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RobertReilly

Map sensor

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Sure can.  There is a tuning company already out there offering this feature and sensor.

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So far they are the only ones that i can find that say they do it but nobody else has returned my emails about it so i was trying to figure out if there are options out there or why nobody else seems to do it, i believe that its the best way to tune any custom engine setup and always hated the cheat methods.

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I would think most 7 bar map sensors with the right voltage range would work just fine.  Might have to drill a hole as Calibrated suggests but gains could definitely be worth it.  The pin-out is easy to find and I would venture to guess that you could make an adapter to plug right into the stock harness with a little help from google.  It could be done for much cheaper.  I started looking into the parts myself but haven't had a chance to get back to it for a couple days.

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Aem make a 100psi 5volt map for $150 but i didnt want to get it until i could get some good tuning feedback, thanks for answering.

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I found a few calibration charts that should get a person dialed in.  I'll see if I can find them again and post a link.  If I end up forgetting and you are looking for the info, send me a reminder and I'll get on it.

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So i found a map sensor that's  100 psi from holley for $114 and it's 1/8 npt so that makes the install easy, just talked to chris at calibrated performance and I'll be driving to Illinois to have a mm3 tune done on their mustang dyno, $1300 for mm3 hardware and about $800 for the tune.

Edited by RobertReilly
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I guess I'll ask... why is it needed? So far I haven't seen the need for it, but that doesn't mean I'm not missing something. 

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I've been looking into that myself @AH64ID.  There aren't many parameters we currently have access to that could benefit from a map sensor with a higher scale.  I see the post injection events can be set to take into account 200 inHg max scale for boost adjust.  The linearization chart looks like it can handle a 10 bar sensor.  Its hard to tell what exactly the ecm is capable of using but it may have the potential of allowing the ecm to more accurately self calculate builds out to 150 psi.  We've nearly got enough air density selections to fly to the moon.  O.o

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Yeah that's along the same lines as my thinking. Unless a guy wanted to see 100+ psi on his touch screen or data logs I don't think it's needed for proper tuning. 

 

Post... who uses that :-)... it actually can be useful in some applications but more at low boost and not high. 

 

We have too many air density selection tables as it is in 04.5-07 and the 6.7 guys have it way worse! The 03-04's are how it should be. @4Play Have you had any luck with figuring out how the ECM chooses table 0 or 1? I thought I had it figured out but the results are unreliable. 

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@AH64ID I'm still picking away at it when time permits.  It may come down to creating a flow chart to keep my head straight about which parameters interact and when.  Even a list of what all parameters contribute to or get contributions from A/D.  Its a little tough to keep track of everything being as it is scattered throughout the hierarchy tree.  I also think we may be missing a selection option or two from looking at another platform.  I don't envy the gents over the pond trying to sort out the wants/needs/misc.  

I'm still trying to find the thread to see where we left off but to no avail yet.  I think it was from the period between site updates and may have been lost but I don't believe we had made much headway.

As for the MAP, I'm wondering if it may be a benefit for guys like us who see major elevation changes potentially at boost levels above stock limits.  You would definitely need to be using the variations of A/D tables to see much if any benefit though. 

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My background is with turbo gassers so i wanted my ecm to be able to see and be able to calculate from 1psi to 100psi for accurate tuning that ranges from racing to hauling heavy loads up n down mountain ranges and elevations and best mpg possible without getting tickets for blasting black smoke in every state i travel through, i understand our trucks are way more forgiving than turbo gassers but im an old fashioned guy so thats why i chose this tuning method as its always been the most reliable for making power with longevity for me, i am in no way saying its the only way to tune nor am i trying to bad mouth anyone who tunes without it, i have not run across anyone running a 100psi map but i do believe its the best overall way and with more states cracking down on the rolling coal it might be the new normal.

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@RobertReilly I agree wholeheartedly that the more complete you can make a tune the better.  I believe what @AH64ID is alluding to would be that most of your smoke and emissions concerns come during pre-boost conditions (snap test) which would make a 7 bar MAP irrelevant in most cases and the current sensor is more than adequate to create a great tune.  Some of the sled pulling trucks with a huge single turbo may benefit greatly from a 7 or even 10 bar MAP since they are running up to and possibly above 150 psi and 6k rpm.   @paulb might be able to give some insight and examples on what is possible with the stock MAP on his personal truck if it hasn't been upgraded yet.

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1 hour ago, RobertReilly said:

My background is with turbo gassers so i wanted my ecm to be able to see and be able to calculate from 1psi to 100psi for accurate tuning that ranges from racing to hauling heavy loads up n down mountain ranges and elevations and best mpg possible without getting tickets for blasting black smoke in every state i travel through, i understand our trucks are way more forgiving than turbo gassers but im an old fashioned guy so thats why i chose this tuning method as its always been the most reliable for making power with longevity for me, i am in no way saying its the only way to tune nor am i trying to bad mouth anyone who tunes without it, i have not run across anyone running a 100psi map but i do believe its the best overall way and with more states cracking down on the rolling coal it might be the new normal.

