Chips and FMIC

mramage

Registered User
Joined
Jan 5, 2003
Messages
520
Reaction score
5
Points
18
Location
Scotland
There's been a lot written about the benefits of an FMIC, particularly on hot days in chipped cars running 98 optimised maps.

Two things are running round my head about this though..

1) If you get a 98 optimised map, what happens if you run the car on 95 (or even 97) sometimes? Will the ECU just ****** timing? What I'm getting at is there actually any benefit in taking a 95 program over a 98 regardless of which fuel you intend to run on?

2) If a 98 program gets more power through more agressive timing, would running standard ICs on a 95 program with 98 fuel balance each other off? I accept that the FMIC is ultimately better, but if your not trying to run agressive timing in the first place, would the use of 98 fuel balance off the drop in performance though increased air temps? Even if it does, are the further issues by not having the FMIC?

Hope that makes sense /ubbthreads/images/graemlins/smile.gif
 
I've got the both maps Mark with the standard ICs (at the moment), if you run the Optimax map with 95 fuel the car pinks.
 
[ QUOTE ]
Andy bS3 said:
I've got the both maps Mark with the standard ICs (at the moment), if you run the Optimax map with 95 fuel the car pinks.

[/ QUOTE ]

And you definately dont want that happening!

Rich
 
[ QUOTE ]
2pac said:
'pinks' - 'pinking' - DETONATION. DET will do your engine in very quickly!

[/ QUOTE ]

Actually, if im correct, Pinking (aka pinging, aka pre-ignition) is different to detonation... Same thing in general, but has a different cause.

Either way, basically what happens is the mixture is ignited BEFORE the piston is at its optimum point... This can mean that the mixture fires while the piston is on the upstroke, therefore tyring to push the piston in the opposite direction... This can have serious effects on an engine. namely bending con rods, cranks, knackering piostons .etc.

Pre-ignition is where the mixture is ignited due to a hot spot... This can lead to a hole being blown through the piston as well as other problem.

None of these are pleasent as you can imagine... Timing needs to be retarded to run low octane fuel as it burns easier.... High octane is harder to ignite, to timing can be advanced to reap the benefits.

Rich

ps - someone correct me if ive got the wrong please!
 
In regard to your original question, you should not mess around with different fuels on different maps trying to 'balance things out'. Its a recipe for disaster!! The only benefit of using a 95octane map is fuel economy, and if u re-map for peformance then its a bit pointless usless you use a 'switchable' map. ie one map for 95, driving normal, one for 98 or race fuel for fast road or motorsport.

But if decide to fit a front mount do it b4 the map or U will need it re-mapped. Front mounts provide a large opportunity for more performance. The front mount on most GtiR's (from experience) caused an increase in boost pressure, as much as 0.2 bar on one occassion! They are very important in decreasing intake air temps and most standard item are very restrictive.

U can't and shouldn't mess with your map or the intended fuel it needs. And further mods need to be careful though out as the map of a car is carefully plotted and increases in air flow or fueling after the map has been done on a car will cause rough running.
 
[ QUOTE ]
comeone correct me if ive got the wrong!


[/ QUOTE ]

No mate your quite right, but pre-ignition in-turn can lead to det. I class the noise, either way, as 'pinking'

In the circumstances mentioned above I wud have said it was det /ubbthreads/images/graemlins/confused.gif
 
[ QUOTE ]
Mark R said:
What I'm getting at is there actually any benefit in taking a 95 program over a 98 regardless of which fuel you intend to run on?

Hope that makes sense /ubbthreads/images/graemlins/smile.gif


[/ QUOTE ]

I actually find the 95 map better fun to drive it seems to have more torque bottom end although the 98 does pull harder higher in the rev range.

p.s. I always use Optimax
 
Yes I can confirm - 98RON Chip with council fuel = Pinking. I heard it once when I couldn't find a Optimax retailer and oh boy did I [censored] me shelf!

 
I believe REVO do the SPS3 which can adjust the timing for different fuel ratings e.g. 95ron driving normally and then changing it on a track day for the different fuel you use.

