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Running Skyline on low octane fuel

Duncan

By Duncan,
in R Series (R30, R31, R32, R33, R34)

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Duncan Grand Master

Duncan

Posted
Posted

My understanding is that Rb25s, and presumably other skyline motors have knock sensors in the block. When the stock ECU detects knock it retards timing, reducing power and preventing further knocking.

Is my understanding correct?

Specifically, I've got a long trip coming up and don't expect to find anything better than PULP (95), and I may even have to use 91 at times.

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https://www.sau.com.au/forums/topic/29273-running-skyline-on-low-octane-fuel/
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Kinks Grand Master

Kinks

Posted
Posted

nulon is the only one that actually works..

http://www.angelfire.com/mb/southo/Octane.html

or

http://www.fbody.com/members/stevenmh/Fire...ane_booster.htm

or

http://members.rennlist.org/951_racerx/Oct...Comparison.html

(I think they all quote the same test results).

Toluene is way too much hassle IMO.

Duncan Grand Master

Duncan

Posted
  • Author
Posted

Thanks all.

Yeha strutto, I guess thats the problem....it will be hot and it will be under high load. I'll turn boost down to stock but it wasnt too high in the first place.

And of course highly flamamble 20l can in the back isnt my idea of fun either :(

hippy Grand Master

hippy

Posted
Posted

i've been using shitty petrol for a couple of weeks now ... i find the theres less power .... not that much ... but i've found it a little strange in that the car still runs smoothly and my feul economy is slightly better in that using 98 ron i was getting just over 400 ... but using 91 ron i'm getting 450+ ... i've got a pod and full exhaust on an auto ... so i'm not too sure whats going on LOL ...

before i had a dump pipe my economy was

91 ron - 350-450k's

95 ron - 450-500k's ... usually very close to 500 so thats what i used.

98 ron - 350-400k's

strange huh?? anyways i can't run 95 ron with the full exhaust cause the bp that used to have only has ultimate.

my question is ... will a SAFC correct whats going on and let me get the same or better mileage ie 500+ k's of a tank using 98 ron??

blind_elk Grand Master

blind_elk

Posted
Posted

I did a trip last Easter Melb - Bris - Syd - Melb - Adel - Melb. At times, I could only get PULP. I ran some Nulon OB as well, as a safety precaution. But I would think that under general highway cruise you shouldn't be loading the engine so much that you could induce knock. These things run like 40 deg advance on cruise, I believe.

kjb_r33 Experienced

kjb_r33

Posted
Posted

retarding ignition timing by the crank angle sensor also retards injection timing (not overly good if your after economy). If the knock sensors dont retard it enough to stop any damage occuring you will hear it pinging, back off. Ideally, if PULP isnt available then use an octane booster, but keep in mind it only raises the octane rating a very small amount.

franks Veteran

franks

Posted
Posted
so can anyone give me a better discription than "ping"  ??  :D

lol..sorry dude, i should've put my 2c forward - pinging sounds like shaking a tin can filled with nuts and bolts ...

wether this be the case of "zzzeeeeaaaaaaaa" i would hazard a guess thats either a) induction noise or B) your turbo :D

druzilla32 Mentor

druzilla32

Posted
Posted
as said adjust the crank angle sensor should do it

and your a typical race car driver.

My engine is pinging.

I did an ecu test and came up i got a fault in my knock sensor.

Can i prevent further pinging by retarding the timing more?

do i turn the CAS anti clockwise?

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