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Swapping Si-drive onto an 05 GT?


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Sooo. . . bought an 08 LGT limited parts car this week, it showed up today.

 

I'm looking at all the cool shit on it that my 05 does not have and thinking "why not zoidberg?"

 

Swap the rear seat? No prob.

 

Steering wheel & head unit so I get steering wheel controls and a HU with a proper aux-in? Meh, doesn't look too bad. . .

 

Now. . .the Si-drive seems novel. I know I don't *need* it, but it's a cool feature.

 

Both cars are 5MT. I have the ability to program keys. I know I'll have to swap the ECU, BIU, and cluster. . . probably the dash harness and maybe even some of the underhood harness, then program my existing key (or a new one) into it. Still seems do-able.

 

Has anyone here been crazy enough to attempt something like this? I'm really more curious if there's anything specific about the driveline on the Si-drive equipped cars that my 05 won't have. Not like I can't swap it. . .

 

Before anyone asks, I'm being greedy. No parts for sale on the 08 or my 05 yet.

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Steering wheel is easy but controls is kinda hard since the roll connector behind the wheel(controls the electrics) is different then our 05. It can be done but not plug and play and not really easy. As for SI-Drive while it is a cool feature to have it has a lot of stuff entailed in it to get it working on an 05. 1 is the ECU itself. The ECU in the 08 is connected throughout the dash while our 05's just kind have lines jumping from one to another. So that is a feat in itself, again it's electrical so it is do-able but will take a while to figure out. Then there is the entire trans axle part. That is where it gets insane. You really need to take all the real workings of the car and swap them in to get the SI-Drive to work.
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Well, started tearing into the parts car today and right off the bat noticed a major difference under the hood: 2008 has an air pump, my 2005 does not. . . so for that reason alone it probably won't work unless I swapped that, too. It's a fairly high-current device that has it's own relay. . . don't think it could be spliced in easily. Looks like the left head may even be machined differently to accommodate that.

 

Nothing fancy about the trans. . .it only has the same small 2 harnesses just about every Subaru MT has (aside from DCCD equipped models).

 

I got everything stripped under the hood and all the wire harnesses ready to pull. I'll start on the interior tomorrow. . should be able to pull everything in a day.

 

That 08 cluster is sooooo sexy tho.

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Seems to be the "tattoo" of the GT. You either like it or you think it's a worthless waste of money.

 

Truthfully I think I like the gauge cluster more than anything. . .but swapping that into my 05 means swapping the works, I'm pretty sure (ECU, BIU, clulster), and that means SI-Drive.

 

I am gonna miss having the seat heater switches where they are if I go that route.

 

kong: so you're saying I can delete the air pump with no adverse effects? I realize it's just for emissions, not driveability, but I can't see how removing it won't turn on a CEL. Can that be worked around via tuning?

 

Which brings up another point. . .I kinda like the idea of being able to switch between tunes. . . particularly if I want to build one for E85 and a couple more for dead dino juice.

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Like code said, SI is a useless extra step. It's muscle memory at this point...just wait for the blue light to go out...flip the switch. Hell, I waste more gas in "I" or "S" since the response isn't there, which leads me to mash it. If the ECU didn't require the coolant temp to allow S#, you could just wire in the resistor value. Bah humbug.

 

Air pump delete is common, pretty sure there is a DIY on here.

 

EDIT:

 

msprank comes through, as usual: http://legacygt.com/forums/showthread.php/2007-2009-air-pump-delete-cel-codes-and-ecu-fix-140259.html?t=140259&highlight=air+pump+delete

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Even with having setup my SI-Drive for different boost levels with DBW changes, I never use it. If I want less boost I just give it less gas.. I have I-mode setup for wastegate boost only, but I almost never have a reason to switch to that.

 

I do plan to do the AIR pump delete though when everything is accessible.

