HP Tuner 2 bar + MAF, will it work for boost?
Here's my question:
Say I have a single turbo on my 2001 F-Body that is running 7-10lbs of boost. I upgrade to the 2 bar setup so I can fine tune my VE table for the boosted parts. Once I am happy with my SD tune using the 2 bar, can I switch it back over to closed loop mode and use the MAF?
Would I have to get a new MAP sensor for 2 bar?
Basically, can I have the best of both worlds, have an expanded VE table to help with boost fueling while getting good fuel economy by using the MAF and using my O2s to provide me with a constant/average 14.7 A/F when cruising around.
My best guess would be yes since the 3.8 SC engine has boost and run a MAF all the time from the factory.
What do you guys think or is this how it is done anyways with either the 2 or 3 bar setups?
Thanks for your comments and suggestions in advance.
Bill
Tuned correctly there is no difference in economy using the MAF or SD.
You need a 2bar MAP sensor for 2bar.
Chris...
Tuned correctly there is no difference in economy using the MAF or SD.
You need a 2bar MAP sensor for 2bar.
Chris...
What would be your steps in correctly tuning a 2 bar SD tune?
Say you aim to set your part throttle cells for 14.5 A/F and your in closed loop SD mode, your Ltrims will stay slightly negitive and lock at zero when you go WOT?
Also, the O2's will still command 14.7 A/F during part throttle even though there is no MAF?
What 2 bar MAP sensor would I use, do you have a part number?
Does HP Tuner have a write up on how to tune the 2 bar SD enhancement?
Any detailed info you can provide will help me understand all the benefits of the 2 bar SD enhancement...
Thanks...
Bill
another good thing about the extended SD would be having the dual spark capability, as normally when you go to SD you lose the High octane one, and just run off one.
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What would be your steps in correctly tuning a 2 bar SD tune?
Say you aim to set your part throttle cells for 14.5 A/F and your in closed loop SD mode, your Ltrims will stay slightly negitive and lock at zero when you go WOT?
Also, the O2's will still command 14.7 A/F during part throttle even though there is no MAF?
What 2 bar MAP sensor would I use, do you have a part number?
Does HP Tuner have a write up on how to tune the 2 bar SD enhancement?
Any detailed info you can provide will help me understand all the benefits of the 2 bar SD enhancement...
Thanks...
Bill
teh 02's always command 14.7...yes...without a MAF too(its still closed loop after all unless you put it in open loop
and they will ALWAYS pull the fuel back to 14.7 even if you set up your fueling in your VE to be at 14.5.....
GM has a 2 bar Map they sell...I know a few other companies have them too..I'm sure a sponsor on here has one that they sell
benefits of 2 Bar SD:
retain dual spark tables in SD mode
no need to reconfigure tables in teh tune to "mimic" teh 2 bar setup like you would need to with a 1 bar MAP
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another good thing about the extended SD would be having the dual spark capability, as normally when you go to SD you lose the High octane one, and just run off one.
98 Camaro with an STS running 9psi right now working there way up to as high as the turbo will take them and there is NO maf on that car.
Being done with the Stock PCM and HP Tuners and the owner Rick's know-how.
With a 2/3 bar OS you can tune the VE table for different boost settings and then just change your boost controller/pulley without fear of running lean/rich, having to retune or make major changes to the fuel system.

I should clarify in my above post. Stock 98 PCM, 2 bar MAP, no MAF, SD tune.
yeah...there are a bunch of tables to half to make it work.....it just takes time....
but it can be done
teh 02's always command 14.7...yes...without a MAF too(its still closed loop after all unless you put it in open loop
and they will ALWAYS pull the fuel back to 14.7 even if you set up your fueling in your VE to be at 14.5.....
GM has a 2 bar Map they sell...I know a few other companies have them too..I'm sure a sponsor on here has one that they sell
benefits of 2 Bar SD:
retain dual spark tables in SD mode
no need to reconfigure tables in teh tune to "mimic" teh 2 bar setup like you would need to with a 1 bar MAP
That is good to know. So if you can still have closed loop without a MAF, then what is the benefit of having one then if fuel economy will stay the same?
Some say that a MAF doesn't work until 4k rpm's, well I disagree. If you rescale the whole MAF table, your Ltrims change at part throttle.
Could anyone explain how the 3800 SC systems/tune works, they have boost and use a MAF. I figure if GM did it in the 3800 SC cars, then why can't we do it in ours?
In either system you can use the MAF but once it maxes out you only have the PE table to "wing it" on the fuel. ie. setting the PE to command a richer AFR than normal because the airflow side of the equation has maxed. For the V8's, a 2 or 3bar SD mod is not too hard to code (just extending tables for the most part) but on the V6's there are other limitations on the VE table due to the code structure.
well..a 2 bar map sensor that outputs the same total voltage that a 1 bar does would mean the VE table would be half resolution as 50 would now mean 100 and 100 would now mean 200.....
hows that for a start and an example








