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  #1  
Old 09-03-2009, 01:03 PM
Steele Steele is offline
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87 Octane

So... I recently bought a '92 SVX, and I need to get some info. I tried searching and found little that was useful.

In interior Alaska, you can buy diesel fuel anywhere. There is not a single fuel station I have seen that does not sell diesel, unlike down in the states. The tradeoff, though, is the frequent lack of high-octane gasoline; and, while I am readily able to buy $4.45/gallon diesel for my pickup, I sometimes have difficulty finding $3.75/gallon high-octane for my new car.

So, the question is, what can I do to the car to allow it to run reliably and safely on 87-octane fuel? Is there an additive available? A way to adjust the timing easily? A magic carburetor that Detroit doesn't want me to know about?

Another question, somewhat unrelated... Is there anything special worth doing to an SVX that will be driven in extreme cold? Temperatures as low as, say, -60F? It's been "winterized," which means that it has the normal assortment of engine and accessory heaters. Are there special considerations for the transmission or engine that a different model car wouldn't need?

H
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  #2  
Old 09-03-2009, 01:12 PM
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y2daniel1981 y2daniel1981 is offline
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Re: 87 Octane

Quote:
Originally Posted by Steele View Post
So... I recently bought a '92 SVX, and I need to get some info. I tried searching and found little that was useful.

In interior Alaska, you can buy diesel fuel anywhere. There is not a single fuel station I have seen that does not sell diesel, unlike down in the states. The tradeoff, though, is the frequent lack of high-octane gasoline; and, while I am readily able to buy $4.45/gallon diesel for my pickup, I sometimes have difficulty finding $3.75/gallon high-octane for my new car.

So, the question is, what can I do to the car to allow it to run reliably and safely on 87-octane fuel? Is there an additive available? A way to adjust the timing easily? A magic carburetor that Detroit doesn't want me to know about?

Another question, somewhat unrelated... Is there anything special worth doing to an SVX that will be driven in extreme cold? Temperatures as low as, say, -60F? It's been "winterized," which means that it has the normal assortment of engine and accessory heaters. Are there special considerations for the transmission or engine that a different model car wouldn't need?

H
The best, easiest, cheapest, way I know of to retard the timing to run 87 is to get the ECUtune Stage 1 chip. Ive been told it retards the timing 5 degrees to safely run 87 or for use with nitrous or f/i. I plan on using it if I go nitrous or f/i (once I get the rest of the car back up to par.) You could also put in octane boosters, but it'd be cheaper in the long run to just get the chip. If you have all the normal things to "winterize" a vehicle in such a way that everyone else does, you should be fine as far as I know.

Last edited by y2daniel1981; 09-03-2009 at 01:16 PM.
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  #3  
Old 09-03-2009, 01:26 PM
1986nate 1986nate is offline
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Re: 87 Octane

+1. Get the ECUtune stage 1 ECU from here (http://ecutune.com/svx-stage1.htm) or PM "longassname" here on the network. His name is Mike and he is the one who runs Ecutune. Just make be sure to tell him that you want the second map to be setup for 87 octane
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Old 09-03-2009, 04:11 PM
Steele Steele is offline
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Re: 87 Octane

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Originally Posted by 1986nate View Post
+1. Get the ECUtune stage 1 ECU from here (http://ecutune.com/svx-stage1.htm) or PM "longassname" here on the network. His name is Mike and he is the one who runs Ecutune. Just make be sure to tell him that you want the second map to be setup for 87 octane
Sounds like a plan. This can be switched back and forth, right? I mean, I won't always use 87, only when I can't find high-octane gasoline.
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  #5  
Old 09-03-2009, 06:10 PM
1986nate 1986nate is offline
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Re: 87 Octane

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Sounds like a plan. This can be switched back and forth, right? I mean, I won't always use 87, only when I can't find high-octane gasoline.
Correct, You wire up some type of switch and then are able to swith between the normal map and the lower octane map
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  #6  
Old 09-03-2009, 07:09 PM
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Trevor Trevor is offline
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Re: 87 Octane

Nearly twenty years have elapsed since the car was first produced and since then, there have been changes in what was then standard fuel.

