Carb Jetting w/nitrous

Old 09-01-2008, 08:31 AM
  #1  
jreiley
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Default Carb Jetting w/nitrous

What does the use of Nitrous do to the jetting of the carb? The reason I ask is a car I bought, bbc w/bigshot 400, runs very rich without turning on the nitrous. I don't know what it does with the nitrous on. I broke it on the first pass.
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Old 09-01-2008, 09:38 AM
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hammertime
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I dont richen mine up but a lot of people do its safer for the nitrous to make sure it has plenty of fuel, so I guess the answer is yes most people do this to keep splent of fuel with the big amount of nitrous.
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Old 09-01-2008, 01:24 PM
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jreiley
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Default Carb Jetting w/nitrous

Thanks. What you say makes sense. One other, of probably many, question is the activation of nitrous system. There is a button on the shifter to, I guess, start the flow. Forgive me ignorance, but is this a situation where I have to hold down the button or do I just punch it once to start and again to stop it.
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Old 09-01-2008, 01:27 PM
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dparker
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Originally Posted by hammertime
I dont richen mine up but a lot of people do its safer for the nitrous to make sure it has plenty of fuel, so I guess the answer is yes most people do this to keep splent of fuel with the big amount of nitrous.
J, If you hit the button without the NOS bottle turned on its going to be way rich because your giving your engine fuel with no air.
and if you hit the button with the jet setting from the NOS with everything on youll still be alittle rich. But thats why NOS doesn't break as many parts as some of their competers. Some of the other systems may even put out alittle more power than NOS, but NOS systems are alot easier on parts. Which will help keep you from burning a hole in a piston. If you go any bigger than 300 hp NOS it would be a very good idea to put a vac pump on your engine. good luck
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Old 09-01-2008, 03:07 PM
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dparker
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Default Re: Carb Jetting w/nitrous

Originally Posted by jreiley
Thanks. What you say makes sense. One other, of probably many, question is the activation of nitrous system. There is a button on the shifter to, I guess, start the flow. Forgive me ignorance, but is this a situation where I have to hold down the button or do I just punch it once to start and again to stop it.
No hit the button to activate release to deactivate. You have to have your NOS bottle on first. Its a real good idea to put a micro switch on your carb, that will make it to where the nitrous cant come on unless you activate the button and the carb is at full throttle. If you activate the button while the engine is not running, then try to start it BOOM!! I hate to tell this story, but bout 15 years ago, I had a toggle switch and full throttle micro switch. The only problem was my engine died and I mashed the pedal to the floor to start, thinking it was flooded. Well, I saw a puff of white smoke come out of my hood scoop right before BOOM!! I got lucky it only blew a spark plug out of a Aluminum head. Just be careful and use common sense youll be just fine......
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Old 09-01-2008, 07:20 PM
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us7race
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From the people I know and myself when I used Nitrous you jet the carb for motor and leave it alone....your Nitrous Tune-up is completely seperate. Start out with the recommended jets and sneak up on leaning out the fuel jet and the fuel pressure. VERY small steps and read those plugs!!! JMO

As far as Activation I have always used a WOT switch on the carb.
A safer way to go and 1 less step to do while trying to make a pass.
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Old 10-01-2008, 01:42 PM
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chevyfireball
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You need to set the carb jetting so the car runs well without nitrous. Then set the nitrous fuel jetting, whether its a fogger or plate system. The nitrous fuel has nothing to do with the carb jetting. With a plate it is sucked straight on through the carb to the intake. With fogger its straight into the intake runners. If you want to run a little rich for safety, alter the jets in the plate or foggers, NOT the carb.
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Old 10-02-2008, 08:41 AM
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ARUSSELL
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I have alwayse run my fuel and n.o.s seperate, and never had to richen up the carb. I do run the nitrous rich to be safe but want the engine to run god N/A
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