ok, car magic to go with windows magic

[Steevo]

?

I always thought if you let your car run out of gas and it starts knocking that it was a bad thing.

Almost all fuel injected cars have a knock sensor that reads the harmonics caused by knocking and will alter the ignition timing to prevent damaging knock. Some knock however is good, it allows the fuel-air to be completely burned at maximum pressure in the cylinder to provide the most power.

I have done enough research on chamber design, flame front travel, quench zones, water injection, rotating mass, and ignition to almost fill my head.


For example the Hemi is the worst cylinder design for flame travel and pre-detonation characteristics, But one of the better designs for pressure area. The Caddy Northstar pent roof chamber is the best design for flame travel and pre-detonation, but has a lower efficiency in pressure transfer.


The optimal design is a pent roof to provide a open space for flame travel, quenching the areas near the outer edges of the piston with no sharp edges to impede flame travel or to get hotter than the surrounding surfaces to prematurely ignite the mixture.


Water injection is only beneficial if you can further lean out your mixture and generate more heat to effectively use the water in both lowering detonation tendency, and increasing cylinder pressures.


The length of the connection rod, and compression ration in a proper breathing engine (80% +) are the factors that determine HP and torque ratings and at what RPM, a short stoked engine with a short rod will allow faster acceleration of the piston away from the highest pressure point during combustion, and will cause low torque but more HP, whereas a short stroke engine with a longer connection rod increases dwell time during the high pressure phase of the combustion. This increases torque, but decreases HP. All these are factored by the piston pin height in relation to the top of the piston. A shorter rod will increase cylinder wall wear from the piston canting more, but a anti-friction coating can be applied.


So many people talk today about the size of valves, intakes, exhaust, etc.... But what really matters is the flow of a engine, a 70% flow efficiency 350 might achieve 80% with the bolt on and standard mods like high lift cams with more duration, increasing the valve size, porting and polishing. With all that it can have a streetable 500WHP in numerous cars for a price of $3000 for the engine if you can do most of the easy work yourself.


Take a 85% 280 WHP 3.8L car and add a turbo and you have 135% efficiency, add water cooling and you jump to 145% and are putting 460HP + down As the turbo pressure increases the flow and efficiency % over a naturally aspirated engine rises, more dramatically with higher efficiency engines, and with a proper set of cams to provide overlap and add the scavenging effect that number rises again. Take your daily driver and $2,000 and have a hell of a car.

 

[Perris Calderon]

Almost all fuel injected cars have a knock sensor that reads the harmonics caused by knocking and will alter the ignition timing to prevent damaging knock. Some knock however is good, it allows the fuel-air to be completely burned at maximum pressure in the cylinder to provide the most power.

I have done enough research on chamber design, flame front travel, quench zones, water injection, rotating mass, and ignition to almost fill my head.


For example the Hemi is the worst cylinder design for flame travel and pre-detonation characteristics, But one of the better designs for pressure area. The Caddy Northstar pent roof chamber is the best design for flame travel and pre-detonation, but has a lower efficiency in pressure transfer.


The optimal design is a pent roof to provide a open space for flame travel, quenching the areas near the outer edges of the piston with no sharp edges to impede flame travel or to get hotter than the surrounding surfaces to prematurely ignite the mixture.


Water injection is only beneficial if you can further lean out your mixture and generate more heat to effectively use the water in both lowering detonation tendency, and increasing cylinder pressures.


The length of the connection rod, and compression ration in a proper breathing engine (80% +) are the factors that determine HP and torque ratings and at what RPM, a short stoked engine with a short rod will allow faster acceleration of the piston away from the highest pressure point during combustion, and will cause low torque but more HP, whereas a short stroke engine with a longer connection rod increases dwell time during the high pressure phase of the combustion. This increases torque, but decreases HP. All these are factored by the piston pin height in relation to the top of the piston. A shorter rod will increase cylinder wall wear from the piston canting more, but a anti-friction coating can be applied.


So many people talk today about the size of valves, intakes, exhaust, etc.... But what really matters is the flow of a engine, a 70% flow efficiency 350 might achieve 80% with the bolt on and standard mods like high lift cams with more duration, increasing the valve size, porting and polishing. With all that it can have a streetable 500WHP in numerous cars for a price of $3000 for the engine if you can do most of the easy work yourself.