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Like most people said to them it is useless. IMO I am the type of person who is attached to the car when I drive. I know the in's/out's of how it drive. To me it would be a great feature to have but like the other Useless mods that people think I have done to my car I use them ever so often. When I do use them though it is a blast. Also as for the Air pump like stated most people remove it and never use it. Personally I have no idea what it even does for the car so I would also remove it. It's not that hard and there is a DIY for it.
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Like code said, SI is a useless extra step. It's muscle memory at this point...just wait for the blue light to go out...flip the switch. Hell, I waste more gas in "I" or "S" since the response isn't there, which leads me to mash it. If the ECU didn't require the coolant temp to allow S#, you could just wire in the resistor value. Bah humbug.

 

Could just copy the S# map into the S map and reflash your ecu = always in S# map!

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Roger that. . . remove air pump.

 

In reality, I won't be removing it, i'll just be putting the ECU on an engine that never had it to begin with (the 05). Good to know I can delete all the DTC's via tuning.

 

Pretty sure the 08 engine ate a valve or twelve as the LH exhaust cam pulley got crushed in the crash, and the timing belt obviously wasn't doing much after that. Might get lucky, dunno. Waiting on a leakdown tester and a used belt/pulley from another forum member to evaluate this motor before spending any money on air pump deletes.

 

It got thumped hard enough crack the compressor housing on the turbo and seize it. Ironically the air pump system survived unscathed.

 

I know you guys are saying "why bother?" but look at it this way: it's a no $$$ mod for me. I have the parts, all I have to do is move them from one car to another. At this point it would be more work to ditch the SI-Drive than to leave it intact if I want to use the 08 cluster.

 

I might replace that big honkin' knob with 3 momentary switches if I can find some tasteful ones. . that way I can retain my 05 seat heater switches.

 

Thanks much for the info on deleting the air pump system!

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Could just copy the S# map into the S map and reflash your ecu = always in S# map!

 

SI doesn't affect fuel mapping in any way. It simply adjusts the throttle response, by "ramping" the reading from the TPS.

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SI doesn't affect fuel mapping in any way. It simply adjusts the throttle response, by "ramping" the reading from the TPS.

 

Yes I'm aware of that... you can alter the SI throttle response maps in the ECU ROM... never mentioned fuelling

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Yes I'm aware of that... you can alter the SI throttle response maps in the ECU ROM... never mentioned fuelling

 

I will now place foot (or keyboard?) in mouth. When I had read about it before, nothing talked about SI affecting throttle response AND requested torque. Thanks!

 

EDIT:

For those wanting to know - http://legacygt.com/forums/showthread.php/si-drive-and-tuning-170223.html

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I love my using my SI.

 

I drive 98% of the time on I mode. There is really no need to mash your foot. I drive casually and it picks up and passes just fine.

 

Driving in S# after driving in I mode for awhile makes you love the car all over again.

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Subtle differences:

 

08 (from a 3.0R but gauges are pretty much identical)

 

http://media.caranddriver.com/images/media/200855/2008-subaru-legacy-30-r-limited-steering-wheel-and-instrument-cluster-photo-200861-s-1280x782.jpg

 

05

 

http://media.caranddriver.com/images/media/35777/subaru-legacy-25gt-limited-instrument-cluster-photo-143403-s-1280x782.jpg

 

08 has a multifunction pixel display for driver info, . . . 05 uses a segmented display that's pretty much just an odometer. 08 has fuel econ. gauge, 05 does not.

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I live the si drive. I drive in I mode on highway in cruise control, sport for normal driving around town etc and sport sharp when I want to have a little more fun.

Sport sharp I have tuned for about 20 psi. Sport is 16-17 and I is around 12-13 with a better fuel economy map.

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You have CAN bus in the '05 too, just not the same configuration. There are two CAN buses on the '05 while the '08 only has one.

 

But I agree - the harnesses are not really the same, and the ECU connectors different.

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Exactly what the 2 posts above said. The wiring harness and CAN issues really prevent the newer items from being installed into the 05-06 cars. I mean if you pulled the entire harness and basically swapped everything over and "electrically" the ecu thought it WAS the newer car it would work. We did that on an 02 RS we basically took it down to the frame and swapped over an 04 STi to it. As far as the STi ECU was concerned it was still in the original body.

 

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