Alright, WTF is this?

It claims the advance the ignition timing by giving a false engine temp.
I don't know if modern ecus advance the timing when cold. Older syetems
like the L-Jetronic (most 205gtis) would probably just run richer
thinking the engine hadn't reached operating temp yet, they do not
control the ignition timing. In any case it's just a cheap resistor.

 

<http://www.20uk.net/carmod/>

OR

<http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2432329135
&category=32094>

OR

<http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2432173313
&category=43120>

Yes I know they've been mentioned before, but check the last link, look
at the sellers feedback!!

Can anyone give me a reason why this wouldn't work? Or why I shouldn't
buy one?

Cheers guys ;o)

 

It looks like a ceramic body wirewound resistor.... cost around 50p from RS
Componenets

Don't see any feedback to say it works....just quick delivery and as
described, super ebayer etc.

extra power with no extra fuel consumption.....does it sound likely?

Or why I shouldn't

Nope, you've got me there

 

This resistor just fools that there is "extra" air and gives more gasoline
to injection. Real Chipping changes also ignition timing with different revs
and usually with normal driving fuel economy is better what you dont never
get with this. But its up to you if you wanna try this expensive
resistor....

-307 1,6 Wagon-

 

As stated by other people, it's just a resistor - which, as described, will
make your ECU think that the air intake or engine temperature sensor is
colder than it actually is. How exactly your ECU will respond is up to the
way it's been designed. I don't believe the part which says that it makes
the system 'send the sparks quicker'. If you have an older injection system
with 'normal', distributor-driven, ignition, then there's no way on earth
that the ECU can make the sparks 'quicker' - which I suppose is meant to
mean that it'll advance the timing. IMO, the most likely thing that'll
happen is that the fuel map will change - probably to it's 'cold' setting -
like when you first start your car and it idles high for a while until it's
up to temperature. The ECU would probably want to increase the richness of
the air/fuel mix - probably by pumping more fuel into the cylinders. The
outcome I see is that your car will run rich - in the long term, worst-case
scenario, the plugs will foul up and you may have a problem with pinking
which can cause engine damage.
The other outcome is that the resistor might actually fool the ECU into
thinking that the engine is very hot or at the correct temperature - leading
to poor cold running and no difference when the engine is warm.. unless the
driver suddenly feels more compelled to stick their foot flat to the floor
to test out their new-found performance and surprised at how quick the car
accelerates in first gear at high revs. They might have been equally
surprised if they'd tried the same thing before fitting the resistor.

I wouldn't recommend it, as you're basically trying to get the ECU to do
something that it is not designed for, you'd be taking out one of the
variables that the ECU uses to decide what is best for the engine and since
different ECUs can work in different ways, you'd really have no idea how
your system would react unless you knew exactly how the ECU works and what
value the resistor was.

Definately don't bother paying £8 for this resistor. If you really want to
do something like this, then find out what resistance range your temperature
sensor reads at and then buy a variable resistor which runs between those
ranges from Maplin or RS Components for something like £1. Then you could
mount it on your dashboard, run the wiring to the temperature sensor and
hey-presto, you'd have fitted something akin to a manual choke.

Chris.

 

It's a device aimed at the one that's born every minute, a bit like the
magnet next to the fuel line that lines up all the fuel molecules ;-)
If there were a simple way to make ANY car more economical or give 15BHP
gain for a 10p W/W resistor (Or a 2p magnet for that matter), the
manufacturers would be doing it already. imo.
Strange thing is, with human nature being what it is, people that buy these
things want to believe they are working.

jim.

 

the important part is in the last line of the last link.
"For best results use premium fuel"
Premium fuel would be optimax which gives better performance anyway.
It's a con.

Simon

 

higher octane rating 98 not 95.

 

You are obviously under the misguided impression that the octane
rating has something to do with performance.

It's actually a measure of the fuels resistance to detonation when
compressed. A fuel with a higher octane rating can be compressed more
than lower octane fuel before it spontaneously combusts. So it is more
resistant to "pinking" or pre-ignition.

