Do you gus think its possible that i would have 425hp with a NX 150 shot. If not what do you think. Also what would my car run, with my traction mods and bfg comp ta drags.

 

What size cam do you have. you may be pushing the threshold on the stock internals so I wouldn't do it if I were you. You will need a high flow fuel pump to. If not bad things will happen.

 

I forgot the exact specs, Its a comp cams 2030 i Think its like 264-274 Ad Durr. and a 480 Lift I will install a jacobs nitrous mastermind and a walbro 255 fuel Pump.

P.S. Dont quote me on the specs

 

Do you have any 1/4 times for that combo as it is now? It sounds like a pretty good setup if its tuned up properly.

 

Your TBI unit will not flow enough to support the power you want. I don't think that you will see the advertised 150 if you use it. If I were you I would add a 75 shot and I am pretty sure that you will get all of that. I would say you are at 230-250hp now and could shoot for 320-350 with spray.

Forgot to mention:

I think your gears are a bit to steep and may hurt your ET's. The TBI does not make that kind of high end power to benifit from gears like that. With that aside and with your suspension upgrades I think you could easliy be in the low 13's and high 12's Fully Fully Fully tuned with a larger TBI unit. Someone on the board (can't remember) has hit high 12's with a similar set-up to yours. He runs low 14's off the spray and a best of 12.9 on it.

 

No offense shifty, but you are dead wrong. The tbi has no effect on the nitrous at all. It is a plate system so regardless of what type of fuel system you have the nitrous will work great. The NX kits are guaranteed to provide within 2% of the advertised hp top the rear wheels so you WILL see the full 150 shot. I know of a couple people who have done exactly what you are doing and had no problems. I wouldn't run the 150 shot long though. If I were you I would step down to a 125 shot to be on the safe side. I think you could hit mid 12's with stickies. You very well could see 425 flywheel hp with that setup. I believe the person you are referring to is zrated, who went 12.8 with stock heads and an LT1 cam with a 125 shot.

 

I am pretty sure I am not "dead" wrong. I may be off slightly but not just nay fuel system can run serious nitrous. If you do not have the fuel system to keep up with any amount of nitrous you will destroy your engine in a second. If your fuel pump cannot support 300+ HP above 3000rpms (which stock TBI pumps cannot) you will have an instant disater. I realize that it is a plate system but that doesn't take away from the fact that it will need added air and fuel to make the nitrous reach is advertised power numbers. You need air to feed that extra power. 400hp is 400hp regardless if it is all motor or on spray it requires a certian amount of air, of which a stock TBI unit cannot support. I don't think he will see the numbers the kit claims. If he was bone stock than he could see the 150 increase (with fuel) but not with the stock TBI unit that is at it's max right now. He has the fuel system to keep up but I do not think his TBI can handle it. Other EFI systems don't have this problem because their fuel systems can keep as well as thier induction set-ups can feed the on demand extra fuel and air.

 

this concept is where you are 'dead wrong' and off base.

yes the fuel system has to be up to par, because with a wet (or dry for that matter) there is quite a bit of added stress as the jets for the fuel side of the system open up.

BUT with nitrous you don't need extra air. it is N02 as in 1 part nitrogen 2 parts oxygen. the 'air' that the combustion processes uses is 02 (2 oxygen molicules) which is essecialy what no2 is, but there is an extra nitrogen attached. when mixed with gasoline, and with a cumbustion sourse, the 02 reacts to produce the chemical reaction. the by product is nitrogen, i beleive that it then combines to create n2 (not sure on this) it might also combine with some other chemicals that are by broducts of the hydrocarbons. but it is early. but you get the point. the whole point of nitrous is that it acts like a liquid form of oxygen. so you don't need to have the airflow needed to get that much oxygen content from the normal induction process. you could completly block off the TB, and run nitrous without any outside air.

 

Nitrous can be thought of like a blow torch that is advertised to reach temperatures of 1,000 degrees. As long as there is sufficient oxygen to support the flame it will happen...I'd like to see any kind of flame with a lack of oxygen.

Nitrous can reach 150 HP so long as there is enough fuel and air to make it happen.......It's not like the nitrous acts on it's own, the amount of fuel and air in the mixture plays a significant part in the combustion process....

 

then you must realize that the TBI itself has absolutly nothing to do with the plate wet nitrous setup.. the only thing he has to worry about is his fuel pump pushing enough volume. i would really use a fuel pressure switch


btw.. you're still talking about air... you DO know how nitrous works right?

