i just recently installed a zex kit on my 08 and am curious about a/f ratios.

at around 900-950 lbs of bottle pressure my a/f is around 10.5-11. should i swap fuel pills or nitrous pills? i could go with a little less fuel in the intake to lean it out some and maybe get around 11.5-12 or swap nitrous pills for the same effect and more power. zex recommends pulling 4* of timing on 100 shots or more though. the car runs good now with no detonation but im just curious as to what others are running.

 

For safety, I'd recommend changing your fuel pills to adjust your AFR. However, if you're spraying under 100 shot, then I guess you could try going slightly bigger on your nitrous jets. When you're fine tuning it (and not drastically changing the jet size) using the jets to achieve minor changes in the AFR, it really doesn't matter since you're only moving up or down by small increments, like using a step or two smaller fuel jet, in your example.

BTW, as a rule of thumb, you want to retard 2º of timing for every 50 shot.

 

well will i gain power by switching the fuel pills? zex (as well as what i read on forums) claim the power is gained more from fuel than nitrous. ideally i would like to have an efficient 75 shot setup and then increasing to a 150 shot after i get a dyno tune

 

According to ZEX you're going to need an aftermarket fuel pump when going above 100 shot.. FYI

 

You gain power from fine tuning your AFR, either via fuel or the nitrous. Again, I recommend that you mess around with the fuel jets in the smallest increments possible, even though doing the same with nitrous will yield similar results.

Also, you don't need an aftermarket fuel pump for 150 shot. Many of the nitrous guys have sprayed 150 as-is + a tune.

 

i think thats what ill do. right now im running a .016 fuel jet (if im not mistaken) and i think i have a smaller size in the bag. that would make a nice little saturday afternoon project.

im scared of going over 75 on a stock tune. once i get a dyno tune for the nitrous i will up the shot to either a 125 or 150, whichever the HR motor can hold safely on a good tune

 

Just making sure, you have 2 foggers (both with same jet sizes) on your HR, correct?

 

Quick question, i have a a lean safety switch on my microedge for nitrous. What should i set it at to shut off the nitrous?

 

You want to stay in the 11s ideally, but sometimes you will see some lean spikes. I don't know if Microedge accounts for those, but I'd personally set it around 12.

 

yes. i have one nozzle with a fuel line and nitrous line in each intake. and obviously both intakes have the same fuel and same nitrous pills in each line

this is the kit i have

http://www.zex.com/zx/nitrous-system...trous-kit.html

plus zex's window switch

http://www.zex.com/zx/nitrous-add-on...ml?___store=zx

 

Pardon my noob question but what are these pills?
I just read through the whole introductory thread and I did not see any info. relating to these "pills".

Thanks^^

 

Pills = jets

 

Kkk andthe jets are guna be ur 50 shot, 75 shot, 100 shot, etc. Etc... Correct?

 

The sizes of the nitrous and fuel when matched correctly to your particular application is what determines the size of your "shot."

 

3hree5ive0ero is always so helpful lol

 

to add to the already good info you got from others here, the lean spikes can happen, and usually the system will allow you to set a predetermined time limit to allow for those spikes. for example, if you set the limit to 0.5 seconds and the a/f ratio to 12:1, then once it sees an a/f ratio above 12:1 for more than half of a second, it will cut power. this is how you can allow for the lean spikes.

 

Ok thanks. I was looking into that now. Thanks for all the help guys.

 

My car gets a pretty bad lean spike on the initial activation of the system, but once it's running the a/f's are dead on, same as all-motor with around 900psi bottle pressure. I'm holding upper 11's and the car pulls really strong.