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Automatic STI 2011

2K views 11 replies 4 participants last post by  titter 
#1 ·
Hi guys i think i'm in the write place to ask my question... i have an automatic STI hatchback 2011, it has a k&n typhoon air intake and a 3'' bellmouth downpipe and the rest is stock, i got it tuned and was told that automatic's come at around 273 hp (stock) and when it got tuned it went up to 313hp, my tuner told me that there are restrictions on the gearbox. Is that the maximum hp i could get with my current settings??? what can i do??? did my tuner go wrong???? and all the readings were from a dyno, any help would be great. thanks
 
#2 ·
First we need to know your location, as the USDM STi never EVER came auto. So I take you either have an EJ205/EJ207 or you have a WRX with STi parts. Titter should chime in after we know more about your car/etc.
 
#3 ·
if he means CVT, then thats out of my ballpark lol. but then again, there are no CVT STI's either... i know automatic sti's exist in japan as police cars, but nothing like this exists over here unless your crazy enough like me to make one.

aside that, there is too little info given to give a proper answer. is that bhp or whp? location? what fuel? what motor, what turbo, what dyno, etc...
 
#4 ·
Hey guys, i live in Lebanon (Middle East) and the STI's we get here are Japanese as far as i know, the engine is 2.5 and everything is stock except for the downpipe and the air intake, and definitly it's not a CVT or i would not have bought it, it is an STI was told so at the dealership where i got it. Was doing a bit of research the restriction might be from the torque limiter, might be something else any ideas would be appreciated there must be a way to further modify the car. thx
 
#5 ·
an answer to your questions "titter" the horsepower was read on a dyno so i think it's engine whp, Location: Lebanon at an altitude of 200meters and a temperature of 18 degrees celsius, Fuel: 98 octane, Motor: 2.5liters, Turbo: original stock turbo, and the car has 40,000 km and it's in very good condition
 
#6 ·
There was a JDM 2011 STi with an automatic call the "A-SPEC". That transmission was never sold in a USDM Subaru so I don't think we'll be able to give you much info on it.

Transmissions don't really limit power, they just break when they get too much of it. Your turner I assume is saying he's reluctant to increase power and put your transmission at greater risk of failure. Changing the transmission alone will not increase the engine's power output.
 
#8 ·
I completely forgot about that unicorn lol.

And I think that STi used a 5EAT similar to the Legacy GT, also auto trans don't like high HP, they slip too much and cause heat buildup which fries the clutch packs and other things like line pressure go up over time/etc, causing the ECU to default to "limp mode" or the tranny just gives out depending on how you were driving when it decides to let go. Titter you might know about this in your 4EAT :p

Back when I had a toyota people would turbo their autos and find out quickly they need another couple thousand to build up the tranny too.
 
#7 ·
newer automatics have torque limiting strategies inside the TCU to prevent exactly what mosc says. in the past a trans would just keep taking power untill they break, but now-a-days there are multiple computers to prevent this from happening.

now does this mean your car has this type of torque limiting strategy? no idea... you have a model that never existed over here so we dont know much about it. it wouldnt suprize me at all if you did though. those techy japanese are pretty crafty.

from a power standpoint, it looks like your tuner did a pretty good job extracting 313whp out of your car with those mods. 300+hp on pump gas and stock parts is good.


can you post a pic of your car? i would like to see it if you dont mind sharing.
 
#10 ·
nice and clean looking. reall cool to know they make automatic impreza STI's. i know auto STI foresters exist but thats a different car. thanks for sharing!

yes, excessive heat will kill your auto trans very quickly. get a good aftermarket transmission cooler to help keep temps down. if its got a fan thats even better. if you manage to keep temps down, and get a decent torque converter, the auto trans can actually hold more HP than the 6 speeds.

what happened to mine was a bit different. when i drained my 15yr old trans fuild and did all my flushing... i "thought" i was helping. turns out you really shouldn't drain 15 year old burnt tranmission fluid. there is actually science behind the myth. i drained out all the clutch pack material that had been fused with the fluid. thats why it started slipping. the new fluid firmed up shifts, which made me think it was going good, but with each flush the slippage got worse and worse and the shifts got firmer and firmer.

this is probably the best video i have found:

so my new trans is getting new fluid once a year regardless of mileage. i mean $80 in fluid to save my trans? i'd be stupid not to lol.
 
#12 ·
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