How much nitrous for a stock piston?

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I have jets # .063 and .072, for nitrous and fuel respectively, I chose a .072 instead of .071 to richen it slightly for safety, in a small engine. I got the system from a guy who ran it on a stock 302. But I assume you are saying it will frag my 318, I can always go pick up a .055 for the juice and run the .063 on the fuel side, should give me 125, right? Or should I go down to 100?
 
I have ran it on a higher compression engine with cast pistons.

1. Engine needs to be in "Known" to be good condition.

2. You can NEVER have detonation.

3. You can NEVER go lean.


If you can guarantee the three above you should be ok until the tranny or rear end blows.

With nitrous if you go lean or detonate it will "F" things up so fast you will never shut it down in time to save anything.
 
I have a dedicated fuel pump for it, and the engine is in excellent condition. Very very good. I have holley strip annihilator ignition, but the only retard function is startup retard up to 20*. I have the rpm switch set to kick it on at 3400, I wonder if an msd boost timing retard would mess up my holley ignition, I have a second rpm switch I don't use. In the manual for the ignition it claims using any ignition product other than holley with it could blow it up. I would want it to drop 5 or 6 degrees.
 
LOL, I never ran any "controlling" stuff (didn't really have it)….. But this was YEARS ago….

All I had was a micro switch on the carb that turned on the spray at wide open throttle. This was a 125hp shot on a 396 though with 10.25 compression.

I think you will be ok but Im far from an expert.
 
My concern in if my timing is at 4* btc it will be a bit sluggish off the line, not rev as hard. I want it to retard in conjunction with the nitrous, as the fuel pump kicks on. I'll have to figure that part out.
 
You are asking questions beyond my experience.

I just ran a "t" in my fuel line after my mechanical pump for the fuel side…..

Looking back…. Im probably lucky I didn't blow it up.
 
I'd rather go lean than rich. Lean, it will pop/backfire and shut off. Rich it will run til the ring lands/pistons come apart. Neither is a god situation.

The tunes in most kits are usually pig rich.

Try to figure a way to retard the timing when the juice is in use. You need to learn how to read plug really well when trying to tune for juice. Or get a wideband reader and learn to tune with that.

If you have too much timing, the electrodes usually start to burn up.
 
with that little amount of compression i wouldn't retard the timing at all. exemple, my 7-1 ratio 440 i had 2 150hp stages and 1 250hp stage and didn't retard the timing any. didn't ever hurt anything. you only need to retard when you have high compression. the trick is getting max cylinder pressure several degrees after tdc. read your plugs, yor looking for small flecks of aluminum, use a magnifying glass to see them. msd makes 2 different timing retards that i have used for nitrous. 1 is a single stage the other 1 is 3 stage. like cracked said rich is BAD and is how the stock jetting is set up from the factories, especially the nos brand. youi won't hurt the motor with the stock jetting but you can if you richen it up pass the stock stuff. lean it out by adding nos jet not by taking fuel from it.
 
I dont think 150hp is a problem. I've run 175 on a stock 318 and a stock 383 with no issues, and no dedicatef fuel system. It's not the safest, but it worked. If you are serious about running nitrous and plan to in the future, invest in a progressive controller. It will help you here, and be expandable later. You dont need to pull a lot of timing out and I don't think there's any need to mess with jetting. I pull fuel pressure out normally. The 175 kit I had a steady 4.5psi on it because 6psi ran it way rich like Bob mentioned. If the car feels lazy, that's what the bottle's for. I used to hit it in 2nd with a stick but with an auto, right off the line.
 
I agree that you may not need to pull out any timing, but if i was you i would...depending on how much of a shot you want, lets say the 150, id retard about 4-6 degrees...it probably wont need this, but its better to do this, read the plugs, and then advance it from there if need be...the key to having your motor live is all in the tune and the only way your gonna know is by getting REAL good at reading plugs...remember when you read them to shut the motor off right after the run, otherwise it will not be accurate

oh and a window switch will definitely be your friend, so i would invest in one no if's and's or buts about it....what kind of pump are you using as the dedicated pump?
 
1968FormulaS340 said:
http://www.youtube.com/watch?v=0jCr8QSGYss
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LOL!!!

I had a nitrous backfire in my dakota that gave me a new custom hood scoop, blew my intake sky high, froze time, and turned every head in my direction for a mile...including the entire local mustang club.:angel9:

That was the day I shot MY eye out. So this post gave me some extra LOL.
Was one of the most embarrasing days of my life.

I think if you build the power into the motor and do it right, (and you can!) you dont need it.
This is what I am currently doing with 2 motors right now.

