2 bar map sensor..what does it take
03-10-2008, 03:30 AM
#21
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all i hear is people on this forum saying u need a SD tune for everything which is a bunch of crock,don't beleave me then check out LPE they have 900hp vetts on a mas tune that they kick out left and right.
03-10-2008, 06:33 AM
#22
From my understanding after talking to a local tuner, my 98 PCM will support a SD 2 bar tune (14.7 lbs of boost), the 99+ PCMs will support a SD 3 bar (22 lbs).
The stock MAF is only good to manage up to 14 lbs of boost, this being it's threshold of an accurate reading. He recommended not going over 13 lbs of boost on a MAF tune. It costs nearly twice as much to do the SD tune on my car, and I'm not going to be boosting over 13 lbs for a while so I'm planning on tuning the car with a MAF to start with due to cost and my puny converter/tranny that's in the car currently. I'm going for about 8 lbs of boost to start so a MAF tune will be fine. When I get a th-400 in the car and a 9" or 12 bolt rear and I'm ready to go all out with it, I'm going to max the MAF, see how it does, then possibly go SD with it.
The stock MAF is only good to manage up to 14 lbs of boost, this being it's threshold of an accurate reading. He recommended not going over 13 lbs of boost on a MAF tune. It costs nearly twice as much to do the SD tune on my car, and I'm not going to be boosting over 13 lbs for a while so I'm planning on tuning the car with a MAF to start with due to cost and my puny converter/tranny that's in the car currently. I'm going for about 8 lbs of boost to start so a MAF tune will be fine. When I get a th-400 in the car and a 9" or 12 bolt rear and I'm ready to go all out with it, I'm going to max the MAF, see how it does, then possibly go SD with it.
I will proably turn up the boost even more if I can keep the heads down
03-10-2008, 06:36 AM
#23
I will probably be running somewhere areound 14-15 lbs of boost , I will not be using the the stock MAF I will be getting a LPE MAF that I was told form Greg Banish that it comes with a much greater table to plug into the maf table of your software . Thats how I am going to do the tune . I just thought that I still needed to change the map sensor.
I will proably turn up the boost even more if I can keep the heads down
I will proably turn up the boost even more if I can keep the heads down
03-10-2008, 07:06 AM
#24
No, not you, calm down a little. I should have said one person, lmt705 who said:
"the problem is when you have any kind of a temp change it will affect your tune because theres no sensors being used to adapt to air flow, temp and pressure changes AKA your MAF"
Which is totally untrue. You do lose the MAF which actually measures airflow, but there are still sensors that measure temp (IAT) and pressure (MAP) which are used to calculate airflow.
"the problem is when you have any kind of a temp change it will affect your tune because theres no sensors being used to adapt to air flow, temp and pressure changes AKA your MAF"
Which is totally untrue. You do lose the MAF which actually measures airflow, but there are still sensors that measure temp (IAT) and pressure (MAP) which are used to calculate airflow.
Yup, what he says....
03-10-2008, 08:06 AM
#25
What none of you is figuring on is hes talking about an LT1, NOT an LS1. So, a 2 bar tune is completely different. No custom OS.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
03-10-2008, 09:06 AM
#26
What none of you is figuring on is hes talking about an LT1, NOT an LS1. So, a 2 bar tune is completely different. No custom OS.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
I am talking about an LT1...Done it time and time again, but as you say, You need to know what you are doing.......Mine, 95 2 Bar Map, 12lbs 648 RWHP DD,Pump Gas, AC and all.......14lbs 722 RWHP Fast Gas.
03-10-2008, 09:55 AM
#27
What none of you is figuring on is hes talking about an LT1, NOT an LS1. So, a 2 bar tune is completely different. No custom OS.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
To make a 2 bar work with a 1 bar OS on something like a LT1 there some top secret **** that needs to be done.
Without giving away too much stuff, do a search on camaroz28 and you'll find most of the info. Be warned, its difficult to get right, and its not something you want to be trying as your first tune.
Dang you and Moe beat me to the punch.... I was reading all of the HPT custom OS crap wondering how they all missed the fact that it was an Lt1.