Take a 85% 280 WHP 3.8L car and add a turbo and you have 135% efficiency, add water cooling and you jump to 145% and are putting 460HP + down As the turbo pressure increases the flow and efficiency % over a naturally aspirated engine rises, more dramatically with higher efficiency engines, and with a proper set of cams to provide overlap and add the scavenging effect that number rises again. Take your daily driver and $2,000 and have a hell of a car.

nice post Steve, educational

let's talk about the ecu and the real reasons going low on gas is bad

first, the ecu recognizes knock and pulls timing to compensate, knock is caused by the fuel igniting before the engine can use it, so when it happens the knock sensors trip the ecu, the ecu pulls timing to the point that the fuel isn't igniting when it shouldn't

but the ecu can only pull timing so much, it doesn't have an infinite range and depending on how high an octane the engine is tuned for, the ecu can only pull timing within a certain perameter

for instance, my car is tuned to about 98 octane straight from pontiac, no ecu reflash, they did this because the advanced ecu has no problem dealing with lower octane, it just pulls timing in real time

I can use safely common gas, 93 octane is recommended and this ecu is capable of pulling timing down to accommodate as low as 87 octane

if I have lower then that there will be knock the ecu cannot compensate and there will be engine damage

now to the low tank of gas as it relates to knock

if driving on a low tank of gas caused knock it's because of contaminants making the fuel more volatile, the ecu is probably not going to be able to pull timing accordingly the octane is too low, so even though there are knock sensors and timing pull, if there is more volatility then the engine is capable of accomodating, you will get engine damage

but knocking or internal engine damage is not the real reason you don't want to run low on gas Steve

the real reason is you don't want to kick up the sludge that develops from contaminants you acquire pumping gas

you don't want to tax your gas filter

you also really don't want the fuel lines to run dry, though today with electric fuel pumps re primming the engine doesn't take much but here's an example of why it's bad

I have the ecotech direct injection variable valve twin turbo engine, I believe there is not a more advanced design on the market, this tiny four cylender engine displacing only 2 litres makes 260 horsepower out of the box and that is ecu restricted with it actually making about 320 no mods what so ever...to put this into perspective, the old 8 cylendar super cars were rarely rated over 300 horsepower and that was the engine before install, it wasn't even rated at the flywheel, they only held up for about 50,000 miles too, so this little 2 liter is a marvel of technology

this engine actually uses the gas injected as one of the cylinder lubricants and cylinder coolants

if you run out of gas on this car and the fuel pump surges the remaining bits of fuel, you are left with an engine starving for coolant and lubricant as it spins waiting for the next charge of fuel

now, I am not certain the engine will realize damage from that lubricant starvation but you wouldn't know until the engine almost ran it's complete duty cycle, instead of needing rings at say 300,000 miles you might need them at 280,000 and you wouldn't even know to attribute that wear on running out of gas

in any event, the real reason is to keep your fuel filter from having to filter out the sludge you kick up when you run the tank close to the bottom

now about that water injection;

the real purpose of water injection is to raise the octane of your fuel so you can use more spark, with water injection you are running at virutally 115 octane and if the ecu can see that there is no knock it can advance timing to that level, wherein most ecu's aren't tuned to take advantage of octane that high, water injection wouldn't do as much as it can regardless of the type of aspiration, in addition, a normally aspirated car should benefit from water injection if you tuned the ecu to advance spark accordingly

 

[Steevo]

nice post Steve, educational

let's talk about the ecu and the real reasons going low on gas is bad

1) first, the ecu recognizes knock and pulls timing to compensate, knock is caused by the fuel igniting before the engine can use it, so when it happens the knock sensors trip the ecu, the ecu pulls timing to the point that the fuel isn't igniting when it shouldn't

but the ecu can only pull timing so much, it doesn't have an infinite range and depending on how high an octane the engine is tuned for, the ecu can only pull timing within a certain perameter

for instance, my car is tuned to about 98 octane straight from pontiac, no ecu reflash, they did this because the advanced ecu has no problem dealing with lower octane, it just pulls timing in real time

I can use safely common gas, 93 octane is recommended and this ecu is capable of pulling timing down to accommodate as low as 87 octane

if I have lower then that there will be knock the ecu cannot compensate and there will be engine damage

now to the low tank of gas as it relates to knock

if driving on a low tank of gas caused knock it's because of contaminants making the fuel more volatile, the ecu is probably not going to be able to pull timing accordingly the octane is too low, so even though there are knock sensors and timing pull, if there is more volatility then the engine is capable of accomodating, you will get engine damage

but knocking or internal engine damage is not the real reason you don't want to run low on gas Steve