No more of that crap.:angry7:

But would you believe that 360 still runs?
best of 12.55 at 105 in a 4500lb truck.=P~

Now i am going to beat that time n/a.
 
I have a holley ignition with rpm window switch. The fuel pump is a mr.gasket electric 4.5-7 psi unit. None of which matters at this moment, cause I just found cracks in my cam bearings and if I'm not mistaken that's a sign of a cracked block. I am not happy.
 
stroker mike said:
I have a holley ignition with rpm window switch. The fuel pump is a mr.gasket electric 4.5-7 psi unit. None of which matters at this moment, cause I just found cracks in my cam bearings and if I'm not mistaken that's a sign of a cracked block. I am not happy.
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did you see any cracks in the block?
Surely if you saw them in the bearings, you would see them in the block too without too much effort.
 
stroker mike said:
My concern in if my timing is at 4* btc it will be a bit sluggish off the line, not rev as hard. I want it to retard in conjunction with the nitrous, as the fuel pump kicks on. I'll have to figure that part out.
Click to expand...

You need to pull timing, it WILL NOT be sluggish, always remember that N2o is not flamable, its just "oxygen" in a bottle, think of it as changing Altitudes from say 5000ft. too sea level, there is alot more "air molecules" at the lower Alt., you then need "less" timing & more fuel, this is basically how Nitrous works, but to much higher extreams, i play it safe anymore, i'll list the bare minimums that i run to be safe, N2o can be fun, but it will add up.

Bare safety:

Bottle heater/warmer (you NEED to maintane a propper bottle pressure to benefit)

Window switch: This allows the control of when you want the nitrous to come "on & off" in any given RPM, this is a cool device to have.

Bottle pressure gauge: a no brainer.

Dedicated fuel system: Wether its a 100 hit, or 200, it is always a good idea to do this so you can program/maintane propper flow for the plate.

Propper plugs: Its always best to drop at least 1 heat range colder, even on 100/125 shot, along with narrowing up the gap to around .032", now if you go with a higher like 150-200, i'd drop 2 heat ranges.

Propper fuel/octane: As you know, pressures in the cylinder dramadically increase, so it never hurts haveing a higher octane for the N2o.

Rev. limiter:, this is just incase something lets go in the drivetrain, you already have your "window switch" to kick off the nitrous, so it still won't be "spraying" when its on the limiter & of coarse you won't over-rev & spin a bearing.

PULL timing accordingly!!

Play it safe & nitrous "can" be your friend. My 2 cents.
 
JoeDust451 said:
You need to pull timing, it WILL NOT be sluggish, always remember that N2o is not flamable, its just "oxygen" in a bottle, think of it as changing Altitudes from say 5000ft. too sea level, there is alot more "air molecules" at the lower Alt., you then need "less" timing & more fuel, this is basically how Nitrous works, but to much higher extreams, i play it safe anymore, i'll list the bare minimums that i run to be safe, N2o can be fun, but it will add up.

Bare safety:

Bottle heater/warmer (you NEED to maintane a propper bottle pressure to benefit)

Window switch: This allows the control of when you want the nitrous to come "on & off" in any given RPM, this is a cool device to have.

Bottle pressure gauge: a no brainer.

Dedicated fuel system: Wether its a 100 hit, or 200, it is always a good idea to do this so you can program/maintane propper flow for the plate.

Propper plugs: Its always best to drop at least 1 heat range colder, even on 100/125 shot, along with narrowing up the gap to around .032", now if you go with a higher like 150-200, i'd drop 2 heat ranges.

Propper fuel/octane: As you know, pressures in the cylinder dramadically increase, so it never hurts haveing a higher octane for the N2o.

Rev. limiter:, this is just incase something lets go in the drivetrain, you already have your "window switch" to kick off the nitrous, so it still won't be "spraying" when its on the limiter & of coarse you won't over-rev & spin a bearing.

PULL timing accordingly!!