I know what WILL come in handy when doing the tune.... a spreadsheet to track what you are doing inside of the PCM or at least a notebook... some way to keep up with the table trickery
03-10-2008, 05:12 PM
#30
Yes you are right, what I meant was a 1 bar reads vacum and a good signal to 14 inches (and beyond) and a 2 bar reads pressure. Again you can use a 1 bar even if you are running 15lbs of boost or 2 bar up to 30lbs, but it makes tuning a task where as a 2 bar map will be linear in KPA vs TPS vs RPM up to 14-15lbs of boost..
03-10-2008, 07:08 PM
#31
03-11-2008, 12:04 AM
#33
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The good part about voltage based MAF's that it's easy to multiply/divide voltage. frequency based MAFs are more precise, but the whole idea of multiplying/dividing the range goes out of the window, unless you figure out a circuit that can multiply frequencies.
the reason why some cars deal with a lot of power on MAF is the voltage trick. for example, if your MAF describes 500g/sec at 5volts, and at that moment you'll be doing 20ms pulse width on your Xg/sec flowing injectors, you can cut the MAF voltage in two, while sizing your injectors to flow 2*X.
so at 2.5v computer thinks you're flowing 250g/sec of air, which needs X/2g/sec of fuel. but in reality you are flowing 500g/sec at 2.5v, and your injectors are dumping twice what X/2 would be, which is X. so you're back to the same air/fuel amounts (500g/sec and X fuel, just like in the starting case) but at 2.5 volts, not 5.
this way at 5v computer thinks that it's flowing 500g/sec and needs X fuel. in reality it's flowing 1000g/sec of airflow, and injectors will dump 2*X fuel, keeping AFR the same. so you end up with twice the range on the same voltage range.
this theory goes out the window when things go nonlinear, and since very few things in reality are linear, this method is plagued with assumptions and fudge factors. in the end to have a proper tune you'd have to make up for the imprecision somewhere else, and that's why i'd rather do things right from the getgo--if both methods will ultimately take the same amount of work, but one of them is going to be working off wrong numbers, might as well do it proper.
The 2/3 bar Custom Operating systems way of doing it:
* Low cost (2) credits from HPTuners & 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.
Disadvantages of using MAF in boosted applications
* 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
Take your pick.
Last edited by MFIC; 03-11-2008 at 12:05 AM. Reason: left some info out
03-11-2008, 04:09 AM
#34
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listen to mfic ^^^^^he knows what he is talking about. there is always more than one way to skin a cat, but some people are so used to doing one way, they refuse to learn a new way, even if it is better, they had to hack tunes and pull all kinds of tricks out befor they had the capabilitly to do it other wise, but now you have options.......y not do it right?
03-11-2008, 06:10 AM
#35
Disadvantages of using MAF in boosted applications
* 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
Take your pick.
Your statement makes sence if you are running a stock maf table . The LPE maf comes with a wider rage table to alow for a lot more air . I am not sure the TSP one does.
Also my car wount let me use RTT and dosent seem to want to alow me to SD tune and the maf seems a lot easier to me .
IMO you dont really need a low octane table if it gets knock it will pull timing thats it . Mustang tuning software only alows maf tunnig they do it the same way and they don't ween to have problems making big power on sc cars .
03-11-2008, 06:43 AM
#36
This is *such* an old argument that has been gone over SO many times, what's one more right?..
He didn't say "tune your car to 5 and then run 10".... If you are running 10psi, your MAF is almost absolutely maxxed out, never seen one that wasn't at that level. Nobody said the freq won't go up, but the PCM stops caring about it at 12ish Khz regardless of how much higher it goes.
Stock MAF table... so then, how do propose getting around the fact, without blind halfing/fractioning tables (as eluded to elsewhere in this thread), the PCM's internal MAF airflow limit is 512g/sec? Sure you can change any number BENEATH that, but that's all that is supported and no aftermarket MAF will change this for a 98-02 f-body. Here's another point.... mustang engine management and GM engine management aren't written the same way and don't work the same way, does that help you out?
Why whould you tune your car to 5psi then boost it to 10 psi ? If you tune your car to 10 psi with a maf ,so long as the maf table isnt pinned at any point if you run 5psi it will add fuel for that frequency ,then when you add the extra air from more boost it will add more fuel due to the high frequency . Unless the maf table has been pinned at a lower PSI it should work fine till it maxes the maf table .
