OCTANE and IGNITION TIMING
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Joined: Jul 2002
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From: Long Island USA
Originally Posted by fyrhog
I run 87 octane in my V-10.Does it change the ignition timing if I put in higher octane fuel?
Thanks Guys,Ron
Thanks Guys,Ron
And, the higher the octane, the higher the compression needs to be for the engine to "burn" correctly... the V10 and the other modulars are all setup for 87, period.
Post Fiend
Joined: Jan 2002
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From: USA
Ditto ,on What Art said
It does not change timing.And may cause problems after prolonged use.
There is carbon build up that happens alot quicker(IAC and on the 02 sensors)
Also the cats can be come clogged because the unburned fuel is trying to burn in the cat.
Rich
It does not change timing.And may cause problems after prolonged use.
There is carbon build up that happens alot quicker(IAC and on the 02 sensors)
Also the cats can be come clogged because the unburned fuel is trying to burn in the cat.
Rich
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Senior User
Joined: Feb 2004
Posts: 162
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From: Calif.
Thanks guys for the good info.I thought it might advance the spark if the sensor did not pick up the knock or ping when under a load.Its easy to stay with the 87....its the cheapest numbers on the pump and I always get that BSEG when I dont have to grab for the geen pump nozzle.
Ron
Ron
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From: Albuquerque
Originally Posted by fyrhog
I run 87 octane in my V-10.Does it change the ignition timing if I put in higher octane fuel?
Thanks Guys,Ron
Thanks Guys,Ron
Just my .02
biz
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From: OK
Originally Posted by krewat
while there's a knock-sensor it only serves to retard the timing if it pings
Post Fiend
Joined: Jan 2002
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From: USA
Originally Posted by biz4two
You were almost correct. However the ignition timing does change when using a lower octane level fuel. I owned a 2002 Mercedes-Benz C230 that required premium fuel. If I filled the tank with the 86 octane (that is the minimum here in NM)...the car would automatically retard the timing. The C230 would be very sluggish of course. That could have caused the plugs to get fouled...etc.
Just my .02
biz
Just my .02
biz
I know nothing about Mercedes Benz ignition and there octane requirments.
But tritons v-10 and v8s have no way of determining octane.
Past or present.
They can detect ping and will retard timing to save detination(life of the engine) result will be loss of power.
They follow a program in the pcm for timing curve and fuel stratedgy
It will advance timing the same for higher octane as for low octane
unless the knock sensor detects knock /ping, then it will only retard.
Now if you run a tuner or programer then ,yes higher octane is required.
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Post Fiend
Joined: Jan 2002
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From: USA
Originally Posted by NoMo
But won't the ECM advance the timing (within limits) until a 'knock' is detected? If yes, then timing will advance further with higher octane fuel than with 'regular'.
When running tuners/chips yes then the advance or timing has more capability to go further because thay are running on there own program.
which you already knew.
Rich
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Joined: Nov 2004
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From: north west new jersey
high octane burns slower in the chamber there by allowing the timing to be advanced and emprove performace. with the low ratio in our v10's we don't need h.o. untill we tune the heck out of them as i have tried. as to timing the pcm controls that not the gas used.
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Just a little off topic. I have a 99 stupid duty that I installed the Hypertec program on and I have to burn the mid-grade gas 89 octane vs. the 87 or my particular setup pings. I did select tuning for 87 octane on the programmer. It did make a HUGE difference in driveability with 89 vs 87. No big change in mileage, I'm still stuck at 9 in town and if I pray really really hard I get 11 on the highway.
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From: Long Island USA
Originally Posted by JasonSmith
Just a little off topic. I have a 99 stupid duty that I installed the Hypertec program on and I have to burn the mid-grade gas 89 octane vs. the 87 or my particular setup pings. I did select tuning for 87 octane on the programmer. It did make a HUGE difference in driveability with 89 vs 87. No big change in mileage, I'm still stuck at 9 in town and if I pray really really hard I get 11 on the highway.
FTE Leadership Emeritus
Joined: Jul 2002
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From: Long Island USA
Let's go over the facts:
1) Base "standard" timing in the V10 or any other Ford modular OBD-II system is setup for 87 octane. The knock sensor will only RETARD the timing when it detects a ping.
2) Running anything more than 87 octane is pointless on a 9.0:1 or 9.2:1 (3-valve) compression motor. In fact, it can lead to increased carbon buildup, cold start problems, clogging your cats, etc.
3) Even when tuning for higher octane, there is still the static 9.0 or 9.2:1 compression. This makes cold starts take a little longer to fire, etc. and still doesn't make the engine as efficient as it could be on higher octane.
4) The only way to truly benefit from higher octane is to get higher static compression in the motor, and re-curve the spark advance as necessary.
art k.
1) Base "standard" timing in the V10 or any other Ford modular OBD-II system is setup for 87 octane. The knock sensor will only RETARD the timing when it detects a ping.
2) Running anything more than 87 octane is pointless on a 9.0:1 or 9.2:1 (3-valve) compression motor. In fact, it can lead to increased carbon buildup, cold start problems, clogging your cats, etc.
3) Even when tuning for higher octane, there is still the static 9.0 or 9.2:1 compression. This makes cold starts take a little longer to fire, etc. and still doesn't make the engine as efficient as it could be on higher octane.
4) The only way to truly benefit from higher octane is to get higher static compression in the motor, and re-curve the spark advance as necessary.
art k.
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From: north west new jersey
good points art, i have pushed the limits with retuning on 91 octane. just to where it starts pinging on hard pedal then backed off 2 deg's at a time. funny thing is i'm useing a tune for 93 on 87 and this motor runs and feels truly great. no ping. no after run. nothing abnormal. other then i can very easiliy make my tires start smoking. seems to me 93 is a waste.
now hypertec i have used them don't like them! as i feel they do as much in advertiseing as mb does with the hemi thing. i have found in my own screwing around a sct proracer soft ware kit you can really finely tune to your own needs.
ok it's costly to do so $400.00 total at list prices but in my own personal case worth every penny to me.
the proracer kit includes a 4 slot flasher, usb cable and sct software to tune 1 pcm . but man does it work.
now hypertec i have used them don't like them! as i feel they do as much in advertiseing as mb does with the hemi thing. i have found in my own screwing around a sct proracer soft ware kit you can really finely tune to your own needs.
ok it's costly to do so $400.00 total at list prices but in my own personal case worth every penny to me.
the proracer kit includes a 4 slot flasher, usb cable and sct software to tune 1 pcm . but man does it work.
