3266 replies to this topic

[FLD]

Its not always octane that dissapears from your fuel Joe. It doesn't chemically change but you'll loose the high volatiles. I'd suggest draining the tank and using it in your lawn mower or shopping trolley. Put fresh in your car. Octane boosters are usually toluene or xylene based. 10% gunwash (mostly toluene) in your fuel gives a decent boost in octane.

[Seb.F]

There's no way you want an afr of 14.6 at idle. In fact, I don't think I've ever seen a car running at 14.6 at idle. Lean is better on idle, rich is better higher up in the revs.

[The Batman]

I will take the fuel pipe off and drain it that way... Some how Seb it's only 14.6 when the ignitions on/engine is off

[alanoo]

Its not always octane that dissapears from your fuel Joe. It doesn't chemically change but you'll loose the high volatiles. I'd suggest draining the tank and using it in your lawn mower or shopping trolley. Put fresh in your car.

Octane boosters are usually toluene or xylene based. 10% gunwash (mostly toluene) in your fuel gives a decent boost in octane.

and of course, never map a car with an octane booster in the tank !

[fezzasus]

Its not always octane that dissapears from your fuel Joe. It doesn't chemically change but you'll loose the high volatiles. I'd suggest draining the tank and using it in your lawn mower or shopping trolley. Put fresh in your car.

Octane boosters are usually toluene or xylene based. 10% gunwash (mostly toluene) in your fuel gives a decent boost in octane.

In fact you're unlike to lose much of the high volatility stuff as the fuel tank is a closed system, meaning it hasn't got anywhere to go.

The main cause of degradation is radical attack; metal species in the fuel will break down the fuel to shorter hydrocarbons - essentially lowering the octane number and causing more pre-ignition.

Advice is spot on though

[leevx2.2]

Joe take fuel pipe of fuel rail extend pipe to a plastic petrol can . Then hard wire pump by taking relay of and put positive feed to pump positive job done Put old petrol in your mums car or in the astra :-))

[NickB787]

I dropped Jon a message to drain my tank as the fuel has been there since Sept last year,

[Mike (Cliffie)]

Joe take fuel pipe of fuel rail extend pipe to a plastic petrol can .
Then hard wire pump by taking relay of and put positive feed to pump positive job done
Put old petrol in your mums car or in the astra :-))

But do not run the pump dry at any time.

[Mangham54]

If you are feeling generous. Fill with fresh fluid and then drain off 31litres and refill. That way you should clear most of the old stuff out and avoid damaging the pump. Bit like you do when flushing the brake system. But then I am preaching to the converted.

[The Batman]

yeah i will drain 15L (20L left in tank) so this prevents the pump being run dry then get 27L of 99 ron fuel and fill the tank up this will be fine imo off to go get some nuts

[Nev]

There's no way you want an afr of 14.6 at idle. In fact, I don't think I've ever seen a car running at 14.6 at idle. Lean is better on idle, rich is better higher up in the revs.

Stage 4 Klassen/Courtenay maps idle at 14.6 precisely (+/- 0.1). I have had a wideband in my car for 3 years and it's always read that at idle. Yes, you can run leaner at idle but it's not a good idea as the turbo + manifold will overheat far faster in traffic which we all know is bad in poorly ventilated mid engined car.

[Seb.F]

Strange, never seen a car run that on idle before, but if that's how they do it, fair enough. Even on previously tuned engines I've had them running about 10% leaner.

[Nev]

I have a full list of different fuels and associated interesting (but faily unusable!) info on my web site here.

Edited by Nev, 18 July 2011 - 01:11 PM.

[FLD]

'introduction to the internal combustion engine' has a good chapter on fuel composition and the effects of each part. It also covers the various octane meanings and what affects them etc. Worth a read if you're bored.

[The Batman]

now having the wideband lambda sensor fitted i can see that the car when revving on vxr and let injectors that it runs very lean and very rich in certain areas of the rev range up to about 3k havent gon higher than this. After speaking to Jon at courtenays we both agreed that le mans is out the question as the mapping just isnt going to be ready and if it will be then i will then have to take it home run it in and then drive to get the final map which just isnt logistically possibly within the limited time frame to le mans. after dropping out the national due to tthe car not being ready it left me with no room for error which was alot to ask for a ecu that has never been put on a z22 before. So we agreed that the best thing to do is wait until nicks car is ready and running perfect on the ecu to then put that map on my ecu and run it in and then go for the final remap which is the safest option we can both think off, this engine owes me alot of money and to be honest i cant afford for it to break! so to be continued another day/month...

[Seb.F]

Bloody harrops

[Mike (Cliffie)]

After speaking to Jon at courtenays we both agreed that le mans is out the question

Boo-Hiss.

No Lee, no Fab, no Joe, no Nick.

[The Batman]

bad year for the clique

[Sticky]

bad year for the clique

Are you still coming for the social?

Sure you can grab some driver/pax laps

[techieboy]

Just noticed you'd cancelled in the LM thread. Ballcocks.