trever1t

iTrader: (14)

Just a small (may be way off track) question for you about 2bar tuning. If it deletes the MAF from calculating A/F then what or how does the PCM compensate for IAT's and Altitude changes?

kbracing96

iTrader: (26)

You have to keep the temp sensor, and you have already relocated it with your Radix. It uses Baro pressure reading from the MAP and IAT for A/F calculations. Manufacturers have made millions of cars from the factory that run on SD running. It really compensates better then most people on here think. I'm in SD and getting ready to go on vacation from WY (4800ft elev) to OR (600ft elev) and don't anticipate any problems.

trever1t

iTrader: (14)

I may see elevation in excess of 10K' here, just going to Lake Tahoe. Temps vary from 109* (lately) to -20 in the Sierra's although those are extremes. Thanks for helping me comprehend a little better.

dc_justin

iTrader: (13)

Agreed. By nature an SD tune can very easily handle altitude changes. Since fueling is determined entirely by RPM and atmospheric pressure, as you increase elevation, atmospheric pressure decreases, tune can accomodate.

One thing to consider though is the baro update on a 2 bar tune. With a 1 bar, the system has no problem in being able to determine what atmospheric pressure is, as it takes a reading at heavy throttle.

With a forced induction setup, that same 50+% throttle would yield a MAP value greater than atmosphere and would throw off some calculations.
Make sure you have baro update disabled on a 2 bar tune and just let it update at key-on.

Bill, unless you're maxing it out, I would suggest running MAF'd in addition to the 2 bar. Adds one more level of precision...

trever1t

iTrader: (14)

That's how it is tuned now. MAF+2 Bar. Me likey

dewmanshu

iTrader: (4)

okay okay, so if you have the maf on with 2bar, what about the whole +4K rpm is all maf? This means you are still tuning WOT/PE with the MAF right? Obviously using pe/be ratio's to tweak instead of the ve table?

So...why go 2bar if you are gonna stay with the maf? I mean, if I understand it all correctly, who cares if your FI vehcile ve table can see boost or not if you have an operational maf...hence these blower companies having no prob selling us blowers on 1bar setups.

Just curious trever, what are you getting out of the 2bar that someone with 1bar and a maf isn't.

Lord Aries

iTrader: (6)

Stupid question here... DO i need to go to a 2bar Map with my new motor since i plan on running 15lbs of boost? IF so, where do I get one and is there a recomended brand??

Whippled 496

iTrader: (4)

i think 15lbs is the 2 bar cut off. 1 bar = up to 0psi....2 bar = up to 14.7psi....3 bar = up to 29.4psi. You dont HAVE to run a 2 bar, i think it just allows for better fueling control after the motor sees boost. After the motor see boost, your running blind as far as fueling is concerned under a 1 bar/MAF setup. I have gotten split feedback as to which is a better tune to run with F/I. I am leaning toward the 2 bar because it does allow for a more refined tune and progressive fuel control through each pound of boost. As soon as i get EFILive, i am going to start working on it.

Wilde Racing

iTrader: (26)

This is a "plug and play" MAP for up to 15 lbs boost:
GM P/N: 12580698 AC Delco: 213-1631

Hey Dewey, I just noticed... your green...... Congrats..

dewmanshu

iTrader: (4)

woo-hoo!!! Thanks!

Plug and play map, but not operating system! Can't just put it in a drive away...just in case you thought you could Lord Aries.