2) the real reason is you don't want to kick up the sludge that develops from contaminants you acquire pumping gas

you don't want to tax your gas filter (TRUE)

you also really don't want the fuel lines to run dry, though today with electric fuel pumps re primming the engine doesn't take much but here's an example of why it's bad

I have the ecotech direct injection variable valve twin turbo engine, I believe there is not a more advanced design on the market, this tiny four cylender engine displacing only 2 litres makes 260 horsepower out of the box and that is ecu restricted with it actually making about 320 no mods what so ever...to put this into perspective, the old 8 cylendar super cars were rarely rated over 300 horsepower and that was the engine before install, it wasn't even rated at the flywheel, they only held up for about 50,000 miles too, so this little 2 liter is a marvel of technology

this engine actually uses the gas injected as one of the cylinder lubricants and cylinder coolants

3) if you run out of gas on this car and the fuel pump surges the remaining bits of fuel, you are left with an engine starving for coolant and lubricant as it spins waiting for the next charge of fuel

now, I am not certain the engine will realize damage from that lubricant starvation but you wouldn't know until the engine almost ran it's complete duty cycle, instead of needing rings at say 300,000 miles you might need them at 280,000 and you wouldn't even know to attribute that wear on running out of gas

in any event, the real reason is to keep your fuel filter from having to filter out the sludge you kick up when you run the tank close to the bottom

now about that water injection;

4) the real purpose of water injection is to raise the octane of your fuel so you can use more spark, with water injection you are running at virutally 115 octane and if the ecu can see that there is no knock it can advance timing to that level, wherein most ecu's aren't tuned to take advantage of octane that high, water injection wouldn't do as much as it can regardless of the type of aspiration, in addition, a normally aspirated car should benefit from water injection if you tuned the ecu to advance spark accordingly

1) A few degrees after TDC (top dead center) is enough to compensate for predetonation as long as no other factor is involved. Regardless of fuel mixture. Some cars cannot do this, and have a remote possibility of damaging the engine with pressure spikes caused by the detonation instead of a burn.


2) Every car has the fuel pickup tube placed in the lowest part of the tank. Otherwise there would be no way of completely pumping a tank dry so you could remove it safely. I have done this on numerous cars when replacing the in tank pump.

3) Gasoline is NOT a lubricant, ever. Every time you rev the engine and then let off there is no fuel present in the cylinder. None, ever, when the RPM is higher than the cutoff point and the throttle is at idle the fuel is cut completely. Gasoline DOES act as a coolant, but for it to achieve that status it has to be a much higher mixture than stoichiometric and thus the problem that it DILUTES the oil residue on the cylinder walls making the oil burn. But that is a issue more between the oil anti-friction additive and the lubricity index for a particular motor. For your motor GM did a whole study about spray pattern to make sure the spray was confined and wouldn't wash the cylinder walls.

4) Octane is the rating of tendency to spontaneously ignite at a set temperature and pressure. The higher the rating the less the tendency to detonate and instead burn in a controlled fashion. http://www.familycar.com/Classroom/fuel.htm Adding water injection has been a topic of hot debate for a few years now, one side saying that water injection will improve anything, but providing little more than seat of pants feel or one example with no control group. For example one man has a site up about adding a fish tank filter and a hose for water injection, not realizing that he was really only leaning out the mixture of his carburated car, and implying his profoundly better fuel mileage was due to this contraption, no hard evidence was provided. When I drive normally my Celi gets about 24MPG, but when I have a cake in the car I drive more gently avoiding fast starts and hard braking then I get 31MPFG. So in all reality I could say that a cake has added 7MPG to my car!!!!!!!!!!! That is meaningless data, when we look at hard data we find that water injection does two things.

Reduces air charge temperature thus increasing density.
Takes heat away from the combustion process.


So with those two definates in place we can derive the benefit to cost of adding water injection.

First we must understand that heat is what drives the engine, the gasoline burns in air causing rapid massive expansion of the gases in the cylinder. The less heat the less expansion.

Second that the amount of fuel able to be burnt during the process is what determines power output. When you have a less then optimal mixture, to lean or too rich you cannot derive the maximum amount of power from the fuel available. Many times extra fuel is added to control the burn temperature and detonation tendencies of a particular design. The extra fuel cools the burn providing protection for parts that have no direct cooling such as the piston and exhaust valves. To lean of a mixture may increase power, but by doing so it increases what damages a engine, heat. Heat drives a engine, when you fully understand this you will have the foundation to build on.