 

edit... you guys beat me to it.

 

I should have refrased this a little better. I know that nitrous has the oxygen supply in it and that is what is used in it's combustion process. However, I din't think that you could pull enough air in through the stock TBI for the fuel that needs air to combust. I know the nirtrous doesn't need air but you are speeding up the engine at a rate where incoming air is flow limited for the gasoline. I didn't think the gasoline used any oxygen from the nitrous in the cumbustion process but instead still relied on incoming air from the throttle body. therefore you can split this up into two control volumes. One that is throttle body dependant and one that is nitrous dependant. If it does than you are air limited for the gas, not nitrous. Am I making sence now?

 

Just out of curiousity, how does nitrous work with the fuel side of fuel injection? Wouldn't you have to change the fuel distribution in the chip? Given that you have a capable pump, pressure, and injector rating of course.

 

nitrous = air

at least in this context. nitrous is not the fuel. gasoline is the fuel, air and or no2 it doesn't matter. the reason for nitrous is to over come the airflow limitations. the same thing as a turbo or supercharger, you are forcing oxygen into the system. in nitrous you get a very dense oxygen source, so you can overcome that airlow limitation of the system. because you introduce the oxygen in liquid form.

 

at wet flow nitrous system jets fuel and nitrous. so it is indepentant of the FI system. so long as the fuel pump can keep up with the added fuel flow.

 

theres 2 forms of nitrous systems.

wet and dry.

wet systems spray the fuel in themselves... if it was physicly possible, you could take off the carb, TBI or take out the fuel injectors when the motor was running on the system, and it would still run. because we know how much air (nitrous) we're putting in there, we know how much fuel we can add.

the other kind is a Dry system

a dry system does not add fuel. instead, it relys on the fuel injection (or in the case of sneaky pete, the carb running rich) to add the fuel.
because most FI systems run in open loop at WOT, you can compensate for the nitrous somewhat by jacking up the fuel pressure... this is how most dry kits work.
others, like the LS1 kit, use the cooling effect of the n2o into tricking the MAF to tell the computer to add more fuel.

the basic idea comes down to, spraying nitrous and adding fuel.

 

Ok Dewey I get it. Thanks guys. I was under the assumption that the nitrous itself combusted and that the gas still went through its normal combustion with ambient air and not the liquid additive. I viewed it like a booster that burns on liquid oxygen alone. I thought we were dealing with the same process here. What do the different nitrous jettings do as far as compression goes. If we are at 9.3:1 or whatever do we jump up to 10.3:1? That is if we double the amount of intake charge entering the chamber.

 

umm, the RATIO will not change, however you're close..


because you are adding a set amount of air and fuel, the engine has to spin so fast... otherwise the cyl pressures become HUGE.

a 50shot at 1000rpm could make enough cyl pressure to break a rod...... yet the same 50shot at 4000rpm makes the same amount of power, with less cyl pressure..... and your rods are safe.

id describe it better, but im at work and can only spend so long typing between things... perhaps someone can rephrase it better and go a lil more indepth?

 

But since you are running more air and fuel per unit volume doesn't the compression raise per stroke. Engine RPM aside I thought that since you add in the extra oxygen in nitrous form, and you mix it with the right amount of gas you build a higher cylinder pressure. And isn't that the danger of nitrous, building serious cylinder pressures and keeping the mixture from exploding.

 

yes that is part of it, but the cam, cyl head design ect really start to play a very importan roll in this. cams with large overlap are going to be more forgiving when it comes to the high cyl. pressure. this is also why with nitrous you tend to run you mixture richer, and back off timing, to help prevent detination due to the mixture being much more volatile.

 

Oh I realize this, I was trying to put it in simple persepective for my dumb brain. Thanks guys. See this is why I am a mechancal engineer and not a chemical

 

well, i won't tell you what i do for a living....

but i do have alot of spare time.

 

It's N2O, 2 parts N, one part O. This is howevery (and obviously) more oxygen than "air" but still not as strong as pure O. Reason for N2O vs pure O is stability, O2 is dangerous and will burn VERY hot, you wouldn't be able to supply more than a 25hp shot of straight O2 before you would see damage to the pistons.
Let's not get too indepth about nitrous.

 

i disagree.... you SHOULD go indepth with everything.


that would shutup alot of the people on here that only know the basic or general answer...... and they dont know WHY


indepth info is good.... general overviews are for magazines.