I have run on approx. 87 octane, our standard fuel, for more than two years, much of it stop start driving, and have never detected anything near knock or pre ignition. However my car is JDM and fuel rating can not be assumed as accurate, country to country. Run a test and observe.
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Old 09-03-2009, 07:41 PM
NiftySVX NiftySVX is offline
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Re: 87 Octane

I agree with what everyone has said here, including Trevor's bit about fuel quality coming up, and I agree with him that you could try it and report back. Though I am not a petroleum engineer and I don't know if it could be said that today's 87 octane is as good as 1992's 91. I tend to doubt it, because if that were the case they would have changed the scale to phase out 87 like they did 85 in the US. But it is true that today's 87 is better than 92's 87. Theoretically, if the engine is operating as it is designed, the use of 87 octane fuel will cause predetonation, which will be detected by the twin knock sensors, which will retard the timing until there is no more knock. This is of course assuming that the ECM is able to retard the ignition timing enough. I am not familiar with the limits of the ECU's ability to retard timing, but I suspect that it would be able to compensate. This is especially true if you're at a low altitude.

Oh, and as far as cold weather prep, I don't see any thing else you could do, but if it were me I would try to make sure that I didn't ever drive the car with the ATF fluid temp below -10 or so as -60 is at the lower limit of the fluid's intended range.
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Last edited by NiftySVX; 09-03-2009 at 07:45 PM.
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  #8  
Old 09-03-2009, 11:06 PM
Steele Steele is offline
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Re: 87 Octane

If the car was designed for 92 octane, I'd rather run it on 92 octane. I used to have an older Mercedes, which wanted high-octane fuel. Once in a while, we'd run it on 87-octane or whatever, and you could tell the difference between the two. Mileage went down, power went down, it knocked quite regularly. It worked, though, and sometimes there was no other choice, so I did it.

I've no experience with an SVX, though, outside the last four days.

I will order the ECUTune module, and try that.

Regarding the cold: the car will be run in cold temperatures, whether it likes it or not. It has a pad heater on the transmission, though, so the ATF should be quite a bit warmer than -60F.
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  #9  
Old 09-04-2009, 05:35 AM
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Re: 87 Octane

Mine starts very well, even at -35°F. A block heater would be a good idea at -60°F though. Cheap and easy to install.
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Old 09-04-2009, 03:15 PM
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Re: 87 Octane

whats the worst that could happen if you run on lower than 92 octane?
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  #11  
Old 09-04-2009, 03:37 PM
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Re: 87 Octane

I've run 89 for years without any problems.
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  #12  
Old 09-04-2009, 04:08 PM
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Re: 87 Octane

You never hear of someone trying to keep trans temps higher. Maybe a expert can chime in here but couldn't you bypass the cooler to keep the temp higher?I wouldn't try it without a temp gauge though.
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  #13  
Old 09-04-2009, 05:14 PM
1986nate 1986nate is offline
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Re: 87 Octane

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Originally Posted by michael View Post
You never hear of someone trying to keep trans temps higher. Maybe a expert can chime in here but couldn't you bypass the cooler to keep the temp higher?I wouldn't try it without a temp gauge though.
If the trans fluid temp is too cold, it will also cause major problems with the transmission as the fluid becomes more of a sludge than a fluid at such low temps, same thing with engine oil if the temperature is low enough. Also the transmission fluid temp needs to be above 150 degrees F in order to function properly, otherwise it will never lock the torque converter in order to raise the temp to proper operating temperature.
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Old 09-04-2009, 05:16 PM
1986nate 1986nate is offline
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Re: 87 Octane

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Originally Posted by Gamesy View Post
whats the worst that could happen if you run on lower than 92 octane?
the worst is, that although not very likely, you could be in need of a new engine if the ECU/knock sensors aren't able to adjust enough or adjust soon enough.
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  #15  
Old 09-04-2009, 05:47 PM
FUDDMAN FUDDMAN is offline
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Re: 87 Octane

I use 87 octane in my 96 without having to do any changes. The ECU takes care of eveything. Stormin Normin uses regular in his all the time.
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