A lot of information out there on these sensors and what they do but the info is scattered and everyone doesn’t have a specific spot to go to toknow what sensor they can actually use for there boosted application so here it is!

Note: “lsj has 3 map sensors” 1 bar sensor, on the block/ 2 bar sensor, the scip sensor, on the top of the blowers snout, also stock in the 2nd&3rd gen camaro/ and the 2.5 tmap sensor, on the left.

(1 bar sensor) not typical used in boosted applications, but if running below 14.7 psi and don’t have the intentions of going any higher, it will work! Advantages: it has more resolution for the tuner, it’s stock on l61 & le5 intake manifolds as well as lsj, but for the lsj it’s mounted on the block. Disadvantages: it’s limitations, only reads up to 14.7psi, you still need a separate iat sensor & have to tap the manifold if supercharged, unless using the lsj 2.5 tmap sensor for iat readings. Not 100% on turbo applications if tapping is needed.

(2 bar sensor) like said it’s the sensor on the s/c cobalt ss snout, and on the Camaro 2nd/3rd! Less resolution than 1 bar sensor, but more than 2.5 tmap when tuning. Also Comes stock with 2.4 gm supercharger kit, and zzp kit as well!

(2.5 tmap) best sensor for almost all boosted applications, it’s a little more expensive, but can easily be found cheap from a used cobalt ss online or or the junk yard. It has the iat combined and no need to tap the manifold for 2.2 and 2.4. Resolution is lost a little tuning, but a good tuner should have no problem!






Yungnwrenchin#boosted

IIRC, the 1 bar sensor only read vacuum. The 2 bar read vacuum and 14.7psi of positive pressure and the 2.5 bar read vacuum and up to 21-22psi of positive pressure. 3 bar vacuum and 28 - 29psi, and just keep adding 14.7 psi for every bar you increase.

soo much miss information here. The sensors are not the limiting factor. It is the OS. Putting a 2 bar map sensor in on a jbody does not make it read boost.



FU Tuning

This was from my tuners website, and I’m not miss informing anyone, I just think there’s a miss understanding of what was said.

2 and 3 bar tune?
Two and three bar tunes are actually special operating systems that are speed density and designed for higher horsepower boosted applications which will exceed internal airflow limits for the MAF within the ECM. These operating systems require the corresponding 2 or 3 bar MAP sensor and allow the ECM to "see" boost (the stock ECM is blind to MAP levels that result from boost) and adjust fueling accordingly. This is particularly important for turbo charged applications which can make boost in many different RPM ranges based on engine load, unlike superchargers whose boost is physically tied to rising engine RPMs.

In my situation, I had a custom tune done for my 03 supercharged cavalier and I was set up to run the gm reflash, and planned to, so the 2.5 tmap sensor, but the tune my tuner gave me was a 2 bar tune and he didnt say that! So that’s why I made the map sensor thread, cause I went through the whole engine and searched all over trying to figure out why the car wouldn’t start, then I had the problem of figuring out which sensors would work with the car and that’s why I listed all the map sensors that work for a boosted application!


Yungnwrenchin#boosted

Gaetan Anderson wrote:This was from my tuners website, and I’m not miss informing anyone, I just think there’s a miss understanding of what was said.

2 and 3 bar tune?
Two and three bar tunes are actually special operating systems that are speed density and designed for higher horsepower boosted applications which will exceed internal airflow limits for the MAF within the ECM. These operating systems require the corresponding 2 or 3 bar MAP sensor and allow the ECM to "see" boost (the stock ECM is blind to MAP levels that result from boost) and adjust fueling accordingly. This is particularly important for turbo charged applications which can make boost in many different RPM ranges based on engine load, unlike superchargers whose boost is physically tied to rising engine RPMs.

In my situation, I had a custom tune done for my 03 supercharged cavalier and I was set up to run the gm reflash, and planned to, so the 2.5 tmap sensor, but the tune my tuner gave me was a 2 bar tune and he didnt say that! So that’s why I made the map sensor thread, cause I went through the whole engine and searched all over trying to figure out why the car wouldn’t start, then I had the problem of figuring out which sensors would work with the car and that’s why I listed all the map sensors that work for a boosted application!

