Switching between maps

[Jayme]

just put ign 12v to one side of the relay and the ecu will earth it.

[benk]

so the flex outputs are only on off switches to earth and not a variable output?

[Jayme]

they are a PWM, the number you type in the cells is the duty cycle. if you want to actually drive a motor or something with the PWM like a speed controller does, then you need to make up a driver box with some heavy mosfets in it. if you want to go the easy route and use a relay, then you just use 100% duty cycle.

[Holden202T]

see here for pwm controller
https://pcmhacking.net/forums/viewtopic.php?f=14&t=397

i am using this to drive my davies craig electric water pump, haven't had a problem with it since installation!

[benk]

now it's starting to make sense

[trikky73]

sorry if this has been answered before but are you able switch between two eeproms? I am running LPG vapour injection and it does not like the new tune I have to suite the mods done to my motor but runs OK on a stock tune although at reduced power even on petrol. What I am wanting to do is use the aux output of the BRC injection system to automatically switch between maps while driving. Car is a VS V6 with a tune from THE1. Would it be as simple as just using the chip enable of each eeprom as the selection method? of would I need to go with the nvram setup?

Cheers

Chris

[antus]

What engine and transmission are you running?

If its a v8 manual you will be able to use $12p and use its map a/b switch to do it on the fly. If its not, then you can use a larger eprom with 2 tunes on it, and switch the highest address line, but you wont be able to do it while the engine is running as it'll probably crash and reset the processer (which wont hurt it, but I wouldnt do it on a running engine).

Better would be to tune the gas injection for the new tune. What type of gas injection is it?

[VL400]

There is this option .. https://pcmhacking.net/forums/viewtopic.php?f=7&t=1713


However simply switching an upper address line (without all the complex circuit) of a larger EPROM works fine for map switching with the engine running if you use the same bin (just different tune data).

[trikky73]

Hi it is a VS V6 Auto and running the BRC vapour injection, I have been having no end of trouble finding someone who knows how to tune the LPG system in the Sydney Newcastle area. Even the places IMPCO recommend do not know what to do since it is "worked/modified" last guy said that the BRC is only good for stock motors - something I find hard to believe

specs of the motor are
20thou oversize mahle pistons
rebuild heads with hardened seats, new valves/springs etc.
120/120 duration @ .050" .507 lift 113 LSA comp cam
double row timing chain
deleted balance shaft
new lifters/push rods
69mm TB
extractors
full balance job

not that much over stock really, as mentioned THE1 has done a great tune for petrol but the gas seems to not like this tune hence wanting to go dual map that can switch when the fuel type is changed on the fly

[antus]

most the gas injection ive seen use a reasonably low resolution table something like map vs rpm, and have a corection % against the petrol injection timing. with the 2 petrol tunes side by side i think you should be able to see what correction the gas tune needs, though you'd need appropriate licensing to touch it. if you know what system it is i might have the software for you to take a look at.