Your statement makes sence if you are running a stock maf table . The LPE maf comes with a wider rage table to alow for a lot more air . I am not sure the TSP one does.
Also my car wount let me use RTT and dosent seem to want to alow me to SD tune and the maf seems a lot easier to me .
IMO you dont really need a low octane table if it gets knock it will pull timing thats it . Mustang tuning software only alows maf tunnig they do it the same way and they don't ween to have problems making big power on sc cars .
Also my car wount let me use RTT and dosent seem to want to alow me to SD tune and the maf seems a lot easier to me .
IMO you dont really need a low octane table if it gets knock it will pull timing thats it . Mustang tuning software only alows maf tunnig they do it the same way and they don't ween to have problems making big power on sc cars .
Stock MAF table... so then, how do propose getting around the fact, without blind halfing/fractioning tables (as eluded to elsewhere in this thread), the PCM's internal MAF airflow limit is 512g/sec? Sure you can change any number BENEATH that, but that's all that is supported and no aftermarket MAF will change this for a 98-02 f-body. Here's another point.... mustang engine management and GM engine management aren't written the same way and don't work the same way, does that help you out?
03-11-2008, 10:23 AM
#38
HPTuners has a 2-bar OS for you! And I see even some mods on here in other threads state that you are "limited" to 14.7psi, and this is just not true. If you are running 18-19 psi then the last line in your VE will need to be rich enough to accomodate that 18-19psi and it will be a tad rich from 14 to 18-19 PSi as a result. The turbo will be coming up so fast that you won't even notice it though.
I feel like I have typed this description a lot lately...
I feel like I have typed this description a lot lately...
03-11-2008, 01:05 PM
#39
This is *such* an old argument that has been gone over SO many times, what's one more right?..
He didn't say "tune your car to 5 and then run 10".... If you are running 10psi, your MAF is almost absolutely maxxed out, never seen one that wasn't at that level. Nobody said the freq won't go up, but the PCM stops caring about it at 12ish Khz regardless of how much higher it goes.
WHat I was saying is if you want to run 10#'s at the track an 5# ont the street if you tune for 10 #and run 5 there should be no need to re flash the tune .
Not sure why your getting so mad but . There are ways around it I was told form a very repertable tuner Grag banish that one, the LPE MAF will read higher then that and 2 that you can shrink the base car in the tune like instead of a 5.7 make it think its a 3.6 (not exact #'s) and it will also extent the maf table . But what whould he know he only writes entire calabrations for major car makers .
Stock MAF table... so then, how do propose getting around the fact, without blind halfing/fractioning tables (as eluded to elsewhere in this thread), the PCM's internal MAF airflow limit is 512g/sec? Sure you can change any number BENEATH that, but that's all that is supported and no aftermarket MAF will change this for a 98-02 f-body. Here's another point.... mustang engine management and GM engine management aren't written the same way and don't work the same way, does that help you out?
He didn't say "tune your car to 5 and then run 10".... If you are running 10psi, your MAF is almost absolutely maxxed out, never seen one that wasn't at that level. Nobody said the freq won't go up, but the PCM stops caring about it at 12ish Khz regardless of how much higher it goes.
WHat I was saying is if you want to run 10#'s at the track an 5# ont the street if you tune for 10 #and run 5 there should be no need to re flash the tune .
Not sure why your getting so mad but . There are ways around it I was told form a very repertable tuner Grag banish that one, the LPE MAF will read higher then that and 2 that you can shrink the base car in the tune like instead of a 5.7 make it think its a 3.6 (not exact #'s) and it will also extent the maf table . But what whould he know he only writes entire calabrations for major car makers .
Stock MAF table... so then, how do propose getting around the fact, without blind halfing/fractioning tables (as eluded to elsewhere in this thread), the PCM's internal MAF airflow limit is 512g/sec? Sure you can change any number BENEATH that, but that's all that is supported and no aftermarket MAF will change this for a 98-02 f-body. Here's another point.... mustang engine management and GM engine management aren't written the same way and don't work the same way, does that help you out?
I am going to give it a shot on my car and if it doesent work Ill SD tune but till then I thats how I will do it . I dont forsee any problems with the maf
Last edited by CamaroSS19; 03-11-2008 at 01:28 PM.
