my secs monitor is only showing 28.6 psi max im sure it used to read more than thet

anyone?

 

mine wount even read that and i run over 30 psi

 

thing is if it is supposed to read more than that, and i run 32 psi, the fuelling will be rich enough at the highest point of the map reading on the 3 bar for the peak boost figure, so if its under reading im gonna melt

it should be 1 bar below atmos, and 2 bar over i guess? so 1 bar is 14.7 psi iirc? so 2 bar is 29.4psi?

 

Mine has read 29.6 before m8.

 

its fudged then ive even moved it so it wont get wet

 

A 3 bar sensor is only specced to 2 bar boost (28.8 ish psi)

Some sensors read slightly higher than that some dont.
They tend to drift with old age especially if over boosted.
Also, the ecu reference voltage and wiring loom will have some minor
bearing on the reading which is small enough not to worry about.

For the record, any conversion running a 3 bar sensor using more than 2
bar boost and the ecu is guessing the fuelling, it cannot measure it.

 

the fuelling at the maximum reading the map can give will be rich eniough to suit the highest boost point ,so ie at 28.8 psi it would be rich but at 32 it would be good?

thats how i see it?

so if i have 28.6 im ok?

 

JTECHSAFF,

Correct.

The ecu will be seeing the maximum reference voltage despite the slight
variation so the accuracy is irrelavant at that point as the ecu will fuel for
32 psi for any boost level from 28 psi and above.
(depending on how yours has been mapped of course)

 

thats what i wanted to hear

thrash on tomorow then

 

68332
so how come mine wount read abouve even though my boost gauge reads 2.1 bar

 

what does your read up to?

 

I guess I didnt explain it well enough.. ???

A 3 bar sensor CANNOT measure more than 2 bar boost.
(exclude the slight variations which can be positive or negative)

A simplified explanation....

The boost is transmitted from the sensor to the ecu as a voltage.

The varying voltage ranges from 0 to 5 volts.

At 2 bar boost, the sensor is ouptuting 5 volts (just under)

It cannot give any more !

Hope that explains it.

 

and when the ecu sees the 5 volt reading ,it gives the max fuel allowed in the map, this being rich at 2 bar ,but hopefully correct for whatever the max boost is

id say you would get away with this at 32 or 33 psi, but anymore than that and you would have to fit a 5 bar sensor as the fuelling difference would be to great

 

Of course the problem with the 5 bar map is that you have reduced the resolution of your map everywhere else. Effectively, if you fit a 5 bar, you only get the same sized table to map the car. This means that more interpolation is required between points, which is why most choose to use a 3 bar!

JJ

 

that is true to some extent, i.e. the analogue to digital conversion can only divide the 5 volt signal into a certain number of 'chunks', so each chunk of the 5v will be a greater pressure when using a 5 bar MAP sensor

but it doesn't mean that you have to use the whole 5 bar scale in your maps, so the interpolation going on there needn't necessarily be much different

nothing wrong with interpolation of the map anyway - it's certainly better than running off the map imo

 

all maps interpolate

as nick says its in the resolution of the AtoD converter

 

and the flux capacitor gareth

 

 

just to confuse some people even more webber 3 bar map sensor has a span of 0-5volts and reads absolute pressure and never reads 0 and never reaches 5 unlike a flux capacitor

 

why does a flux capacitor go full scale? both 0v and 5v? i didn't know that

 

no body does gareth because there is no such thing incase you didn't know

 

but ive seen one in a film? confused now


edit

its even on wiki
http://en.wikipedia.org/wiki/Flux_capacitor

 

they got it from an episode of blake 7

 

PMSL @ Tony & Gareth .... you clowns

 

The problem with the flux capacitor being rare is that it was a product form simon at secs.I ordered mine in 1973 and am still waiting

 

 

when it eventially arrives I intend to install it zap back to 1973 and get a fookin refund roflol

 

Map sensor resolution isnt an issue !!

On weber ecus, the analog to digital converter is 8 bit.
This gives a possible 256 readings of the sensor. I.E. a value between 0 and 255.

So for a 3 bar sensor, this equates to 0.0117 bar (0.1699 psi) per bit.
This isnt that bad actually and can provide pretty accurate fuelling
if mapped correctly in the first place of course.

(figures are not exact but represent what happens)

 

I'm still laughing at this and I wrote it

 

PMSL @ Tony, you cooooooont

WHEN I invent time travel, I will go back in time and make sure you stick to that diet.

 

Diet simon i have always been slim no diet required .

 

That is absolutely wonderful techie info but unfortunately no use to the webber ecu as it only has a 13x13 map or 16x16 at best so the map sensor is well over specced for the ecu

 

i would go back in time and sell those "turbosystems stickers" someone must of made a million from them

 

There are alot of people who wish you would invent time travel then you could go back in time and supply them the goods you promised roflol

 

our stickers were free with every conversion those where the good old days
Simon i need my flux capacitor so i can go back in time when cossies where the in thing.
Good job simon wasn't our sticker supplier gareth

 

Tony,



You can get turbo system stickers/windcreen banners at our local sticker place.

I think people were buying them and the cars didnt perform as they didnt
have your conversions so thats why you arent doing so well these days ...
ROFL

You should have copyrighted your trade mark

 

It's fookin hilarious mate

 

nope simon it's because i sell secs products and i haven't got any to sell roflol
i recon there is such a thing as a flux capacitor they are less rare than a secs s8 ecu

 

stop moaning be grateful you are lucky to have one

 

I was still at school in 1973 so I cant see how thats relevent


AJ,