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What octane is everyone using?

What octane is everyone using?

  • 87 Octane

    Votes: 31 6.0%
  • 89 Octane

    Votes: 7 1.4%
  • 91 Octane

    Votes: 176 34.3%
  • +93 Octane

    Votes: 299 58.3%

  • Total voters
    513
Messages
331
Likes
144
Location
Gloucester, VA
I'm finally back in Virginia and running the good stuff right out of the pump. 93 octane w/10% ethanol, no booster added. I have upped my baseline from the Cobb OTS Stage 3/91 to the 3/93, but I've tweaked the WGDC and Load tables to target ~28psi max boost and 3.0 Load across the entire rev range. The little turbo will hit the 28psi target and pull a 2.9 peak Load. The ECU is still adding a few degrees of timing, but I will leave it alone for now. The ambient air temps are running in the 20-30 deg F range.
 


Sourskittle

4000 Post Club
Messages
4,567
Likes
860
Location
Lakeland
I made 354ft lbs of torque at 2900rpm on the stock turbo with 29.5psi, lmao.

Hits like a sledge hammer and then just completely takes a poo on its self. Its entertaining, just not effective for going fast.
 


Messages
57
Likes
7
Location
State College
I'm curious what the dealer is going to put in mine when I pick it up for the first time. I told him 91 is recommended and asked what they would put in. But, I'll never know... they could easily tell me 93 when they really put in 87. God only knows.... Until I put in 93 and see if the butt dyno notices.
 


westcoaST

1000 Post Club
Messages
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290
Location
Corona
I've been playing with an e40 mix. There is a Propel/Shell gas station in Fullerton on the way to work. I add about 4 - 5 gallons of e85 to 7 gallons of 91 octane Shell. I put in the E85, drive 10 feet then put in the Shell 91.

I'm doing a couple of logs this week to see where I'm at before I spend 150.00 for a tune by Randy, or a dynotune by Cobb. Engine seems to like e40 with the 93 Cobb OTC tune. Gas mileage went down 2 MPG though. It looks like e40 is 97 to 98 octane.
 


Sourskittle

4000 Post Club
Messages
4,567
Likes
860
Location
Lakeland
That's too much ethanol to be running long term without telling the computer. I'd do 3gal MAx. Or 3.5 gal if you filling a tank of fuel that was previously only 91oct only. 2.5 would be nice and safe
 


Messages
320
Likes
59
Location
Newark
Watch those air/fuel ratios using too much ethanol in a car without a flex fuel sensor. Alcohol air/fuel ratios are very different than gas and an ECU that isn't tuned with alcohol maps can be very dangerous.
 


westcoaST

1000 Post Club
Messages
1,157
Likes
290
Location
Corona
That's too much ethanol to be running long term without telling the computer. I'd do 3gal MAx. Or 3.5 gal if you filling a tank of fuel that was previously only 91oct only. 2.5 would be nice and safe
I'm getting a tune this week, so I got to make a few pulls and send the datalogs to the tuner. I'm not worried about e40 in my tank for a week before my tune.
 


westcoaST

1000 Post Club
Messages
1,157
Likes
290
Location
Corona
Watch those air/fuel ratios using too much ethanol in a car without a flex fuel sensor. Alcohol air/fuel ratios are very different than gas and an ECU that isn't tuned with alcohol maps can be very dangerous.
I have a flex fuel sensor. Its in my sig. I was probably the 2nd or 3rd person to install one after Razorlab put together his how-to.
 


Messages
255
Likes
54
Location
Medina
Shell 93. Found it to give me the best MPG. Do your MPG's get better as the mileage gets higher? I'm at 2300ish and I've only gotten 31 at best.
 


Sourskittle

4000 Post Club
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Location
Lakeland
Got ya. Still, just like Razor told me, the stft should be around 3-7% from 0. E10 to E40 is about 18% off the base stock tune. I'm seeing upto -17 to -21% at some RPMs on my car right now, so i can't say much,'lol. But I'm only it danger of having TOO MUCH fuel, not "not enough fuel".

Your going like the tune. Not sure how cobbs tune is, or Randy's ( Randy once posted on another forum that did wasn't sure E30 was making much difference to be worth it. High sight is 20/20, but knowing what we know now, its more than worth it, its likely the biggest difference you can make without changing the turbocharger.).

I'd point you toward Panda or freaktune. I'm sure cobb can handle it, as Randy can too. The thing is.... Fuel wise, its like 1 change that takes like 20seconds in the software, then your fuel is calibrated. But how that fuel is used, how aggressively its used, and how much you gain from it may vary. For instance. On a stock turbo unit, I made 354ft of torque at 29.5 psi at 2850rpm on E40. Your prob not gonna get that tune, lol, but who will ? Would you even want it ? ( I hate driving on the stock peaky turbo ).

Keep everyone updated if you can, with logs and V-dynos :)
 


westcoaST

1000 Post Club
Messages
1,157
Likes
290
Location
Corona
Got ya. Still, just like Razor told me, the stft should be around 3-7% from 0. E10 to E40 is about 18% off the base stock tune. I'm seeing upto -17 to -21% at some RPMs on my car right now, so i can't say much,'lol. But I'm only it danger of having TOO MUCH fuel, not "not enough fuel".

Your going like the tune. Not sure how cobbs tune is, or Randy's ( Randy once posted on another forum that did wasn't sure E30 was making much difference to be worth it. High sight is 20/20, but knowing what we know now, its more than worth it, its likely the biggest difference you can make without changing the turbocharger.).

I'd point you toward Panda or freektune. I'm sure cobb can handle it, as Randy can too. The thing is.... Fuel wise, its like 1 change that takes like 20seconds in the software, then your fuel is calibrated. But how that fuel is used, how aggressively its used, and how much you gain from it may vary. For instance. On a stock turbo unit, I made 354ft of torque at 29.5 psi at 2850rpm on E40. Your prob not gonna get that tune, lol, but who will ? Would you even want it ? ( I hate driving on the stock peaky turbo ).

Keep everyone updated if you can, with logs and V-dynos :)
I bit the bullet and decided to go with Randy at Mountune. [biggrin] I know about him from when he worked at FSWERKS, and he is familiar with the fullerton area, where I get my gas and e85. I was surprised when he told me Arco was better than Shell. I was using Arco in my ST, and it showed no problems, even with the 91 stage 3 tune from Cobb. I decided a while ago that I'd try e40, I installed the Razorlab flex fuel setup earlier this year. I put it in my glove compartment, and wired it up with quick release plugs, so I can remove it quickly when I need to make a dealer visit. I figure I'm ready for an e40 tune. Ill be posting my progress in my build thread.

http://www.fiestastforum.com/forum/threads/2353-WestcoaST-Performance-blue-build/page8
 


Messages
62
Likes
15
Location
Macau
I'm from Macau and our regular gas is 98 octane and premium is 100 octane....or so they say. When I get a tune put on the car I'll probably keep it pretty conservative in case the rating is bogus like in China
 


Messages
156
Likes
39
Location
Edmonton
This last tank was 91. There will be no more of that shenaniganry. Found 94 in the city I'm in, and that'll do just fine going forward.
 


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