Stupid Fuel Question

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Big Perm

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Always hear you guys talk about running rich, and running lean, and all that other crap I don't understand :D

I always put 93 in mine, but I hear others running 91 (I think some places only serve 91)....on a stock truck, does it really matter :dontknow:

In listening to you guys, read about how the tuners have to take this into account for modded vehicles, but just curious if it makes a 1/4 mile difference in a stock truck????

Thanks,

Jason
 
Big Perm said:
Always hear you guys talk about running rich, and running lean, and all that other crap I don't understand :D

I always put 93 in mine, but I hear others running 91 (I think some places only serve 91)....on a stock truck, does it really matter :dontknow:

In listening to you guys, read about how the tuners have to take this into account for modded vehicles, but just curious if it makes a 1/4 mile difference in a stock truck????

Thanks,

Jason
Click to expand...


My understanding is that it was more of an issue with the 04's. On the 05's and up they have knock sensors.

:dontknow:
 
This question could take a while to answer....:D

First let's start with the octane rating of 91 vs 93...this number is mostly determined by the area you live in and its emission requirements.

Rich vs. Lean...

the brass tax is you have a fuel MIXTURE than is being injected into your motor....that is a mixture of Air and Fuel thus the A/F ratio... the lower the number the richer the mix (more fuel less air) therefore 11.2 is RICHER than 12.0

Now here is where the Silverbacks and Fstjacks need to take over..when you are rich....you are leaving power on the table (unburned fuel) = black tailpipes....at this point you can add timing and take advantage of this extra fuel in doing so you burn more fuel...generating more power and leaning out your A/F ratio....go to far and you get detonation and we call you Blake..

like I said there are another 100 pages of info here but this a over simplified start that even I could understand...:D
 
I was curious about this too as I have noticed the tell tale black tailpipes. Admittedly I do not run my truck hard. I cruise to work and back which is a total of 8 miles r/t. Is part of the problem that I am driving too slow?..never above 50 in town. Someone told me that it has to do with the truck never warming up properly because of the short trips..
Thoughts? Suggestions?
I do occasionally take it out for a longer trip, and push it alittle harder..hehe
 
Riff62 said:
I was curious about this too as I have noticed the tell tale black tailpipes. Admittedly I do not run my truck hard. I cruise to work and back which is a total of 8 miles r/t. Is part of the problem that I am driving too slow?..never above 50 in town. Someone told me that it has to do with the truck never warming up properly because of the short trips..
Thoughts? Suggestions?
I do occasionally take it out for a longer trip, and push it alittle harder..hehe
Click to expand...


On some newer cars the ECU will force the A/F lower (richer) when the car is cold and starting up but this is temporary (like a choke)...as a rule they come rich from the factory
 
Nowwhat said:
This question could take a while to answer....:D

First let's start with the octane rating of 91 vs 93...this number is mostly determined by the area you live in and its emission requirements.

Rich vs. Lean...

the brass tax is you have a fuel MIXTURE than is being injected into your motor....that is a mixture of Air and Fuel thus the A/F ratio... the lower the number the richer the mix (more fuel less air) therefore 11.2 is RICHER than 12.0

Now here is where the Silverbacks and Fstjacks need to take over..when you are rich....you are leaving power on the table (unburned fuel) = black tailpipes....at this point you can add timing and take advantage of this extra fuel in doing so you burn more fuel...generating more power and leaning out your A/F ratio....go to far and you get detonation and we call you Blake..

like I said there are another 100 pages of info here but this a over simplified start that even I could understand...:D
Click to expand...


Many thanks for the info it is most appreciated!
Stay safe
 
Octane has nothing to do with running rich or lean. Octane is a number that relates to at what point an engine will suffer from detonation. The lower the number, the greated the risk of detonation in our engines.

For the life of me, I do not know why our engines run so rich. It wastes gas, increases emissions, and cuts down on power. Maybe Boomer or Jack can address this one. Oh, almost forgot. If you are stock it will run rich (read black pipes) regardless of what you do.
 
