higher octane fuels

[Cannonball]

is it safe to run higher octane un-leaded fuels in the GTR?
will the ECU adjust? can you expect any more power as a result?

[bluebird]

is it safe to run higher octane un-leaded fuels in the GTR?
will the ECU adjust? can you expect any more power as a result?

Let me clear up a few things here for you. Higher oct fuels do not make more power. They allow you to make more power. Now that we got that striaghtened out. In this case its all about tuning. If you plan on running higher oct fuel and increasing boost yes you will make more power, but as of right now we are not quite sure how the stock ecu will react to this or if it will be safe.

Most would like to say that it would adjust accordingly, but we do not know this for sure yet. My best advice to you is hold on and stay tuned when this info has been confirmed we will let you know.

[Cannonball]

thats what I meant...will the ECU adjust to the higher octane gas and allow for more power. with my Porsches the ECU adjusts to the higher octane fuel with much more aggressive tuning resulting in a noticeable difference.

[bluebird]

thats what I meant...will the ECU adjust to the higher octane gas and allow for more power. with my Porsches the ECU adjusts to the higher octane fuel with much more aggressive tuning resulting in a noticeable difference.

There re electronic devices that do allow for the tunability to allow more boost levels and higher oct levels. However, as of right now we do not have any conclusive evidence that the stock ecu actuates to these differences.

What year and model is your porsche? And what exactly does your ecu do to accomodate for the higher oct levels. You said you notice a huge difference. Well what do you notice?

[Cannonball]

I have 996TT and a 997. the 997 is a converted race car, not a cup car. I keep the car at my local track (like a country club) where they only ever have pump gas, but when I take the car to a race I run sunoco 110. on my loacal track, I have been able to do a few laps with the 110 still in it, and I am on average about 2 sec faster, its a 1.7 a track that I know very well.

with my 996tt, the times that I have run higher octane fuels the car feels wicked fast, I have never dynoed it with and with out to know the true difference

[bluebird]

What track do you run at? And your times could be attributed to many other things other than race fuel. If you did nothing mechanically (ie. increase boost) to accommodate the race fuel then you literally are just dumping race fuel in for no reason.

And I can gaurantee you that you are running faster times due to different reasons.

Now I dont know everything there is to know about porsche but there could be something like a electronic boost controller embedded into the stock ecu system that actuates the increased boost when it detects higher oct levels in the fuel system but something like this is highly unlikely and you would know about it if there was something like that.

But like I said unless you had actually increased boost somehow your time differences could be attributed to something like tire pressure or better apexi choices.

[Cannonball]

my 997 is not turbo its just a regular C2, I run it nationally, but I keep it at a local track in texas, thats where I notice the difference with and with out the race gas. and its noticable with in fillups 10 min apart. Usually I run 1:20s on 110 I am running 1:17s, and at the end of the straights I am seeing higher RPMs, I also change tires every 20 min. The ECU is suppose to adjust for the higher octane fuel. its a stock motor, not a cup car motor, stock ECU.

my turbo is something else, I might see if someone will dyno it with and with out

[bluebird]

Well if the ecu is allowing higher rpms due to fuel oct that the first time I have ever heard of that. And I just dont think its attributed to the ecu allowing higher rpms cause fuel oct has nothing to do with rpms. Now compression yes. But rpms are regulated by a governor(thats if the porsche comes with one stock).

[Cannonball]

no I am hitting higher RPMs at the end of the straights, before braking, so I know I am accelerating faster. not adding RPMS

[09-TITANIUM]

Let me clear up a few things here for you. Higher oct fuels do not make more power. They allow you to make more power. Now that we got that striaghtened out. In this case its all about tuning. If you plan on running higher oct fuel and increasing boost yes you will make more power, but as of right now we are not quite sure how the stock ecu will react to this or if it will be safe.

Most would like to say that it would adjust accordingly, but we do not know this for sure yet. My best advice to you is hold on and stay tuned when this info has been confirmed we will let you know.

bluebird - have you seen any recent news about the addition of higher octane to a tank to raise the running octane; for track purposes?

[bluebird]

bluebird - have you seen any recent news about the addition of higher octane to a tank to raise the running octane; for track purposes?

I am not so sure I have your question correct. Are you asking if you add higher oct fuel to pump fuel will it raise the oct levels?

