Ulp 91ron Ignition Timing

[Cubes]

Hi ppls,

I decided to slap $35 BP ULP in tonight as I hit the red.

I've always wanted to see for my self exactly how much ignition timing differs between ULP and BP98.

Light to moderate throttle with ~7psi knock was no different.

A little more throttle and 10psi at peak torque I had to pull 6 degree's of ignition timing, the rest was 5 degree's.

Quite a large pull of ignition timing, I was expecting maybe 3degree's. Not 6!!

Most definitely not worth the extra $5-$6 it costs to fill with BP98 over ULP.

Limpity limp for me until $35 worth of fuel is gone.

Edited October 8, 2005 by Cubes

[Gav]

Personally I reckon that this is an underated topic - one of the great advantages of having a programable ECU is to be able to "ride" the octane versus power curve - i.e. if you want economy, you can have it - albeit at the expense of performance

[Sydneykid]

I have tried having 92 ron and 98 ron maps, both tuned on Shell fuels. What I found was around 5-7% lower fuel economy. I put most of that down to the engine loosing efficiency at retarded ignition timing, maybe a little to the more efficient burn of the 98 ron. And the balance was me trying to get the same performance out of the car ie; more heavier application of the throttle.

After a month of driving around on 92 ron the fuel bill in $ terms was much the same. I would have improved that by driving for more fuel economy, but I could have done that with 98 ron just as successfully.

cheers

[lordsnipe]

you could always whack in some octane booster so you don't have to limp it...

[Cubes]

Octane boost won't raise it enough.

Octane boost really is a scam.

[race_snooze]

toulen. From your hardware store, there is a thread covering this as a octane booster, 4L brings the ron up a lot from memory

[Cubes]

Its all good.

I can't hammer it anyway as it needs to be tuned.