upgrade map sensor to a 3 or 3.5 bar map sensor?

[KurtP]

stocker only reads up to a 22.5 psi, upgrade the sensor?

[LittleBlueGT]

stocker only reads up to a 22.5 psi, upgrade the sensor?

 

You can. I tend to think that on the stock block that might not be wise.

 

If you do, then there are just two values in the tune that need changing, very simple to do.

 

Why did you want to do this? Anything under about a 30R in size will not require higher then 22.5 to make max WHP. Many smaller turbos, like a 20g or 68HTA can run higher boost in the mid-range, and make more torque there, but as rpms rise boost will fall, and will be less then 22.5 at peak whp.

 

If you want to go this route, I had a 3.5 bar MAP, and the really nice little anodized aluminum adapter for it. I sold it to Infamous, but he never used it. He may still have it, might sell it to you.

[KurtP]

Im going to want more than 22.5 on my race gas file.

[LittleBlueGT]

Im going to want more than 22.5 on my race gas file.

 

On what turbo? I thought you were getting an 18g. If so, then it really isn't worth it IMO. Sure you could hit 25 psi with it at about 3600 rpms or so, but then it will drop pretty hard after that. Will make no difference at all in drag racing.

[KurtP]

i have a 20g. What exactly is the point of upgrading the map sensor? If i can exceed teh 22.5psi on the stock one, why upgrade or change.

 

edumicate me.

[LittleBlueGT]

i have a 20g. What exactly is the point of upgrading the map sensor? If i can exceed teh 22.5psi on the stock one, why upgrade or change.

 

edumicate me.

 

I tend to think by your comments that you still have lots to learn. No worries, been there done that, still doing it to some degree.

 

A 20g could benefit by it, but I would only run it above 22 psi in the mid-range if you were running alky or E85. Even then it will taper down to 21 psi or so at high rpms, so it will not make much difference in 1/4 times.

 

Changing the MAP will allow the ECU to control boost above 22 psi. You can leave that sensor stock, run a MBC and run whatever your turbo will do (which is not much more then that anyways, unless you step up to a bigger turbo), but then you disable the ECU's ability to cut boost if it sees fit.

 

So if you get a 3.5 bar MAP, then you could run up to almost 35 psi (if you have a turbo big enough to support it) and still have the ECU control things, with the ability to cut boost if it sees fit.

[m sprank]

I use a GM 3BAR MAP sensor in my car.

 

Had to.

 

My 23psi made my dash light up like a Christmas Tree. 08 sensors have a max value lower than 05-06 models. So even though the sensor should theoretically work the upper threshold was limited causing the CEL.

 

Shamar still has the trick 3.5BAR sensor somewhere. He told me he did.

 

The GM sensor is used by lots of STi owners and is readily available cheaply. It is good to about 28-30psi. So it should work with just about anything I will use.

 

I did a "how to" in the forums with install and scaling.

 

I now have my boost cut back.

[KurtP]

I use a GM 3BAR MAP sensor in my car.

 

Had to.

 

My 23psi made my dash light up like a Christmas Tree. 08 sensors have a max value lower than 05-06 models. So even though the sensor should theoretically work the upper threshold was limited causing the CEL.

 

Shamar still has the trick 3.5BAR sensor somewhere. He told me he did.

 

The GM sensor is used by lots of STi owners and is readily available cheaply. It is good to about 28-30psi. So it should work with just about anything I will use.

 

I did a "how to" in the forums with install and scaling.

 

I now have my boost cut back.

 

Thats what I was reading that lead me to ask the question. As I was reading up on the 08+ it was only good to just over 22psi by a smidge.....and ill be busting that.

[m sprank]

22.5 and it goes pop. Still works, does not stop the car from running or anything. Does not even kill boost. Just annoying lights and the fact that you can have NO boost cut.

 

So, to get my boost cut back I might have been the LGT guinea pig with the GM 3BAR. But I have it working fine, is only $65, available at many auto parts stores and used by lots of STi owners (for years) so it is proven. There are even write ups on romraider.

[KurtP]

I tend to think by your comments that you still have lots to learn. No worries, been there done that, still doing it to some degree.

 

A 20g could benefit by it, but I would only run it above 22 psi in the mid-range if you were running alky or E85. Even then it will taper down to 21 psi or so at high rpms, so it will not make much difference in 1/4 times.

 

Changing the MAP will allow the ECU to control boost above 22 psi. You can leave that sensor stock, run a MBC and run whatever your turbo will do (which is not much more then that anyways, unless you step up to a bigger turbo), but then you disable the ECU's ability to cut boost if it sees fit.

 

So if you get a 3.5 bar MAP, then you could run up to almost 35 psi (if you have a turbo big enough to support it) and still have the ECU control things, with the ability to cut boost if it sees fit.

 

lol. Dick....guy doing his first Subaru asks questions and gets dubbed the guy with a dunce hat from the local data log mafia boss. Classy.

 

Im not planning on running much higher than 22. Shooting for between 22 and 23 on pump and more on race gas. The factory one on cars 08+ only read to about 22 flat, so either way ill be out of control range.

[LittleBlueGT]

lol. Dick....guy doing his first Subaru asks questions and gets dubbed the guy with a dunce hat from the local data log mafia boss. Classy.

