hey guys, just recieved my new ecu, and SF manifold, wondering, if anyone out there has noticed much gain, in advancing their ignition timing, and running their car only on 98 Octane.
was their much gain? some one mentioned here the amount of power for amount of advancment in timing.
and is the improved fuel effiecency balanced by the more expensive fuel? might to a tidy up of the A/F too

a retune will show benefits accross the board... a retune for 98 ron however I doubt will be much better than just the norm 95...

then you also have the inconvenience of only being able to use 98 ron..

if you travel small servo's may not always carry 98 ron. etc etc..

even with my car I can still "only if I have to" run 95ron just in case.. IMO its a small gain for a big risk..

If your ECU has switchable maps you can switch between the 2 based on what fuel you are running at the time

if you travel small servo's may not always carry 98 ron. etc etc..
+1... I come from a city of 30,000+ people, yet both the BP and Mobil only carry Premium - no 98 RON :nuts: A lot of the servos on the highway up there only stock Premium too. Worth considering if you intend on driving to regional areas.

yeah, i was thinking that, i was even pondering on 100 RON :woot:, but thats Rare, even in Sydney.
and i havnt seen it around in a while, think they droped it, was called shell Ultimate.

hmmmm i know its fairly easy to switch maps, i might get a second tune, saved on a laptop, and upload it. so i can switch it to 95 or even regular if need be. then back to 98
but besides the availability, and the benifit of keeping the injectors cleaner, any other reason why i shouldnt?

im pretty sure that regular petrol is only 93 ron.. and then theirs 95 ron, and 98 ron above it.. although dont know if they even still have 95 ron anymore? did they drop it??

I was thinking how much difference would thier be if you tuned for ethanol Vs non ethanol petrol..
would be interestering if you could pull more outta the ethanol..

regular is 91 RON, premium is 95 RON and then there is also 98 RON available

a retune will show benefits accross the board... a retune for 98 ron however I doubt will be much better than just the norm 95...

then you also have the inconvenience of only being able to use 98 ron..

if you travel small servo's may not always carry 98 ron. etc etc..

even with my car I can still "only if I have to" run 95ron just in case.. IMO its a small gain for a big risk..

Could not disagree more.

There's substantial gains to be had from tuning for 98 RON petrol. Power, torque (across the range) and better fuel economy. There's no reason not to tune for 98 RON, unless you live somewhere where it's not easily accessible.

As a comparison,there's a guy over here with a Ralliart motor in his AWD. Its tuned for 95 and makes 1kw. more than my AWD with standard motor which is tuned for 98.....same dyno.

Isn't the Ralliart motor higher compression than the standard motor? So they would react better if tuned on higher than standard unleaded?

Isn't the Ralliart motor higher compression than the standard motor? So they would react better if tuned on higher than standard unleaded?

yes thats right .

Isn't the Ralliart motor higher compression than the standard motor? So they would react better if tuned on higher than standard unleaded?

yeah but .4 of one compression point aint much at all especially with manufacturing variences within the ralliarts CC chambers (some were known to have more or less cut out around the valves when the deshrouding was done thus effecting the chamber volume and hence the actual compression ratio).

yeah but .4 of one compression point aint much at all especially with manufacturing variences within the ralliarts CC chambers (some were known to have more or less cut out around the valves when the deshrouding was done thus effecting the chamber volume and hence the actual compression ratio).

what are your thoughts on the 98 tune?

what are your thoughts on the 98 tune?


Should be fine, just keep a bottle of octane booster in the boot and add some of that if you have to fill up with 95octane fuel instead of 98

Should be fine, just keep a bottle of octane booster in the boot and add some of that if you have to fill up with 95octane fuel instead of 98

that stuff actually works?

that stuff actually works?

If you buy the proper stuff then yes it does work. I used to use tolulene in my subaru to raise the octane rating of the fuel

I remember having a similar conversation with my tuner when he tuned my car. He said if 98 wasn't available fill up with a little bit of 95 and drive like a grandma until i could fill up with 98 and have a bottle of octane booster in the car for 95 emergencies. Never had to do this as 98 is all over the place.

I remember having a similar conversation with my tuner when he tuned my car. He said if 98 wasn't available fill up with a little bit of 95 and drive like a grandma until i could fill up with 98 and have a bottle of octane booster in the car for 95 emergencies. Never had to do this as 98 is all over the place.

I know on EVOs, being tuned for 98 RON, even if you do fill with 95 RON, if you just take it easy like you have said Mohit, the knock sensor will do the rest and protect the engine. Different for Magnas of course.

