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Discussion Starter · #1 · (Edited)
Hi Guys,

A couple of questions. In a couple days I'm resieving the DiabloSport inTune: Gas and Diesel (I1000). For the most part I'm using regular unleaded for my Charger. But I was reading is that the diablo sport's best programs were 91 octane. Is it ok to just switch octanes? Is their any harm I could cause to the engine?

Also say if I wanted to run the fuel economy and then on the weekends switch to a preformance program. Is it ok to to just switch tune programs when I feel like it or does it cause problems down the road and I'm better off sticking with just one?

I know these sounds like kind silly or basic questions but I really want to know. I'm learning quickly the new 5.7 chargers are a bit more complex then the old school b bodys lol So I want to make extra sure I'm doing things right.
 

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Hi Guys,

A couple of questions. In a couple days I'm resieving the DiabloSport inTune: Gas and Diesel (I1000). For the most part I'm using regular unleaded for my Charger. But I was reading is that the diablo sport's best programs were 91 octane. Is it ok to just switch octanes? Is their any harm I could cause to the engine?

Also say if I wanted to run the fuel economy and then on the weekends switch to a preformance program. Is it ok to to just switch tune programs when I feel like it or does it cause problems down the road and I'm better off sticking with just one?

I know these sounds like kind silly or basic questions but I really want to know. I'm learning quickly the new 5.7 chargers are a bit more complex then the old school b bodys lol So I want to make extra sure I'm doing things right.
Running a higher octane wont hurt anything, especially with the tune, without the tune you are just wasting money on gas.

Switching tunes would be ok, HOWEVER DO NOT do run a 91 or 93 octane tune if you still have 87 in your tank.
 

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You need to run the appropriate fuel for each tune, as stated.
You CAN run higher octane with a lower tune, although it's a waste.
You don't want to run 87oct fuel with a 93 tune.

Try the 93 tune, I've had best power with it, I can't imagine why people say the 91 is better than 93 if you can get the right fuel.


You asked a fuel octane question.

Wait for it...


3


2


1...
 

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Discussion Starter · #5 ·
Good to know. Thanks for the reply. So you just have to the octane gas for the tune and I should be all good.
 

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Shop around. I notice different results depending on the gas station too. There's a Sunoco that has 93 octane and it's like rocket fuel with 93 tune. Other stations like Hess, Delta Sonic, Mobil don't offer as much of a kick with their 93 octanes.
 

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I dont think the OP understands how all this works....You cant pump 93 octane gas in your tank and run a 93 tune if you have a lower octane gas left in your tank....To make it simple lets say you have 10 gallons of 87 in your tank. You then pump in 10 gallons of 93 octane...the octane of the gas in your tank is now 90 octane....

In other words you need to decide what tune you want to run and stick with it....
 

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Discussion Starter · #8 · (Edited)
That makes sense.

The reason I ask is because new cars CPUs are different and I want to keep my charger running good. The hemi 5.7 is a pretty versatile engine from what I was reading. It can be put in a car or truck and tuned in a certain way and configs to do its job. One of the reasons I decided to get the tuner.

So I really wanted to know if switching octanes has a bad effect on the engine over time. Or switching tunes. So I just should make sure I have the gas in the tank for the tune. Maybe run through a tank for the tune I want to due 1st. From what I taking from what you guys say.
 

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Your best bet is to use (for instance) a 91 tune, the appropriate gas, and stick with it.

Let me explain a few things.

First of all, the higher octane ratings don't mean there's more power in the gas. As it happens, there's less, but that's not important. Higher octane fuel is more difficult to ignite. Lower octane fuel is more volatile and ignites more easily. So, if you've got an aggressively designed and tuned engine, it's possible for an air/fuel mix to ignite before you want it to in your cylinder stroke. Imagine really volatile fuel that could ignite simply because of remaining heat in the cylinder. It'd pop the moment it was injected into the cylinder, not when the spark plug fires. Well, more ignition-resistant fuel wouldn't do that, it'd wait until it was intended to be ignited. The point here is that if your tune calls for 89 and you put in 91 or 93, nothing bad happens because the higher octane fuel doesn't pre-ignite (knock). If your tune calls for 93 and you put in 87, that fuel is likely to pre-ignite (knock). Knock both screws up your performance and fuel economy but can also damage the engine.

Next, about flip-flopping between tunes. Once a year or something, sure. Before a really long trip, sure. But each time you flash a tune into your PCM (powertrain control module), a bunch of adaptive values are reset. The PCM goes to a defaults mode until it can gather a bunch of statistics. Say you've been running an aggressive tune on high-octane gas. You fill the tank with 87, drop to your stock tune (which can adjust to use that), and start driving. The engine is not optimized yet, and will therefore burn more fuel than it eventually will. It takes maybe half a tank to gather appropriate stats to mellow out. So for your first tank switching back to "cheap gas", you're going to waste some of it.

After I got my cam job done, I was going to through tuning cycles and it really, really sucked. I had some mechanical issues at the time but each time I flashed a tune in, the next tank was brutally sucked dry. Only once I could make it into a second tank on a given tune would I see reasonable fuel economy return.

Shift (fuel) or get off the pot. The price difference from 87 to 91 isn't that big a deal compared to what you must have paid for the inTune.
 

