Si've I've bought my FD, I've moved to a different climate. I owned it in a low altitude high humidity and heat (gulf coast) to an area of high altitude, and high dry heat. At night, when it cools down, the car runs amazing...

Anyway, I used to have 93 available, but where I am now they sell 91. No 93 for as far as I know, and I've done some exploring. I was thinking about running water/meth...But the question still lies. If I ran water/meth, could I run it just enough to where it would run at temps equal to 93 octane? I don't want to mess with the tune as the car is running an RE-amemiya tune.

Is there a good way around this? I did try to search but was unable to find something similar to my current situation.

 

i would get a meth kit, they always work and help lower intake temps and will compensate for the octane drop, another more expensive option is to switch to ethonol if its possible for you to get.

 

When you step back and look at the facts this thread is simply rediculous.

1. you are running LOWER octane
2. you are in a completely different climate
3. you wanna run meth/water only to bring your temps down to what they were with 93?
4. you don't wanna retune your car to run safely beause you currently have a "JDM tune"

I don't mean to be an @$$ but this is plain stupid.

 

Buy a water inj kit and get it tune for 91. Only way to work .

 

I'm sorry I'm not god's gift to automotive vehicles, bro. I was ASKING.
Thanks for the input otherwise from the other users, I'll take it into consideration.

 

not to sound like a dick but if you like your car you wont consider it youll do it. get it retuned your AFR's are going to be all messed up due to the change in air density and the lack of a higher octane fuel.

 

I understand, but I live in BFE, where I must do all work myself, and wrenching I have no issue, but getting a good tune, would be a pain in the ***. I cant think of a place that would tune a car let alone a rotary.

 

pull two degrees of timing on the leading and 4 degrees of timing on the trailing in rows P15-P20

 

I used to drive my car 6 hours to Gotham to have kahn street tune it, then turn back and drive 6 hours home.

I don't know how far the closest rotary tuner is to you but I'm sure it will be well worth the drive.

 

I'm going to have to agree that a re-tune is really your only safe option. Water/meth is great, but not a substitute for a good tune.

 

Just add some water injection. Don't bother with meth. It will make up the difference.

thewird

 

I agree with thewird,

Just use water as it does not affect AFRs

Why does everyone insist on retuning a car when going to a different climate?
If you have a GOOD ecu and properly TUNED with Correction factors tuned not just base tables there isnt a problem with going to warmer climates or higher altitudes as tuning these things isnt a problem from a good tuner.

 

Try rereading the OP origional post. You might notice that he said he had an "RE Amemiya tune". Unless Amemiya son came to the USA to personaly tune this guys car in the sticks, then it sounds to me like it's a generic tune mapped for bolt ons (similar to what you would see on the BASE MOD map of a PFC). In other words the correction factors are not properly tuned because this guys car probably NEVER properly tuned. I'd guess this car has never even seen a wideband.

And maybe you also missed the fact that he is running LOWER octane...

OP water/aux injection is definatley a step in the right difection, but do yourself and your motor a favor get it properly tuned.

 

In the mean time why not just get some good quality octane booster? NOS sells one that actually raises the number, not just the octane points (10 points = 1 number)

You can also make your own but I wouldn't do it without doing some good research.

Here is a good write-up that shows test results on a few boosters and results on homemade boosters.

http://www.europeancarweb.com/tech/0...ted/index.html

 

^ I assumed he bought his RHD from Japan already tuned so it would be tuned for his car. Water injection in the right amount would more then make up the difference between 93 and 91 octane. It's not like he is trying to run 87. If nothing else was changed on the car, I see no reason for a retune.

thewird

 

According too Howard Colemans water injection write-ups, water injection should more than cover the difference. Octane booster might be a safe temporary fix.

 

Does anyone know what the difference between running at sea level and high altitude is?Maybe there is so little oxygen up there no change is required!

 

The amount of oxygen decreases by about 50% every 5000 meters. So going from Houston to Denver, for example, you'd see about 15% less oxygen. The oxygen isn't going anywhere, it's just a lower air pressure, therefore, less of everything.

 

If it was tuned right to begin with, since an FD uses a MAP sensor, it does not matter.

thewird

 

So you are saying it doesnt have correction factors in the ecu Just as a question would you drive a stock standard rx7 to a warmer climate or put in a aftermarket ecu and get it retuned ?
Lower octane does not mean anything if the car does not detonate on the lower octane.

 

You guys act like you know the car was tuned on 93.....The fact is you have no idea if the amemiya tune is on 93,87 or or 103. And if the wind is right and the car was actually tuned in japan then I would be even more nervous about detonation. 91 octane is crap here (at least in OK)
I'm not sure I understand your question but either way we are not even talking about a stock FD,this is a modified FD (two completely different animals.

 

the difference between 91 and 93 octane is miniscule, but there. Honestly get water injection and a good tune from a rotary tuner and you'll be set.

edit: what ecu are you using?

 

The difference between a good tank of 93 and a bad tank of 91 can get very expensive very fast...

 

and a medium tank of 93 and a good tank of 91 are identical (assuming the 91 has no ethanol) and a bad tank of 93 can lead to a blown motor anyways.

 

LOL, I feel like I'm arguing for the sake of arguing (which is pointless and very frustrating).

Jkor- slap your FD on a dyno and let the AFRs do the talking. If they are safe, then throw your water injection kit on and call it a day. If something doesn't look right then find yourself a tuner. ( and throw your water injection kit on)