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.

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.

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

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.jpg1STi by SplatSTi, on Flickr

https://farm4.staticflickr.com/3867/...153fbf1c_o.jpg620362_10151634281173032_878172471_o by SplatSTi, on Flickr

https://farm4.staticflickr.com/3917/...1022ca7b_o.jpg10258645725_a9574d7d66_b by SplatSTi, on Flickr

The day I got her:
https://farm6.staticflickr.com/5172/...7645a0c0_o.jpgKAI_5422 by SplatSTi, on Flickr

Under the hood

https://farm8.staticflickr.com/7206/...b42c3829_o.jpgKAI_5448 by SplatSTi, on Flickr

Inside:
https://farm6.staticflickr.com/5504/...0e88160c_o.jpgKAI_5439 by SplatSTi, on Flickr

Winter mode
https://farm8.staticflickr.com/7325/...d7ee403c_o.jpgIMG-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:
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?

Im in Cincinnati.

Welcome to EM!

it'll be fun to see both of our cars evolve over time to achieve better fuel efficiency.

Since you're one of the few STi owners out there trying to achieve fuel efficiency, I've got lots of questions!

1) Did you notice an MPG gain from Cobb Accessport with the OTS stage 1 tune? I've read unconfirmed reports on Nasioc and iwsti that the basic stage 1 tune achieves approximately 3mpg increase AND a HP increase. It's like icing on the cake with a cherry on top. However, the $650 pricetag is a bit steep. However, with a 3mpg increase, I calculated it'll take at least 10,000miles for it to pay itself off back in fuel savings.

2) Im definitely interested the Rallispec taller 5-6 gears. I've been looking for something like this ever since i got the sti. I've only found companies that made shorter gears for track use. Sub's dont have the luxury of Honda's with easily swappable taller gear transmissions. How much does the kit cost? how much did installation run you? Do you have to buy any extra miscellaneous parts to make it work? 2600 rpm at 70mph will allow me to drive "normally" on the highways now :)

Yes, there is an increase of mpg when you go stage 1 OTS. Infact in comes in quite handy when your out of town and they dont have 93 oct, you can switch to a 91 oct map and just keep going. Now The last time this happened to me, I averaged 26mpg highway with 2 of us in the car fully loaded. I was quite happy about the mpg on that trip. Now that price is for the new Cobb Access port, if you look around, people are selling the previous gen much cheaper you just need to make sure its unmarried because if its married to the original car it will be absolutely useless to you.

Now as for HP differences etc. ( keep in mind this is a VERY LOW reading Dyno, Ive seen 700hp cars dyno at 580 on this one)

This is a dyno graph we did on testing every option with the accessport.

Stock with I
Stock with S
Stock with S#
Stage 1 W/93 & I
Stage 1 w/93 & S
Stage 1 w/93 & S#
Custom Stage 1 for DAVCS w/93 I
Custom Stage 1 for DAVCS w/93 S
Custom Stage 1 for DAVCS w/93 S#

https://farm8.staticflickr.com/7222/...5ef2aa99_o.jpgIMAG0099 by SplatSTi, on Flickr

Now as for the 5 and 6th gear swap, its not just the gears you have to buy, it will be the syncro's, bearings and washers etc. In order to get those gears out you destroy other parts, there is no way to save them, you need to replace them. All up I think parts were around $600. Then you need to buy gearbox oil, and then you need to pay labor to get it done. Now you can save yourself some by taking the gearbox out if your comfortable doing that, I just let them do it. I know in total it cost me around $1500.

You will have to do your homework to find out exactly which parts you need, Im sure somebody has a list somewhere, Im just glad Turn in Concepts knows what the heck they are doing, they have done this swap many times. They did it on my 05 STi as well.

Would you be willing to do ABA testing between Stock vs Stage 1 to help out the EM community (ie me) ? lol

Whats ABA?

"ABA" is a term on this forum used to measure any MPG changes between two variables.

For example: to test to see if there is any mpg improvement between stock vs cobb stage 1

A - do one run with stock tune - measure the mpg
B - do one run with Cobb Stage 1 tune - measure the mpg
A - do one run with stuck tune - measure the mpg

Hopefully, you should be able to see mpg differences between Stock vs Cobb stage 1....thus solidifying that Cobb Stage 1 can increase mpg.

The reason why we do ABA is to further eliminate any outside variables that can affect mpg (weather, traffic, driver's right foot), so that the goal is to be able to say "X mod definitely increased my mpg by Y"

http://ecomodder.com/forum/showthrea...ery-11445.html

Very similar to dyno tuning:
A - Stock with I
B - Stock with S
C - Stock with S#
D - Stage 1 W/93 & I
E - Stage 1 w/93 & S
F - Stage 1 w/93 & S#
G - Custom Stage 1 for DAVCS w/93 I
H - Custom Stage 1 for DAVCS w/93 S
I - Custom Stage 1 for DAVCS w/93 S#

OK so I was fortunate to have my home shop be able to tune me today, which means I dont have to go to Indiana tomorrow.

Outside Temp 83F / Inside the building? No idea, but it was hotter than hell
Humidity: 80 to 90%

https://farm4.staticflickr.com/3880/...14dae673_o.jpgDomtune Stage 1 by SplatSTi, on Flickr

Stock is 209HP on this dyno, Off the shelf map got me 229hp to the wheels. I gotta say Im very happy with 246HP on this dyno. Now before you say, thats not much, this dyno reads low. Real low. From the factory the car is 305hp to the crank. So regardless of what the dyno reads, its about the incremental gains you get after the baseline. Plus Im happy, and thats what matters.

I also did some instant mpg logging on the way home. On average on a flat surface I was getting 34.1, down a hill, 99mph. Up the hill to my house? 6 to 8mpg lol

On your DOWNHILL COMMUTE...there are 2 things you can do to get better average mpg

1) Coast in neutral - you'll most likely average 100+ mpg on the downhill section

OR

2) (Depending on the steepness of the hill) Coast in gear - you'll average "infinity" mpg because injectors will shut off due to deceleration fuel cut off. This method will work if the hill is steep enough where the drag of being in gear will allow you to keep a decent speed in traffic.

Just like incremental HP gains, using different driving techniques will give you incremental MPG gains as well :)

I believe the cobb access port only goes to 99, I might have to find my tactrix cable and do some logging with the laptop.

Now I forgot to mention, I did fuel up today and on a 20 mile run to my tuner, I did average 28.4mpg, but that was totally destroyed after the dyno tune. It was at like 16mpg lol. So I just reset and watched it as I came home.

Leaving for Florida tomorrow, and prepping the car for the trip.

Radar detector hardwired and installed - confirmed working
Tire pressure raised from 35psi to 40psi.

Last weeks tank got me 22mpg city. As I will be driving all highway, I will record as I go and I have 2 different maps to test to see how my mpg will go. 975 miles each way, should be enough testing time :)

Sounds pretty sweet. Looking forward to hearing all the results!