New to boost tuning, start up help.

[triple4x4]

I am new to boost tuning and speed density tuning. When doing boost and SD tuning do you have to change to the 1/2/3 bar OS? Really is my biggest question. Then is it just tuning everything as usual according to fuel trims and wideband correct?
Thanks for the input.

[traviz06]

How much boost? I run 11psi on a stock 1bar map with MAF tuning.

[triple4x4]

Right now we are starting off with 10-15 psi but I want to know for the future for more boost.
Thanks

[SultanHassanMasTuning]

whats the car and operating system

[triple4x4]

This one is in an S10 not sure what the OS is, car is not here. I know it came out of an 2005 truck. I'm also wondering when you need to do the VCM enhancements in general?

[68Camaro]

VCM enhancements are free now so I use them every chance I get. I believe with the operating system you are using there might be a resolution difference between 2 and 3 bar so if you are never going to go above 15 psi boost - upgrade to the 2 bar system. if you are going to exceed 15 psi - upgrade to the 3 bar system. The difference in resolution is really not a problem in my opinion and if it were my vehicle I would just upgrade to 3 bar OS and tune away (you will need a good 3 bar MAP sensor also - or 2 bar if you decide on that OS).

[triple4x4]

Cool. Thanks for the info. Good to know.
Holden

[squetman]

does he have to go sd for under 15 psi as a stock map is good for 15 psi

[traviz06]

A stock map sensor is good for 0 psi. It is all maf tuning beyond that

[68Camaro]

does he have to go sd for under 15 psi as a stock map is good for 15 psi

a stock 1 bar map is indeed good for 15 psi - which is what the air pressure is at sea level (14.7 psi actually). The stock 1bar map sensor reads from full vacuum (0 kpa or -14.7 psig or 0 psia) to atmospheric (14.7 psia at sea level or 0 psig or 105 kpa). A 2 bar map is required to read from a full vacuum (0 kpa) to 15 psi positive boost (210 kpa).

psia = pounds per square inch absolute
psig = pounds per square inch gauge
0 kpa = 0 psia = -14.7 psig
105 kpa = 14.7 psia = 0 psig

I hope this explanation makes sense to you

He can still tune MAF also if he wants to but the best tune will be to upgrade the operating system (now the VE table will cover the full range of boost), fail MAF, tune VE table, then fail VE and tune MAF and then re-enable both VE and MAF to run hybrid again as GM designed. Most folks won't do all of this work and just choose one or the other (VE or MAF). If I was only going to choose one for a boosted application I would always just choose VE (speed density).

[traviz06]

I understand what you said and I stand by my point because the original poster asked if a one bar map is good for 15psi, which *technically* it is, but not for 15psi positive pressure which I believe is what the original poster implied in his post since he mentioned a turbo