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OH-2013 Subaru STi Hatch

Motor: 2.5
Horsepower/Torque: Stock 209 / Stage 1 229 (on dyno @ TiC ) 300hp\tq factory
1/4 mile: N/A
Preferred shop of choice: Joseph Subaru / Turn in Concepts

Engine:
Cobb Access Port Stage 1
Cat back exhaust.

Drivetrain:
Rallispec tall gears - (5&6)

Suspension:
Stock

Brakes:
Stock

Exterior:
Flawless Reflections Opti-Guard treatment
Rear tail light painted red.

The car has a mpg gauge but it seems to be all over the place, and Im trying to figure it out. I already have a scangauge but its in my other car, I might have to put it in this one especially if I plan on doing proper logging.

The best mpg I have gotten in the car was 33.9mpg with a custom tune I got from my tuner but I could never replicate it. I did manage to get 398 miles on that tank so I must have done something right. I average around 24.6mpg with mix driving, I have seen up to 29mpg highway but I live at the top of a hill and it pretty much destroys what ever mpg reading I was able to get. For example, I reset my mpg gauge and drove home, I actually hit 30mpg, but then I hit the hill, it went down to 27mpg by the time I hit the top. After starting the car in the morning and going back to work, I was down to 25mpg and going back up the hill, Im down to 22mpg lol. It sucks when work is 6 miles away, the car doesnt even get a chance to warm up.

So I need to do more.. no better logging with what my car is doing. With the taller 5th and 6th gear I see 70mph at 2600rpm but I need to figure out load vs rpm to see which has the better mpg.

OK enough rambling when I have more info, I will post :)

Cool set-up, man. You've pretty much got the exact car that I want: hatchback STi. Pictures anywhere?

I'm sure this has already occurred to you and I don't know your driving routes situation, but maybe look at trying to find an alternate route that might be a little longer but has more flow to it than your current 6 mile commute. Coasting as much as possible without being a road hazard will be your friend.

Also, look into getting an engine warmer and/or oil pan heater to help your car get a leg-up on warming up before a short drive. I imagine any aero mods/blocks you might be willing to consider, a la jedi_sol's 2013 STi, might help keep heat in and provide for a quicker heat-up too. I'm thinking specifically of those grill blocks or any variations on them.

And keep asking around here. Lots of very knowledgeable and creative people are here to help.

I want a wrx or an sti hatch really bad.

Here is the link to Jedi sol's thread if you're interested http://ecomodder.com/forum/showthrea...-26612-20.html
He has a sedan but the grille block and underbelly tray and spats will all apply to your hatch as well plus all the wiring related stuff like a kill switch or other electronics.

Quote:

Originally Posted by SplatSTi (Post 427733)

...
After starting the car in the morning and going back to work, I was down to 25mpg and going back up the hill, Im down to 22mpg lol. It sucks when work is 6 miles away, the car doesnt even get a chance to warm up.
...

I see the issue. EOC!

And my Mustang does the same. I might keep 40 mpg for a whole tank, but the readout just keeps going down. It's been as off as 8 mpg.

Quote:

Originally Posted by backpacker3 (Post 428059)

I want a wrx or an sti hatch really bad.

Here is the link to Jedi sol's thread if you're interested
He has a sedan but the grille block and underbelly tray and spats will all apply to your hatch as well plus all the wiring related stuff like a kill switch or other electronics.

Thanks, I actually found his post before I joined the forum and have posted in there since I have joined.

Quote:

Originally Posted by Eastwood (Post 428022)

Unfortunately, the alternative is worse, it has both hills going up and down. The current route goes straight down a hill and straight on to the highway. I actually gain mpg going to work, I just loose it climbing the hill going back home, as it is a constant hill around 25deg for about a mile.

Thanks everyone, Yes I have seen Jedi's thread and have posted in it. While I see what he is doing, I think Im going to go a little different way. I upgraded my gearbox to give me taller gears, and tuning to give me the mpg I need. I need to install my vacuum and boost gauge as well, so I can see how it is affecting my mpg, I also need to mount my Cobb Access port so I can monitor the load on the engine.

