DCCD. It has VDC, which stands for Vehicle Dynamics Control, which uses brakes to help with stability, and is in turn able to be turned on/off.

[f1anatic]

My bad...i must have read some mixed report that also talked about the new Sti with two types of centre diffs.

 

That being said...'cause of the VDC, the centre diff is no longer viscous...must be some hydraulic operated , electronically ctrl-ed shit ?

[axis008]

From media.subaru.com's '07 spec.B spec sheet, it says this under Symmetrical All-Wheel-Drive:

 

"Viscous-coupling locking center differential; 50:50 torque split; Torsen® limited-slip rear differential "

[f1anatic]

Got it thanks

[LGT Dave]

My question is this...

 

So the knob, you turn it left and you get Sport mode, you turn it right and you get Sport Sharp mode. If you push it down, you get Intelligent mode.

 

Then what is the center notch for? Can you only press the knob when it's pointing up for Intelligent mode? Or--the subaru.com website with the little flash of it shows the knob turning all the way down to where the Intelligent mode writing is. So once again, what could the middle notch be?

 

Perhaps it is a self centering knob so that after you turn it to the right or left, it automatically returns itself back to the center notch. That's the only reason I can see for having the three marks yet making you push the knob down to turn on the Intelligent mode.

[Brady]

here's the thing, that MPG guage is to mock us.

[SLegacy99]

Ok. Now integrate with hybrid system for optimal eco boost

[Ken S]

From media.subaru.com's '07 spec.B spec sheet, it says this under Symmetrical All-Wheel-Drive:

 

"Viscous-coupling locking center differential; 50:50 torque split; Torsen® limited-slip rear differential "

 

That's the part I don't get. VDC used to need VTD to work as it will not only do the ESP thing with brakes but also try and move torque fore/aft as needed. With the standard VC center diff, VDC has no control over the torque split.

 

Ken

[Beanboy]

A few folks have mentioned the center limited slip vc and how it works with the stability control... Wait and see I guess.

 

Can see it working when wheels are all still moving and individual wheels are being braked, the vc isn't doing a thing. But if you get into a sliding situation where stability control can help get back in control (say in an oversteering situation), that vc is going to try to start to lock.

[jikhead]

what kind of gas mileage are we talking about with that econo setting?

[Joel Gat]

Hello,

 

In terms of gas mileage, the press release said 10% better, which is inline with what people get with their Cobb economy maps. So that makes sense. It's basically a dial that lets you switch to an economy map that's not really a great improvement in fuel economy (but makes you feel good about yourself) and is much slower feeling to drive.

 

I think the real fun will begin when Cobb and others release accessports or whatever designed to take advantage of this - you could have your daily map, your weekend map, and your track/100 octane map stored and not have to even use an AP to switch - just jog the dial.

 

Mmm...

 

Joel

[fzanetti]

Hello,

 

In terms of gas mileage, the press release said 10% better, which is inline with what people get with their Cobb economy maps. So that makes sense. It's basically a dial that lets you switch to an economy map that's not really a great improvement in fuel economy (but makes you feel good about yourself) and is much slower feeling to drive.

 

I think the real fun will begin when Cobb and others release accessports or whatever designed to take advantage of this - you could have your daily map, your weekend map, and your track/100 octane map stored and not have to even use an AP to switch - just jog the dial.

 

Mmm...

 

Joel

 

That would be really ideal!!!!

 

hehehehehe

 

Flavio Zanetti

Boston, MA

[wrxSTI]

I think it awesome....now if we could integrate with aftermarket e.m.....yeah!

[Silver05LegGTL]

My question is this...

 

So the knob, you turn it left and you get Sport mode, you turn it right and you get Sport Sharp mode. If you push it down, you get Intelligent mode.

 

Then what is the center notch for? Can you only press the knob when it's pointing up for Intelligent mode? Or--the subaru.com website with the little flash of it shows the knob turning all the way down to where the Intelligent mode writing is. So once again, what could the middle notch be?

