I'm considering getting a 125hp Nitrous kit. I've never used one nor do I know anyone that has one. My understanding is you only hit the button under WOT conditons. Being I'm useing a 4-speed is fourth gear the only gear I can use it in? I'm thinking that if you try to shift gears with it on your find parts everywhere. I'm running a 3:73 gear and I'm also thinking if I run it at a 1/4 mile strip once in a great while I'll never get out of 3rd gear. This car will see mainly street use.

You can use it on every gear. But use it only on WOT.

start with a smaller amount of N20

You say I can use it in any gear, but what happens when I want to shift from say 3rd to 4th. Won't the RPM's go out of sight? Plus how can you shift at WOT?

The best bet is to run a window switch with a WOT switch. Have the window switch hi side set a couple of hundred rpms less than your rev limiter rpm..experment with the low side chip..so you can have traction out of the hole and on shifts

Like I said I've never run Nitrous so I need a little hand holding here. What is a window switch? Also I don't have a rev limiter. This is a street car.

Looking at your website, I wonder if a Saginaw tranny is going to hold up in your car. I would also get a rev limiter, even without the nitrous. Most nitrous kits come with a WOT switch to only permit the operation of the nitrous at WOT. You can also install a clutch switch, to only allow the nitrous at WOT with the clutch pedal up.

That's interesting. As far as the saginaw goes I ran this tranny when I was running 13.5:1 and a 305H 575/575 cam and it held up. But you are correct it does bother me some.

a window switch is a programable switch that allows for a certain rpm turn on and Off(a window of rpm) this means if you miss a shift( I know..never happens) you wont run N20 while on the rev limiter..or over rev bad with out a limiter. clutch switch is a good idea..except its one more mechanical device to go bad. When a window switch goes bad(happen to me last weekend) the switch will not fire the N20

Question about the window switch.

When I wire it up, I believe that it is triggered from the tach output on my 6AL box, but I have my tach trigger connected there. Where do I trigger the window switch from? (using a 6AL box with a Pro Billet MSD dist; magnetic pickup and a multistep retard)

I've been runnin that stuff for years.At 125hp on sbc is a good choice.Any less and you won't even feel the hit. I still run a button system, their funner to drive on the street. 4spd makes for a blast. :D

Originally posted by 71454Chevelle:
Question about the window switch.

When I wire it up, I believe that it is triggered from the tach output on my 6AL box, but I have my tach trigger connected there. Where do I trigger the window switch from? (using a 6AL box with a Pro Billet MSD dist; magnetic pickup and a multistep retard) With out going outside to look...I believe it "T's" with the tach output

Originally posted by BB485:
I've been runnin that stuff for years.At 125hp on sbc is a good choice.Any less and you won't even feel the hit. I still run a button system, their funner to drive on the street. 4spd makes for a blast. :D But I'm not running a SB. Is 125HP to small?

for a stick car or automatic for that matter the use of a micro switch on the carb works great........basic wiring and nothing complicated.......you have a toggle switch to turn on the system and when you have the car floor it triggers the micro switch that starts the flow of the nitrous and fuel.......i have ran both ways using just a button that i hit with my finger and with a micro switch mounted on the carb.......

run just a regular 6al box and pick the rpm for which you dont want the engine to rev over say 6500 rpms........this will save the motor for over reving....

then mount the micro switch on the carb where it only gets activated on wot........this will allow you to take off and as soon as the car id floored the nitrous comes on.....and when you shift gears there is a slight moment of lift off the gas while changing gears and when it is floored again it is switched back on(nitrous)........this assumes your not power shifting where you never lift off the gas between gears.......

I just set up a nitrous express hitman plus in a 454 elcamino. The 1st stage 100 you could barely feel pull. Put 150 2nd stage set bottle presure to 1050 fuel at 5.5psi. Kit hits good now. Big blocks like more juice. smile.gif

ddeennis makes a good suggestion. To add to his suggestion and as an added safety feature you could add another switch to the clutch pedal. This would kill power to the NOS when you stabbed the clutch...a nice safety so just incase you forgot to lift when you snatched the next gear. Also I would recommend a RPM activated switch so the NOS will not come on untill a preset RPM is reached. This will keep you from loading the engine real hard at low RPM.

I ran nitrous 20+ years ago on my 427 Camaro w/automatic 125 shot. I kinda liked that button on the B&M shifter handle. :D

So how does N2O work with a trans-brake? You couldn't be spraying while sitting there stalling up the converter, could you? You'd have to have the spray come on when the trans brake is released. So you'd actually stall higher the instant after the brake is off than when the brake is on. Am I thinking about this correctly?

I just hit the Nitrous button for a half second in first then let it off to shift, then once in second I hit it again until it's time to shift to 3rd, then hit the button in 3rd then let off to shift again and hold it on in 4th.
I don't let off the gas pedal to shift, I speed shift, with the engine at wide open throttle, but I do let off the Nitrous. I have always gotten my best times at the track using the nitrous from first gear as described above.