Nitrous Oxide - my buddy finally sprayed and wow afr=10.9????




aug181983
06-03-2009, 01:05 PM
my buddies car and a wet kit when he finally sprayed he watched the wideband and while in it, it went to 10.9 and thats rich but good by the means. But still very rich what can he do to make it run a little leaner like low to mid 11's on the afr. i found some other thread but didnt make sense to me about downsizing the fuel jet or so. im a little lost :confused: can someone tell me how to make his car run a little safer. o yea he has a 255 pump and 36# injectors on this wet kit..


camscam02
06-03-2009, 01:22 PM
go down on the fuel jet size. watch your timing though.

Jon5212
06-03-2009, 01:30 PM
Tune it?


aug181983
06-03-2009, 01:31 PM
i have a 685 box to pull timing, say i have a 33 in there now what should i go down too. what shall the afr be after going down say 1 jet size to a 32???

krazy4
06-03-2009, 01:37 PM
There is a number on the fuel jet. Go with a jet that has a lower number, therefore adding less fuel.

Pretty easy concept lol.

aug181983
06-03-2009, 01:45 PM
well i know that im just making sure, but does anyone how much it will lower the afr if i go down 1 size? or is there a website i can check even?

thanks

ShiznityZ28
06-03-2009, 02:04 PM
What is the nitrous jet size?

aug181983
06-03-2009, 10:15 PM
sorry the nitrous jet is a 35 and its a nx kit. i also have a 33 jet but is that to small now?

tripblackls1
06-03-2009, 10:26 PM
up your bottle pressure some instead of changing the jet

gregrob
06-04-2009, 12:04 AM
You can see what the fuel pressure is and maybe play with that too if you have an adjustable fpr. A lot of wet kits are rated at stock fuel pressure and if you are running higher, or even at the higher end of the stock range, the fuel jet will flow too much and throw the AFR off like you're seeing.

See where your fuel pressure is and go from there. Like was said you can up the bottle pressure too if it's low. I'd shoot for 950-1000 in the bottle

camscam02
06-04-2009, 01:27 AM
no need to up bottle pressure. doing that will cause it to drop more severely in most cases. too many variables.900 is fine

best bet is to change jets and adjust timing accordingly while reading plugs. but what do i know...

ATVracr
06-04-2009, 09:13 AM
no need to up bottle pressure. Doing that will cause it to drop more severely in most cases. Too many variables.900 is fine

best bet is to change jets and adjust timing accordingly while reading plugs. But what do i know...


x2 :)

camscam02
06-04-2009, 12:02 PM
x2 :)

YES! im learning im learning. haha :D

robsquikz28
06-04-2009, 01:15 PM
i pm'd the dude telling him i had a .34 nitrous jet for sale and at the same time he told me his fuel pressure is 48 and its on a Lt1 motor, he has the motor done up he says,
so he using the factory line pressure specs given from nx for his jets, so he will have to definately go down atleast 1 size to accomodate for his rise in fuel pressure.

ShiznityZ28
06-04-2009, 02:15 PM
with a .035 nitrous at 48-52 fuel psi you should be .020-.022 on the fuel jet. but you will have to look at the plug.

bjamick
06-04-2009, 04:55 PM
I believe he's running a .35F jet not N. If you want to lean it up a tad just put in a bigger nitrous jet :D. One way or the other, either smaller fuel jet or bigger nitrous jet will lean it up. Just keep an eye on the wideband and watch your timing. Get it around the 11.8-12.2 range should be pretty safe on the A/F.

Ray@Nitrous Outlet
06-04-2009, 05:16 PM
I would not go up on the nitrous jet....only down on the fuel ;)....unless you want to make more HP. I am assuming you are running a .062N jet and shooting for a 150HP gain.

ShiznityZ28
06-04-2009, 07:10 PM
if its a 62 N a 35F is to big 32 or so. depending on plugs.

aug181983
06-04-2009, 09:25 PM
I would not go up on the nitrous jet....only down on the fuel ;)....unless you want to make more HP. I am assuming you are running a .062N jet and shooting for a 150HP gain.

you are correct its a .62N and a .35 fuel jet....and thats what the card says for a factory 58psi Ls1 engine...now this kit was on his Lt1 before with 30# injectors and the afr was a 11.7, now he did a few other things and runs 36# injectors and on the fuel pressure gauge it shows 48 psi....and the same kit with same jets runs a 10.9 afr.
So what size Nitrous jet to go smaller with now since the closest thing i have now is a .32N jet, or get the .34N jet and be good.

camscam02
06-04-2009, 10:54 PM
.032 would prolly be good. might even need lower. depends on the plug. how much timing is pulled?

aug181983
06-05-2009, 02:19 AM
well as of right now 6* is being pulled for safety reasons and the plug being used is a autolite ar93 i believe its like the tr7 but its a non projected tip. so a .32 should be good huh

bjamick
06-05-2009, 03:01 PM
well as of right now 6* is being pulled for safety reasons and the plug being used is a autolite ar93 i believe its like the tr7 but its a non projected tip. so a .32 should be good huh

We don't know if the .32 is good. You need to just take a few jets with you to the track and let the plugs tell you if it's the right jet or not.

Ray@Nitrous Outlet
06-05-2009, 03:29 PM
We don't know if the .32 is good. You need to just take a few jets with you to the track and let the plugs tell you if it's the right jet or not.

+1 :nod: