re mapping my vts!

18th March 2009, 23:25

hello. now i no a fair bit about cars but i dont no everything. id like to no happens when you re map an ECU. can anyone on sax p enlighten me about what the full process and what it entails? so far i no the differnce between generic mapping and live mapping but thats about it. any info is much appriciated cheers

19th March 2009, 08:19

i was gonna post the same question mate , any ideas anyone ? ?

19th March 2009, 08:30

A generic map is not specifically for your car where as a live one is specifically for your car and will take into consideration what other engine modifications you have.

There isnt really a point in gettign a remap unless you get cams, or your car is overfueling as it will sort out your idle etc And with cams it will also gain you a few more BHP.

19th March 2009, 08:42

Can also remap a standard car to get better mpg and squeeze a few more horses.

19th March 2009, 08:47

you want to go piggyback on these really. (Dastek/Unichip) as you'll notice better gains and they are far easier to remap should you want to change the setup at a later stage.

19th March 2009, 09:32

I would always go for a live remap, as a generic one may not always be right for your car. My A3 1.8T was remapped at Jabbasport and they start with a generic map and then adjust it to suit your car with time on the rollers and time on the road. It was running far too lean initially and they had to adjust it. This would obviously not have been good in the long run if it had been generic. Was well worth the extra £'s.
Plus you know what you are getting bhp wise as it will be the true reading. It is easy to say this remap will give 40bhp but it may only give 20bhp if your car is not set up right.

19th March 2009, 09:47

the process of mapping is simple in theory

the ecu runs on a set of values
mapping it you plug a computer in and alter those values to correct the fueling on the car to suit modifications
most places will first put in a generic map
then tweak it to suit your car (live mapping is actually changing it then doing a dyno run then tweaking again ect till its at peak)
my vts probably did 15 runs during mapping
and spent about 6 hours sat on a dyno

19th March 2009, 09:52

I don't agree that a piggyback ECU is "easier" in any way, shape or form. Fitment involves cutting into wires for a start. Then, the process of mapping is fairly similar, you change values in a table to correct fuel and ignition at the different loads -vs- RPM.

I guess being in the business of PnP ECU's I think 'easy' is just plugging it in, calibrating the throttle, and driving off!

Andy

19th March 2009, 10:09

Quote:

Originally Posted by luthor1

I don't agree that a piggyback ECU is "easier" in any way, shape or form. Fitment involves cutting into wires for a start. Then, the process of mapping is fairly similar, you change values in a table to correct fuel and ignition at the different loads -vs- RPM.

I guess being in the business of PnP ECU's I think 'easy' is just plugging it in, calibrating the throttle, and driving off!

Andy

plugging it in, calibrating throttle and driving off is very easy- maybe sub 5 minutes from my experience

19th March 2009, 11:01

Quote:

Originally Posted by robert_waite

I would always go for a live remap, as a generic one may not always be right for your car. My A3 1.8T was remapped at Jabbasport and they start with a generic map and then adjust it to suit your car with time on the rollers and time on the road. It was running far too lean initially and they had to adjust it. This would obviously not have been good in the long run if it had been generic. Was well worth the extra £'s.
Plus you know what you are getting bhp wise as it will be the true reading. It is easy to say this remap will give 40bhp but it may only give 20bhp if your car is not set up right.

LOOL a remap alone wont give 40bhp increase, or 20bhp even with breathing mods you would be lucky to see the remap gain you 10bhp.

19th March 2009, 11:48

Sorry, I was talking about my 1.8T engine, just using it as an example. Some people quote 240bhp from the 180bhp engine after a remap and mine made 211bhp which is a more honest figure. It then went back for more mods and made 230bhp.
I agree you only get a very small increase with a normally aspirated.

19th March 2009, 11:50

Quote:

Originally Posted by robert_waite

Sorry, I was talking about my 1.8T engine, just using it as an example. Some people quote 240bhp from the 180bhp engine after a remap and mine made 211bhp which is a more honest figure. It then went back for more mods and made 230bhp.
I agree you only get a very small increase with a normally aspirated.

If you have a turbo then a remap will gain you a more yes.

19th March 2009, 18:10

thanks everyone for your input. i no the differnce between generic mapping and live mapping. im curious as the which cells in the ecu get altered? is it all of them? and yea the car needs mapping badly/ it only made 136.5 at fly and thats a cammed VTS. you should see my fueling on my graphs its all over the place! now the car has started reving itself for no reason at all. ive changed the idle speed control valve aswell as the temperiture sesor on the side of the block and thwew is no error codes on the ecu so i have ran out of ideas altogether now or could this problem have been caused by the car needing mapping? BTW it has run fine for 4 monnths cammed unmapped?

19th March 2009, 18:20

It could be you driving it like you've stole it.

Mapping is generally simple, its your fuel and spark plugs that get tweaked to suit your engine setup. Generally when the injectors open and how long they open for, when the plugs fire and your cam timing might be played with too. But the ECu also reacts to what its sensors tell it so the mapping gets very complicated when it comes to how it reacts to certain AFR and certain temps. Which is why they use tables;

The software that maps an ECU uses aload of tables and simple values to control each setup. Basically telling the injectors to open a certain ammount at a certain revs. So say if your at 1000 rpm, you only want the injectors to open a small ammount when the inlet valve is open. So it picks up a signal from a crank sensor, it fires the injector, the spark and it cycles over and over calculating what it needs to do a few million times a second.

What yours is doing is picking up the details from the lambda/map sensor etc etc, and reacting to the situation. The MAP sorts the tables out and helps it do its calculations properly and get the most from your engine.

19th March 2009, 19:55

thank you very much ste. just what i was after. although i am starting to think that my car keeps revving itself for one of reasons-

1. it now has a 3.5 bar fuel pressure reg and i think it could be running rich and causing itself to run very rich and reving itself.

2. it has not been mapped so when i get the VTS mapped would that cure the problem as the ECU would be altered and mapped to run the 3.5 bar reg? or would i be better putting the 3 bar reg back on and getting it mapped with that on instead?