 

Yes turbo gas motors are very picky on accurate boost due to the air:fuel ratio requirements in a gas motor. Diesel doesn't have those same air:fuel ratio requirements and thus it's not as important. Gas motors have to run at their Stoichiometric AFR whereas we want diesels running just leaner than Stoich AFR. 

Where boost reading are important on a diesel is at low boost to keep from smoking out an intersection. Once a certain amount of boost is obtained the ECM doesn't really care. I could look, but I think 23 psi is that magic number on a stock tune. Above 23 psi the ECM allows full fuel as the turbo is spooled by that point. If you're making black smoke at 30, 40, or 50 psi it has nothing to do with the MAP sensor range and everything to do with timing/rail pressure. 

I'm curious to hear your report, but I truly don't think you will ever even notice the change from running a MAP sensor that reads higher than stock. 

 

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Its going in to get tuned after i get back from a job in Hawaii, I'll definitely update this thread after it's done and let everyone know if changing was of benefit or if i just blew some extra coin that wasn't necessary. This is why this is the best forum for talking about our diesels, we can discuss things and learn without the attitude ya get in other forums ! Thanks guys for all your input!!

Edited by RobertReilly
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So I decided to look... Above 21 psi the ECM allows full fuel. It has OEM tables to 32 psi but they are all maxed. 

 

On very high rpm applications it might be nice to be able to add/subtract timing based on boost but even then I am not sure that is something that would be noticeable outside of dyno tuning. The boost adjust table for main timing is also limited to 49 psi max so it's not a big gain in tuning range. 

 

1 minute ago, RobertReilly said:

Its going in to get tuned after i get back from a job in Hawaii, I'll definitely update this thread after it's done and let everyone know if changing was of benefit or if i just blew some extra coin that wasn't necessary. 

 

Looking forward to hearing the results!

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@RobertReilly hopefully they give you a stock tune with the 7 bar map enabled so you can compare.  If not the tuning itself will be a drastic enough change that you wouldn't be able to differentiate.  I'll be very interested to hear the results and see what differences you find.  Enjoy Hawaii!

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Thanks hopefully I get to eat lots of bbq? i get 4 tunes so i will request a stock tune for comparison, thanks for mentioning that cause i would have spaced it out.

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I would hope they could do that for free. Hate to waste a purchased tune level on a single parameter change. 

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20 minutes ago, 4Play said:

I would hope they could do that for free. Hate to waste a purchased tune level on a single parameter change. 

Agree. They should be able to do 2 versions of one tune for the MAP sensor change. 

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This is an interesting topic, and everyone has good points. The benefits/disadvantages are different depending on the year of the truck. Highly modified 2nd gen VP trucks would probably benefit the most. They are highly boost referenced.

I am assuming that this option is only being considered for modified trucks. As John pointed out on stock trucks especially stock turbo trucks if you exceed what the map sensor is capable of, you are way outside of the turbo map anyway. 

On my 05, I have a Wide Band O2 sensor, that I use to modify the tune. This truck does full fuel to 5000 rpm. The reason I use that information is because the fuel delivery needs to be modified by air flow and not by boost. These are not the same. At higher rpm, the amount of air that flows through the engine decreases with the same amount of boost. This is because of air flow restriction in the head, cam shaft design, and just because there is less time to fill the cylinder on each intake stroke. I make the same amount of boost from about 2500rpm to 5000rpm, and I can tune to deliver the same amount of fuel in that range as well (I don't, but I could). If I did that, you can watch on the O2 sensor, the mixture get richer as rpm increases. So for me, having a 7 bar map sensor is of no use. Now replacing the map sensor with a Wide Band O2 sensor.... :-) That maybe a winter time project.

On a 4th gen, they don't have boost reference maps per se. A 4th gen uses an air flow sensor, as well as a map sensor and an intake air temp sensor. The fuel calculations are based on air density (not just boost pressure). Unless you are making an MAFless tune, then just replacing the map sensor would not be of benefit. On 4th gens the ecm leads with air flow (increased air density) and then follows with fuel. On third gens the ecm leads with fuel and limits based on boost.

Another thing with using a 7bar sensor is that each cell in the maps become less granular. You have the same number of cells, to use to control fuel over a wider range of boost. That means that the transition between cells will be larger. The ecm will interpolate the differences, but the fuel control will not be as precise with small changes.

I know this post sounds negative, but it's really not. Under certain circumstances I think there can be some gains. I don't think you will see much from a truck with a stock turbo, or one that is highly modified. I hope someone can prove me wrong though...

Paul

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