87 Octane Tune or Octane booster?
 

Usually when people ask about 87 octane tunes, the response is a resounding "don't do it" or "don't bother". My question is for a different reason, so maybe I'll get a different answer.

My friend wants me to go on a road trip with him later this summer to Northern Canada. I am worried that I will not be able to get 91 octane once I get beyond normal civilization. There will be stretches as long as 250 miles where there will be no fuel at all.

So, my question is whether it's possible to tune a 2002, with its high compression and everything, to run on 87 octane with a turbo safely. I don't really care about loss of power, and I'm sure I'll lose a couple MPGs. I'll put it back on the 91 tune as soon as I get back to civilization.

The other option, if I decide to go, is octane booster. Can I just add a bottle of that with each fill-up and keep the same tune?

Octane booster is like a cat in a bag. Unpredictable, and not a good idea IMO.

If you drop the timing, stay out of boost and high load, and "take it easy" I don't see why you couldn't get away with 87 on a road trip.

Telling me to simply "take it easy" is like telling Fae to go easy on his transmission. Or to have his car run. I am not opposed to disconnecting the wastegate if I have to, and dropping the timing, but if I remember right it still builds boost at higer RPM even with the wastegate disconnected.

Then run the risk of melting pistons? LOL

It's not like I don't want to take it easy, I just know myself better than that. I can't be trusted to keep my foot out of it for 3000 miles.

If there's a way to tune megasquirt so it won't let me do anything crazy, I am open for that idea (as long as it's not just a fuel cut at 100kpa or something, this trip is supposed to be fun, not torture). I just know I will forget that I'm supposed to be easy on it for a second when my friend pulls away from me on his bike and I try to keep up, then have engine strewn all over the road 800 miles from the nearest tow truck.

18psi nailed it. It's easy enough to pull 8 degrees timing and stay out of it. I wouldn't think you'd have any problems with that. I'd carry a laptop with me so I could swap tunes, hopefully you won't run into the problem in the first place.

super ultra retard and you will melt your valves.

i say program spark cut revlimiter at 4500rpm. Problem solved. Plus you will still get your taste of drama.

Wire the wastegate open and set the Rev limit lower? Or just stay out of it?

Then take another car.

As you know, I'm a relative noob when it comes to turbos, but that isn't going to stop me from throwing my 2 cents in. :D When my brother filled my MR2 turbo from running on fumes empty to full with 87 octane. I did the math based on the promised octane of the booster. It was going to cost more in off the shelf "octane booster" to actually realize 91 octane than the cost of dumping the fuel and filling it again.

Don't you have an 8 psi wastegate and a knock sense? So you could pull 2 psi out of the tune, and retard the timing a bit more in response to boost, and as long as it isn't super hot, it would be ok on 87 octane. 87 just burns faster and has less detonation/preignition resistance. It isn't all evil. And retarding the timing with spark timing is a counter to advancing it with 87 octane, so it isn't like you are going to burn up the valves and destroy the turbines from a little retard.

Alternately, you could actually boost the octane. Find out what beer Chris likes, and see if you can get some of his 110 octane stuff that they deliver to his house in sealed 10 gallon containers? How many times are you going to be in that situation? 10 gallons of 110 will make around 58 gallons of 91 out of 87.... (his 110 isn't even all that evil to cats, iirc).

Well hello, noob! :giggle:

I am thinking about options for this trip. One option on the table is renting a motorcycle, which (if we do enough miles each day) could pay for itself in gas. I can't very well just "take another car" like y8s suggested, because my other car is a turbo subaru, which also frowns upon 87 octane, though not as much.

I will consider this 110 octane suggestion... I can get quite a ways on 58 gallons of fuel. Maybe even far enough to not need an 87 octane tune. Do you think Chris would actually sell me 10 gallons of that stuff?

Get some self control. Its cheap, easy and helps your motor last a long time.

Ok, ok. I have decided that I can practice some self-control and be nice to my gas pedal while on an 87-octane tune.

Now, for a related opinion-question: Would you trust your turbo miata 1700 miles into the canadian wilderness, hundreds of miles from the nearest town (literally) with no cell service for a week?

My answer to your question is no, but it isn't really a good question. I'm sure your turbo miata is orders of magnitude more reliable than mine right now :D

As far as Chris' 110 octane fuel, I'm pretty sure he would help you order you own and help you get it (bring it to an event?)

Well, it looks like my friend is too chicken to ride his motorcycle that far, so if we go we will probably both ride in his tacoma and do a little more off-pavement exploring. I guess that settles all of this.

Knowing us, though, this will change 3 more times before we actually go anywhere.

So should I start calling Kyle a pansy around the office, or different friend?

Different friend, though I actually met him through Kyle. Kyle doesn't have a motorcycle, does he?

Also, off pavement exploring out that way with only one rig sounds way more scary than taking a bike... if you got it stuck enough to need help with recovery, you'd die of blood loss from the mosquitoes before you made it to one of those call boxes.....

Not real off-roading, just gravel roads with spare tires in the bed of the truck.