[09-TITANIUM]

I am not so sure I have your question correct. Are you asking if you add higher oct fuel to pump fuel will it raise the oct levels?

bluebird - you gave us some excellent advise (7-29-09): "If you plan on running higher oct fuel and increasing boost yes you will make more power, but as of right now we are not quite sure how the stock ecu will react to this or if it will be safe.

I was just following up on that. Thanks.

[bluebird]

bluebird - you gave us some excellent advise (7-29-09): "If you plan on running higher oct fuel and increasing boost yes you will make more power, but as of right now we are not quite sure how the stock ecu will react to this or if it will be safe.

I was just following up on that. Thanks.

Oh yes ok. As of right now we still do not know that if adding higher oct fuel to the A/F mixture if the stock ecu will adapt. This is something not likely to happen as many stock ecu systems dont have that capacity to reprogram itself according to the oct of fuel.

Now I can confirm to you that there are devices that piggy back the ecu to adapt to these changes in the fuel and they are available to the market very soon. You can also add on a mbc or ebc to control boost levels for the higher octane and the ecu will act accordingly. So theres your answer in a nutshell.

Hope that answered some of your questions.

[09-TITANIUM]

Oh yes ok. As of right now we still do not know that if adding higher oct fuel to the A/F mixture if the stock ecu will adapt. This is something not likely to happen as many stock ecu systems dont have that capacity to reprogram itself according to the oct of fuel.

Now I can confirm to you that there are devices that piggy back the ecu to adapt to these changes in the fuel and they are available to the market very soon. You can also add on a mbc or ebc to control boost levels for the higher octane and the ecu will act accordingly. So theres your answer in a nutshell.

Hope that answered some of your questions.

It does and thank you.

[RastaKid]

Higher oct fuels don't make more power.If you run higher oct fuel and increasing your boost you'll have more power.But I don't know if it's safe.

[bluebird]

Higher oct fuels don't make more power.If you run higher oct fuel and increasing your boost you'll have more power.But I don't know if it's safe.

Please read the rest of the thread as this has already been covered. thank you

[DarinF]

The answer is YES, using higher octane fuel gives you better performance with no mods.

I use 100 Octane here and did dyno runs using a stock map and then the 93 octane stage 1 map from the Cobb AccessPort.

See dyno here. 100 Octane fuel got stock all wheel horsepower to 444! Almost 490 with the stage 1 93 octane map!

http://media.budez.com/gtr/kunani/kunani_gtr_dyno_mustang_100oct.jpg

Most dynos with 91 Octane are coming in at around 420 for a stock 480hp at the crank GTR. Which is about 12% loss. Using that calculation you can guestimate about 505 at the crank with just 100 octane fuel.

[bluebird]

^Darin, it is inaccurate to say 100oct with no mods makes more power. Because that is false you did mod it via the dyno tune w/ the accessport. That is a modification. You are modifying the parameters of the vehicles ecu. May not be a bolt-on mod but its definitely a mod nonetheless.

You cant just add in 100oct to any vehicle and utomatically make more hp without doing some type of tuning or increasing boost levels.


Btw, usually on a mustang dyno you will get lower numbers than on a dynojet or a dyno dynamics dyno. So on those dynos you would probably see a 5-10% increase in numbers. Just letting you know.

But very impressive nonetheless.

[DarinF]

No, the stock run is stock, no cobb tune.. only 100 octane. Stage 1 with 91 octane pulled 459 at the wheels. So the 444 at the wheels is a stock car with 100 octane.

[bluebird]

No, the stock run is stock, no cobb tune.. only 100 octane. Stage 1 with 91 octane pulled 459 at the wheels. So the 444 at the wheels is a stock car with 100 octane.

That makes no sense darin. If you put 100oct in and got less power then why would you even mention this? So the stage1(which I am assuming you mean the your first dyno pull) is with 91 oct no modifications or tuning involved? And then when you put 100oct in and on your second dyno pull with no dyno tuning or mods you got 444awhp which is a 15whp loss when compared to your first run with 91 oct.
Also why did you mention the accessport if you never used it on those runs?

It looks like you used the accessport for the 93oct dyno pull and didnt for the 100oct pull. Because thats what you had said in your post unless I am misreading it but then again I am a little confused on this entire ordeal here.

My point is this just adding a higher oct fuel into a car without any tuning or midification WILL NOT net you any gains in hp or tq. A matter of fact its actually worse due to the fact that the fuel is harder to burn. And these cars from the factory were designed to run on 91 or 93 oct.

