2bar map sensor and tuning for it
2bar map sensor and tuning for it Im working with a bud on his whipple charged 8.1L, I currently dont have the HPT setup to tune for boost. He is installing a 2bar map sensor and getting rid of whipple electronics.
Is it possible for me tune for boost at all with a speed density setup, without having the HPT upgrade?
Any recommendations?
Is it possible for me tune for boost at all with a speed density setup, without having the HPT upgrade?
Any recommendations?
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
I haven't attempted this... but probably not a good idea (if you're doing SD only) ...
You would have to go through any tables that refer to VE and double them... so 50kpa would in reality be 100kpa ... but you're losing tons of resolution (especially if it's a car that uses the secondary VE table)
Plus the 2/3 bar OS upgrade offers boost reference fueling and such
So it's possible I would think, but can get dangerous
You would have to go through any tables that refer to VE and double them... so 50kpa would in reality be 100kpa ... but you're losing tons of resolution (especially if it's a car that uses the secondary VE table)
Plus the 2/3 bar OS upgrade offers boost reference fueling and such
So it's possible I would think, but can get dangerous
In order to do what horist stated you have to halve the map scaler so whith the key on the map reads 50 kpa instead of 100 but its a hack job and you will be losing tons of resolutions as stated. Spend the extra 200 or whatever it si and get it upgraded to do it right i am pretty sure doing the way listed above will get messy over time
This is a truck so it doesnt have the second ve table. Im wondering when he puts the 2bar map in will hp tuners still read only to 105kpa or will it go higher and I wont be able to see anything on the ve table when he hits boost. Or will it automatically divide the entire ve in half so in actuallity 52.5kpa will be 105kpa and anything over that will be boost.
hpt 2 bar software extends the ve table past 105 kpa so when you hit boost you will actually see 105-200 kpa in the scanner. The software extends the tables and the hardware needs to match. So if you out a 2 bar sensor in without the software conversion you will still only get 105 kpa. You need both to work with each other
Where does the 1/2 resolution come in at. Im thinking where it will normally read 100+kpa with the 1bar map now with the 2bar map and the 1bar software it will read around 50kpa. Obviously anything over 52 is gonna be boost if it actually works like Im thinking.
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
before you had a VE cell at every 5kpa for every 400RPM (these values are blended together automatically by the PCM)
Now, 2 bar sensor running on a 1 bar OS, you only have 10kpa for every 400RPM, so you don't have as much wiggle room....
Another issue is w/out a custom OS, in Speed Density you lose your low octane spark table... not a good idea w/a supercharger (it's a good safety net)
I think in the end, you'd find yourself wishing you'd spent some money up front and done it right, rather than potentially damage the engine (since you'd be a pioneer on this, I haven't heard of anyone else here running 2 bar map w/a stock 1 bar OS) and go through all the frustrations of figuring out which tables need to be modified and such...
Now, 2 bar sensor running on a 1 bar OS, you only have 10kpa for every 400RPM, so you don't have as much wiggle room....
Another issue is w/out a custom OS, in Speed Density you lose your low octane spark table... not a good idea w/a supercharger (it's a good safety net)
I think in the end, you'd find yourself wishing you'd spent some money up front and done it right, rather than potentially damage the engine (since you'd be a pioneer on this, I haven't heard of anyone else here running 2 bar map w/a stock 1 bar OS) and go through all the frustrations of figuring out which tables need to be modified and such...
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just doing some math, numbers are easier to look at.
the stock ve table we have a total of 420 cells between 0-8000 rpms and 0-105kpa realisticly on a big block engine Im shifting at 5200 so I only use a possible 273 half that is 136.5
speaking generally the resolution of 1cell/400rpm/5kpa seems course to begin with. This explains why when tuning other engines I find things run smoother with a polynomial smoothing factor of 1x10^-5 and throttle response is greater with a smoother ve, it accounts for the errors in between the 5kpa we dont see.
Im thinking with using greater polynomial smoothing and the trial and error of SD tuning even a low resolution ve table (136.5 cells)can behave well and be close enough to get the +-5% error that we all look for.
this is all gonna be shot out the window if the OS doesnt behave the way we think it will
the stock ve table we have a total of 420 cells between 0-8000 rpms and 0-105kpa realisticly on a big block engine Im shifting at 5200 so I only use a possible 273 half that is 136.5
speaking generally the resolution of 1cell/400rpm/5kpa seems course to begin with. This explains why when tuning other engines I find things run smoother with a polynomial smoothing factor of 1x10^-5 and throttle response is greater with a smoother ve, it accounts for the errors in between the 5kpa we dont see.
Im thinking with using greater polynomial smoothing and the trial and error of SD tuning even a low resolution ve table (136.5 cells)can behave well and be close enough to get the +-5% error that we all look for.
this is all gonna be shot out the window if the OS doesnt behave the way we think it will
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Originally Posted by Magnus
Are you guys using VCM Suite 1.x? If so send me an e-mail with your customer ID # and I can upgrade your account to VCM Suite 2.x.
- Keith, HP Tuners
- Keith, HP Tuners
Even me????
Originally Posted by HumpinSS
hpt 2 bar software extends the ve table past 105 kpa so when you hit boost you will actually see 105-200 kpa in the scanner. The software extends the tables and the hardware needs to match. So if you out a 2 bar sensor in without the software conversion you will still only get 105 kpa. You need both to work with each other
except that teh calibration of 0~5 v0lts still applies....
so 0=10kpa and 5-105kpa...
on 2 bar MAP 0v=20kpa and 5v=210 kpa....
all that happens is when it registers a voltage that would be more than 105kpa on a 2 bar it just reports it to the PCM as voltage...and that voltage will correspond more to 52.5ish KPA in the PCM
without th esoftware conversion you will still get 210kpa.....you just wont get resolution in 5's...its gonna be in 10's instead..
30,40,50,60... instead of 15,20,25,30
it also takes some fancy math on some other tables to make it all get proper fueling...
Originally Posted by soundengineer
it also takes some fancy math on some other tables to make it all get proper fueling...