So with that in place you have a engine that is rated for a specific combustion temperature, and octane rating. Adding water to a engine and making no other changes will generally DECREASE power. However if you can derive extra power by leaning the fuel to air mixture and increasing the combustion temperature to a point unsafe for the engine you have a candidate for water injection. By adding water injection you can lean out the mixture to a point previously unattainable, decrease detonation tendencies with a set octane rated fuel, and protect the engine components thus increasing power and fuel mileage.


One direct example is a man I know in Australia. Driving a 2.0L Celi with a turbo with standard air to air intercooling with a maximum 72% efficiency he was running 294WHP at 9PSI at 9degrees before TDC at 4,500 RPM under load and achieving a relative 40% knock. After adding water injection to the after air cooler air stream he was able to lower his fuel mixture by 1.5% and still have a lower 20% knock rating, increasing his output to 307WHP. However adding the water injection to the "hot" side of the air stream from the turbo he was able to lower the fuel amount by an additional 2% and gain a extra 6WHP. The water evaporated more readily in the hotter air, and cooled the air charge before the intercooler thus decreasing the thermal loss and accompanying drop in air pressure from one side of the intercooler to the other.


When we look at this example we fine that two things were present that made the water injection work.

1) He was at the limit for detonation for the amount of fuel-air charge present in the cylinder.

2) The fuel-air mixture had to high of a temperature to prevent spontaneous detonation, removing more fuel to bring the mixture closer to stoichiometric was possible.

In your car Perris it uses a area of high fuel density to start the ignition and areas of lower fuel density, relative to the air, to start and complete the burn. You will find that as pressure increases even a mixture that is too lean will ignite, so a area around the point of ignition that is too rich and areas around the outer edge of the cylinder that are too lean will still completely burn, using less fuel, allowing a stoichiometric mixture to be used, with thermal coatings to control the heat absorption of the piston.

 

[Perris Calderon]

1) A few degrees after TDC (top dead center) is enough to compensate for predetonation as long as no other factor is involved. Regardless of fuel mixture. Some cars cannot do this, and have a remote possibility of damaging the engine with pressure spikes caused by the detonation instead of a burn.

steve, my car cannot compensate for octane less then 87 octane, this is with no mods what so ever since it's tuned from the factory to take advantage of pretty high octane

most cars cannot compensate for below 82 or so octane, if contaminants are adding volatility enough to lower that octane then there will be knock and engine damage, i'm sure you know but knock is an ignition when the engine isn't prepared and those ignitions stress the internals

2) Every car has the fuel pickup tube placed in the lowest part of the tank. Otherwise there would be no way of completely pumping a tank dry so you could remove it safely. I have done this on numerous cars when replacing the in tank pump.

that does make some sense to me but you are assuming the lowest point in a tank will also be where sludge settles, I don't think that's the case

also, it doesn't show up under practical situtations, if you ever drove a car with a mechanical fuel pump you would know the feed does not get all the fuel at all, your car will surge, stop, go, you can usually go an extra mile or so once you run out of gas if the car has a mechanical pump as it scavenges the bottom of the tank, no maybe fuel tank technology has improved since then but I think there will still be puddles and areas of settlement as is demonstrated when you do not have an electric fuel pump

I really don't think they've changed the configuration of fuel tanks that much but if they did and there is no sludge settlement then you make a good point here but as I said, I think the only differance is now we use electric fuel pumps so the scavenging is not noticed when you run out of gas

I don't think it's a good idea to run your engine below 1/4 of a tank

even if you're correct, let's suppose you are right and the feed is comming from the lowest point in the tank, with a full tank, fuel contaminants which are not soluable will be x parts per x, that concentration will have to be higher as the fuel level gets lower and that's the point

and as I said, I also believe there are areas where sludge can settle in a fuel tank that have nothing to do with the lowest point for the liquid to settle, if there are, these areas will kick up that sludge the lower the level of fuel in the tank

but I am speculating to be sure and you sure seem to have researched this issue

3) Gasoline is NOT a lubricant, ever. Every time you rev the engine and then let off there is no fuel present in the cylinder. None, ever, when the RPM is higher than the cutoff point and the throttle is at idle the fuel is cut completely. Gasoline DOES act as a coolant, but for it to achieve that status it has to be a much higher mixture than stoichiometric and thus the problem that it DILUTES the oil residue on the cylinder walls making the oil burn. But that is a issue more between the oil anti-friction additive and the lubricity index for a particular motor. For your motor GM did a whole study about spray pattern to make sure the spray was confined and wouldn't wash the cylinder walls.