Still miss information when it comes to Jbody's. When using a facotry jbody ECU the only tune-able speed density OS is the GM reflash for the 00-02 LD9. GM did release a reflash for the ecotec charger kits, but it is not tune-able. Also Jbody's do not have MAF's.



FU Tuning

Unless you did the swap to a 00-02 LD9/LN2 PCM the only OS you can be running is Alpha-N. The most common/successful way of tuning supercharged Ecotecs in J-bodies is using the 2.5bar fake method. Addicted to meth will have to go into the specifics of how it is done, since I outsource my tuning to a friend. But I can verify that while it is not ideal, it does work pretty well.

Tinkles(KGM) wrote:Unless you did the swap to a 00-02 LD9/LN2 PCM the only OS you can be running is Alpha-N. The most common/successful way of tuning supercharged Ecotecs in J-bodies is using the 2.5bar fake method. Addicted to meth will have to go into the specifics of how it is done, since I outsource my tuning to a friend. But I can verify that while it is not ideal, it does work pretty well.

Believe it or not both Ryan and myself prefer using the stock 1 bar sensor for M62 setups. That said the 2.5bar Tmap sensor makes for a good IAT sensor.

OP, for a 1 bar sensor.. it reads no boost (ok, a tiny bit but assume none). Keep in mind atmospheric pressure varies a little based on altitude but let's assume sea level. Therefore 1 barometric unit (bar) = 14.7psi = 101.35 kpa = 1 atmospheric pressure unit. If you turn the key to on without running the engine, a 1 bar map sensor is all but maxed out at the 14.7psi that is the atmospheric pressure we enjoy to hold our soft tissues inside our bodies.

When you start the motor and let it idle, it's sucking air in with the throttle plate mostly closed, creating vacuum in the intake manifold. When you tap the throttle you can hear it suck more air in. Those pressure readings, because vacuum is present, are below 14.7psi. This is how naturally aspirated cars work. Always in vacuum. At wide open throttle, you see close to 0 vacuum because the throttle plate is all of the way open. Hope that makes some sense..



"In Oldskool we trust"

Oh, and here's this, too.



"In Oldskool we trust"

Addicted to meth wrote:GM did release a reflash for the ecotec charger kits, but it is not tune-able. Also Jbody's do not have MAF's.

I'd be willing to bet it's just a really good fake, but who knows? Something I'd love to know just for fun.



"In Oldskool we trust"

Quote:

Believe it or not both Ryan and myself prefer using the stock 1 bar sensor for M62 setups. That said the 2.5bar Tmap sensor makes for a good IAT sensor.

I completely agree with you!!!

Quote:

I'd be willing to bet it's just a really good fake, but who knows? Something I'd love to know just for fun

Oh it has been confirmed that is it is a very crappy fake. Not even on the same level as the LD9 reflash.



FU Tuning

Addicted to meth wrote:

Quote:

Oh it has been confirmed that is it is a very crappy fake. Not even on the same level as the LD9 reflash.

I'm not surprised but tell me more! How was this figured out? Did they just fudge injector constant too?



"In Oldskool we trust"

Quote:

I'm not surprised but tell me more! How was this figured out? Did they just fudge injector constant too?

It is my understanding the Trifecta guy was looking into making the it tunable, but once he got into it he found it to just be a really bad 2.5 bar fake. I got this information from Ryan Egleston.



FU Tuning

Addicted to meth wrote:It is my understanding the Trifecta guy was looking into making the it tunable, but once he got into it he found it to just be a really bad 2.5 bar fake. I got this information from Ryan Egleston.

That's hilarious. Though, I take what Vince says with a grain of salt.



"In Oldskool we trust"

Y3llowCav wrote:

Addicted to meth wrote:It is my understanding the Trifecta guy was looking into making the it tunable, but once he got into it he found it to just be a really bad 2.5 bar fake. I got this information from Ryan Egleston.

