just to add I don't think anyones mentiooned yet it also depends which ECU you have - the older 16bit cars with carberry can make use of the higher reading 3 or 4 bar sensors but not on the stock ECU with ecutek as some of the roms won't allow a value over a certain limit. It's the same with load readings too some of the ROM's are limited in what they allow you to run (but not carberry). 32bit ecu's (hawks/hatches etc.) have much better scalability there and with the ecutek stuff you get all the fun features to play with as well.

Stock ecu
Ecutek race rom , boost set to 1.7bar with 4bar map sensor

Same as me same mapper too dom zero complaints

Try using a 4 bar map sensor on a 16 bit ecu and see what happens ... lol

There are ways of running higher boost than the rom limits allow if you know what to do and how to do it

Why use a 4 bar sensor for 1.7 boost (2.7 bar absolute)? 3 bar would have been better choice I would have thought?

Curious.

What would happen with the 4 bar sensor ?

What do you do when asked for big boost on the 16 bit ecu ?

Am i correct in saying a jdm spec c map sensor is one way ?

I'm surprised a 16 bit ECU is a problem with a 4 bar MAP sensor - even a 32 bit would use a 16 bit analogue-to-digital converter, giving .06 millibar resolution.

Unless the problem isn't the resolution of the sensor per se, but some issue with the calculations, or tables?

because I was advised to by bob rawle and I trust his opinion when it comes to my ecu and mapping :thumb:

it had a 3 bar so if it was a better option I'm sure bob would of kept it in place

I Think from reading the thread what tidgy touches in is when you raise the boost level above the factory cut how a oem ecu can cope even with a 4 bar map sensor and if there are any built in safety levels to protect against overboost
Maybe one of the mappers might be so kind as to clear this up

https://cimg8.ibsrv.net/gimg/www.sco...2f93724edc.jpg


I may be wrong here but if you have the correct supporting sensors and setup correctly you can input whatever boost cut you like within reason.

I find that alot of Ecutek dealers like to frighten you with horror stories about Carberry,

Plenty cars running big boost on Carberry in the states

Too much "if you know how" ;) instead of educating folk.

I thought it was because the sensor has to read 1 bar below atmospheric pressure for when the engine is running under the boost threshold and then there's 3bar for above

So you might want 3 bar above atmospheric if you were running 2.7 bar of boost, yes. But running 1.7 boost, which is 2.7 absolute, and you'd usually use a 3 bar sensor. That allows for atmospheric pressure of 1300mBar which is pretty unlikely!

The stock map sensor is not a 3 bar, thats only on a Spec C, its a 2.68 bar (minus 1 bar plus 1.68 bar)

The 32 bit ecu's work in all departments using a correctly calibrated 4 bar, the 16 bit ecu's don't, there are annoying issues :-)

4 bar sensors in a 32 bit car are an easier option than trying to get hold of the Spec C 3 bar

There are map sensor calibration curves in my Hawk project thread if you hunt through

Now that's absolutely the best reason for using a 4 bar - they can be more easily obtained in OEM fitment :thumb:

Ah so the spec c one i have is a rare find :idea:

I read the spec c ecu 16bit has extra features too such as cyclic idle and other things, any truth in that ?

the group N 16bit ecu has antilag and cyclic idle - it's what the carberry rom is built from (carberry is now a patch to the stock group N rom and adds regular car features to it as far as I understand).