I know on EVOs, being tuned for 98 RON, even if you do fill with 95 RON, if you just take it easy like you have said Mohit, the knock sensor will do the rest and protect the engine. Different for Magnas of course.

On a car with no knock sensor (like the 3rd gen magna) you'd be silly to run the timing that close to the knock threshold anyway.
Basically if you take a few degrees of advance off the "ideal" for 98 octane fuel then you should be ok if you have to use 95 to get you out of trouble and still have a more power/torque than with the factory 91 octane timing map.

On a car with no knock sensor (like the 3rd gen magna) you'd be silly to run the timing that close to the knock threshold anyway.
Basically if you take a few degrees of advance off the "ideal" for 98 octane fuel then you should be ok if you have to use 95 to get you out of trouble and still have a more power/torque than with the factory 91 octane timing map.

SKR tuned mine with a fair safety margin...a couple of times when i first had it done i forgot and stuck 15-20 lts. of 91 in till i realised and topped up with 98....did'nt have any pinging etc.
I also had to run an octane booster in my 265 Hemi so that it did'nt 'rattle'.

On a car with no knock sensor (like the 3rd gen magna) you'd be silly to run the timing that close to the knock threshold anyway.
Basically if you take a few degrees of advance off the "ideal" for 98 octane fuel then you should be ok if you have to use 95 to get you out of trouble and still have a more power/torque than with the factory 91 octane timing map.

yes, i wasnt going to put it right on the limit, just tune it to 98 then pull the timing back a little.
i have seen a generic electronic kit, to install a knock sensor, incase of a poor batch of fuel, or other factors. but this will only sense the knock, and have a warning light come up, and will not alter the timing for you. not sure but would i need the provision in the block for the sensor?
or is the whole thing silly and i would just notice the knock myself?

yes, i wasnt going to put it right on the limit, just tune it to 98 then pull the timing back a little.
i have seen a generic electronic kit, to install a knock sensor, incase of a poor batch of fuel, or other factors. but this will only sense the knock, and have a warning light come up, and will not alter the timing for you. not sure but would i need the provision in the block for the sensor?
or is the whole thing silly and i would just notice the knock myself?

No it's not silly, the sensor will detect knock before you can...iv'e got one ready for my new motor...yes some bolt onto the motor externally.

No it's not silly, the sensor will detect knock before you can...iv'e got one ready for my new motor...yes some bolt onto the motor externally.

Having a sensor that give a warning/flashs a light etc is ok but one that actually links into the ECU and retards the timing is the only ones i would consider as when you have a modded engine and are giving it some stick, by the time you have noticed the light etc and back off the throttle, damage can already have been done. On boosted applications this is even more so.

On all the magna engines ive built, knock has not been a problem at all, if the tune is done properly and you tune it to the best fuel available to you at all the places that you think you will travel.

That's why i'd go with an ECU that has switchable maps (either automatic or manual) based on the fuel being used. I know when tuning a Holden LS1 V8 engine (flash tuning), tuners set up 2 tables (one for 98 and one for 95 or 91). This works well as this engine has knock sensors. So even if you have to run lower quality fuel you are still driving a car that has better performance and fuel economy than an untuned car.

Having a sensor that give a warning/flashs a light etc is ok but one that actually links into the ECU and retards the timing is the only ones i would consider as when you have a modded engine and are giving it some stick, by the time you have noticed the light etc and back off the throttle, damage can already have been done. On boosted applications this is even more so.

On all the magna engines ive built, knock has not been a problem at all, if the tune is done properly and you tune it to the best fuel available to you at all the places that you think you will travel.


Jason, thats all very sage advice. Your right about the knock thing, having something signalling 'when' knock is occuring but doing nothing more isnt desireable. With previous things we've built and having tunable ECU's, we've always allowed for a secondary or 'lesser' map to interpolate with the higher 98 map for those 'just in case' scenarios. I'm talking road cars here, not competition based stuff, and on that basis I question wether it's actually worth investing the dollars.

On a competition car we would tune the thing alot more agressively as the danger of getting the wrong fuel is minimized, usualy because we would buy the fuel in a batch in drums, wether it be 98 or even something like a 102 octane elf racing fuel.

We are always very careful of what goes in, but what we have found in the past is wth hard tuned cars, when they have changed hands and are into the second and third owner, thats when lax behavior takes place and when you here of an engine going bang!

As Jason says, on boosted applications 'knock' can be very detrimental VERY quickly.