Play it safe & nitrous "can" be your friend. My 2 cents.
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hit it on the nose!!! and all i can say is READ the plugs constantly, they will tell you everything! too many people are scared of nitrous or have had bad experiences with it per se whether they overjetted the motor till it was alot of extra power, or because the tune was horrible...learn to tune and you'll probably never want another power adder
 
I will add this, back in the day (80s), i would T off & run a mech. parts house fuel pump on my 360 dart sport, ran the good old 125 power shot system, never pulled timing, no heater, no anything, just the kit, with that 125 hit (god knows what the bottle pressure was at), i dropped a solid 3/4 & 7-8 MPH on ET, i thought that was good (this was back in south fla), fast forward to my 97 6sp. Z28, i decided its time to do it right, i found a good used NX 300 hit kit for 400.00, it had everything, purge, new NX heater, blow-down tube, big noids, you name it, i ran a 100 shot to start off slow, got a window switch, max timing was 28* (4* pulled) from factory tuned setting through the computer, off the bottle it ran 13.4/13.5 @ 100/101 on 2.00 60fts. consistantly, on the bottle, after my 3rd. pass (working on the launch), it ran a 12.01 @ 115 on a 1.81 60ft., there was an 11.8 in it i'm sure, so this is why its very important to do this stuff right the 1st. time & keep everything in tune, i dropped almost 1.5 seconds & 15 MPH on just a meesely 100 shot, bottle pressure was at 950 in the lanes, had the window switch set for 3000 (on), 5600 (off), shifted at 6000 (so it wasn't always on the nitrous through the run), launched on that 12.01 pass at 2500 & it got into the nitrous early.

oh, get a purge kit too.
 
JoeDust451 said:
I will add this, back in the day (80s), i would T off & run a mech. parts house fuel pump on my 360 dart sport, ran the good old 125 power shot system, never pulled timing, no heater, no anything, just the kit, with that 125 hit (god knows what the bottle pressure was at), i dropped a solid 3/4 & 7-8 MPH on ET, i thought that was good (this was back in south fla), fast forward to my 97 6sp. Z28, i decided its time to do it right, i found a good used NX 300 hit kit for 400.00, it had everything, purge, new NX heater, blow-down tube, big noids, you name it, i ran a 100 shot to start off slow, got a window switch, max timing was 28* (4* pulled) from factory tuned setting through the computer, off the bottle it ran 13.4/13.5 @ 100/101 on 2.00 60fts. consistantly, on the bottle, after my 3rd. pass (working on the launch), it ran a 12.01 @ 115 on a 1.81 60ft., there was an 11.8 in it i'm sure, so this is why its very important to do this stuff right the 1st. time & keep everything in tune, i dropped almost 1.5 seconds & 15 MPH on just a meesely 100 shot, bottle pressure was at 950 in the lanes, had the window switch set for 3000 (on), 5600 (off), shifted at 6000 (so it wasn't always on the nitrous through the run), launched on that 12.01 pass at 2500 & it got into the nitrous early.

oh, get a purge kit too.
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some great advice your giving him joe!
I will add that dynotune makes a great bottle heater for only 99 bucks, and that a purge kit is a good idea too...some like to purge through the motor, but i think its better to do it with the line...just make sure you dont put on a huge purge show so that the bottles start dropping in nitrous and pressure like crazy- thats gay lol....cold fusion makes a nice and affordable purge kit, might wanna check out before going to a NOS or NX brand solenoid (there all from the same company anyways the noids)
 
mshred said:
some great advice your giving him joe!
I will add that dynotune makes a great bottle heater for only 99 bucks, and that a purge kit is a good idea too...some like to purge through the motor, but i think its better to do it with the line...just make sure you dont put on a huge purge show so that the bottles start dropping in nitrous and pressure like crazy- thats gay lol....cold fusion makes a nice and affordable purge kit, might wanna check out before going to a NOS or NX brand solenoid (there all from the same company anyways the noids)
Click to expand...

I picked up a used NX system for 200.00 last month from a guy close to me, it has the big noids (checked them & there good), bottle, lines & nozzle for EFI, i'm looking at a plate kit from (yeah i know) Procomp for 59.95, it has a 40 hole spray bar, bottle brackets (which i need), 8 jets, braided fuel line & fittings, i'm alittle leary because its from Procomp, but maybe its not so bad.

Thanks for the heads up on the other stuff, i'll look into it, because NX heaters are 200.00.
 
JoeDust451 said:
I picked up a used NX system for 200.00 last month from a guy close to me, it has the big noids (checked them & there good), bottle, lines & nozzle for EFI, i'm looking at a plate kit from (yeah i know) Procomp for 59.95, it has a 40 hole spray bar, bottle brackets (which i need), 8 jets, braided fuel line & fittings, i'm alittle leary because its from Procomp, but maybe its not so bad.

Thanks for the heads up on the other stuff, i'll look into it, because NX heaters are 200.00.
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i dont know about procomp man, they seem a little shaky lol...for the money it doesnt hurt to try, but then the question is what if something happens to the motor?? either way though goodluck...and yea check out that heater, its the best one ive found for the price without paying name brand stuff
 
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