 

Im not planning on running much higher than 22. Shooting for between 22 and 23 on pump and more on race gas. The factory one on cars 08+ only read to about 22 flat, so either way ill be out of control range.

 

 

I didn't know there was a difference in the later model cars.

 

My turbo can run higher, but for boost cut I just run it at 21.5 psi, easier on the tranny. Sure I have a little less power when I roll on the gas in 5th (2800 rpms), but for any real fast driving (above 4500 rpm) it doesn't matter.

 

FWIW the limit is not 22.5 psi, it (if I understand it correctly) is based on the absolute limit of the sensor. So if it is 22.5 at sea level (I don't know exactly right now) it would be 24 psi limit at 3000 feet, as ambient air pressure there is about 13.2 psi. it is the ABSOLUTE limit of the sensor that matters, not what your relative pressure (boost) is.

 

Just throwing that in there in case you tune at 2500 feet or so, and then go to a lower elevation.

[KurtP]

There isnt a difference, Ive just never had to upgrade one.

 

Im at sea level, so the conversion for altitude doesnt apply. Comments from some other sti folk leads me to believe that the absolute limit of the sensor isnt the full 2.5 bar.

[m sprank]

^This is true.

 

But is also true of all MAP sensors. Reading is compared to atmospheric pressure and subtracted giving relative pressure.

 

So at 2000ft my car was fine. Boost was 22 psi. At sea level my car was all it up. 23psi and the sensor was out of range.

 

It is good to approx 22.5 psi at sea level. I did the math, lol. I also verified ROMs from an 05 and 08. Different hi level threshold. Most people don't know that the 08 cars are set to throw the cel earlier. It was not a problem previously. The older cars go to 23-23.5 no problem (at sea level).

 

Kurt, if you need specifics to what I did and pix of my install (it is CLEAN) let me know. I have worked around the problem for under $100 and it is reliable. Worked for all 1986 Pontiac Firebird 3.8l V6 turbo cars, lol.

[KurtP]

Yeah man, hit me with all the details to PM if you can and give me the details.

 

I need to get this thing in before the tune.

 

Ive had second thoughts about running E85, but I dont think the 750's im running are going to be near enough.....but then 1000cc's are 600 bucks. siiiigh.

[mwiener2]

ID1000's should be closer to $460

[NSFW]

data log mafia

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Where do I sign up?

[NSFW]

ID1000's should be closer to $460

 

$650ish for the side-feed-conversion with rails.

[ClimberDHexMods]

Data log mafia... It's the revenge of the nerds

[ClimberDHexMods]

http://justskylines.com/knowledgebase/images/turbo/compressor_maps/td06h-20g-cfm.gif

 

It's going to be short lived. My guess is you're aiming for the 2.65 area at the MAP sensor (intake manifold), but you have to add in a little for pressure loss for a TMIC, and a couple PSI if you have a FMIC. That's because you will always see some undetermined increase of pressure at the compressor over the manifold. If you have a TD05-20G, map should shrink a bit too. Either way, slightly bigger turbo will solve this issue. GL.

[LittleBlueGT]

http://justskylines.com/knowledgebase/images/turbo/compressor_maps/td06h-20g-cfm.gif

 

It's going to be short lived. My guess is you're aiming for the 2.65 area at the MAP sensor (intake manifold), but you have to add in a little for pressure loss for a TMIC, and a couple PSI if you have a FMIC. That's because you will always see some undetermined increase of pressure at the compressor over the manifold. If you have a TD05-20G, map should shrink a bit too. Either way, slightly bigger turbo will solve this issue. GL.

 

As you can see, the max flow of that turbine is at about 2.35 PR, so if at 14.7 psi ambient, it is 19.85 psi relative at the compressor housing, which would be about 1psi lower at the manifold.

 

Therefore, to get the max out of that turbine, one requires a 2.5 liter (about) engine w/ decent flowing parts. A 2.0 liter engine would be at a much higher PR, and would not be able to flow as much air.

 

As you can see, a very good compressor for a 2.5 liter engine, responds well! But 24 psi or something like that at red-line is not going to happen.

 

 

If you were at 2.65 PR at the MAP sensor, that would be about 2.72 PR at the comp outlet, which would indicate a max airflow of about 610 CFM vs 675 or so.

[mwiener2]

$650ish for the side-feed-conversion with rails.

 

then add another $200 for plumbing the rails

[m sprank]

My 68HTA maxed out my 750cc top feeds on e85. I am now converting to 1000cc. 850cc is enough, but why go small again? This way I am set for the future too.

 

Either way a 68HTA on e85 at sea level will cause an 2008 to be unhappy. I HAD to swap MAP sensors to get my boost cut back. Turning off the CEL just stopped the lights. Raising the voltage limit just delayed the lights.

[KurtP]

$650ish for the side-feed-conversion with rails.

 

I have top feeds

[mwiener2]

The ID1000's are some of the best performing injectors I've ever seen. Even the ID2200 (that's over 2000cc's ) idle just fine.

 

I am referring specifically to Injector Dynamic Bosch EV14's and not just EV14's in general.

[KurtP]

Cool.. Do i need a special adapter to make them work in my car? or do they drop right/plug in.