It comes up alot that people insist on tuning a blown or turbo'd application while still using the maf and although you can tune this way there are some drawbacks when doing so & there are some advantages to going SD instead.
Advantages of HPTuners 2/3 bar Custom Operating systemsDisadvantages of using MAF in boosted applications
- Low cost (2) credits & the price of a 2 or 3 bar Map sensor to be up and running
- Full use of both the High & Low Octane tables even with no maf sensor in place
- Real Time Tuning Available(Most Calibrations)
- Extends VE table from 105 kpa all the way to either 210kpa or 315kpa for LS1 applications
- Adds a boost enrichment table for different boost levels-this is great when you want to run 6psi on the street but 10psi at the track as you can set your boost enrichment table to add a bit more fuel for that 10psi setting without the need to reflash again for the changes.
Here's a Small summation done by RedHardSupra on this matter http://tuning.wikispaces.com/tuning+Forced+Induction
- Your fueling will be completely wrong under many conditions because once you max the maf table the computer looks to the other fueling tables & pretty much is just guessing at that point. Fueling isnt always just rpm dependant so when you've only got 1 wot fueling table(power enrichement) which is done by rpm only your basically guessing at what # to put in. This also limits you in the fact that you can't have variable boost levels...once the maf maxes it maxes but you've only got one pe table thats only rpm dependant rather then boost dependant so if your commanding 11.5:1 at 5500 rpms on 5psi its still going to command 11.5:1 at 5500 on 10psi yet your flowing a ton more air at that point meaning your going to go leaner at 10psi more than likely.
- Unless you opt for the MAF RTT custom 1 bar OS you probably don't have access to Real Time Tuning and if you did consider the 1 bar maf OS your only now 1 credit from the 2 bar custom SD OS and doing it the right way.
- No way to change boost levels without reflashing in a different tune
Bottom line is you've probably just spent $4000-$7000 on that new blower or turbo it would be wise to use 2 credits & $50 for a 2 bar map sensor & 2 bar SD custom Operating system.