ya, I kind of think it's not a lubricant too but it is a coolant in my car, this is a fact

4) Octane is the rating of tendency to spontaneously ignite at a set temperature and pressure. The higher the rating the less the tendency to detonate and instead burn in a controlled fashion. http://www.familycar.com/Classroom/fuel.htm Adding water injection has been a topic of hot debate for a few years now, one side saying that water injection will improve anything, but providing little more than seat of pants feel or one example with no control group. For example one man has a site up about adding a fish tank filter and a hose for water injection, not realizing that he was really only leaning out the mixture of his carburated car, and implying his profoundly better fuel mileage was due to this contraption, no hard evidence was provided. When I drive normally my Celi gets about 24MPG, but when I have a cake in the car I drive more gently avoiding fast starts and hard braking then I get 31MPFG. So in all reality I could say that a cake has added 7MPG to my car!!!!!!!!!!! That is meaningless data, when we look at hard data we find that water injection does two things.

there's no debate, water injection increases horsepower on cars that can use the added octane, it's dyno'd, it's a fact

Reduces air charge temperature thus increasing density.
Takes heat away from the combustion process.

possibly that as well, but it increases the octane of the fuel and when any car, normally aspirated or turbo charged can use that added octane they will get more power, IF that decreased volatility is overcome by enough spark advance, sometimes decreased volatility will be greater then added timing can overcome

When we look at this example we fine that two things were present that made the water injection work.

1) He was at the limit for detonation for the amount of fuel-air charge present in the cylinder.

2) The fuel-air mixture had to high of a temperature to prevent spontaneous detonation, removing more fuel to bring the mixture closer to stoichiometric was possible.

In your car Perris it uses a area of high fuel density to start the ignition and areas of lower fuel density, relative to the air, to start and complete the burn. You will find that as pressure increases even a mixture that is too lean will ignite, so a area around the point of ignition that is too rich and areas around the outer edge of the cylinder that are too lean will still completely burn, using less fuel, allowing a stoichiometric mixture to be used, with thermal coatings to control the heat absorption of the piston.

all interesting and a great read but I think most of what you've said translates into a higher octane fuel.

I think you are forgetting that most water injection applications are actually water/methanol...and all engines should experiment with what mix is best for their engine and aspiration

my engine is released in quite a few configurations, some of them are normally aspirated and they are incredibly efficient due to the direct injection there is a complete burn.

if the na is tuned to run on higher octane even though it is normally aspirated it's gonna benefit from water injection, the mix will have alot to do with it but don't forget, most water injection applications are not water, they're a mix of methanol and water

and don't forget, most engines run better on a day with high humidity

in any event, my engine water injected and with the proper instruction set will out perform the ls 8 cylendar engine swaps, it gets to the point where there is more horsepower then stick even with slicks

 

[Steevo]

Water injection does NOT change the octane of the fuel. It merely elimenates some of the potential causes of pre-ignition. Water/fuel mixture is used on other applications to lean out the fuel mixture and provide a alcohol based fuel for part of the burn as it burns cooler, and has a higher octane rating than gasoline.


Volatility is the ability to evaporate or disipate. So a high volatility fuel mix is used in winter when air temps are low to provide easier starting, and a lower volatility fuel is used in the summer to prevent the fuel from boiling in the injection lines and injectors. Most racers mix race fuel to a specific blend for their car/engine to match the volatility and octane to their application.


Yes, cars do run better on a cool humid day, my Celi (Warning: Seat of the pants statement) feels alot more powerful when we get our odd rains in the spring and fall here, when there is 6" of fog coming off the highway from the warm asphalt and the cool air picking up the moisture. My truck never did as it was always breathing the under hood air. Since I have wondered about adding a cold air induction and water injection to it as I have to run a very rich mixture to keep the burn temps down.


The fuel pickup on my car is placed in the lowest part of the tank, but is a small oriface, and when out of fuel it still has a small amout left sloshing through the baffles in the tank. So driving easy and allowingn the fuel to settle into the cener of the tank instead of being thrown aroudn the outside allows the extra fuel to be consumed.


If the fuel pickup wasn't placed in the bottom of the tank, and the "gunk" wasn't picked up by 200K on my car the tank still woudn't be full, but partially full and causing problems. A car company would probably want to sell wear or expendable items like filters instead of needing your fuel tank dropped and cleaned every 50K from buildup. Plus in most reputable fuel stations these days they have filters in line before the fuel hits your tank, and they keep their supply clean. But there are always those "cheapo" stations, we have one and I used to do fuel filters galore on cars from it. Rusty old tanks, the fill part of the in ground tank was in a low spot so it would always leak water in around the fittings.

