ST215w MAP sensor output - Graphable from this?

[fivebob]

If you're going to use it with an aftermarket ECU then in reality it doesn't matter if the curve is exact

I actually intend to use it with a factory ECU in a vehicle that uses a 2 bar sensor from factory

Assuming you're changing injectors at the same time, then you need to know the curve of the stock sensor first to see if it will be too lean at any points. If you're planning on using stock injectors then forget it, chance that it work is minimal.

The other problem is that you will be altering the advance curve, and most likely in the wrong direction unless you're planning on running very high octane race gas, or some sort of ignition signal modifier.

In short it's not something I would recommend as you're more than likely to destroy an engine, and that's (probably) worth more than setting it up properly with an aftermarket ECU in the first place.

[TWSTD]

Yes - will be matching injectors to suit and yes of course I need to plot the output of the stock 2 bar sensor - I have already made arrangements to this end and in all likelihood will get both sensors done at the same time. Since the output at any given pressure level between the caldina (2.6bar?) and the stock 2 bar sensor will be relatively small (at least compared to the difference between a 1 bar and 2 sensor), only a mild injector upsize should be required to maintain correct AFRs. Any shift in mapped timing values will indeed be in the "wrong" direction (advance), but this is easily combated by adjusting the distributor slightly - and it should only be slightly. The other thought I have entertained is the likes of MSD's Boost Timing Master - if it will work on the vehicle in question. Altogether a cheap solution.

[vvega]

contact glenn aka ezy10's
what your wanting to do has been done before and has worked quite well

all you need to do is work out teh percentage differance of teh map sensors
and then use that to calculate your injector size

boost sensors are linear its the ecu that does the corections
this is why you need a fair bit of electronics to convert a afm signal because in a afm teh resiter panel is what carries the "map" of the fueling
wereas in a map model its in the ecu

this info is realised from lots of hard work testing afm's from various cars
and graphing resistace values vr's apature size

v

[TWSTD]

Yes I have done this before myself with great success on a 7afe that I turbo charged a few years ago (in a 97 toyota carib 4wd). I had great results then, hence looking to go down the same route again. Glen actually rang me some time ago asking how this should be done

[vvega]

Yes I have done this before myself with great success on a 7afe that I turbo charged a few years ago (in a 97 toyota carib 4wd). I had great results then, hence looking to go down the same route again. Glen actually rang me some time ago asking how this should be done

lol now i remeber he did mention you
he did it with very good success on his 1jzge
no internal mods no compression mods
just boost bigger injectors and a applicable map sensor
by the end of it he was able to run at stock base timming without detanation (tested useing s knock block)
i think his afr's were about 12.5:1 at 14 psi


and to be honest
it ran like 1jzgte but with a hell of a lot more off boost responce

v