rpholz Posted January 26, 2015 Share Posted January 26, 2015 Hello! looking for someone with a bit more experience than my own. I'm looking to pick up a 91 Legacy with a bad trans, I was set on turning it into a rally car, problem is its absolutely georgous and would be a crime to race it, SO! My question is I currently own a 97 Impreza L 383k on the clock, perfect rally car. what troubles will i encounter with a drivetrain swap? two cars are as listed: 91 Legacy auto/2.2/awd 97 Impreza 5spd/awd/frankenmotor my plan is to swap Engine, trans, shifter, rear end(4.11 final drive) pedal box. I'd really like to do a partial harness swap to keep obd2. id also like to swap over the 2.5rs brakes. I'm also aware i will need the trans crossmember. will my driveshaft work or do i need a manual legacy driveshaft? will the pedal box carry over? are the legacy rear axles roll pin or stub style? will the brakes carry over? id assume yes but want to be sure. will the impreza seats bolt in as my RA seats would look fantastic in there. the Impreza on the otherhand is getting a 04 wrx harness, 2L turbo, 4/2 pot wrx tr brakes, 4.44 trans, cage, yada yada appretiate the advise as I need to make this swap as smooth as possible Link to comment Share on other sites More sharing options...
heartless Posted January 26, 2015 Share Posted January 26, 2015 my plan is to swap Engine, trans, shifter, rear end(4.11 final drive) pedal box. I'd really like to do a partial harness swap to keep obd2. id also like to swap over the 2.5rs brakes. I'm also aware i will need the trans crossmember. Why swap engines? is there something wrong with the Legacy motor? wiring differences between the 2 years would make this a VERY labor intensive proposition - not saying it cant be done, but you are basically talking completely rewiring the car from under the dash & forward... will my driveshaft work or do i need a manual legacy driveshaft? Impreza is shorter wheelbase, you would need the proper driveshaft or have one made. will the pedal box carry over? should, but others can tell you more on that... dont forget about all clutch related components - especially if it has hydraulic clutch... are the legacy rear axles roll pin or stub style? I will let others with the experience discuss this - I have never had to mess with rear axles will the brakes carry over? id assume yes but want to be sure. should, but again, I will let others with more experience discuss... will the impreza seats bolt in as my RA seats would look fantastic in there. Probably, but you will more than likely need to swap out the seatbelt buckle end (part attached to the seat) as there are differences. May also need to swap the seat rails... Not saying you cant do what you are proposing, but it would be a big undertaking to do it. You would be much further ahead to swap in a good used auto tranny in the 91, fix whatever else may need fixing, sell it, take the money & find something else that is more appropriate for your needs/wants. Link to comment Share on other sites More sharing options...
rpholz Posted January 26, 2015 Author Share Posted January 26, 2015 What I need/want is a clean DD. This legacy looks like it's straight off the show room Why swap the engine? Easy, more horsetorques, 2.2 are miserably slow and this is atleast entertaining. I mean all things considered I could have the mechanical swap done in under a day with some help. The electrical is not concerning as this would honestly be the least labor intensive of harness swaps I've done.. and honestly most of the pins look to be the same so I may just add a secondary harness over top the factory for things I'd like to add. Pretty straightforward. I'm also not done with the motor in the wagon, I want to see more power out of it via some headwork, cams, ecu and injector changes, I really want to see how far a frankenmotor can go within a reasonable budget. So far the jump from 70hp/80tq to 114/134 on our mustang dyno has been really rewarding and would like to see 130/150 someday Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 27, 2015 Share Posted January 27, 2015 What I need/want is a clean DD. This legacy looks like it's straight off the show roomIt sounds more like what you want is a race car. When you start swapping engines and transmissions and drivetrains that "showroom" look goes right out the window no matter how hard you try to keep it "clean". The only thing that keeps it "clean" is to leave it stock stank. That's been my experience at least. What Frankenmotor setup do you have that gave you a 44hp and 54tq bump? Link to comment Share on other sites More sharing options...
rpholz Posted January 27, 2015 Author Share Posted January 27, 2015 Not quite exactly. It was like 75ish hp and 80 some odd tw. So a bit less of a gain but certainly a big one. Went with a 251 block, brand new coated 253 pistons, rods were. . Eh some laying around. No telling from what. Acl bearings etc. it certainly makes good power and has supporting mods to help. Plan on finding ej25d injectors and a 98 2.5rs ecu to see where that puts me As far as looks on the legacy, my remark was more toward the interior and exterior look great, the rest, meh as close to stock would be nice, but it is my profession on building clean cars, this would certainly be within the realm of what I've previously done. Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 28, 2015 Share Posted January 28, 2015 Still a decent bump at the wheels. Supporting mods I suppose are intake/exhaust? Was the original engine 1.8 or 2.2? Link to comment Share on other sites More sharing options...
rpholz Posted January 28, 2015 Author Share Posted January 28, 2015 2.2 I had a randomtech cat pipe and Sti catback with a oem cotton air filter. A header and spt axle back broadend the power band a bit but didn't change the peak numbers. Added a wrx snorkus here recently and it feels punchier but haven't redyno'd it yet Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 29, 2015 Share Posted January 29, 2015 I think alot of people here would be interested to see actual dyno numbers for a Frankenmotor like this. Its a common build, and we see lots of questions about how much power it will make. If you get a chance to dyno it again (with its current mods) please post up a graph or a pic of the datasheet. Link to comment Share on other sites More sharing options...
rpholz Posted January 29, 2015 Author Share Posted January 29, 2015 I'll probably throw it back on in a week or so, also I could dyno the legacy once I swap it in there to see the difference in the ecus Link to comment Share on other sites More sharing options...
rpholz Posted January 30, 2015 Author Share Posted January 30, 2015 quick dyno sheet from when i built it. Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 30, 2015 Share Posted January 30, 2015 Cool thanks! What is the dotted set of lines? Link to comment Share on other sites More sharing options...
rpholz Posted January 30, 2015 Author Share Posted January 30, 2015 The dotted lines show the hp/tq of a 99 2.5rd with full exhaust. Blue is torque red is hp. I plan on making a full thread this weekend with graphs, info, mods, what worked and what didn't. Hopefully that'll answer some questions for those thinking of making the change Link to comment Share on other sites More sharing options...
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