Perry 951

John and I discussed the calibrations for a while now. I'm datalogging the MAF volt out for future chipsets, if needed. I'm not sure what he's done for mapping, but he feels it should be close enough to begin datalogging.

I've had these chips for about 5 months. Unfortunately I've not been able to put them in service. John lives about 20 minutes from me so I hope we'll be able to work together and get enough data for him to provide a good chipset for general use.

toddk911

Let me know when you do

Tom M'Guinn

The ARC2 modifies only the ARM/MAF signal. The ARC2 will affect timing to the extent the DME uses the AFM/MAF signal in calculating timing. If, when and how much the DME uses the AFM/MAF signal to calculate timing is something I've been trying to figure out -- anybody willing to share good data on that?

jimbo1111

It you are able to get the a/f correct than the timing should follow.Make sure you max out the afm signal at your max output that you plan on running with your car. If you are using the 75mm it's much closer to stock and easier to tune with. Just don't use 72lb injectors with afm chips. 48,52 and 55's are easier to tune.

biggles

daniel951,
Do not mean to hijack this thread - How has the Apexi worked for you? I am using one with a MAF from Lindsey, TO4E, 55 lbs injectors and GURU chips and have had a hard time with setting a good A/F and getting maximum power, especially in 2800 - 3800 RPM range as A/F tends to be very lean, Recently added adjustable FPR. Can you share your correction factors.
Thanks!
biggles

toddk911

"Make sure you max out the afm signal at your max output that you plan on running with your car."

Can you explain in more detail?

toddk911

"especially in 2800 - 3800 RPM range as A/F tends to be very lean,"

My understanding, if not TOO lean, is that is ok and will aid in spool up.

I also have GURU chips and TO4E, when do you see full boost?

Also, what is the difference in stages of the Huntley? I have stg 3.

Perry 951

AFM max out should be 5 volts. The MAF max out may only be 4.5 volts. If the highest airflow I see results in an output of 4.5 volts, I (thoretically) have .5 volts of headroom, or lookup tables that won't be used. I'd then need to adjust the signal to make it 5 volts or modify the lookup tables to show a max of 4.5 volts.

The maximum airflow and voltage out for each sensor and motor will be slightly different. (or more than slightly depending on mods) This is where the ARC 2 (or a piggy back) can be used to adjust the final voltage out to make sure the lookup tables are correct.

I've noticed, with the little I've datalogged, my max is about 4.45 volts on the Huntley MAF. I also noticed that I get 88% max throttle opening. I'm currently trying to find out how to get the throttle to open all the way and then find out what my max airflow is.

toddk911

"I've noticed, with the little I've datalogged, my max is about 4.45 volts on the Huntley MAF. I also noticed that I get 88% max throttle opening. I'm currently trying to find out how to get the throttle to open all the way and then find out what my max airflow is."

So with the Huntley MAF we are only getting 88% of the possible performance?

Can the ARC2, or any other piggyback, compensate for this?

I take it this is where the difference in AFM chips and specific MAF chips come into play?

special tool

Perry - the porsche tps s a weirdo (of course) - it only maxes at 4.7 or so.Your datalogger is expecting 5 volts. Could this be the discrepency??

zeitronix had to make special software for this.

kasturbo

ST and BP what does your TPS voltage max out at in full boost? Should it be hitting the full 4.7 volts? Mine maxes out at 3.3 volts and I've replaced the tps. I'm wondering if it is bad wiring.

Perry 951

I was confused when I was seeing about 4.1 volts when my foot was all the way to the floor. I could push really hard and get it to go up, so then I pulled the throttle boot and saw the throttle blade was not opening all the way. 4.7V, give or take .5V, is about the max I've seen holding open the throttle by hand. If I can get under the dash and figure out if I can adjust the throttle cable I should find some hidden power and properly log the MAF out.

Currently I'm logging the following with the WBO2.
WB
RPM
MAF volt out
AFM volt in (after ARC2)
TPS volt out
Temp before IC
Temp after IC
Combined exhaust temp

I will put the following on a dip switch to log on the fly:
KLR boost out (to gauge, simple way to log MAP)
GM 3 bar MAP (to calibrate KLR out)
Knock out (voltage stepped and regulated)
Narrowband O2 (to log agaist WB)

With all this data, we should be able to monitor things quite well and log some comparative numbers for new maps.

Tom M'Guinn

FYI, the KLR boost out voltage is not what I expected -- not a 0-5v signal. It's a much lower voltage that I suspect is a pulse width, but have not had time to confirm.

Perry 951

I've not messed with it much either but thought I'd wire it while I was in there.

Tomas L

I get 3.5 volts and my TPS is almost new. This is from the LM-1 datalogging, I have not verified it with a normal voltmeter, the LM-1 signal could be a little of due to ground potential differences.