EMB - MAP Sensor as TPS Input

[HLxDrummer]

Has anyone here done this?

I know somehow with the eManage you can use the MAP sensor for the vertical axis of airflow adjustment maps, but not sure how:

-Only with EMU
-Only with eManage "Gold"
-Only with MAP wired into TPS

I'm pretty sure I don't have gold and I'm not solder anything inside the unit, I definitely don't have ultimate, so I'm considering wiring the MAP sensor into the TPS input of the eManage.

A few issues I need to figure out if doing this:
-I have the harness for the MAP sensor and would like to use it so I can control timing based on boost. So if the sensor is going to the harness AND the TPS, do I just tap into the 0-5V wire and use that also as the TPS input (so it's a 3-way connection)?

-If I use this as the TPS input, will I be able to make the vertical scale in PSI/kpa/etc or will it be throttle percent still?

-How do you calibrate the eManage's "TPS". Normally you just floor it and let off, but I can't really max out the MAP sensor. Do I need to get a 5V battery to calibrate it? If so how would I do this? lol


Any ideas? I just think tuning the airflow map by boost will make the tune more consistent (if you are using TPS, you can be at 100% throttle and 2 psi or 100% throttle and 16p psi - yet it's using the same correction given that your at the same RPM) at consistent max boost levels, not even considering adjusting boost (won't have to constantly adjust tune).

If I can just update the firmware or something and change the airflow map scale that would be great, too.

[Forest Gump]

keithmac has done this, I would pm him.

[HLxDrummer]

Alright, thanks!

Also, if anyone happens to know the jumper settings/etc. to make it work on our cars I would appreciate it. Bought it used and want to double check I got them right.

[HLxDrummer]

Got ahold of him and he gave me a lot of good tips.

He said he just wired his MAP sensor into the TPS input on the eManage.

Now I need to figure out how to calibrate the "TPS" on the eManage. I'm considering just grounding it for closed throttle and giving it 5V's for WOT then scaling the MAP to the pressures I normally see.

Another issue is that the eManage will be converting volts to TPS % although it's really boost. So I'll have no idea what actual boost is. So I'm thinking I'll do a couple of pulls and get the peak readings off the eManage as well as my boost gauge and make a chart for what TPS % correlates with what PSI. Does this make sense?

Do you think this is plausible? Worth it?

I think tuning based on pressure will be a much better tune, but kind of a PITA..

He also said I can adjust the airflow map -40% all the way across and then add pulse width right at the injectors with another map that supports the MAP sensor. Makes sense but I don't know if I want to mess with injector control quite yet.

[Forest Gump]

your best bet would be to just hook your pressure tester to the car and adjust your compressor regulator to the boost you want. Then you can see what each boost point means in volts without having to drive the car at all.

[keithmac]

Can anyone chuck up a volts vs pressure chart for the Greddy sensor?, would make life easier.

[HLxDrummer]

Originally Posted by Forest Gump

your best bet would be to just hook your pressure tester to the car and adjust your compressor regulator to the boost you want. Then you can see what each boost point means in volts without having to drive the car at all.

Ya I was thinking that would work too, thanks for the tip.

I found a link though that has MAP sensor voltage v. pressure:

S2KI - S2000 Forums -> EMU Question, Converting Fuel Map

So if I calibrate the TPS input with ground and 5V's I'll just have to look up what TPS % correlates with what pressure and make a chart, right? Or just do the map trace/log like we were talking about.

Would it be better to use ground and 3.5Vs to calibrate the TPS input since the MAP sensor reads 3.5V's at 30 psi which I'll never get to? Would it give better resolution or anything? Can't think of a way I'd get a controlled 3.5V's besides messing with my wideband output which is a pain though..

[BlackStealth]

Greddy's pressure sensor is 4 bar, I tested this to 41psi or 42 psi about two days ago. I didn't want to accidentally exceed the maximum 43.5psi not knowing if it would damage the sensor or not. The math formula given here works very well. I compared it against a greddy knock off pressure sensor and learned that the greddy pressure sensor is a "gauge type" where it reads 0.00psi regardless where you're located elevation wise. The knock off reads absolute and takes your elevation into play, so unless you're at sea level you'll start off with a negative number.

[HLxDrummer]

Wow, thanks man!

I think I'm going to do this and calibrate it so 100% throttle is around 30 pounds of boost by hooking up my compressor to the vacuum line that goes to my gauges map sensor and my greddy map sensor. Then I'll calibrate 0% throtle by grounding the wire.

I think I'm going to wire it all up and just jump the "signal" pin of the plug and ground it when calibrating and if need be jump it to the 5V supply at the same plug instead of having to solder it all up, calibrate it, then do more wiring.

Thanks so much for that chart man! Very helpful. Once I get of all figured out I'll post up so it can help others in the future hopefully.

[BlackStealth]

Originally Posted by HLxDrummer

.. and just jump the "signal" pin of the plug and ground it when calibrating ...

Grounding the signal may damage the pressure sensor (that's a short circuit).