LT1 and Boost

[roughneck427]

http://www.camaroz28.com/forums/comp...uction-560089/

[freshda9]

i was fairly happy with the results considering it was my first try tuning boost with that ecm, but there were still subtle driveability problems. probably due to pressure-related functions that haven't been mapped out yet in EE. but it is being driven daily right now and he's happy.

if you install a 2 bar map on an ecm designed to read a 1 bar map, it'll produce half the output.

first, you need to disable atmospheric pressure updating somehow, otherwise it'll think your car is falling from the sky. i really hope obd-ii tunercat you can do that, otherwise you're kinda screwed.

then, anything that deals with MAP KPA needs to be cut in half.

in logs, it'll read 50kpa at 100kpa.

if you specify a constant as 50kpa, it'll actually mean 100kpa. so if you're thinking 'engage power enrichment at 80kpa', set it to 40.

Do i physically scale the the axis or do i assume when installing the map these kpa values are now cut in half? I completely understand that i will be using 1 VE and it is scaled to 100kpa as im veiwing and of course adding a 2 bar will now make 50kpa actually be atmospheric. It does suck this way since you lose the resolution.

sure you can but the stock maf (between the air filter and the turbo) seems to work just fine once you change the curve of the maf table a bit.

IS the stock Maf limited to say 10psi max? I knwo the early ls1 mafs peg very quickly and i would assume these would also?

You mean just under 15 psi, 3 bar would be just under 30.

3bar is = to 44psi absolute or 29.3psi gauge. He means the KPA is scalled to 2bar which 100kpa would now be 2 bar and 50kpa would be 1 bar or atmospheric. Also 3bar = 300kpa

http://www.camaroz28.com/forums/comp...uction-560089/

Thank you i skimmed threw as its a long thread. found a converter to convert the file from .LT1 to .Bin but I need to convert it to a Cal file to open it.

[steveo]

IS the stock Maf limited to say 10psi max? I knwo the early ls1 mafs peg very quickly and i would assume these would also?

this maf doesn't really know what pressure is. it's only some wires, and only really measures airflow at near atmospheric pressure. that's why i'd pull through the maf and not push boost into it. the stock lt1 maf will max out or start behaving strangely somewhere just above 450afgs as far as i know, but i've never taken it that high. i dont think with a mild turbo build the MAF is going to be a limitation. the one i was tuning never exceeded 10 psi or so, and it certainly didn't have any problems.

Thank you i skimmed threw as its a long thread. found a converter to convert the file from .LT1 to .Bin but I need to convert it to a Cal file to open it. [/QUOTE]

i doubt that is going to happen for you, that file is likely for OBD-I (EE) ecm. it's different. either way you should do it manually, im sure there's nothing special in that file, you just have to find every table and constant that uses MAP, and there aren't even that many.