So all you're doing is pulling timing? Not making any changes to the WOT lambda for the fuel the o2's will be pulling? Maybe I missed something!
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Cobra Jet Manifold: Nitrous Install **Pic Heavy**
- Thread starter jn2
- Start date
$1,400. This is for everything nitrous I ended up installing
I pulled some timing to prevent KR, this is a must on higher shots, or if you are on a aggressive NA tune(as I was). There is no need to adjust your WOT Lambda, you want to run your WOT fueling at whatever makes optimum power when you are NA. In my case I command .83 lambda all the way to redline.
Since we have factory widebands and the nitrous jets are set up to supply equal amounts of fuel and nitrous there is no changes needed. I did increase my enrichment rate to .100λ/s to help the STFT adjust fast enough should it need to add little extra fuel.
Below is a log of a 4th gear pull on a 100 shot. As you can see fuel trims were +1% through out the whole pull, which is perfectly acceptable and show very little additional fuel was needed for the nitrous.
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Very nice setup.
OK, I gotcha....
Here's a video showing a quick 2nd>3rd>4th pull.
[video=youtube;2CH5VX5yUno]https://www.youtube.com/watch?v=2CH5VX5yUno&list=PLcK0RJ1Dfy7XhKcpsVWxC-tFlpoz3PNT0&index=3[/video]
[video=youtube;2CH5VX5yUno]https://www.youtube.com/watch?v=2CH5VX5yUno&list=PLcK0RJ1Dfy7XhKcpsVWxC-tFlpoz3PNT0&index=3[/video]
Nice vid man and thanks for posting! How much power you think its putting down?
The nitrous and fuel is equally distributed between both banks. If you notice the last row is logging bank 1 and 2 lambda vs commanded. There is an initial lean spike(also equally distributed) when the nitrous first hits, this spike looks long in the log bc i zoomed in a lot, but it only lasts .5-.6 seconds. Once the fuel catches up and starts to spray you will notice actual lambda for both banks vs commanded is within +/- .1λ
The lean spike is due to the nitrous beating the fuel to the plate, since its coming out at 900+psi and the fuel is only coming out at 55psi, it makes it there faster. The fix to this is to run a shorter fuel line. The lean spike is also why you see the fuel trims jump up to +5%, the ECM is using STFT to compensate for the nitrous, once the fuel makes it to the plate the fuel trims only need to compensate within +1/2%(due to varying ethanol percentage in the fuel).
I was just at Nitrous Outlet's HQ this morning and picked up a shorter fuel feed line for this purpose. Right now both the nitrous and fuel lines are 24" from the solenoid to the plate. The new set up will be a 24" nitrous line and a 12" fuel line, this should lead to both reaching the plate at the same time and eliminating the lean spike seen in the graph.
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I have found that a fuel line about 1/3 of the length of the nitrous line works very well. I have a very brief lean spike-- it is very very short and small. It only goes to about .86 Lambda on the spike and for about .1 seconds.
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Yeah a spike that short lived is nothing to worry about, even mine at half a second isn't bad, I just want to minimize it as much as possible. I ended up having to order a new line, the one I got from nitrous outlet yesterday morning was 4an to 3an, well turns out only the inlet to the solenoid is 4an, the outlet is 3an, so what i needed was a 3an to 3an line.
So I had to swap out the previous 12" line bc I actually needed a 3AN to 3AN line, the one I had gotten last time I was at Nitrous Outlet was a 4AN to 3AN.
Here's the new set up. 12" Fuel line, 24" nitrous line. I might rotate the plate so the lines attach from the bottom, i'm not a fan of the way it looks right now.
Here's the new set up. 12" Fuel line, 24" nitrous line. I might rotate the plate so the lines attach from the bottom, i'm not a fan of the way it looks right now.
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Very clean.. How power did you make?
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