 

 

The center setting is where the knob goes when you are not making a selection (sort of like neutral), and it is spring loaded. So when you want to put it in Sport mode you turn it to the left and it returns to the middle position. If you wish to put it in Sport# mode you turn it to the right and again it returns to the middle position. Finally, if you should ever choose to drive in Intelligent mode you just push the knob. I hope that clears things up for you! Personally I think it is cool.... the Intelligent mode would be nice in 6th gear during a long interstate drive... Other than that I think I would probably have it in Sport#, that's just more fun!

[axis008]

The center setting is where the knob goes when you are not making a selection (sort of like neutral), and it is spring loaded. So when you want to put it in Sport mode you turn it to the left and it returns to the middle position. If you wish to put it in Sport# mode you turn it to the right and again it returns to the middle position. Finally, if you should ever choose to drive in Intelligent mode you just push the knob. I hope that clears things up for you!

 

Yup! Just found that out earlier today and was going to post about it. They updated their little flash animation on the Subaru website . It used to not have a spring action if you know what I mean.

[daady_love]

[Bob N]

Yes. Both transmissions. The advantage of having it on automatics is that things such as the transmission torque lock-up converter engagement is modified depending on setting, as are shift points and strength.

 

And the advantage for a MT is??? Apparently you don't see it either. I think it sucks for anyone using a manual transmission. Kind of makes sense for a AT but not a MT. If somebody doesn't know how to use a MT for "Sport" or "Economy" than they shouldn't be driving a MT. "I don't need no stinkin' SI-Drive".

[Joel Gat]

Hello,

 

Bob N, how, with a manual, do you change the throttle response? IE, if you floor the gas pedal in an LGT, it takes "X + foot-movement" amount of time for the throttle plate to fully open. In an STi, it takes about "1/2 X + foot-movement" amount of time.

 

You can't change that with your hand on the stick. For all LGTs before this new one, you needed to change that through a reflash. Now they're doing it for you...

 

So, I see some advantage to SI-Drive. Only some, though, because I like my car to be responsive all the time and I see no need for the slight improvement in smoothness afforded by the slow throttle response

 

Joel

[Bob N]

Hello,

 

Bob N, how, with a manual, do you change the throttle response? IE, if you floor the gas pedal in an LGT, it takes "X + foot-movement" amount of time for the throttle plate to fully open. In an STi, it takes about "1/2 X + foot-movement" amount of time.

 

You can't change that with your hand on the stick. For all LGTs before this new one, you needed to change that through a reflash. Now they're doing it for you...

 

So, I see some advantage to SI-Drive. Only some, though, because I like my car to be responsive all the time and I see no need for the slight improvement in smoothness afforded by the slow throttle response

 

Joel

 

Ok, Joel, so it's about throttle response, at least with the MT. THe sport mode is essentially the same as the 2006 GT and Econ mode will result in a slower response and hopefullly provide a smoother transition of power resulting in a savings in fuel consumption. I guess the "super sport" or whatever they call it will be the quicker response and allow a more athletic feel to the engine. Alright it makes some sense but I also think it benefits AT drivers a little more.

[godwhomismike]

I wonder how S# mode will affect 0-60 and 1/4 mile times.

[WiseYoda]

what would actually be pretty cool is if the next-gen AP could interface with the SI Drive knob and manipulate the equivalent of Cobb realtime maps.

 

Imagine if the "Intelligent" mode could give you the Economy AP map (realtime), the "Sport" mode gives you the regular AP map (Stg 1 or 2 depending on setup) and the S# setting offering the Stage map with more aggressive throttle mapping and/or boost profile without having to hook up the AP.

 

Now That would be Cool!

 

I know this is an old thread... but has AP come out with this yet? Searching around I found some older threads of people saying it's coming out Mid-January. This feature would be amazing though.

[sirsimon]

Latest word on the 07/08 AP is sometime this summer.