That's why i'd go with an ECU that has switchable maps (either automatic or manual) based on the fuel being used. I know when tuning a Holden LS1 V8 engine (flash tuning), tuners set up 2 tables (one for 98 and one for 95 or 91). This works well as this engine has knock sensors. So even if you have to run lower quality fuel you are still driving a car that has better performance and fuel economy than an untuned car.

yep that would be the best.

That's why i'd go with an ECU that has switchable maps (either automatic or manual) based on the fuel being used. I know when tuning a Holden LS1 V8 engine (flash tuning), tuners set up 2 tables (one for 98 and one for 95 or 91). This works well as this engine has knock sensors. So even if you have to run lower quality fuel you are still driving a car that has better performance and fuel economy than an untuned car.

Yeah but on a 3rd gen magna we dont have the luxury of knock sensors, so i always err on the side of caution and not go to "hardcore" with the timing advance.
Also each engine is vastly different, ive seen 2 "identically" stock engines on same octane fuel get tuned and one of them could run a fair bit more advance than the other. SKR has also seen that with EVO's that he has tuned.

The above is also the same when it comes to AFR's, some engines can run leaner and get good power gains yet other engines of the same type actually go nowhere or even backwards when leaned out to the same amount.

I guess its like us males, we dont all like the same beer or like the same type of woman, its called variation.

Ahhh the joys of vehicle modding ;)

Yeah but on a 3rd gen magna we dont have the luxury of knock sensors, so i always err on the side of caution and not go to "hardcore" with the timing advance.
Also each engine is vastly different, ive seen 2 "identically" stock engines on same octane fuel get tuned and one of them could run a fair bit more advance than the other. SKR has also seen that with EVO's that he has tuned.

The above is also the same when it comes to AFR's, some engines can run leaner and get good power gains yet other engines of the same type actually go nowhere or even backwards when leaned out to the same amount.

I guess its like us males, we dont all like the same beer or like the same type of woman, its called variation.

Ahhh the joys of vehicle modding ;)

Cold beer. Big boobs. Done. :facejump:

i might have a look if my ECU (pro sequential) can retard the timing, if i install a knock sensor.
or even a rev limit, when knock is detected

update: ended up getting my Prosequential, retuned for 98 RON.
tuner said the A/F ratios were fine, and he didnt want to touch them.
only advanced the timing
if i ever need to swap maps, i just plug in the laptop, via USB in the glovebox, and load the stock tune. i picked up 7KW at the wheels, and 15Nm of torque.
not quite the 30Kw gains ive herd someone get from a SKR Reflash,

there was a fault with the dyno at the time whereby the 30kw gain was made, fault was identified at the rear rollers, believe car was an awd. Information has since been mentioned and power reading has been amended. Although i dare say most with skr tunes saw greater gains than 7kw on 98ron.

mate 7 kW is pretty good gain just for a tune. What cams are you running?

And don't forget if you have an SVI gas system installed to go a 98 tune as gas is over 100 octane rating.

I gained over 8kw in my AWD by a 98 tune and a similar gain on gas as well.(before ralliart cam install)

Still yet to get a readout after ralliart cams.

mate 7 kW is pretty good gain just for a tune. What cams are you running?

standard "6" cams, pacemaker, 3inch metal cat, rear muffler, nz intake and K&N panel...145.6kw atw (manual)

i didn't have a before flash dyno run done... just got him to flash it than dyno run it to make sure everything is right, but its fair to assume before ecu reflash car would have approx 125-130kw atw

But if there is anything to go by, Type40's after ecu flash without ralliart cams was 145.2kw atw and before flash was 131.7kw atw mine should be about the same before ecu flash as our cars are near identical

there was a fault with the dyno at the time whereby the 30kw gain was made, fault was identified at the rear rollers, believe car was an awd. Information has since been mentioned and power reading has been amended. Although i dare say most with skr tunes saw greater gains than 7kw on 98ron.

yeah this is kinda why i was curious as SKR flashes are not specific dyno tuned.
mine was, dyno tuned to 98 RON

yeah this is kinda why i was curious as SKR flashes are not specific dyno tuned.mine was, dyno tuned to 98 RON

WRONG! most tunes are done on SKR's dyno unless he's working interstate (local dyno) or a postal tune which is a little milder, safer for obvious reasons.

i was refering to the send him your ECU and he flashes it for you, and sends it back

I had the SKR tune done on 98RON when we got Steve up here to QLD. Manual, custom CAI, high flow cat and 2.5" straight through exhaust system, we gained 13hp atw. Now making 194hp atw.

I think that is pretty good. Steve said that ralliart cams should be the next thing to do :)