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Fogey
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4,298 Posts
Discussion Starter #1
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
 

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Fogey
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4,298 Posts
Discussion Starter #3
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.
 

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Fogey
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4,298 Posts
Discussion Starter #6
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.
 

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Fogey
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4,298 Posts
Discussion Starter #8
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.
 

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1998ccs of fury
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10 Posts
I will definitely be doing this in my car as soon as I figure out my headlight power issues. :eek: 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. :)
 

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1998ccs of fury
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10 Posts
cburwell said:
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.
 

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Fogey
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4,298 Posts
Discussion Starter #13
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.
 

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Boost Addict
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3,414 Posts
david said:
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)
 

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Casual Lurker
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2,135 Posts
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 ...
 

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Fogey
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4,298 Posts
Discussion Starter #16
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
 

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Casual Lurker
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2,135 Posts
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??? ..
 

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Fogey
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4,298 Posts
Discussion Starter #18
You really think I would run a stock ecu? :p

its a JWT ecu.
 

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Casual Lurker
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2,135 Posts
i figured not but hey i have to ask can't assume :D ...lol... well i wonder what the maps are at in that range ..
 
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