Subzero's car

[Mach1Marauder]

It's a big difference actually as mentioned. Too rich you loose power and too lean you loose your motor. Sure there is more to it but thats the skinny of it as I see it.

This confuses me...
In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 - 13.3:1 or λ of 0.850 - 0.901.

http://en.wikipedia.org/wiki/Air-fuel_ratio

Please......no wiki references.

Too fat can kill an engine just about as quick as too lean. Too fat can wash oil of cylinder walls and lift ring lands.

 

[Shane361]

Please......no wiki references.

Too fat can kill an engine just about as quick as too lean. Too fat can wash oil of cylinder walls and lift ring lands.

Glad to see I didnt understand it for a reason..numbers looked off but not sure if ratios were different for different cars/applications/etc or the same accross the board. So is 11.8 optimal?

 

[Mach1Marauder]

Blower, turbo, NA it doesnt matter..your go lean and have detonation and the head/ head gasket is usually the first to suffer. Which is what happened to me when the KenneBell first went on.

Remember......we're talking a stock engine non-cobra engine.
MOST of the time, detonation will kill cast pistons well before you blow a head gasket.
In your case, you went super lean, it prolly hammered the hell outta your rod bearings too. Heat and massive cylinder pressure took out your head gasket.

 

[Mach1Marauder]

Glad to see I didnt understand it for a reason..numbers looked off but not sure if ratios were different for different cars/applications/etc or the same accross the board. So is 11.8 optimal?

for a "broken in" 2V engine under modest boost

 

[Shane361]

Remember......we're talking a stock engine non-cobra engine.
MOST of the time, detonation will kill cast pistons well before you blow a head gasket.
In your case, you went super lean, it prolly hammered the hell outta your rod bearings too. Heat and massive cylinder pressure took out your head gasket.

Can see that...pistons for non-built are the weakest link and head gasket for built engine.

 

[02gt]

i have a question...i understand timming a little, but what is it and how it works in relation to the engine operation...

 

[Mach1Marauder]

i have a question...i understand timming a little, but what is it and how it works in relation to the engine operation...

Timing advance is the the number of degrees before top dead center the spark plug fires to ignight the fuel/air mixture.

 

[02gt]

now when i have 20-23(which i was actually at in with the meth) degrees what is the "degrees" reffering to...

 

[Mach1Marauder]

now when i have 20-23(which i was actually at in with the meth) degrees what is the "degrees" reffering to...

The degrees on the crank before that piston reaches TDC.......not temperature

 

[02gt]

The degrees on the crank before that piston reaches TDC.......not temperature

ok i didn't how degree's were measured thanks for info!!!!!!!
now it makes more sense to me, when the SC is forcing more air in the cylinder along with more fuel, advancing the timming is essentially delaying the spark, in which the delay of the spark allows the cylinder to create more PSI in side the cylinder and basicly more power to push the piston down...correct????

 

[wickedstangs]

PV = NrT

[ame="http://www.youtube.com/watch?v=BtnbzeUqddE"]YouTube- Broadcast Yourself.[/ame]

 

[Gibs]

That was cool.....what was he puting in the bottle?

 

[02gt]

looks like dry ice...

 

[ears]

alright, now that were actually making good use of this thing, i have two questions.

1)as far as afr, what exactly determines what is good and what is bad, and how can you tell for your specific set up what you should be aiming for? so for danny, you said 11.8 was optimal, is that a norm for blown engines, and how does that compare to na motors?

2)talking about degrees here, pretty well the same kind of question. is 15- 20 the norm? does it differ between different engines,,,,, what is a good way to figure out what you should be aiming for? and how does it differ amongst different motors?

both are general questions, im not looking for a engine specific answer just something to give us an idea. thanks!

 

[wickedstangs]

 

[Mustangcwo]

Nice work Danny. Glad you took it to Bruce at JBA and had it tuned to your liking. Everyone likes their car tuned a certain way to optimize performance and you seem happy. It does not matter where you take your car to get tuned...what matters is that you like the end results. For all you guys with broke **** cars, quit complaining until you can put some rubber on the road. You know who you are...Boosted...Ears...when you beat Danny or I at the track, then you can run your suck muscle about JBA cars.

Oh yeah, there happens to be a Killer Bee out there with a JBA tune that is stomping all your street cars.

 

[wickedstangs]

ok i didn't how degree's were measured thanks for info!!!!!!!
now it makes more sense to me, when the SC is forcing more air in the cylinder along with more fuel, advancing the timming is essentially delaying the spark, in which the delay of the spark allows the cylinder to create more PSI in side the cylinder and basicly more power to push the piston down...correct????

:teateateatop:
The four strokes are known as:
Intake
Compression
Power
Stroke

 

[Tommy]

dayum,


talk about a thread hi jack!

 

[DrunkFatguy]

20-23 Degrees of Spark advance before Top dead center of #1 Piston/Cylinder. That would be total timing advance however at 6000 rpm, your engine would run like crap if it ran at 20-23 Adv. at say 600 rpm. The reason we have timing advance is when we Increase Engine RPM, we Increase the intake of the proper ratio Air/Fuel, However the one thing that does not change in speed is the Burn rate of the Air/Fuel (wit the exception of a wacked out a/f ratio). Because of the Increase in Proper Air/Fuel mass in the cylinder we need to give the burning process more time- we advance the timing in a controlled and gradual manner in accordance with RPM, Load etc..Blah blah(as well as Inputs from various sensors). As we know pressure and temperature are relative in most cases, Increasing Ignition timing during high load, High RPM(such as drag racing) and burning all that A/F charge is one of those cases. All of that heat is transferred to the Cylinder walls, Heads, valves, and Piston so how do we make more power assuming everything is correct such as your A/F ratio? Easy, one way is to Install a Methanol Injection kit such as what 02GT has, what it does is the same as what happens at an Orifice tube or TXV valve in a Refrigeration system, it takes a High pressure Liquid and Injects it into a Low pressure environment through a Nozzle that disburses and helps vaporize it, When it goes through the nozzle and into a low pressure environment, it's temp drops also. As it vaporizes/flashes it absorbs(Don't confuse this with Temp-pressure relationship) Latent and sensible heat lowering the Intake air temperature, bringing the Oxygen molecules closer packed together creating a more dense Air charge without the heat(helping to reduce Cylinder temps also). This allows for a more aggressive timing curve and/or Boost pressures, I.e more potential for power. Man I hope I didn't out too much Alcohol Induced Gibberish, I really get strange when I drink.

 

[sdsubzero4]

Wow, just got off work and this thread really took off. To where, I don't know, but took off. LOL! But I appreciate everyone's input and Orange thank you for your concern about my car. I guess the only thing I can do is hook my gauges up once they all arrive and see where they are at. Bruce also did suggest that I take it to another dyno just to double check on the boost number also. But nonetheless, the car is tune and soon, I'll give it a test on the track once I get all the essentials in the car, the gauges, tranny cooler, and of course the slicks.

Mach1 and all others interested, heres the file on the final run today.