How hard is it to find 91 to 94 octane?
 

I'll keep this brief. Going on road trip from Victoria, BC to Redding, CA - will be passing through WA, OR, CA. Currently, my Miata is tuned for 94 octane but I will probably be lowering that to 91 assuming 94 will be impossible to find.

Question is: (a) Is 94 impossible to find? (b) How readily available is anything from 91 to 94 in those states?

CA 91 only

OR/WA has 92 and some places 93, but I don't think any state on the west coast carries 94

Just tune for 91. Real crappy 91.

do you have 94 RON or 94 RON+MON/2 octane?

94 (R + M)/2

What's the difference?

i'd carry some octane booster if you want clean 91 and 94+, the average is 91 max, and a lot of stations have real shitty 91.

The Lucas octane booster actually works:

Volvo Performance Repairs And Modifications

Buy enough bottles to mix up 50% more fuel than you think you need and let it ride.

Oh shiz. I got the car tuned for 91 octane today, still have yet to take it out on the road and actually fill it up with some 91, but we basically added a bit more fuel and brought the boost down from 12 to ~10psi.

I'll pick up some octane booster just in case anyway. You guys in Cali don't always run your cars with octane booster, do you?

No, they just tune for 91 I'm assuming. We're telling you to run the octane booster since it'll be easier and probably safer.

We have 93 here in the Portland area, but I'd suggest filling up south of here in either Wilsonville or Woodburn. Both are right off the freeway, have plenty of places for gas, and avoid the busy cities.

If you fill up in Seattle, then top off in Wilsonville, you should be able to make it down to Grants Pass, then you're only one tank away from Redding.

This is assuming you can get 200-250 on a tank.

edit: And I list Seattle and Wilsonville cause they have 93. Dunno about GP.

Doubt I could get 250 miles on a tank... maybe if I stay out of it.

Thanks guys. This all really helps.

EZ lazy and effective fix is to log into your tuning software and subtract

1* at 5psi
2* at 8psi
4* at 12psi
5* at 16psi

Interpolate and prepare for slow. Your AFRs will be off by a bit but in the rich direction.

octane booster is stupid and a waste of money.

Just run 10psi, 11.5 afr, and no more than 12* @ peak boost and you'll be fine, even on the worst batch of 91 here. Why waste money on octane boosters?

So you don't have to dial the car back to bitch mode for a single trip, duh.

12* peak timing is enough to make you say fucky living life sucks. But yes it would work.

Good job remote tuning 18psi highfives brah

If you don't want to dial it back to bitch mode, re-tune for e85. Plenty of it here (at least in Sac). And it would be in PIMP mode on e85.

But mixing a concoction of booster/pump gas and hoping it will be somewhat close to what you're tuned for is a recipe for failaidz.
You could run more, even on our camel piss 91, but if you're on a road trip I don't think puttin down every last hp is your 1st priority.

The way they come up with the number.

US and CA use an average of RON and MON.

You'll have to back your timing in boost a bit, as CA is 91 at best.

I get 200 a tank driving in traffic...

We've restricted boost a bunch so timing won't hit as high... should I be backing off my timing in the lower boost as well? Dustin came over and fiddled with it for a while and thought that it was probably fine the way it was but backed off the boost and dumped in a bit more fuel to be safe...

Apparently my car is a tank. Assuming you're talking 200 miles, I think the best I have gotten is around 350 km on the highway and mostly saying out of it.

This is mostly true. Definitely don't need every last hp, but some power for blasting out of those windy corners would be nice.

So it seems to be 50/50 between people that think octane booster is worth it and not...

octane boosters are a joke. You need to uy like ten 16oc bottles to bump up the octane. There are easy formulas on google.

if anything you need a gallon can of toulene or xylene. Go see your paint store.

I used to think they were all snake oil (and for a very long time, they were), but the Torco and Lucas octane boosters are legitimate. A 100:1 ratio of 93 and Lucas makes and honest 96+ R+M/2 octane. Read the article I posted. Dude measured them with lab test instrumentation, then confirmed with a knock engine.

WTF is a "knock engine"????

That said this wouldn't be very difficult to test without any meters. Tune your map til it knocks. Back off 2 degrees. Add bottle. Add two degrees, see what happens. The end.