I have pictures, but I havent managed to get my minimum of 5 posts yet, but as soon as I do, I will post pics and links etc.

I also have a 2005 Subaru STi as well, with 1000cc injectors and a much bigger turbo (400hp to the wheels), it actually gets better mpg than my 2013. Its my street/race car, I dont hit boost till 4000rpm so I actually get around 26/27mpg normal driving and around 30mpg highway on long trips.

Ive driven from Cincinnati to Murfreesboro TN and arrived with a 1/4 tank left. In this STi, full tank to 1/4 tank is exactly 10 gallons and the trip itself is 330 miles.

https://farm6.staticflickr.com/5516/...40f9526e_o.jpg 1STi by SplatSTi, on Flickr

https://farm4.staticflickr.com/3867/...153fbf1c_o.jpg 620362_10151634281173032_878172471_o by SplatSTi, on Flickr

https://farm4.staticflickr.com/3917/...1022ca7b_o.jpg 10258645725_a9574d7d66_b by SplatSTi, on Flickr

Winter mode
https://farm8.staticflickr.com/7325/...d7ee403c_o.jpg IMG-20121220-00217 by SplatSTi, on Flickr

Now the gearbox has been upgraded, for taller gears and I did this for the following reasons. When getting on the highway, there was only a 500rpm drop from 4th gear to 5th gear, and another 500rpm from 5th to 6th. This means when getting on the highway, It felt like I needed another gear. The new gears now drop 1000rpm's from 1st to 6th gear, cruising at 70mph is now at 2600rpm's instead of 3000rpms. All the syncros and new bearings were put in as well and the stock gearbox oil was replaced with Motul Gear300 75w90 oil.

The stock synthetic subaru oil was also replaced Shell Rotella T6, which I use in both my 05 STi and this one, and the engine respons well to this oil.

Tuning:

I had a discussion with my tuner regarding the dual AVCS cam system in this car. Apparently this generation of STi uses more gas due to EPA regulations and emissions, with extra pumps on the engine etc. The tuning they did went along with it. I had a custom map created to basically turn off the dual AVCS and basically turn it into a single AVCS system.

The Theory:

Quote:

Having your cams open so high in such low load creates the effect of reverse scavenging. A typical scavenging effect you may be familiar with; when the cams timing on exhaust and intake advance enough or retard enough for exhaust, to assist in the flow of combusted gasses and non ignited gasses through the combustion chamber. The scavenging effect uses differentiating pressures to help evacuate the combustion chamber more efficiently, as well as increase the gas velocity of evacuated gas. Or you may know this more commonly as wave scavenging. You can also see this effect or rather the same theory with ram tuning, or scavenging headers on NA cars.

The reverse scavenging effect im speaking of allows exhaust gasses to be pulled back into the combustion chamber to be re-burned. Thus the EGR effect. To a point this CAN be a good thing for emissions and sometimes fuel economy. However with the crappy winter blends everyone receives with mighty E-10 now a days, we need all the help we can get.

Eliminating the EGR effect in subarus AVCS, I have seen MPG as high as 36 in the summer on a 2.5 5 speed. My sti is now hitting 27 mix with sunnoco 93 varied temps of 30-50 (this also includes some idle time for warm up).

Once you have adjusted your avcs 40* bump in the low load area to smooth to the surrounding timing of the cams, it may also be beneficial to you to run different ignition timing. Remember you have less hot gasses entering your combustion chamber now. DO REMEMBER > use det cans down low as the low load knock can be a pain in the flat four 2.5's.
IF you are not familiar with MBT then please leave this adjustment to your tuner. You may do more harm then good.

We have also made an additional map with no boost and I will need to test this as well. Since I am going to get protested in Indiana this weekend, Im going to test my "Economy" map there and then get protuned and see what the mpg difference is on the way back. I do expect the protune to be better, these cars like more hp and they become more efficient when tuned that way as well.

Where are you all at in Ohio?