JDM Evo IX MAP sensor group buy
I've got my JDM MAP installed and it's logging via EvoScan v.99, but I'm pretty sure it's giving me some incorrect data. While my GM 3Bar says I'm boosting 23psi, the JDM MAP says I'm closer to 30psi! 
MrFred and I have gone back and forth on this trying to solve the problem, but haven't been able to as of yet. I'm posting this in case others experience the same issue. If this is common, perhaps someone will come up with a calculation routine for the data that's a bit more realistic. Here's a sample from today:
MrFred and I have gone back and forth on this trying to solve the problem, but haven't been able to as of yet. I'm posting this in case others experience the same issue. If this is common, perhaps someone will come up with a calculation routine for the data that's a bit more realistic. Here's a sample from today:
Code:
RPM Load2Byte MAP 1781.25 101.5625 1.74812 1843.75 104.375 1.74812 1875 105.9375 1.74812 1906.25 105.625 2.13498 1937.5 106.5625 2.52184 1968.75 110.3125 2.71527 2031.25 111.875 2.71527 2062.5 115.9375 2.71527 2125 117.8125 3.10213 2156.25 120.3125 3.29556 2187.5 122.1875 3.68242 2250 124.0625 3.87585 2312.5 127.1875 4.06928 2343.75 130 4.26271 2406.25 132.8125 4.843 2437.5 136.5625 5.03643 2500 140.625 5.22986 2562.5 145.625 6.00358 2593.75 149.375 6.39044 2656.25 154.6875 7.16416 2718.75 159.0625 7.74445 2781.25 163.125 8.51817 2843.75 168.4375 9.09846 2906.25 175 10.25904 2968.75 180 11.03276 3062.5 188.75 12.19334 3125 196.875 13.35392 3218.75 204.6875 15.09479 3281.25 214.0625 16.25537 3375 227.5 17.99624 3468.75 239.6875 20.3174 3562.5 255.9375 22.05827 3656.25 274.6875 23.60571 3781.25 292.8125 26.1203 3875 299.0625 28.82832 4031.25 295.3125 29.21518 4125 291.875 29.9889 4250 288.125 28.44146 4375 278.125 28.63489 4500 275.625 27.28088 4625 281.5625 28.24803 4750 285.3125 27.47431 4812.5 287.5 28.44146 5000 282.8125 27.47431 5093.75 282.1875 27.47431 5187.5 281.25 26.31373 5312.5 282.1875 26.1203 5406.25 281.875 26.1203 5531.25 281.5625 25.73344 5593.75 280.625 25.34658 5718.75 278.4375 24.95972 5843.75 274.375 24.57286 5937.5 273.75 25.15315 6031.25 270.9375 24.57286 6125 268.4375 23.60571 6250 265.625 23.79914 6312.5 262.8125 22.63856 6437.5 260 23.21885 6531.25 258.125 21.86484 6625 255.625 22.05827 6718.75 252.5 21.86484 6781.25 250 20.89769 6875 247.1875 21.47798 6968.75 246.25 21.28455
Last edited by Pd1; Apr 24, 2007 at 10:53 PM.
unfortunately my life situations haven't allowed me to get my sensor in and logged even though I modded my rom last week and have everything sitting. I will give it a shot tomorrow or thursday and let you know what I get
It looks to me that the JDM MAP readings are pretty close compared to your load values. Where is your GM MAP located?
As for the load numbers, the IX + FPGreen and Cosworth cams justify those numbers at a much lower boost pressure than logged by the JDM MAP.
Last edited by Pd1; Apr 25, 2007 at 09:26 AM.
I'm using straight Cali 91 octane and there was no more than 2 counts of knock anywhere in that log. It's been my experience, and many others, that anything on this fuel above about 23psi on a stock-ish turbo will result in a very knock-prone condition. This, combined with the readings from the GM 3BAR (tapped at the standard FPR location) make me question the validity of the JDM MAP readings.
As for the load numbers, the IX + FPGreen and Cosworth cams justify those numbers at a much lower boost pressure than logged by the JDM MAP.
As for the load numbers, the IX + FPGreen and Cosworth cams justify those numbers at a much lower boost pressure than logged by the JDM MAP.
An answer to the difference between that sensors would be helpful.
Unfortunately no. Sorry. I'm not datalogging with the 3BAR since I attached the serial cable to my wideband. I'm also not using ECU+ since I bought the IX (different harness). All I've got at this point is the 3BAR sensor and the Autometer gauge that came with it. I was hoping to sell these soon since I've got the JDM MAP installed now.
Thread Starter
EvoM Guru
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From: Tri-Cities, WA // Portland, OR
update
1.joedr: shipped 4/25/07
2.razorlab x2: shipped 4/13/07
3.Andenbre: shipped 4/13/07
4.Ralph: shipped 4/25/07
5.Laakness: shipped 4/13/07
6.Phenem: shipped 4/13/07
7.Max Power: shipped 4/25/07
8.Pd1: shipping 4/13/07
9.fixem2: shipped 4/25/07
1.joedr: shipped 4/25/07
2.razorlab x2: shipped 4/13/07
3.Andenbre: shipped 4/13/07
4.Ralph: shipped 4/25/07
5.Laakness: shipped 4/13/07
6.Phenem: shipped 4/13/07
7.Max Power: shipped 4/25/07
8.Pd1: shipping 4/13/07
9.fixem2: shipped 4/25/07
Unfortunately no. Sorry. I'm not datalogging with the 3BAR since I attached the serial cable to my wideband. I'm also not using ECU+ since I bought the IX (different harness). All I've got at this point is the 3BAR sensor and the Autometer gauge that came with it. I was hoping to sell these soon since I've got the JDM MAP installed now.
Are the both showing the same vacuum readings at idle?
Nope. The JDM MAP is reading -6psi, and my GM 3BAR reads about -13 in/hg. It seems to read high all over.
Hmmm, I know this is a long shot, but on the coding the equation is given as 1.334*x*14.5/100-14.5
Even though this looks like a conversion from kPa to psi (14.5/100), I'm wondering if there's a problem with the -14.5 term. What is the value of x here?
Even though this looks like a conversion from kPa to psi (14.5/100), I'm wondering if there's a problem with the -14.5 term. What is the value of x here?
http://www.convert-me.com/en/convert/pressure
Thread Starter
EvoM Guru
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Posts: 9,675
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From: Tri-Cities, WA // Portland, OR
I don't think I'm missing something here , but -13 inHg = -6.385 psi
http://www.convert-me.com/en/convert/pressure
http://www.convert-me.com/en/convert/pressure
Thread Starter
EvoM Guru
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From: Tri-Cities, WA // Portland, OR
There is still the issue of why its apparently reading high at higher boost levels. It would be great if someone else with a IX could install their sensor to get some data.