That's hilarious. Though, I take what Vince says with a grain of salt.

I can confirm with my personal experience with running the GM M62 Reflash that it is complete garbage.

I wish I had got on here sooner, I’m always afraid you guys are gunna tear me apart, that I shy away of reading the comments lol but lesson learned, and I really appreciate the knowledge and professional responses everyone’s givin! #100

That said, I’ve tried looking up the company’s tuning software and system,” because long story short”, everything has been a hassle & guessing game for me, from the car setup not being what I asked for “2.5 tmap setup” I told the tuner, then the contact issue, I had with him at first.

After 3-4 months of every single boost thread, and google trying to get this beast running right, I get some answers, seriously I’m the farthest thing from a quiter and I was real close to saying f it!

He use efilive, I know and they also do prototype projects for the military, like ecotec utv’s, rally trucks custom harnesses, im not trying to get all over the place with this, just stating what I think I need to say to answer your questions and mine as well!

The reason I went with these guys, was because they would do the gm 2.5tmap reflash with the ecu out of the car and I had trouble at first finding the vcn# for 2.2 ecotec automatic, which was in the build book lmao!


Yungnwrenchin#boosted

Right now, I am using the tmap sensor as my iat, because I didn’t want to drill and tap my manifold, so I have my 2 bar map sensor, tee’d into the manifold nipple and fpr!

My car is running like @!#$ and I need answers, my idle is at 900, rev perfect sounds amazing if you ask me, reverse has fast acceleration, but first gear, Super Rich, stumbles for a second, then super slow take off, finally starts to build power but nothing like it should, I bet the GM Reflash is better!

I took it to get diagnostic check, cause my cel is lit and I had 5 codes 1. Evap fails to hold sufficient vacuum 2. Low voltage o-5v map sensor 3. Fuel injector#1 incorrect voltage 4. Engine misfire 5. Lean fuel#1

Got new wiring harness, which was my main problem, from splicing for tmap! But after replacing harness, still had cel lit, going up for diagnostic test this morning and will update.

I still think the tune has something to do with the cars performance, but I’ve been laid off work, so money is minimal right now, was thinking of just getting the reflash from dealership, if performance is still an issue, after cel issues are taken care of!


Yungnwrenchin#boosted

Yikes.. a lot of issues. Honestly the GM Reflash might be best for you if you're unable to tune it yourself or find someone more competent. It works, it just runs rich and leaves a significant amount of power on the table. If you go that route, you need to use the 2.5bar Tmap sensor for both IAT and MAP readings and 36lb injectors. A 3.1" pulley helps a lot to get the fueling closer too.



"In Oldskool we trust"

Gaetan Anderson wrote:Right now, I am using the tmap sensor as my iat, because I didn’t want to drill and tap my manifold, so I have my 2 bar map sensor, tee’d into the manifold nipple and fpr!

My car is running like @!#$ and I need answers, my idle is at 900, rev perfect sounds amazing if you ask me, reverse has fast acceleration, but first gear, Super Rich, stumbles for a second, then super slow take off, finally starts to build power but nothing like it should, I bet the GM Reflash is better!

I took it to get diagnostic check, cause my cel is lit and I had 5 codes 1. Evap fails to hold sufficient vacuum 2. Low voltage o-5v map sensor 3. Fuel injector#1 incorrect voltage 4. Engine misfire 5. Lean fuel#1

Got new wiring harness, which was my main problem, from splicing for tmap! But after replacing harness, still had cel lit, going up for diagnostic test this morning and will update.

I still think the tune has something to do with the cars performance, but I’ve been laid off work, so money is minimal right now, was thinking of just getting the reflash from dealership, if performance is still an issue, after cel issues are taken care of!

I know EFI Live can tuned the jbody. They are similar to HPTuners, but I know some things are in one and not the other. Exactly what. I can't say.

I would also recommend the GM reflash until you can get someone who can actually tune your car.