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That makes sense.

The reason I ask is because new cars CPUs are different and I want to keep my charger running good. The hemi 5.7 is a pretty versatile engine from what I was reading. It can be put in a car or truck and tuned in a certain way and configs to do its job. One of the reasons I decided to get the tuner.

So I really wanted to know if switching octanes has a bad effect on the engine over time. Or switching tunes. So I just should make sure I have the gas in the tank for the tune. Maybe run through a tank for the tune I want to due 1st. From what I taking from what you guys say.
Steve, what you have to understand is that your car has a speed density system. This determines the pulse width (time your injector is open) based on parameters that are designed into your car's operating system.

Here is a link to understand more:

http://www.chargerforums.com/forums/showthread.php?t=153841&highlight=speed+density

Remember that the most power is produced by the most efficient burn.....PERIOD! What you want to do is balance the amount of octane with the car's needs. You want the lowest octane value without detonation.

What you are really looking for is the most amount of energy in the fuel released as work at the most appropriate time to produce the most power and torque. Your tuner will help you do that. The other thing that will do this for you is ACES IV in the gasoline. It is designed to produce more power per fuel charge as it converts more of the potential energy of the gasoline into kinetic energy or work energy.

People who use ACES IV with 89 octane fuel can run 91 and 93 octane tunes with your Diablo. Most of the time, you can get more power and torque while getting more fuel economy as well. But remember that a tuner is biased towards performance at the expense of mileage.

Simply dumping more fuel in will not do anything but use more fuel and wash down your cylinders with unburned and partially burned fuel......creating more carbon and wiping out your detergents and dispersants in your engine oil.

Speed density is a good thing, and ACES IV helps you get all you can out of your new tuner!:beerchug:

Regards,
Brian
BND Automotive LLC:driving:
440-821-9040
www.bndautomotive.com
 

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Discussion Starter · #11 ·
Interesting, thank you for the reply. The info about the octanes types was informative. This helpful because I have only made small changes and not done a full on tune with my new unit yet.

Now for the tune I want is, faster throttle response, exell and shift points. But I don't want to over do it, nothing to drastic. My mechanic informed me that my rear wheel bearings need to be swapped out in the next visit or so. He noticed some play. Its not critical but will need to be done. So I don't want to push it too hard.
 

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Sorry to thread jack but I didn't want to start another DiabloSport product question thread.

In the InTune where it says "Reset TCM adaptives", is that like pulling the fuses in the trunk to reset throttle?

Sent from AutoGuide.com Free App
 

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Discussion Starter · #13 · (Edited)
Intune Recap

I applied my 1st tune a few months ago, I decided to go with the (PCM) tune I think its called. It said it was the more balanced of the tunes and did not seem to require a change of octane. Power, Torch and Fuel Econ. I'm going to stick with that and may go with a more aggressive tune after my next service. I also decided to leave the shift points, and other setting alone just for the time being.

Right off I noticed the engine, seems to run a bit smoother. It also seemed quite abit quicker. In some instances it gets much better gas millage, like on the high cruising 55 to 70 mph, I've around 26 mpg and as high as 27. Down hills even higher of course. Accel seems to be much faster in ideal dry conditions. This is with K&N forced air too. One big thing that caught me off guard at 1st was how much new rear wheel torch there was. Using the select able shift and flooring results in the tail and kicking out slightly and light smoke coming out of the rear tires well after a complete stop, which is fun. It did this before but now its more noticeable. This with the traction control on. I learned vary quickly to be careful going around corners in the rain, I had it kick out really bad one time and it scared the crap out of me lol. Because I really didn't apply what I thought would be too much throttle. Not so much fun lol. It almost seems like it maybe new tire upgrade time. It did not do that before the tune, its def more of charger Jackle and Hyde nature that we love.

So I'm def more mindful when the roads are wet or icy. But over all I really think the doing the tune was well worth it over all.
 

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Sorry to thread jack but I didn't want to start another DiabloSport product question thread.

In the InTune where it says "Reset TCM adaptives", is that like pulling the fuses in the trunk to reset throttle?

Sent from AutoGuide.com Free App
No, fuse-pulling typically resets the PCM adaptives - the adaptation associated with the amount of air/fuel/spark. Resetting the TCM adaptives puts the transmission back into a more aggressive mode.

Not sure which fuses in the trunk you're pulling but the ones I'm familiar with for resetting PCM adaptives are under the hood, not in the trunk.
 

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No, fuse-pulling typically resets the PCM adaptives - the adaptation associated with the amount of air/fuel/spark. Resetting the TCM adaptives puts the transmission back into a more aggressive mode.

Not sure which fuses in the trunk you're pulling but the ones I'm familiar with for resetting PCM adaptives are under the hood, not in the trunk.
Or under the hood not quite sure. But is it the same as doing that? Some people swear by it. So I was just wondering. I want to try it but not mess anything up.

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Or under the hood not quite sure. But is it the same as doing that? Some people swear by it. So I was just wondering. I want to try it but not mess anything up.

Sent from AutoGuide.com Free App
If you want to reset the transmission adaptives (for firmer shifting) do the Reset TCM Adaptation from the handheld tuner. It's different than clearing the PCM adaptives by pulling fuses.
 
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