Xr6 N/a To Xr6 Turbo

[Azzman460]

the standard MAP sensor measures vacuum, and up to 5 psi positive intake pressure (this is around 20 psi ABSOLUTE pressure, not guage pressure) after this I think it doesn't read over that.

if your going to run over 5 psi boost, you need a 2 bar MAP sensor which reads vacuum for when theres no boost, and up to 20+ PSI of boost, which is about 35psi absolute pressure.

[104ord]

RDP told me otherwise but what would they know!

[Azzman460]

how much boost are you running in your conversion? maybe your ecu can only pick it up cos your running low boost? like I said if you wanna go over 5 psi boost I'm pretty sure you have to put a 2 bar sensor in. I'd like to be proven wrong though!

[104ord]

im runnin 10psi and with a new cold air intake RDP are going to throw a 12 and 15 psi tune in her.... ill find out more info..

[Azzman460]

I see, well yes I'd like to know how your running the 1 bar MAP sensor with that boost, or if you are running the 2 bar, how RDP come up with the idea that it was a waste of time!

[P4N1C]

Infact a 1 Bar MAP sensor will read approx 0 kPa vacuum and up to 14.7 PSI (1 Bar) which is close to the correct atmospheric pressure at sea level (absolute pressure). A boost gauge reads pressure relative to atmospheric pressure. So 12 PSI of boost would be 26.7 PSI absolute pressure in the manifold.

But remember, the MAP sensor is not there to tell the PCM how much boost is being made, that positive pressure in the manifold is a base calculation to determine the mass amount of air entering the motor. So whilst it's not entirely feasible, it could be done. Wild guess, but I'd say they are tuning AFR based heavily on oxygen sensor value once the reading of the MAP sensor has maxed out and using a stoichiometric or slightly rich AFR during WOT.

EDIT: Unquoted my reply - wasn't directed at anyone's particular post.

Edited 15/03/09 04:28 PM by P4N1C

[Azzman460]

hmm I see, but as you said it reads up to 14.7psi absolute pressure, so if you have boost on top of that how does it read it? its only a 1 bar sensor.

so telling the PCM the mass amount of air wouldn't work with a 1 bar sensor, as it couldn't read the manifold pressure after about 20psi absolute pressure (about 5psi boost)

Even if they were tuning the AFR's off the oxygen sensor value, the PCM still needs to know the amount of mass air entering the engine.

Just a theory, like I said I'd like to know the proper explanation!

[roberts]

iv been thinking about this too. I would go slightley diffrent approch and go:

6boost high mount manifold with extenal waste gate

gt35 turbo, turbo smart gate 38mm

very large front mount cooler, and pipe work

front facing plenum

flash tuner

drill and tap sump

run stock compression with low boost 8psi max, still good off boost toque and high rpm boost.

I would run the whole package in a ba xl ute stock as a rock, white. stock rims with good tyres.

buget $15,0000 including the purchase price of the car.

that's how you build a turbo 6 that wont attraced police attention.

ps: leave the bov for the siliva boys.

lets face it if you buy a xr6t you going to want to mod it with lagers turbos and gates later on so start simple and and purchase once.