MalibuJack

iTrader: (5)

Okay.. In the process of calibrating my blowthrough MAF, I hit 3004hz and the ECU is correctly processing it and associating load with it..

I thought you guys would get a kick out of hearing that.. This was at 20psi and 6919rpm.. I have to do some more work calibrating the curve since I have normal values up to that point now..

Anyway.. look at the capture, its just amusing..

FWIW I'm working on an ignition problem right now, hence the reason its not resolved yet..

Mad_SB

iTrader: (8)

Nice,

I see you are using the new beta software since you are logging vacume as well as boost huh?

MalibuJack

iTrader: (5)

Ahh, yeah thats right, I just noticed that..

MrEvilEvo

thats a dope program i was thinking about using it but wasnt to sure on how it works.

MalibuJack

iTrader: (5)

I do all of my logging using an ECU+.. the software is part of the package.. I use it along side evoscan since evoscan (and logging from the ECU lets me calculate load, but has other serious drawbacks)

RazorLab

iTrader: (8)

ECU+ is the best thing I have bought for a car since I got my drivers license many many moons ago.

MalibuJack

iTrader: (5)

I didn't post the evoscan logs, only because their not very useful (or offer anything other than the load cells it falls into) but at 3000hz the car was indicating the 320% load site at around that point.. Obviously very high for 20psi, but a good indication that the ECU can handle the output without a problem. I'm curious if a stock meter even reads 3000hz or higher though.. I have not yet been able to get it to read accurately over 2500hz without it jumping all over the place.

dan l

iTrader: (3)

When the stock meter stops registering, you know it! Its called MAF over run and early DSM's know it well. What usually happens is the Hz signal drops to 0 and then starts registering again. Due to the design of the meter the karmon vorticies are not produced avove a certian flow level and can't be picked up by the sensor. The car will lean out, IPW starts getting choppy, and inevitably the knock sensor saves your ***. Its kinda like fuel cut but a little less violent.

DCSilvrEvo

iTrader: (5)

Thats crazy! Thats wassup...

C6C6CH3vo

iTrader: (9)

That's quite a volume of air and load for 10.0 A:F, 20 psi, and 13+ degrees at 6900RPM

MalibuJack

iTrader: (5)

I am already aware of this which is why I do not use a stock MAF.. What I was curious about was what the highest anyone has seen it read before it succumbed to overrun.. The stock meter never read over 2200hz in my experiments before the airflow became so disrupted that it was useless... But others have had some level of sucess over 2500hz..

MalibuJack

iTrader: (5)

Yep, the blowthrough meter has a weird calibration that I'm working with, if I use 45hz at idle, the ramp is steeper and faster than 37hz.. Both get my fuel trims in check, but the difference at idle means a drastic difference at higher rpm, so I've been going through and finding the best value (37-40hz so far) and now I have to rescale my injectors so the AFR's again are fairly close to the fuel maps.. THEN I can lean it out in the maps and the car will have good drivability..

The reading is artificially high at the moment, but I posted the image to illustrate that the limitation is the MAF and not the ECU, the ECU will function correctly at over 3000hz and therefore you can tune a 600+ whp car with a stock ECU... Not only that but the ECU can handle 1600cc injectors, since the injector scaling value is arbitrary and doesn't reflect the injector size all that well once you go over 780cc's you can find a workable scale and latency setting for nearly any injector.

dan l

iTrader: (3)

The only thing I can think of to watch for is an injector cap like on 1g and 2g ecu's. At a certian gram/rev the ecu in the DSM's would clamp the calculated load and your fuel injectors would flatline.

Ackerson

I'm a Dsmlink user and it's a common upgrade for us to use the Evo maf sensor. It will accurately measure about 25% more airflow before it overruns, compared to a 2g Dsm maf sensor. That's usually around 3000-3400 hz. As for the ecu, the 2g Dsm ecu will handle about 7800 hz while still putting out correct IPW's. I would think the Evo ecu would be similar.

I don't know much about how these things work but I know with all of the advancements made by the Yahoo DSM ecu usergroup, and the Dsmlink guys they have the Dsm ecu's figured out pretty well. Hopefully the same thing happens with the Evo ecu in the next couple years.

There are a couple of Dsmlink powered vehicles running 9 flat in the 1/4, one of them on really low boost(around 25 psi). So the people that say these stock ecu's aren't capable, don't really know what they're talking about. At some point you guys will have the code all figured out and everything will fall into place.

dan l

iTrader: (3)

Here is a picture of what the injector cap code will do. As you can see the IPW just flatlines at 17.435ms. Oh yeah, and that knock is real.