Obike

That is not lag. That is the ECU control strategy saying that at the current load levels, the amount of throttle you are requesting (WOT) will actually do nothing to improve performance and will be a detriment. Therefore the ECU will wait until load levels increase to the point that the requested throttle actually justifies the further opening of the throttle body.

Lag is the amount of time it takes from the moment the beginning of an event occurs to the the moment that event is detected. In this case the ECU sees the change in requested throttle, and then when conditions are met actually modifies the amount the throttle body is open.

You can change the system, for $10 in parts, to behave like a direct-cable system. But you will see no increase in power or efficiency, and will actually measure a loss.

crush02342002

iTrader: (2)

and why do you think the ecu "stratagy" is the way it is....perhaps cause its a dbw system (amongst other reasons)

why is it all the cable systems out that i have ever driven has better response than the tc. the response i am talking about is the amount of time it takes from the time i hit the gas till the engine's rpm increase...this is what most might consider lag...you can very very easily compair a dbw car and a cable car..no butt dyno involved...all dbw cars that i have heard of have this "lag" that is worse than cable cars.

perhaps this "lag" in dbw is for a good reason but some just want to get rid of it.

stevejohns29

so this thread wasn't about if drive by eire lag exsisted.. cause we all know it does.. casll any real tuner and they will tell you.. it was about if its the condition I have..

now if anyone has any useful info.. please chim in.. thanks!

aen

DBW lag does NOT exist.

any real tuner? wat about asking mechanical engineers or real mechanics or whatnot.

if i recall correctly, obike has more experiance in this stuff than all of us combined.

the moment from the signal of the throttle to the actual command of the throttle movement is less than a millisecond. seriously.

are you guys electrical majors or anything?

Obike

I already gave you the answer, if you want to ignore it then that is your perogative. You also didn't answer any specific questions I asked about your BOV/MAF setup.

crush02342002

iTrader: (2)

easy hieu...lol

im just looking at it through compairison....the time it takes a cable system to respond compaired to dbw....all im saying is that from my experiance ther IS a difference between the two. Im not saying Obike is wrong but perhaps we are looking at it through different eyes so to speak.

crush02342002

iTrader: (2)

sorry aen i though you were talking to me....lol...

stevejohns29

im sorry for the short post earlier.. on my phone. .. my bov isnt recir.. never had a problem with it until the boost increase.(went from 5 to 10 psi) and my maf in on my intake. However im tuned off a greddy pressure sensor.

what i was saying about the tuner was.. call Paul from Dezod. He has seen and dealt with the drive-by-wire lag and is the one who told me that it was my problem. I was just double checking to see what other people thought. Also Rob from Descendent has dealt with this problems (considering they even make a controller for it) I was looking for feedback on if anyone has used these controllers or have had similar problems to mine.

crush02342002

iTrader: (2)

I dont think it "bypasses" the ecu but does something to the signal (or voltage if you will). Rob from decendant posted a sorta scematic of it.

stevejohns29

yeah sorry i deleted that post cause im trying to do more research on the controller itself. From what i see the stock setting are obviously tuned for fuel efficiency not for racing.. the controller allows for a more instantaneous response by taking the fuel economy out of play. Im trying to find Robs write up but i cant seem to find it.

crush02342002

iTrader: (2)

no wonder i was trying to find it and couldnt...lol

stevejohns29

ima call a couple tuners tomorrow. and my one friend whose and electircal engeenier ( has a subie making 600 whp) to see if they can shed any light .. ill post an update tomorrow.

scikotictc232

would an aem ems a cure for this ? I went to race wars this weekend and there was a few evo's and stis that were running those controllers. why do they have so many controllers for dbw lag if it is not part of the dbw system ? there is not one car that is dbw that has as fast as response as a cable car.

scikotictc232

http://www.sprintboosterusa.com/c-256-mt.aspx

stevejohns29

i agree.. ive heard of alot of cars running them.. just no one i personally know to ask. s2000s, 350z, Evos. STIS. alot run them.

stevejohns29

looks like blitz also makes one.. it shows a graph showing how it opens the throttle ..

http://www.jscspeed.com/universal/el...controller.htm

scikotictc232

if those controllers are junk than why are so many guys running them ?

Obike

You are dumping measured air, which is what causes the car to fall flat on it's face. It has NOTHING to do with DBW. That means the sensors, which is expecting a certain air/fuel ratio, will see the car run pig-rich and so it will lean it out. It'll then see the lean condition and then richen it back up, etc etc etc. Your A/F will yoyo around until it finally settles down.

So, here's the solution. Recirculate the BOV, switch to a DV/BPV, place the MAF after the BOV, or go with a stand-alone ECU that is map-based (Hydra, AEM, Bosch, Motech, etc). The sensor you tune off of means nothing in this case, as a piggyback is only altering data from the primary ECU. So when the primary ECU freaks out and tries to correct something, the piggyback is only along for the ride and only can do so much. There are ways you can TRY to fix it, but they are band-aids. The solution is what I've posted.

Get the recirculation fitting, get a weld-on 1" NPT fitting, then get a 1" hose-barb to NPT adapter. You will then use 1" silicone hose back to the intake AFTER the MAF. Voila, problem solved.

Again... nothing to do with DBW here.

stevejohns29

instead of doing all of that.. if i just would go with a WOT box, wouldn that fixmy problem? Considering your blow off wont fire if you never lose boost?

aen

a whole ballload of people are also running turbonators and shop at autozone.