MembersPage/NanassyPeter/Status (2006-01-13 09:52:33)

Looks like I need a different matfactor / thermfactor (and maybe airdensfactor too)!

LCD displays -24..-26C air temp instead of -6 .. -8C

The full vems.hex must be uploaded, but only the first part will be changed, 0x0100..03FF

Do you maybe have new tables ready ?

yes i have new tables ready,but i will have to change the whole thing tough,i realised that for proper everyday use i need more VE resolution on the lowboost section,so i have to change the brake points for the VE table.

any update on these??:

-MAT rescale

-MAT ignition retard

-custom oil temp/pressure gauge with V3.3 and LCD

-5 coil tach?


MAT - airdenfactor - solved a week ago, within appr 3 days after reasonable data was provided

At 0 Celsius the displayed MAT is -16 Celsius. Therefore the ECM enriches appr. 6% (as it should, according to the gas-law), this must be fixed.

We really do not want to hack by raping the gas-law. Instead we fix it the proper way, with proper matfactor and airdenfactor tables. See EasyTherm.

I'll upload a firmware I tested with.

When

This is huge difference (255-201)/(255-231)= appr. 5/2 (*2252 Ohm), so likely your sensor has quite greater resistance than 2252 Ohm.

In this case only this 0C datapoint is just not enough to get good calibration result (it's possible to make it show good at 0C, but we don't want to hide bad readings at higher temp!)

Can you provide another measured data-point ?

Either resistance or temp-reading at known temp.

Should i put the MAT sensor in 100Celsius water??

This would not damage the sensor, the MAT might not be insulated, so it can cheat the measurement.

All i can do is that i put the car in the garage ,where airtemp is approx 18Celsius.

That's nice. Also, at every calibration temp-point (0C and 18C, and maybe 35C when holding in your hand), take note of LCD reading, and preferrably sensor resistance (measured with DVM, sensor disconnected).

The sensor is a regular GM style airtemp sensor,like this one here:

http://www.034motorsport.com/product_info.php?cPath=23_30&products_id=58

Note that these measurements are taken in garage,not in a laboratory,i do not have a special equipment for this,80C measurement was made with boiling water.

Temp in Celsius

Real / LCD / DVM (kOhm) / DVM position / NOTE

0 / -16 / NA / NA /

5 / NA / 5.93 / @20k /

18 / 08 / 4.41 / @20k /

21 / NA / 2.92 / @20k /

35 / NA / 3.17 / @20k /My hand,real temp NA

80 *** / 77 / 0.322 / @2k /HOT water,real temp NA Real temp would be nice, but see below

100 / NA, would be nice / 0.200 / @2k /Boiling water w/ bubbles

The 100C point suggests an appr 3000 Ohm sensor: 200 / 152.75 * 2252 = 2948.60.

From this, we can have a good estimation of the 80C point: 322 Ohm * 2252/2948.6 = 245.93 Ohm for a standard 2252 Ohm sensor, which is appr 84.15 Celsius. This suggests we want +7.2C = +13F at high-temp (so 101C reading ment actual 108C which - if known - would have advantages for the coolant temp, but remember this is all for the airtemp at the moment).


2005-12-31 UPDATE:

tried bot 3000_270 and 3300_270, max MAT increase was 2C with 3300 (from -16C to -14C), but with this i was unable to use MegaTune, because it crashed, i think because firmware version problems ( i used the good one!!).

OK so here you go:

version v3.3

serialnr 312

firmware 1.0.19

Megatune R27

config,tables,vemshex zipped together(renamed,but used with normal original name!)

http://www.vems.hu/files/MembersPage/NanassyPeter/mcd_mct_hex.zip

Your vems_3300_270.hex (btw good name!!) looks bad just after first glance:\nÿ1ÿ

Just copy-paste properly, it's not that hard. On the bad side, this line is responsible for airden at very warm MAT, so not sure it explains all the behaviour.

I tried it again with both 3300_270 and 4200_270.

here the vems.hex files:

http://www.vems.hu/files/MembersPage/NanassyPeter/2006-01-03_VEMSHEX/vems_3300_270.hex

and

http://www.vems.hu/files/MembersPage/NanassyPeter/2006-01-03_VEMSHEX/vems_4200_270.hex

i had no luck with these,if there are still bug in it ,please make me a good vems.hex,this i my best so i cant do it better.

Anyway the symptoms were the same,no MAT reading change after firmware change,

But when you click continue, megatune otherwise works OK ?

This suggests you likely messed up the firmware (used a different one than you intended).

Today i noticed a weird ego thing:

in the lambda table there is 1.00 at idle,and the engines current lambda is approx 1.00-1.04 BUT the ego correction is at -07 - -10.

With ego=+00, lambda would be appr 0.90 .. 0.97, so the direction is right. When lambda is leaner than configured, ego slowly (speed depends on config.ego_pid_kp and ego_lag) moves toward enriching (ego++). It's not the ego correction value (you can get any by configuration) is of interest. But the direction of change: eg. if it's leaner than configured BUT ego keeps climbing down (--), that's suspicious! (shouldn't happen).

Take datalogs if you'd like to evaluate. Trashgrade injector-match (regarding injector-opening : independent of flowrate) especially with big injectors might make it impossible to keep lambda within 1%.

Btw, refer to actually used config if you expect someone to consider the "report". Profanity is no substitute for this.