Jump to content
SAU Community

Running Skyline on low octane fuel

Duncan

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

 Share

Recommended Posts

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.

Link to comment
https://www.sau.com.au/forums/topic/29273-running-skyline-on-low-octane-fuel/
Share on other sites
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?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
×
×
  • Create New...