California Octane

[RToyo86]

Originally Posted by OkieSnuffBox

Québécois are too busy eating smoked meats to know what's going on.

It's probably the poutines.


Some other data points from a 15 car dyno day with different levels of modification. These are two OEM preface lift cars.
https://www.pointmeby.com/2017/10/18...esults-15-86s/

[OkieSnuffBox]

To be fair (2nd reference), anyone who tunes with AFR's looking like that? I'm not really putting any stock into it.

Just leaning it out on the 91 would have yielded some gains, that thing is running pig rich by 5k and is richer than 12:1 near peak. Don't ever let person touch your car.

[Pat]

Originally Posted by OkieSnuffBox

To be fair (2nd reference), anyone who tunes with AFR's looking like that?

I'd like to see this addressed by a professional tuner. I mean....I doubt it was a mistake. I wonder what their intentions were.

[x808drifter]

(in general not for this thread only)
I love how everyone forgets that the variance for a dyno is 3-5ish%.
^ That's back to back the same car the same day the same tune.
That's 6-10WHP at 200 WHP
Something almost nobody looks at or talks about.

[Pat]

Something else they don't often think about is variance can be both positive and negative.

[OkieSnuffBox]

Originally Posted by x808drifter

(in general not for this thread only)
I love how everyone forgets that the variance for a dyno is 3-5ish%.
^ That's back to back the same car the same day the same tune.
That's 6-10WHP at 200 WHP
Something almost nobody looks at or talks about.

Like I said on the previous page, that amount of variance is basically statistical noise.

[tomm.brz]

Those afr are probably taken at the exit of axleback so real afr is more than -1 than those

[RToyo86]

Both runs on the graph above are on OEM tunes with different fuel.

Variance is possible +/-. The article suggested all cars did multiple runs and best of was used for the graph

[PulsarBeeerz]

Originally Posted by x808drifter

(in general not for this thread only)
I love how everyone forgets that the variance for a dyno is 3-5ish%.
^ That's back to back the same car the same day the same tune.
That's 6-10WHP at 200 WHP
Something almost nobody looks at or talks about.

People do talk about it, but rarely back up the statement. The variance can be less than 3% as well. Plenty of YouTube dyno vids show plots laying on top of each other. I dyno'd my old Celica back in the day on a couple different Dynojets in the city. The back to back pulls were with in 3whp or 1.8-2% with SAE correction factors.

[CSG Mike]

Originally Posted by PulsarBeeerz

People do talk about it, but rarely back up the statement. The variance can be less than 3% as well. Plenty of YouTube dyno vids show plots laying on top of each other. I dyno'd my old Celica back in the day on a couple different Dynojets in the city. The back to back pulls were with in 3whp or 1.8-2% with SAE correction factors.

And that is precisely why CSG posts dynos like this



It's easy for a tuner to cherry pick the best and worst pull *WITH ZERO CHANGES TO THE TUNE* and show a large difference. Even showing cold and hot pulls can show a big difference.

It's also a part of why CSG chooses to use a (far more expensive) dynapack, rather than a roller dyno.

[Sapphireho]

Originally Posted by finch1750

Doesn't even have to be a rich community. We have one in Stockton lol

Yea, but the one in Saratoga is the most fun to watch from the coffee house next door on the first nice spring mornings and watch the Veyrons and Paganis with their 95 octane minimum fill up.

[Ezio]

Didn't see anyone post this:
https://find93.com/


Been fairly handy for me in California. Be sure to call or scout ahead. Not all locations seem to be available or existing.


Also has a blend calculator.

[Snoopysvet]

Originally Posted by Ezio

Didn't see anyone post this:
https://find93.com/


Been fairly handy for me in California. Be sure to call or scout ahead. Not all locations seem to be available or existing.


Also has a blend calculator.

Thanks