[david]

So I did some datalogging on my car this past weekend. It was one of those cool nights as well. I did some pulls in 3rd gear. Running 12psi. MSD 50lb injectors at 3 bar and a cobra maf.

It looks as though I'm running out of fuel already. My duty cycle is up near or past 100%. My timing is getting pulled back. Either I am making that much power or maybe my fuel pump can't keep up. Its a Maxima pump which I was told should flow ok, but maybe its not enough.

take a look.

http://www.b15sentra.net/david/12psi.xls

 

[cburwell]

Does anyone actually know what the flow rating for that pump is? I know I tryed looking for some specs on it a while ago and I came up empty.

 

[david]

I'm starting to think its only good for 280whp and I bet I am pretty close to that. Sounds like I may need to put a walbro in there.

 

[cortrim1]

you know its not the injectors. they are good for 350whp on the 3 bar program. how did you end up with a maxima fuel pump? I have heard of using a z32 fuel pump but I have not seen anyone use one of those

 

[cburwell]

I think the disco potato actually used the Maxima fuel pump.

 

[david]

Yeah someone had a stash of them laying around. They drop right into our fuel tanks. I had a discussion with Clark and he didn't seem concerned with the pulse width. I did some more logging last night but either it wasn't as cool or my dataset was just too small as my injector pulse was much lower and maf voltage was much lower.

I'm a little concerned about the pump though. Last night I checked the voltage drop too it and it seems ok. My battery voltage is low though. I am only reading like 13.6 volts. Part of this may be only driving the car for a short time here and there and the fact that small hawker battery may not be putting out that much output.

 

[david]

Here is another log to look at....


http://www.b15sentra.net/david/12psi1.xls

Pay no attention to the mph.

 

[david]

yeah the mph is actually km/h even though I told it to do mph.

So I guess I'm overreacting about the pulse width. Its actually not running out of fuel as you can see my O2 voltage is actually kinda rich.

 

[sr20boston]

I will definitely be doing this in my car as soon as I figure out my headlight power issues. I was working on them a bunch this afternoon but need to power them with a higher gauge wire. Either way, I'm curious what my readings will be adding S3 cams and a fuel pump. I got my consult box back and will track down a laptop tomorrow.

 

[cburwell]

David,

The consult clone that you have (The homemade one), will that work with the stock B15 ECU?

 

[sr20boston]

The consult clone that you have (The homemade one), will that work with the stock B15 ECU?

The connector changed in 2000, so it'll work up until then. I have a 2000 B15 SE and it doesn't work.

 

[cburwell]

The connector changed in 2000, so it'll work up until then. I have a 2000 B15 SE and it doesn't work.

Screwed again!

 

[david]

They changed the protocol in 2000 as well. Chris you have the option to use generic OBD II loggers though. There is no special hardware needed. You can buy off the shelf stuff.

 

[cortrim1]

They changed the protocol in 2000 as well. Chris you have the option to use generic OBD II loggers though. There is no special hardware needed. You can buy off the shelf stuff.

they work pretty good too. the only problem I found is that the sample rate is kinda low and if you are using the palm compatible version you will be limited to the amount of ram your palm has(data logging)

 

[JohnO]

What was your A/F ratio dunring that time. Looks like you may have had slight knock and ECU reacted by dumping fuel and pulling timming .... Then again im sure you guys have already looked at it im just floating stuff out ...

 

[david]

I don't have a wideband so I have no way of knowing. Those are just logs from street driving. Based on the narrowband O2 voltage at WOT it shows I am running more rich though. The way the ecu is programmed when it gets close to a high load it dumps a lot of fuel and the timing usually dumps down to around 10 degrees of advance or so. The only time you will see it lower is on deceleration. You can tell that because my WOT TPS voltage is 4.22

 

[JohnO]

AHHH so 4.2 is the magic number ... and you never really pulled timming once you reached 4.2 so i can imagine that there was no knock.

Usually the narrowband while not very accurately will read to about 12:1 before it goes out of scope.. i diDnt know if your pseudo concult was able to read it .. lol

Is this a stock ecu or a JWT that clark programend??? ..

 

[david]

You really think I would run a stock ecu?

its a JWT ecu.

 

[JohnO]

i figured not but hey i have to ask can't assume ...lol... well i wonder what the maps are at in that range ..