Blown353
November 18th, 2008, 10:08 AM
Hopefully this is a simple question... I did some searching and while it answered part of my question, it didn't answer all of it.
I'm getting ready to build a twin PT-61/76 turbo LS2 for my Chevelle as I just broke 1 piston in my Procharged / FAST EFI Gen 1 SBC. (Lightweight pistons with too-thin ring lands aren't a good match for 15 psi of boost... 5 years is all they'll last. LOL!) The new LS2 should be good for around 900hp and I was planning on running it MAFless with a Speed Density setup.
Anyways, I'm trying to decide on an ECU for the new LS2. I'm torn between a couple of aftermarket choices (Big Stuff 3, etc.) or using a factory E38 ECU and a speed density EFI Live setup.
I live in California, and while I live at 17' above sea level I can drive to 9000' altitude in 2.5 hours. My non-barometric/altitude compensated older FAST box right now can't deal with this and as such I have to load a new VE map when altitude changes significantly to deal with AFR changes going beyond the limits of WB02 correction limits in the ECU. It's a major annoyance to pull over at about the 4000' mark and pull out the laptop to adjust the VE table up or down.
My question is this: when running a factory ECU with an EFI Live Speed Density operating system and the engine is forced induction (meaning WOT MAP/Baro updates will not accurately reflect the barometric pressure), how does the ECU compensate & update for altitude changes? I really want something that will compensate properly for altitude changes in real time without having to pull out the laptop and load a new tune or adjust the current one.
The Big Stuff 3 and Pantera 882X ECU's for example both use separate MAP sensors for real time barometric monitoring and updating, but I haven't found a satisfactory answer of how the factory E38 ECU with a Speed Density OS will handle it in a forced induction application.
Thanks in advance...
I'm getting ready to build a twin PT-61/76 turbo LS2 for my Chevelle as I just broke 1 piston in my Procharged / FAST EFI Gen 1 SBC. (Lightweight pistons with too-thin ring lands aren't a good match for 15 psi of boost... 5 years is all they'll last. LOL!) The new LS2 should be good for around 900hp and I was planning on running it MAFless with a Speed Density setup.
Anyways, I'm trying to decide on an ECU for the new LS2. I'm torn between a couple of aftermarket choices (Big Stuff 3, etc.) or using a factory E38 ECU and a speed density EFI Live setup.
I live in California, and while I live at 17' above sea level I can drive to 9000' altitude in 2.5 hours. My non-barometric/altitude compensated older FAST box right now can't deal with this and as such I have to load a new VE map when altitude changes significantly to deal with AFR changes going beyond the limits of WB02 correction limits in the ECU. It's a major annoyance to pull over at about the 4000' mark and pull out the laptop to adjust the VE table up or down.
My question is this: when running a factory ECU with an EFI Live Speed Density operating system and the engine is forced induction (meaning WOT MAP/Baro updates will not accurately reflect the barometric pressure), how does the ECU compensate & update for altitude changes? I really want something that will compensate properly for altitude changes in real time without having to pull out the laptop and load a new tune or adjust the current one.
The Big Stuff 3 and Pantera 882X ECU's for example both use separate MAP sensors for real time barometric monitoring and updating, but I haven't found a satisfactory answer of how the factory E38 ECU with a Speed Density OS will handle it in a forced induction application.
Thanks in advance...