NorCal (Bay Area) OFF-TOPIC Chat Thread

[Kaotic Lazagna]

Originally Posted by BigFatFlip

I would guess it just has something to do with the formulation of the gas. Different brands have different blends (ie different ratios of heptane, ocatane, detergents, oxygenators, etc.) which can affect the stoichiometric ratio (basically, the ideal/perfect AFR) of that given gas. Since our cars are equipped with a fueling system computer and O2 sensors, it adjusts the AFR to compensate for the different blends. So basically, your car maybe running slightly richer on one blend (hence the black carbon deposits) and leaner on the other. This doesn't necessarily mean one gas is "cleaning" your engine better than the other.

But then again, I could just be full of BS, so I will just shut-up now...

at the last sentence.

Running rich is safer for the engine, correct? Might also explain why I get less mpg with Chevron compared to 76. Hmmm, which company to stick with? Choices, choices. Haha

[BigFatFlip]

Originally Posted by Kaotic Lazagna

at the last sentence.

Running rich is safer for the engine, correct? Might also explain why I get less mpg with Chevron compared to 76. Hmmm, which company to stick with? Choices, choices. Haha

Rich is technically "safer" because its less efficient (engine runs cooler), but can still harm the engine due to fowling. I don't think either is harming your car.

And answer to your question? Shell V-power, because no crickets

[PMok]

Originally Posted by BigFatFlip

Rich is technically "safer" because its less efficient (engine runs cooler), but can still harm the engine due to fowling. I don't think either is harming your car.

And answer to your question? Shell V-power, because no crickets

I preferred to run Shell or 76 because no crickets, but I noticed through monitoring in my OFT that it was causing a little bit of knock. Bringing my IAM down to about 0.85 sometimes. E85 takes the crickets away.
But this last time I switched back to 91 from E85, I filled up with Chevron. Like clockwork the crickets came back, but you know what? No knock / IAM drop. So I think although further testing is required, I will take crickets over knock/loss of power any day. YMMV

[BigFatFlip]

Originally Posted by PMok

I preferred to run Shell or 76 because no crickets, but I noticed through monitoring in my OFT that it was causing a little bit of knock. Bringing my IAM down to about 0.85 sometimes. E85 takes the crickets away.
But this last time I switched back to 91 from E85, I filled up with Chevron. Like clockwork the crickets came back, but you know what? No knock / IAM drop. So I think although further testing is required, I will take crickets over knock/loss of power any day. YMMV

What does "IAM" stand for again? I've never really had the chance or the equipment to monitor my engine, so I just stuck with what "felt/sounded" better. My 6 mile daily commute to work is probably worse for my engine than a slight knock.

[Kaotic Lazagna]

+1 on what IAM stands for again. lol.

So far, with Shell, 76, and Chevron, I've had crickets. lol. I haven't noticed any power differences with the three, but Shell and Chevron give me lower mpg.

[PMok]

Originally Posted by BigFatFlip

What does "IAM" stand for again? I've never really had the chance or the equipment to monitor my engine, so I just stuck with what "felt/sounded" better. My 6 mile daily commute to work is probably worse for my engine than a slight knock.

Ignition Advance Multiplier. Basically when the engine is operating normally, IAM = 1.00 and ECU will allow maximum timing advance. When it detects some knock, it starts to reduce IAM and that in turn bluntly reduces amount of advance your engine is allowed to run. So 0.85 means you are running 15% less advance than you could be on better fuel. Due to poor octane content this is a common problem here in CA and also in Australia it seems. But for what it's worth, when I'm driving around and not paying attention to IAM, I could not really feel much of a difference between what 0.85 and 1.00 feels like. Then again, my butt is not that finely calibrated compared to others...

[Kaotic Lazagna]

Originally Posted by PMok

Ignition Advance Multiplier. Basically when the engine is operating normally, IAM = 1.00 and ECU will allow maximum timing advance. When it detects some knock, it starts to reduce IAM and that in turn bluntly reduces amount of advance your engine is allowed to run. So 0.85 means you are running 15% less advance than you could be on better fuel. Due to poor octane content this is a common problem here in CA and also in Australia it seems. But for what it's worth, when I'm driving around and not paying attention to IAM, I could not really feel much of a difference between what 0.85 and 1.00 feels like. Then again, my butt is not that finely calibrated compared to others...

It's not a good thing to be constantly retarding timing, right?

[PMok]

Originally Posted by Kaotic Lazagna

It's not a good thing to be constantly retarding timing, right?

I'm no engine tech or even remotely scientific, but yeah, retarding timing means you are dialing back to be conservative and trying to save the engine from damage. At a minimum it means you are not making as much power as you could be, if you had better fuel.

A different way to look at it though, is that it means the tune is too aggressive for the fuel provided. Fine tuning the fuel and ignition maps to match the fuel you are using would allow the engine to operate the best it can without needing to retard the timing. Keep in mind our cars are tuned from the factory to operate optimally at 93-94 octane.

[BigFatFlip]

Originally Posted by Kaotic Lazagna

It's not a good thing to be constantly retarding timing, right?

Originally Posted by PMok

I'm no engine tech or even remotely scientific, but yeah, retarding timing means you are dialing back to be conservative and trying to save the engine from damage. At a minimum it means you are not making as much power as you could be, if you had better fuel.

A different way to look at it though, is that it means the tune is too aggressive for the fuel provided. Fine tuning the fuel and ignition maps to match the fuel you are using would allow the engine to operate the best it can without needing to retard the timing. Keep in mind our cars are tuned from the factory to operate optimally at 93-94 octane.

^But seriously though, my thoughts exactly. IMHO cars are meant to function with a range of fuels and environments, which is why the ECUs have feed back loops to allow it to run as efficiently as it can given the conditions. Like P said, these cars are meant to run with 93 octane, and maybe 60-90 deg temps, at sea level, etc. but doesn't mean our cars are better off here than in Colorado (see what I did there P? )

[OmarYasin]

Does anyone have a good recommendation for a DD tires? Want something between 250-350 treadwear, i dont want to spend 900 plus, im currently running evo2 ventus 12 hankooks and want something slightly stickier, options as of now Michelin pilot ss or re11s but again i daily drive 10miles a day and frequently hit some back roads to canyon carve ect

[finch1750]

Originally Posted by OmarYasin

Does anyone have a good recommendation for a DD tires? Want something between 250-350 treadwear, i dont want to spend 900 plus, im currently running evo2 ventus 12 hankooks and want something slightly stickier, options as of now Michelin pilot ss or re11s but again i daily drive 10miles a day and frequently hit some back roads to canyon carve ect

Bridgestone s-04 pole position are comparable to the PSS, but cheaper. Though not sure either would be a huge change from the Hankooks you are running. Another option is Federal 595 Rs-r. May not last too long but are pretty damn cheap to allow more replacement.

And isn't the re-11 a 200tw along with the Rs3, rivals, and zII?

[OmarYasin]

Originally Posted by finch1750

Bridgestone s-04 pole position are comparable to the PSS, but cheaper. Though not sure either would be a huge change from the Hankooks you are running. Another option is Federal 595 Rs-r. May not last too long but are pretty damn cheap to allow more replacement.

And isn't the re-11 a 200tw along with the Rs3, rivals, and zII?

Re11 and rs3 are 200tw but im still considering them

[unsurety]

Originally Posted by Kaotic Lazagna

What's your position there?

Senior lead supervisor of the custodial department

[unsurety]

Jk I'm in parts