To even run 100oct efficiently you would have to increase boost or compression somehow.

Please clear up what you are trying to convey. thanks bud

[DarinF]

Okay to sum it up... the stock run is stock with 100 octane fuel. Day before I ran 91 octane WITH AP tune and it did 459 whp.

So stock with 100 octane did 444 whp, 91 octane Stage 1 91 Octane Tune did 459, and 100 Octant Stage 1 93 Octane Run did 486 whp.

I know its confusing because of the order I did the runs:

1. day 1 was 91 octane stage 1 91 octane tune.
2. day 2 was 100 octane stock tune and 93 octane stage 1 tune with access port.

The way I'm phrasing it is the way it shows up on the access port Stage 1 93 Octane, etc.. Not necessarily running 93 octane fuel :)

Make more sense?

The 100 octane gave it an increase over the 91 octane I have here in Vegas with a stock map. Dont ask me HOW it does it, I'm just showing you the numbers.

[DarinF]

Also, perhaps you didnt see the last bit of my original post, stock 91 octane does about 420 whp which is about 12% loss from the 480 crank hp stated by Nissan.

[bluebird]

Okay to sum it up... the stock run is stock with 100 octane fuel. Day before I ran 91 octane WITH AP tune and it did 459 whp.

So stock with 100 octane did 444 whp, 91 octane Stage 1 91 Octane Tune did 459, and 100 Octant Stage 1 93 Octane Run did 486 whp.

I know its confusing because of the order I did the runs:

1. day 1 was 91 octane stage 1 91 octane tune.
2. day 2 was 100 octane stock tune and 93 octane stage 1 tune with access port.

The way I'm phrasing it is the way it shows up on the access port Stage 1 93 Octane, etc.. Not necessarily running 93 octane fuel :)

Make more sense?

The 100 octane gave it an increase over the 91 octane I have here in Vegas with a stock map. Dont ask me HOW it does it, I'm just showing you the numbers.

Ok that makes much more sense thanks for clearing that up for me. Sorry I was a little confused.

However, I am not suprised that with less oct you made more hp with a tune than without a tune with more oct. Reason being as I stated before because the higher oct is harder to burn.

And to your last notion that the 100oct with stock tune gave is an increase over the 91oct and stock tune I would like to see those numbers as well as it doesnt make sense to me.

However, the dealers hp numbers are all crank hp numbers not awhp numbers. And the dyno numbers are usually always in whp numbers. So 480crank hp from the factory is usually a 10-15%decrease of that for whp. So if you dynoed 420awhp on 91 stock map tune then that soudns about right so nissan was pretty accurate with their numbers.

So pretty much after the tuning and fuel mixture was complete you were able to increase your stock awhp numbers to about 16%. Not bad at all. And I gaurantee you that if you added on a tbe you would break the 500awhp mark.

[DarinF]

Next is Stage 2 100 Octane map with my Amuse Titanium and High Flow cats but will have to wait about a month to get it. I'll post new dyno sheets then!

Going to loose some weight in the wheel/tire area, seats, and trying to get some CF hood research done to see if I can save some weight there as compared to stock (have not weighed the stock hood yet but it sure feels heavy when lifting it :)

[bluebird]

Next is Stage 2 100 Octane map with my Amuse Titanium and High Flow cats but will have to wait about a month to get it. I'll post new dyno sheets then!

Going to loose some weight in the wheel/tire area, seats, and trying to get some CF hood research done to see if I can save some weight there as compared to stock (have not weighed the stock hood yet but it sure feels heavy when lifting it :)

Very nice choice for a exhaust be sure to get the full tbe. And also get the 02housings if you can. Makes a huge difference for spool. As far as your hood is concerned I am pretty sure they are aluminum and if thats the case chances are they are lighter than the cf hoods. I know that is the deal with the evo hoods. They are actually lighter than the cf hoods. The only thing is you have to take off that underpanel stuff because that itself weighs another 5-7#.

But regardless I think your next mod choices are good ones. Also if you really want more hp then get a mbc or ebc so you can increase boost levels however keep in mind when you do this you will obviously have to get retuned and then the 100oct will really come in handy.

[elvenrunelord]

I would advise you to hold off on using anything above 93 octane until the modders have had time to test and play with the higher O fuels.