OH-2013 Subaru STi Hatch

[jedi_sol]

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

[SplatSTi]

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#

IMAG0099 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.

[jedi_sol]

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

[SplatSTi]

Whats ABA?

[jedi_sol]

"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#

[SplatSTi]

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%

Domtune 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

[jedi_sol]

Originally Posted by SplatSTi

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

[SplatSTi]

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.

[SplatSTi]

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

[Eastwood]

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