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Old Jan 28, 2009 | 11:02 AM
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What is the rule of thumb when it comes to race fuel.

A local Meijer gas station has 108 octane.

Do you have to change the timing etc to run that in an engine?
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Old Jan 28, 2009 | 02:24 PM
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the pcm will change timing accordingly what i would be worried about first is if that will gunk up your cat and also keep in mind that the higher the octane the more spark energy it takes to ignite
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Old Jan 28, 2009 | 02:49 PM
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yeah, make sure it's unleaded.... otherwise you'll hose your O2 sensors, plugs, CAT, etc etc...
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Old Jan 28, 2009 | 06:06 PM
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There is no need for more octane in these cars, 91-93 is good enough, at least until you change your compression ratio, or go FI.
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Old Jan 28, 2009 | 06:26 PM
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Yea I don't think you'll gain anything by using race fuel in a stock car, especially not to justify the increased cost.

EDIT: Wooo I'm in your sig haha.
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Old Jan 28, 2009 | 09:23 PM
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Yes yes you did, That comment pretty much summed up the entire rant by that guy....and I was just wondering, the guys in my home town run it in their go fast bikes and muscle cars...even the ricers
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Old Jan 29, 2009 | 10:56 AM
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I don't use Meijer gas for any of my V8's.

But I switched to 87 octane for the winter because we may have had 2 dry road days in the past couple months. Car runs fine with it in 2 inches of snow.
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Old Jan 29, 2009 | 11:03 AM
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I bet your KR sensor is going mad, at least use 89 or 91 octane depending on your location. Detonation or pre-ignition (knocking) is hard on any car, especially an all aluminum V8.
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Old Jan 30, 2009 | 02:21 AM
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if you don't have any knock then you don't need higher octane.. Its kinda like stickers on ricers, some people think it makes you faster lol but it doesn't unless you need it.
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Old Jan 30, 2009 | 07:47 AM
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You cant always here the knock or pinging, with higher compression engines, it is vital you use a quality premium fuel. Have a scanner hooked up to your car and use **** gas or low octane like the 87 that was mentioned. See it it shows the KR sensor and watch that baby work. The last thing you want to do is replace burned piston and valve seats, for a poor choice in gasoline. Read you owners manual, mine calls for PREMIUM FUEL.
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Old Jan 30, 2009 | 10:08 PM
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I meant you don't need any higher octane than 93. Thats all i've ever used. I should of been more clear, i don't have any KR right now.
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Old Jan 31, 2009 | 12:55 AM
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You could try a 2/3, e85/93oct mix. I have done this on an empty tank and it pulls like a beast.

After about 40 miles the traction control light came on and it was in V8 only mode. I ran the codes and everything was fine. So I pulled the plugs and used a scope to check the cylinders and they were clean as a whistle.
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Old Feb 2, 2009 | 08:17 AM
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My owners manual recommends premium as well but says I can run 87, however I may get knock and lose performance.

I thought I could run 87 but switched back - thanks for the heads up! Finally got clear roads ...
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Old Feb 2, 2009 | 08:57 AM
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Stick with 91 or better. If you can get 93 in your state then go with that.
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Old Feb 2, 2009 | 08:58 AM
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Its gonna get slower thats for sure unless you move the timing up. You would not notice it so much in part throttle as the timing is fiarly high under cruise conditions, but WOT it may require around 30* or more to get the same perf as 26*-28* on 93 octane. race gas its self doesnt make power unless its has some oxygenating additives etc. It just allows you to get away with higher cylinder pressures w/ less chance of knock.

race gas burns much slower, so if you dont intiate the flame front sooner, the torque will go right in the toilet.
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