 

[Perris Calderon]

Water injection does NOT change the octane of the fuel. It merely elimenates some of the potential causes of pre-ignition.

for whatever reasons you just stated yourself among others such as reducing volatility, octane is indeed raised with water injection and in fact, timing can be advanced as if you have octane aver 110

it is virtual raising the octane of the charge whether or not you want to call that raising the octane of the gas and water injection can indeed give a gain to an na engine as well as a turbo, not quite as much to be sure but a gain when configured correctly

 

[Electronic Punk]

My car has the magic ;D

 

[Steevo]

for whatever reasons you just stated yourself among others such as reducing volatility, octane is indeed raised with water injection and in fact, timing can be advanced as if you have octane aver 110

it is virtual raising the octane of the charge whether or not you want to call that raising the octane of the gas and water injection can indeed give a gain to an na engine as well as a turbo, not quite as much to be sure but a gain when configured correctly

Same same.


Everyone come look, EP uses his magic stick while in the car. No pics please. :laugh:

 

[Dark Atheist]

i thought you said he couldn't drive stick ?

 

[Steevo]

He tries, ohh how he tries.

 

[Dark Atheist]

oooo you meant ride it - must of been lost in translation

 

[lancer]

norm its on the drivers side anyway - unless you have a volvo

or a sodding saab 95. mines on the passanger side, freaking annoying.

 

[unknownsoul]

I've got a Chevy Pickup, and it's right behind the driver side door.

You lucky guys, I wish I could put in the 87 or 88 octane in my truck. My truck can't compensate for anything under 90. (My brother and I rebuilt it and modded it out a bit.) It would save me a bundle of cash getting the cheap stuff.

 

[falconguard]

I've got a Chevy Pickup, and it's right behind the driver side door.

You lucky guys, I wish I could put in the 87 or 88 octane in my truck. My truck can't compensate for anything under 90. (My brother and I rebuilt it and modded it out a bit.) It would save me a bundle of cash getting the cheap stuff.

If only we had foresight instead of hindsight, huh?

 

[Perris Calderon]

I've got a Chevy Pickup, and it's right behind the driver side door.

You lucky guys, I wish I could put in the 87 or 88 octane in my truck. My truck can't compensate for anything under 90. (My brother and I rebuilt it and modded it out a bit.) It would save me a bundle of cash getting the cheap stuff.

just retard your timing and you're fine with 87 octane, you'll loose some power on wide open throttle and you might but not definately) loose more gas mileage then you save but most cars do the same gas milage

anyway, if you have a mechanical distributer just retard timing a few degress and give the 87 octane a shot

 

[unknownsoul]

it's a newer (1998) chevy, and it's not a mechanical distributor. it's all computer controlled. There's really not much i can do about it unless i take it to a custom shop and have them reprogram the computer on it to retard the timing.

 

[lancer]

a retarded pickup... how obvious.

 

[Steevo]

Water injection will not allow your truck to run a lower octane fuel, as the burn rate will not change in the cylinder. However .10 extra on gas for 20 gallons is $2.00 a fill and most people spend more on the morning coffee.


You might spend more time and gas idling around a parking lot looking for that closer spot, and then on a gym membership as you need to run 2 miles to compensate for the lack of exercise than on your extra fuel bill.



I am NOT pointing that at you unknownsoul, just the population in general. People waiting in line at a gas station with their big SUV's idling to fill up and save a whole .03 a gallon, then driving around the parking lot for a few minutes to park closer, then going to the gym, ahhhhhhh it gives me a headache all the stupid madness people do. Dumb bastards.

 

[Unleashed]

Steevo - I thought you had a Honda?

 

[Sazar]

just retard your timing and you're fine with 87 octane, you'll loose some power on wide open throttle and you might but not definately) loose more gas mileage then you save but most cars do the same gas milage

anyway, if you have a mechanical distributer just retard timing a few degress and give the 87 octane a shot

I won't take a chance on mine with it.

Too many users who have 40/50/60 k and higher who have tried lower octane and had things pinging. No issues when they reverted back to 93 or higher octane.

I have a larger engine and things are running pretty fine-tuned with it. I am going to get a TBS flash upgrade to tighten up the ratios a little bit, it's a dealer option and should drop the car around the 5.7 range 0-60 and under 14 seconds for the 1/4, stock.

My main thing is it sharpens up the manual shift mode which is how I drive it