No, light pinging will not be the end of your motor.

LOL

I'd rather not find out the hard way if it can or can't.

Oh come on. If you have a knock sensor this really isn't that dangerous. Don't tell me you haven't tuned pump gas until knock onset and backed off.

With low boost and lower HP this really is pretty low risk, especially how far off from the MBT plateau most of the boosted timing maps floating around this forum are.

I haven't. Every car I tune I tell them: "I will only go as far as I am comfortable going, if it knocks before then I'll back off, but if it doesn't I won't keep pushing it unless you specifically instruct me to do so"

So far only a couple people told me to keep going and both were on e85 so we stopped "gaining" power well before I saw anything even resembling knock.

So in a nutshell: I'm a big pussy and leave the "testing the limits of motor" part to hardcore badass vegans like yourself:fael:
or PROFESSIONAL tuners:)

/threadjack

totally off topic, but seeing your online portfolio and whatnot, but i'd would totally trust you over myself to tune my 7M when it gets finished at the machine shop, it will have forged rods and pistons and a balancing, but I tend to waste fuel with no power gain with it with fuel controllers (apexi Neo). Can I bring my supra by one of these days so we can cuddle in the car and talk HP? Tuning was a learning experience when I had an MSPNP for about 4 months but I was sooo conservative with the tune in my miata. I dont like most of the california Supraforum guys since they are selfish dicks. If this could be possible ill PM you when the car is finished and ready to drive.


/threadjack

Sure thing.
Though I hate piggy backs. My friend has a built 30r 2j mk3 actually, and after blowing up his motor on a stupid apexi avcr he finally switched over to a real EMS. I advise you to do likewise.

I want an MS so badly, but i'd have to build one and I am to busy (lazy) for that atm. I bought my car with the Apexi Neo already installed, the first owner babied the car, the second owner tuned it with a complete top-end rebuild and overhaul (port polish, Crower cams, titanium valves... bla bla bla), gave the suspension better springs, full 3" freeflow exhaust, Apexi neo and tune, intercooler upgrade, walbro fuel pump, radiator upgrade, etc... tons of shit...), the last guy that owned it was complete trailer trash, all displacement knowledge but no tuning experience, RUINED the tune, and almost ruined the car completely. I bought it from that dude for 2k flat since he couldnt pass CA smog, and fixed it up to the best I could until the inevitable... ate up bearings and low oil pressure.

Nothing wrong with playing it safe. Unless it is way too safe and you are running 10*@7000rpm@9psi.

That said have you seen timing maps of big boost and big power evos? They run like 5* at 7000rpm and 40psi. Evo community tuning r&d is wayyyy beyond miata community and so i would love to talk to an evo tuner to find out why so little timing. This is even with e85 and race gas.

The device that produces the 'Motor Octane' number on your anti-knock index. The cylinder moves independently of the rotating assembly, so that combustion chamber volume and compression ratio can be varied actively. You fire the motor up at low compression ratio, then add compression until it knocks. The compression ratio you end up at yields your motor octane number.

you HAVE GOT TO stop comparing tuning strategies between different cars/engines/setups as if all internal combustion gasoline engines are exactly the same

Get that stupid shit out of your head once and for all, cause I see you posting comments like "how hard could it be, just dial in xx afr xx boost and xx timing and bingo" when referring to other cars.

Don't be an ignoraus and trust me on this: tuning a miata vs evo vs subie is very different if you get into the nitty gritty and go beyond just running "acceptable" afr and getting to MBT then backing off.

that said, it is usually safer and more beneficial to keep adding more flow and more fuel and ultimately increasing dynamic pressure, than adding timing and increasing static pressure......I've tried this before: adding timing and fuel vs adding boost and fuel - most cars responded much better to the boost+fuel while reducing timing. also sometimes its beneficial to drop timing even though you haven't reached knock threshold yet, and adding MOAR BOOST will achieve yet more power.....usually the case in high boost applications


(Disclaimer: I'm not a pro-tuner and semi inebriated ATM, so if something is off idgaf)

:2cents:

Ahh, thank you.


Details on nitty gritty is what I am interested in.