The higher the octane rating of a fuel the slower it burns. That is how it reduces detonation. On a DC pcm under wide open throttle it goes into open loop,meaning it bypasses the o2 sensors and is controlled by the fuel tables in the pcm. On part throttle and idle the o2 sensors read the tailpipe output and adjust fuel mixture through the pcm by controlling injector pulse width (amount of time in milliseconds that it sprays fuel). On an engine with a carburetor a higher octane fuel will make it run richer due to the slower burn rate.
 
Silverback said:
Octane has nothing to do with running rich or lean. Octane is a number that relates to at what point an engine will suffer from detonation. The lower the number, the greated the risk of detonation in our engines.

For the life of me, I do not know why our engines run so rich. It wastes gas, increases emissions, and cuts down on power. Maybe Boomer or Jack can address this one. Oh, almost forgot. If you are stock it will run rich (read black pipes) regardless of what you do.
Click to expand...


rich = less warranty repairs....:D
 
Ok, now I am thoroughly cornfused! ???

I'll just keep putting my 93 in there and call it good!
 
ntw0rk said:
Ok, now I am thoroughly cornfused! ???

I'll just keep putting my 93 in there and call it good!
Click to expand...

If you have the Stage 2 , then yes, continue using 93 octane and you will be good :D
 
So..if the stock truck normally runs rich from the factory, do I need to do anything about it?..And if so, how do I go about this?..Is this where a flash is needed?..Sorry, when it comes to the stuff that make this thing run, I am lost. Also, should I be using an injector cleaner?..and if so, what?
 
It will run rich from the factory because Dodge doesnt want you to damage the motor, specifically because they know that people are DEFINATELY going to run 87 octane in these trucks. Some people are hardheaded or just plain dont listen. So, they have to make the truck where it wont BLOW UP if you do so (put 87 in it). Thats ONE reason why they send em tp us PIG RICH! Also its alot safer and u are less likely to break shit.....oh yeah...kiss my ass Mike, you are about to join the club....hehehe
 
I always run 93. My truck is bone stock. I have seen people talk about
"Flash" or ECM upgrades. Mopar, DC, Boomer, ect... What would be recommended.
I may do an exhaust and Air Intake, but that will be about it.

Any Help would be appreciated.
MN
 
MikeNice said:
I always run 93. My truck is bone stock. I have seen people talk about
"Flash" or ECM upgrades. Mopar, DC, Boomer, ect... What would be recommended.
I may do an exhaust and Air Intake, but that will be about it.

Any Help would be appreciated.
MN
Click to expand...


Hey Mike before you start modding think about what your end goal is going to be. But I will try to help you our here. The flash, ECM and PCM is the same thing. Mopar has one, DC has one and Boomer has one. The flash does a lot of things, but some of those won't benifit you because you have a RC. So that being said a PCM flash will give you the following:

STAGE 2(91 or 93 OCT)- Revised aggressive timing & fuel tables(Auto/Manual), Shift point raised to 5950 rpm, Rev limit raised to 6200 rpm, Hyd fan duty cycle modified approx. 15 degrees cooler, Torque management modified(Automatic only).This upgrade has dyno power gains of approx. 80HP/100 ft lbs torque @ 3500 RPM. "Based on 05SRT10 automatic tested at DCPERFORMANCE

Now as I said you won't get all those as you have a RC. So the things not associated with the automatic you get. Now for exhaust and intake. This comes down to your prefence. A lot go with Magnaflow for the exhaust. Some have borla, other have mopar, roe racing, etc. You should go with the sound you like the best. There is power to be gained by getting rid of all 4 cats. Or you can drop the rear 2 cats and go with hi-flows for the front. If you lose the front 2 cats then you will need sims so you don't throw a check engine light.

Intake is once again what you want. Some say just a drop in K&N filter is just as good as the CAI. There are a few different brands out there. There is one that makes the hood scoup functional. Some say gains with intakes, some say no gains. Again your choice.

I don't know if I helped you or made things more cloudy. I would sit down and think about what I want out of the truck. If you plan on going FI then hold off on the mods till you figure out your plan. If you plan on staying NA then intake/exhaust/PCM flash is a good idea. You can get a VEC2 instead of the PCM flash. Mixed opinions on that one. A call to your vendor of choice might be in order. Tell them what you want to do with the truck and maybe then can help you pick out your mods. Or give me your credit card info and I will just order you some stuff.

Smoke
 
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