Jump to content
SAU Community

Recommended Posts

Obviously their not the same but are the same octane rating. He doesn't run avgas in it at the moment so there is no need to run it and their not really completely separate animals.

They might be the same octane rating but they don't share the same octane numbers. Apart from different burn rates, and the fact that Avgas contains TEL, the differences are vast. I again refer to MoTeC's testing on an engine dyno which suggests that V-Power Racing performed better than Avgas in every situation. The fact that the engine used was a 4G63 from an EVO IX only strengthens the argument that what they found applies to Skyline motors.

They ARE completely different products.

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3189555
Share on other sites

2rismo after all this you are confirming what I said in the first place. I'm in this for a discussion/learn.

The mixture known as gasoline, when used in high compression internal combustion engines, has a tendency to ignite early (pre-ignition or detonation) causing a damaging "engine knocking" (also called "pinging" or "pinking") noise. The discovery that lead additives modified this behavior led to the widespread adoption of the practice in the 1920s and therefore more powerful higher compression engines. The most popular additive was tetra-ethyl lead.

Lead is also a good lubricant for valves which prolongs engine life and the avgas around now is 100ll which is low lead with anti knock additives added.

Avgas also burns slower due to if having to stay as a liquid at high altitudes.

I couldn't find their BTU ratings though.

This might have a little to do with it.

It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion). However, premium grades of petrol often contain more energy per litre due to the composition of the fuel as well as increased octane.

What is the go with the octane rating vs octane number I don't know.

Marine diesel or Jet A-1 could be better :(

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3189670
Share on other sites

thats what i thought too that one tankful wouldnt hurt..

anymore info on toulene mix.. where to buy, how much to mix, how much cost and how much does it boost the octane??

might do some search on toulene..

There's a thread in the performance section I think called "backyard race fuel" I got the link somewhere if you can't find it, but losta interesting stuff in it.

AVgas will also melt your CAT causing it to block up. Yes...in one tank. Much like leaded(super) petrol would do if you ran it.

lol...cat... :(

Marine diesel or Jet A-1 could be better :)

lol, have fun running diesel in a petrol engine and A1 is Kero so have fun running that too :) A1 does smell good though..... :P

I think half the joy of running avgas is the smell :( I'd never put it in my skyline but a friend usees it in his SS all the time :P

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3189759
Share on other sites

I found this in Wikipedia as well.

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, AvGas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116). Typical "octane booster" additives include tetra-ethyl lead and toluene. Tetra-ethyl lead is easily decomposed to its component radicals, which react with the radicals from the fuel and oxygen that would start the combustion, thereby delaying ignition. This is why leaded gasoline has a higher octane rating than unleaded.

Don't hang me on the BTU rating but:

You stated that Avgas made less power why is this? I need facts.

As for Toluene I found it has a octane rating of 114. I have 20 litres at work and I know Snowy was put it in his car a while ago. Its commonly used as a knock deterent as far as I know.

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3189815
Share on other sites

my only reason for wanting to run higher octane was to reduce any chance of pinging...

i rarely have spirited runs let alone many runs in a row all day like in a drag day situation. so although i trust Benno's tune it still is unknown how the engine might behave on the track simply because its never been on one..

power increase was never my intention although i must admit R31Nismoids reply did make me think about fattening the power curve with better fuel..

but after reading the discussion and some good points made i decided to run on v-racing and see how it goes.. definately learned few things from this thread.. thanks for the replies...

thanks also for the links which i will be checking out...

edit: http://www.motec.com.au/fueltest/index.htm

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3190142
Share on other sites

There's a thread in the performance section I think called "backyard race fuel" I got the link somewhere if you can't find it, but losta interesting stuff in it.

yeah i found it last night and read thru most of it, was good reading..

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3190259
Share on other sites

Octane isn't the only measure of a fuel when you're after some protection for a track day. Some of the very high octane unleaded fuels will burn very rapidly compared to pump fuel and could result in a lean AFR. Motec's website has some very interesting fuel test data comparing avgas and v-power racing from shell.

had a look at the motec site, very interesting indeed..

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3190264
Share on other sites

Jetdat

If benno has set your tune with V power racing then don't touch it and race it with that fuel in the tank.

It will be fine.

I ran my car around sandown with his tune on vpower racing and the knock levels were fine all day.

Your engine has been tuned with the fuel characteristics of v power racing, don't go putting a higher octane rating fuel (even if it is unleaded) as this fuel will exhibit different burn characteristics etc

point taken archie01.

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3190265
Share on other sites

Jetdat.

If Benno tuned your car in V-Power Racing, DON'T use anything other than V-Power Racing.

You wont need to change anything. It's not like you are blazing away for 10-15 minutes on full boost, you are only blazing for maybe 10-15 seconds :O

If you are really worried, I can add some fuel to your tune temporarily on the weekend. It's not a permanent setting, it's a very basic add of fuel.

But, yeah, if Benno tuned it, it will be fine.

Link to comment
https://www.sau.com.au/forums/topic/173443-avgas/page/2/#findComment-3191570
Share on other sites

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


  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...