hi after a little info on how chips and boost works on a cossie

right lets say a standered cossie runnin standerd boost
then i put a stage 1 chip in it and the boost goes up and so does the bhp but is it the chip that makes it go up or does the chip just allow u to run more boost by adjustin the acurator
and same again for a stage 3 chip when this is fitted does it allow even more boost and fuel i no u need injector and a map sensor but just wondered how the chips work any lighht would be grate

 

chip is mapped to run more boost by changing the actuator ect the fuel mapp and ignition is changed to suit the boost /charge air temp ect if you do a search stu has done a write up on mapps ect

 

thanks

 

i have read a few
but wot i want to no is wot happens if u stick a stage 3 chip in a car with a ss/zorts standred chip injectors and 2 bar could u just run it at a sfae 15 psi or do the chips fire in tio much fuel for injectors ? oh standered turbo and stuff
cus i understod chips controld boost /boost limits ie standered chip wold only allow 11psi stage 1 allow 15 psi ect im probley well of but just want to no wot would happen if the stage 3 chip was fitted and how would affect it thanks

 

the chip doesn't know how much fuel it is firing in, cos it doesn't know what injectors you've got. all it does it open the injector for a certain time, dependant on the engine speed and load (basically, there are other factors such as ACT, coolant temp...)

same as the load, it doesn't know what boost pressure you have as it doesn't know what MAP sensor you have. all it does is receive a signal between 0 and 5V and converts it to a digital number.

so a std 2 bar MAP sensor will give the full 5V output at 15 psi, but a 3 bar would only be giving 2/3 of 5V.

if using a 2bar MAP sensor with a stg3 chip, the ecu would get the full 5V signal and think it was at 2 bar boost. so it would open the injectors for a certain amount of time per revolution. as you are using std injectors, that amount of fuel would be less than if you were using the proper 803's for the stg3 chip, by approximately the same proportion as the flow rate ratio of the injectors.

the fuelling will probably not be far off, but i wouldn't want to do it. besides that, the stg3 chip will have a different ignition curve in it, as more boost normally means less advance, so it wouldn't perform very well on full boost. the transient response, and low load stuff would probably also be awful.

no need to do it. a decent chip is just 200 quid from motorsport developments, so do it properly.

 

im not doin it dont worry
im just wonderin how they work r they the same in rsturbos?
and i dont no how they work or wot they do
its ok m8 i have greens and 3bar no chip at mo as ill get 1 when i have it set up
so wot sorts the boost out then ?
cus say the car already has a stage 1 chip a -31 and u improve evrthin with stage 3 stuff 3bar and so on wot sorts the boost ? the amal valve ?and the ecu tells that how much boost to run ? am i on the right lines?
thansk info good so far thanks

 

oh wot does the chip do they if it dont no wot fuel and stuff is ? not sarkey comment

 

i'm, only talking cossie yb here.

the chip has nothing to do with how much boost you run really, except for the function of the amal valve.

the boost is basically a function of the spring setting in the actuator, and the pre load on it. for example, a -31 actuator has a stronger spring than a std one, so it takes more boost pressure before the actuator rod starts moving. by shortening the actuator rod, you are compressing the spring inside and making more pre-load on it, again needing more boost pressure to move it.

the amal valve doesn't really do anything, except allow the ecu to cut the boost (ignoring the jets for a minute) in certain situations.

got to go now, top gear is on. maybe more to come tomorrow.

 

if u dont mind m8 the more info the better

 

you basically want to know how the ecu works?

very simply, it stores some tables, commonly known as maps. for example, one basic map is for the fuelling. if you imagine a table (not a bloody dinner table) with, for example engine speed across the top making the columns, and engine load down the side making the rows. something like this:



so, depending on the load on the engine (in this case measured by the voltage output from the MAP sensor), and the speed, the ecu looks up in the map how long to open the fuel injectors. simple.

you will also have a map for the ignition timing, and other maps to take account of air and coolant temperature etc.

there's a fantastic thread that goes into more detail posted by Stu. do a search. if you're really interested, buy a book from Haynes written by dave walker called engine management or something.

 

good man thanks alot