Often high performance engines require fuel with a greater resistance
to pre-ignition due to high compression ratios etc so these will
require a 97 or 98 octane fuel, but only to prevent "pinking", nothing
to do with higher performance.

If your car doesn't "pink" using 95 octane fuel then changing to
Optimax will have no effect on anything apart from your wallet.

 

This is true, but a 1.9 litre 205 has a high-compression engine - it should
run better on higher octane petrol if your ignition timing is set correctly.

Chris.

 

If by run "better" you mean won't pink then yes, but that's it. There
is nothing in 98 octane petrol to make your car go faster/acelerate
more quickly etc than when using 95 octane.

If your engine is designed for 95 octane fuel, then running it on 98
octane will be of no benefit.

It's true they recommend 97 octane for the 1.9 gti (but not the 1.6,
which actually has a higher compression ratio), but mine doesn't pink
on 95 so I'm certainly not gonna shell out an extra 7p/litre on
something I don't need.... Especially when 6p of that probably pays
for all the flash optimax adverts which try and convince people its a
high performance fuel, rather than one with a higher octane rating.

 

so shell are guilty of false advertising when the say Optimax with improve
performance then?

 

Below is from the website:

Shell Optimax - a totally new petrol for the ultimate drive

Shell Optimax is a unique unleaded fuel developed specifically for UK
drivers. In fact it is the most significant fuel we've launched for more
than a decade and we're confident that it will give you optimum performance
and maximum engine protection. Here's why we're sure you'll notice the
Optimax Edge:


a.. Its unique formulation will help your car or motorbike respond quickly
and safely, just when you need it to, in all driving conditions
b.. It will protect your engine like no other petrol
c.. Tests show it's the UK's best performance petrol
d.. It was created by the Shell scientists who develop fuels for the
Ferrari F1 car
So it is a premium fuel like recommended by the seller of the ECU add on
gizmo this thread was about as opposed to a standard unleaded from the local
supermarket.

 

http://www.shell.com/home/Framework...ls/how_optimax_works_3011_1342.html&FC4=&FC5=

 

Remember, oil companies are held in high regard for being very fair
and honest. They would never lie to you, the consumer.

How vague, how is it going to do that I wonder? 98 octane fuel will
burn like any other 98 octane fuel, if it had different burning
properties it would have a different octane rating.

Protect it from what? Petrol doesn't damage your engine...

Hmmm, yeah right. Shell's tests I bet.

Wow, I'm impressed. If they develop fuel for Ferrari then my car is
bound to go like one when I fill up with optimax.

I've never seen standard unleaded anywhere, just "premium" 95 octane

Just google octane rating and read a few of the pages, then if you
decide to buy the shell advertising bullshit about better performance
and fill up with optimax when your car runs fine on premium then you
deserve to be parted with your money

 

higher octane rating 98 not 95.

Some engines employ knock-sensors to detect the onset of pinking and retard
the ignition to prevent it, which reduces the performance. Such an engine
may run more advanced ignition on a higher-octane fuel and produce more
power. If your engine _doesn't_ use a knock-sensor then there is, as you
say, no merit in using a higher octane rating than the minimum which avoids
pinking.

All the best,
Andy

 

Older 205 GTi's don't have a knock sensor. I have no idea if newer ones do -
but basically any car with static ignition probably has a knock sensor to
sort out the timing for you. If you disconnect the battery for long enough,
it might lose it's memory and re-learn the correct timing next time you
drive it.
However, if you don't have a knock sensor - you probably have some way of
manually adjusting the timing. Most likely, you'll have a distributor which
can be adjusted to alter the timing. If your car is supposed to run on high
octane petrol and you were interested in getting a bit more power out of the
car, you could try putting in super unleaded and advancing the ignition
until just before it starts to pink. You might notice a slight increase in
performance.
If your high-compression engine doesn't pink with 'normal' unleaded, then
I'd think your ignition has been retarded.

Chris.

 

Hello,

Perhaps not : remember that octane ratings measurements are made on a
monocylinder engine, the problem with our multicylinder engines (sorry, not
mine, I have a Diesel) is the octane to be equally distributed between
cylinders, even if injection rails possibly does it easier than with classic
carbs.