FU Tuning

Thank you guys so much, honestly!!! Any suggestions on the 3.1, and will I need the hub as well? Stock lsj injectors already and the 2.5tmap I’m using as my iat sensor in the stock location so easily splice then reflash and done! All that money for nothing#punked


Yungnwrenchin#boosted

Just a little update, from what I know the eco cannot get speed density tune, like stated above, but my tune is, that’s what my tuner told me!
So I wanted to figure out a couple questions and this is what I found and tell me if this would allow for my tuner to tune alpha n in speed density!?!

This is from the EFI Live website and pretty much what my tuner was telling me?
Speed Density
Speed Density mode is preferred by most tuners when tuning high performance engines with large camshafts or forced induction. The MAF is removed (or disabled) and the PCM is tuned using the MAP sensor instead. Unfortunately, when the MAF is disconnected the stock PCM has been designed to go into a semi-limp mode (operating from the low octane spark map only). EFILive’s Speed Density Custom Operating System restores the high-octane spark map and full adaptive spark control, when operating in speed density mode.

2 and 3 bar Forced Induction
2 and 3 bar Forced Induction extends the fuel and spark tables to allow the PCM total control over spark and fuel all the way to full boost. EFILive retains the standard fuel and spark tables for non-boost conditions retaining factory drivability and adds new tables for boost control.

I’m gettin the reflash done today, kinda bummed out but atleast the car will be drivable


Yungnwrenchin#boosted

The more I hear about this "tuner" the more I understand why the car runs like a bag of dicks.

Unless he replaced the PCM and re-wired the front of the car, there's no way your fueling is MAP sensor based. In addition, these vehicles are not even equipped with a MAF sensor to remove.



"In Oldskool we trust"

It is possible to tune an Ecotec with Speed Density. It involves swapping the engine harness and PCM over to a 2000-2002 LN2/LD9 PCM/wiring harness and running the LD9/M45 GM supercharger reflash which is tunable. A few people have done it and there are a few threads explaining the basics of the swap.

Y3llowCav wrote:The more I hear about this "tuner" the more I understand why the car runs like a bag of dicks.

Unless he replaced the PCM and re-wired the front of the car, there's no way your fueling is MAP sensor based. In addition, these vehicles are not even equipped with a MAF sensor to remove.

Yeah agree.

Going off EFI Lives explanation our cars are Speed Density from the factory. lol

The shop I use for the dyno uses EFI and they were tuning a Ecotec turbo setup, they even confirmed it was Alpha N.



FU Tuning

The guy knows how’s how to tune Ecotec’s and l61 2.2 Supercharged engines, but he must not have been familiar with the gen 3 jbody pcm. He sure acted confident when I specifically told him, my setup and that it was different than the other 2.2 l61 that came in the cobalt!

He had no clue what he was doin, because I got the reflash and wow!! Yeah definitely rich and I still had the 2 bar map hookup, to intake and fpr and tmap hooked as iat in stock location, but mmmmmmm mmmmm mmm!!! I’ve been waiting so long, “wondering” how fast it would be and I didn’t get crazy just hit it 0-60 once and drove a mile home, but almost 24 hours later and the grin still hasn’t left my face, from wasting this Monte at the light!!! Complete sleeper, lol it sputtered and I was thinking fn pos, next thing I know I’m shifting into second, looking in my rear view to see where he was!

Can’t wait to swap pulleys, and I know I read 3.0 was to lean, so everyone goes 3.1 to be safe, but I couldn’t find any info on someone running the GM Stage 2 pulley and hub since it’s inbetween both and closer to 3.1 than 3,0, then I found a document for a Legit “GM Stage 2 upgrade kit for 03-05 cavalier with stock recalibration” and everyone always said they didn’t make a stage kit ever! I got the proof now, either way thanks for all the help guys and I’m sure we will be talking in the near future, when I finish my car and begin the mods!


Yungnwrenchin#boosted

And I forgot to mention, now my car now doesn’t have a cel!!


Yungnwrenchin#boosted