YOGi
 
Is it only REVO that over the SPS1-3 option. Wot about APR and AmD for instance. I like the idea of having a 95 octane map for normal every day driving. Then an Optimax map for fast road. How do U change maps? Its a bit like having a two stage boost controller
 
2pac, the FMIC on the S3 doesn't change boost pressure, that's IIRC. Also, APR allow you to change the map using the cruise control buttons. Pretty sure you have to have the ignition off to do it though.

So, 98 map will be aggressive and try to keep the timing in that area. i.e. 98 or risk your engine. Not good. Wonder if 97 would be ok, like BT Ultimate etc.
 
[ QUOTE ]
2pac, the FMIC on the S3 doesn't change boost pressure, that's IIRC. Also, APR allow you to change the map using the cruise control buttons. Pretty sure you have to have the ignition off to do it though.


[/ QUOTE ]

What do U mean by the front mount on the S3? Do they have them as standard? I just meant that in my experience of nissan tuning U always get a boost increase. Still learning about VAG tuning /ubbthreads/images/graemlins/confused.gif lol
So the cruise control changer is the same as Revos SPS feature
 
AFAIK the FMIC Ess_Three has is similar to that now sold by the like of Star Performance. As I recall, it doesn't alter boost pressure. Could be wrong though, some might give an increase!

The cruise change is different from the Revo SPS. The Revo dongle is a seperate unit, which plugs into the diagnostic port. APR uses the cruise control buttons and flashing dash lights to change the program and show which one is in use.
 
[ QUOTE ]
Mark R said:
2pac, the FMIC on the S3 doesn't change boost pressure, that's IIRC. Also, APR allow you to change the map using the cruise control buttons. Pretty sure you have to have the ignition off to do it though.

So, 98 map will be aggressive and try to keep the timing in that area. i.e. 98 or risk your engine. Not good. Wonder if 97 would be ok, like BT Ultimate etc.


[/ QUOTE ]

BP Ultimate is fine Mark, I actually tried it the other week for the first time and it felt smoother than Optimax but it was probably down to the weather on the night.
On the direct port you have to have the car at the ignition lights to change progs then take the key out for 5 secs if it's the old chip method then you can change with the engine running IIRC
Do you think it's just the timing that's the difference between the 95 & 98 maps?
 
[ QUOTE ]
The cruise change is different from the Revo SPS. The Revo dongle is a seperate unit, which plugs into the diagnostic port. APR uses the cruise control buttons and flashing dash lights to change the program and show which one is in use.


[/ QUOTE ]

Cool. But wot your saying is, unlike a boost controller u have stop. switch off. and restart to change maps?
 
[ QUOTE ]
Do you think it's just the timing that's the difference between the 95 & 98 maps?


[/ QUOTE ]

Surely the boost pressure must be different. I wudn't fancy running a jap car at 1bar on 95octane.

And your one of a few people who say BP ultimate was better. Everyone I know slates th stuff. Mine ran ok until u dialled in a bit of boost and it just coughed and spluttered. Admittidly it was when it very first came out
 
[ QUOTE ]
2pac said:
[ QUOTE ]
Do you think it's just the timing that's the difference between the 95 & 98 maps?


[/ QUOTE ]

Surely the boost pressure must be different. I wudn't fancy running a jap car at 1bar on 95octane.

And your one of a few people who say BP ultimate was better. Everyone I know slates th stuff. Mine ran ok until u dialled in a bit of boost and it just coughed and spluttered. Admittidly it was when it very first came out

[/ QUOTE ]

Well, I assumed it was just timing, but I don't know /ubbthreads/images/graemlins/angel.gif

Funny, I was asking about Ultimate because I put some in the other day and I didn't notice any difference from Optimax. Good to know it's ok though /ubbthreads/images/graemlins/smile.gif
 

Similar threads

Replies
20
Views
3K
Replies
13
Views
1K
Replies
15
Views
991
Replies
6
Views
946