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Discussion Starter · #1 ·
I'm getting ready to buy the SCT X3 with the 93 tunes. The past tank and a half I've ran 93 Octane instead of the regular 87 to get ready for the tune.

Does the stock engine react different to the 93 octane gas with a tune? Maybe its in my head but the engine seems a little more crisp.
 

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You are definitely getting a more crisp response. It's not just all in your head.
 

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The stock engine tune does compensate a bit for higher octane, but not as much as a tune. With a CAI and tune, you will gain approx 25 HP with 93 octane.
 

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Discussion Starter · #4 ·
I'm just going to get the tune for now, no CAI. I'm thinking there won't be much of a difference not having a CAI under 30MPH. I just want more torque and throttle response.
 

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I'm just going to get the tune for now, no CAI. I'm thinking there won't be much of a difference not having a CAI under 30MPH. I just want more torque and throttle response.
the CAI is only another $300 or so and it will make a big difference. I myself am like you where i do a lot of 30MPH city driving here in NJ. But with the CAI and tune i get much better throttle response, better MPG (you only bump up your mpg really with the CAI), and my exhaust tone is deeper and i like it!
 

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Even untuned, the PCM will throw a little more timing when it senses more octane.
Is this true of older PCMs? Mine's a '98, and I don't really feel a change when I get higher octane fuel... :scratchchin Is there a "break-in" period ,of like 3 tankfuls, of the same octane for the change to take effect? :headscratch: Or do you need to "reprogram" by disconnecting the battery to drain the PCM memory? (We do such a procedure for a CAI install so the PCM assimilates to more air coming in.)

Don't mean to hijack the thread (by going back in years)... but I think it's a valid question. :shigrin
 

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Is this true of older PCMs? Mine's a '98, and I don't really feel a change when I get higher octane fuel... :scratchchin Is there a "break-in" period ,of like 3 tankfuls, of the same octane for the change to take effect? :headscratch: Or do you need to "reprogram" by disconnecting the battery to drain the PCM memory? (We do such a procedure for a CAI install so the PCM assimilates to more air coming in.)

Don't mean to hijack the thread (by going back in years)... but I think it's a valid question. :shigrin
No the older PCMs don't have the adaptive learning and other sensors that the newer (Spanish Oak) PCMs have.
 

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Is there any official word from Ford on this? They do say that the 2010 Mustangs are programmed to provide some additional torque with higher octane fuel, but I have not seen any statements like this on the 05-09s.
 

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No the older PCMs don't have the adaptive learning and other sensors that the newer (Spanish Oak) PCMs have.
OK, thanks for answering! Sucks that mine doesn't "learn", but that just means I have to get a tuner. :shigrin (Also, I didn't think I noticed any change... so it's good that I wasn't supposed to! :hihi:)
 

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OK, thanks for answering! Sucks that mine doesn't "learn", but that just means I have to get a tuner. :shigrin (Also, I didn't think I noticed any change... so it's good that I wasn't supposed to! :hihi:)
Yea, Give Chris a call at Tillmans. He's local to us and they have a new dyno if you want to go that way.


Oh yea, and He's good. :hihi:
 

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The 2008 Bullitt had a dual mode ECU that allowed it to take full advantage of premium fuel when used. The 2009 GTs may have gotten the same system. 2005-2008s did not have it and my car never repsonded to 93 or even 110 octane. Unless your car is trimming back timing on 87, you won't notice because the computer willl only give the maximum allowed for 87.
 

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The 2008 Bullitt had a dual mode ECU that allowed it to take full advantage of premium fuel when used. The 2009 GTs may have gotten the same system. 2005-2008s did not have it and my car never repsonded to 93 or even 110 octane. Unless your car is trimming back timing on 87, you won't notice because the computer willl only give the maximum allowed for 87.
Can you point me in the direction you got that info from?
 

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Can you point me in the direction you got that info from?
I read about the dual mode ECU in the Bullitt in Car and Driver where they pitted a Bullitt against an SRT8 Challenger. Don't know the month though. Sorry man. I'm guessing GTs didn't have it because they were making it sound new and cool and from the fact that my own GT didn't feel any different, even with $8.50/gallon VP Racing 110 unleaded.
 

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I read about the dual mode ECU in the Bullitt in Car and Driver where they pitted a Bullitt against an SRT8 Challenger. Don't know the month though. Sorry man. I'm guessing GTs didn't have it because they were making it sound new and cool and from the fact that my own GT didn't feel any different, even with $8.50/gallon VP Racing 110 unleaded.
I'll have to ask Chris at Tillmans tomorrow. This is the first I've heard that.
 

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I'll have to ask Chris at Tillmans tomorrow. This is the first I've heard that.
http://www.edmunds.com/insideline/d...llit&kw=ford+mustang+bullitt&mktid=ga43150115
"The subtle stuff starts with revised programming of the engine control computer. First the redline has been bumped up 250 revs to 6,500 rpm. Second, a "dual knock" strategy in the fuel map and ignition programming allows the engine to run on either regular or premium fuel — with the V8 making the same peak power either way, but with a slightly more generous torque curve when burning the good stuff. Add in some revisions to the throttle's responsiveness and the result is an engine that actually feels more eager and more capable than the addition of just 5 percent more horsepower would suggest"
 

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Yea, Give Chris a call at Tillmans. He's local to us and they have a new dyno if you want to go that way.


Oh yea, and He's good. :hihi:
haha - yeah, I'd heard that... quite a few times actually. :D Don't worry, I've been talking with him before (in another thread somewhere)... I'll probably hit him up when the time comes. :bigthumbsup
 
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