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HIGHEST OCTANE USED on modified turbo engines ?

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HIGHEST OCTANE USED on modified turbo engines ?

Old 03-02-04, 03:24 PM
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HIGHEST OCTANE USED on modified turbo engines ?

while doing any kind of event like drag racing , road racing where race gas is easily available . has anyone used the leaded type race gas that is 112-116? . ive used only the unleaded 100 but was wondering has anyone mixed these 2 types together or what are the negative effects for using small amounts of leaded while racing with no catalytic converters . does anyone here have any previous expierience with high octane race gas(leaded and unleaded) and boost .?
thanks
jose vela
85 gsl-se turboII conversion TO4E
ran with 100 octane but want higher
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Old 03-02-04, 03:28 PM
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Not with boost... but leaded 114 smells really cool.
~$6.50 a gallon
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Old 03-02-04, 03:58 PM
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travis thanks for the input

jose
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Old 03-02-04, 04:09 PM
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I run 100 octane here in Denver, as the octane points are consistanly lower. It would equate to around 104 at sea level. I have never had any issues with it, and would recommend it for boost.

Like Travis states, there is nothing like the aroma of race fuel!
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Old 03-02-04, 04:50 PM
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There's no point in spending the extra money. Also, the lead will kill your o2 sensor.

If your car is already tuned using 91-93 octane, 100 octane is good insurance for the track. There's nothing to be gained by running higher.
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Old 03-02-04, 04:59 PM
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If you are running a full race prepared turbo engine then the octane will give you added detonation protection. this is vital in turbo rotaries. I ran my turbo 13b for 2.5 years of racing on 110 octane Unocal leaded race gas. After initial tuning the engine ran perfectly until time had worn the apex seals. never had any detonation and aside from normal wear the internals were fine.
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Old 03-02-04, 06:40 PM
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If you plan to really turn up the boost then race gas is cheap insurance. I could run 8* more timing at the track with 10psi more boost with C16 (116 leaded for turbo motors) vs. 93 octane unleaded in my little turbo V6.

You can get heated O2 sensors which are less prone to failing.... or an aftermarket fuel management system with wide band O2 are designed to handle race leaded fuel.

$8/gallon vs. a popped motor. You decide.... racing ain't cheap.... and it is more expensive if you cheap out on the fuel quality when pushing the envelope.

Mixing 100 octane with 116 octane will have no adverse effects aside from the O2 sensor failing. You can take 100 octane and add Xylene (117 octane) to raise the octane level and remain unleaded.

HEre is the recipe the TurboBuick guys have run with no ill effects:
7 gallons 100 octane
3 gallons Xylene (117 octane)
3 ounces MMO (Marvel Mystery Oil) for lubrication

yields 105.1 octane....... you aren't supposed to mix in more than 30% Xylene or it starts hard with cold weather and drives weird. It is a trick from the old Group B rally cars when they would run 40psi+ boost.....

-GNX7
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Old 03-02-04, 07:26 PM
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thanks for the info everyone

thanks everyone for your valuable info . i guess we can use the 116 leaded but will kill o2 sensors and cats as well if we are using them. other than that its ok , i will finish installing my profec-B , egt guage as well so that i can try and use the recipe GNX7 provided at my next race . and for now ill be runnin with 100 just for safe peace of mind .
again i want to thank you all for your time in explaining me this octane bug i had in me .
jose vela
85 gsl-se TurboII conversion TO4E
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Old 03-02-04, 08:31 PM
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Below ~25psi, 100 has been reliable for me, In my Supra, I'll run 116 when running 30+ psi, other than that, I run 100.
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Old 03-04-04, 12:04 AM
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Originally posted by gnx7
Mixing 100 octane with 116 octane will have no adverse effects aside from the O2 sensor failing. You can take 100 octane and add Xylene (117 octane) to raise the octane level and remain unleaded.
Where do you get Xylene?
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Old 03-04-04, 11:08 AM
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Open up a business account (free) at any major paint store and buy it in 5 gallon containers. I got mine at Sherwin Williams for about $31-33 per container.

-GNX7
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Old 03-05-04, 01:02 PM
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I checked on prices because cheep high octane sounds good.

But i can buy real race gas for the same price or less.

Its only $6.80 a gallon for 116 sunco unleaded race gas.
Its only 4.25 for 110 sunco unleaded race gas


Its allmost 7 dollars a gallon for your xylene
and toluol is only a little less expensive
you have to run 100% of either to get their 114 to 116 octane rating


It doesnt sound like such a good idea now huh. =)
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Old 08-19-04, 03:38 PM
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Bump on an old thread, would it be safe to use a gallon of xylene, and two ounces of marvels mystery oil with an almost full tank , just to clean my injectors?
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Old 08-19-04, 05:45 PM
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blacksupra- that won't hurt anything and many use it clean their injectors a few times a year. It is one of the main ingredients in the injector cleaners you buy from your local autoparts store.

Making your own 100 octane isn't necessarily cheaper.... but if you don't have access to it then it certainly is an option to use.

-Mark
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Old 08-19-04, 07:04 PM
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6.50 a gal for 114?? sucks for you, im getting 55gal's of 116 at 4.40 a gal
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Old 08-23-04, 09:43 AM
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you need at least heat range 11 spark plugs (non platinum) for leaded gas
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