huge shot limit??
08-12-2003, 05:22 PM
#1
huge shot limit?? how much nitorus can you put thru a motor? lets assume
422 iron motor
forged everything
good heads studs
oring head?
adaquate fuel system
driveline that could take it
just how much nitrous could you hit it with and what would be the limiting factor? thinking 300shot easy but what about a 400shot or a 500+shot? would a 500shot be harder on the motor than 25psi of boost?
422 iron motor
forged everything
good heads studs
oring head?
adaquate fuel system
driveline that could take it
just how much nitrous could you hit it with and what would be the limiting factor? thinking 300shot easy but what about a 400shot or a 500+shot? would a 500shot be harder on the motor than 25psi of boost?
08-12-2003, 05:38 PM
#2
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Re: huge shot limit?? the limit is your displacement. once your sucking in *ALL* nitrous then no more can enter the cylinder. something interesting that you just made me think of though is what would happen if one were to do that? nitrous boost? would the pressure from the nitrous not being able to enter the engine actually create boost and force more nitrous into the cylinder?
anyway as for 500 shot Vs. 25psi of boost the biggest factor would be how much hp/tq are you making with a 500 shot as opposed to 25psi of boost? either way you would need some serious parts to hold up to once you hit your mark.
anyway as for 500 shot Vs. 25psi of boost the biggest factor would be how much hp/tq are you making with a 500 shot as opposed to 25psi of boost? either way you would need some serious parts to hold up to once you hit your mark.
08-12-2003, 05:39 PM
#3
The Bull
Re: huge shot limit?? Well, if you have good pistons in there as well there is no reason why you couldn't necessarily put 300 to it on a semi-regular basis. I'm about ready to fire mine up next week on my 382 All Bore. Same basic setup. I'll start out around 250 and work up a little. There will be a point where the car simply will not take any more nitrous. You could put 500 to the car and get no more out of it then you did with 400. Also, if you are ready to nuke your investment just start out with 500 and stay there.
Any power adder is hard on a motor. Large doses of nitrous that activate can shock the motor and stress the parts considerably different than a gradual or even aggressive rise in boost. Simply because the boost is introduced into the motor with some slope to the power/boost curve. Whereas nitrous will be more of an instaneous hit. Both techniques are just as capable of damaging parts. Of course at 25 pounds that's a bit aggressive and destined to break LS1 parts anyway.
Any power adder is hard on a motor. Large doses of nitrous that activate can shock the motor and stress the parts considerably different than a gradual or even aggressive rise in boost. Simply because the boost is introduced into the motor with some slope to the power/boost curve. Whereas nitrous will be more of an instaneous hit. Both techniques are just as capable of damaging parts. Of course at 25 pounds that's a bit aggressive and destined to break LS1 parts anyway.
08-12-2003, 05:43 PM
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Re: huge shot limit?? since nitrous and a supercharger both like the same types of cams some people put a blower on the car AND spray it. i think if you max out your engines ability to consume nitrous you could always slap a blower on it. this is just my theroy though.
and derty is right about the shock to the motor. if you do go with such a big shot i would reccomend some type of progressive controller so it doesnt all "hit" your motor right away
and derty is right about the shock to the motor. if you do go with such a big shot i would reccomend some type of progressive controller so it doesnt all "hit" your motor right away
08-12-2003, 06:11 PM
#5
The Bull
Re: huge shot limit?? A motor will reach a critical point where you can stuff as much oxygen into it as you can and nothing will happen. You will have maxed out, volumetric efficiency comes to mind as the term we are looking for here. Take a 76mm turbo and replace it with a 101mm, at some point you will simply not be able to produce any more horsepower with it. It's not a function of buy a bigger blower or turbo when you reach this point. It's the ability to fit enough oxygen into the cylinder before the explosion. That is known as 100% volumetric efficiency, and no superchargers and turbochargers will not give you extra credit. They can only reach 100%, hence the equation (Volume of air admitted to cylinder / volume of air equal to piston displacement) * 100.
At some point the cylinder just becomes cramped and it won't take any more. You can put your boost pressure through the roof if you want, it simply won't help. Same thing with nitrous, once you reach the point where the cylinder just doesn't take it you're done. Granted I believe that turbo and supercharger applications can get higher efficiencies, by how much is not really easy to quantify because they ultimately suffer the same demise.
For the guys that spray through or underneath their blower, it's typically done in the absence of an intercooler and can reduce the temperature substantially and lead to better combustion. This is where things get interesting. A bit overboard for anything we even get into with these cars yet.
At some point the cylinder just becomes cramped and it won't take any more. You can put your boost pressure through the roof if you want, it simply won't help. Same thing with nitrous, once you reach the point where the cylinder just doesn't take it you're done. Granted I believe that turbo and supercharger applications can get higher efficiencies, by how much is not really easy to quantify because they ultimately suffer the same demise.
For the guys that spray through or underneath their blower, it's typically done in the absence of an intercooler and can reduce the temperature substantially and lead to better combustion. This is where things get interesting. A bit overboard for anything we even get into with these cars yet.
08-12-2003, 11:06 PM
#6
Re: huge shot limit?? The one thing you guys are forgeting is cylinder vol and how it relates to rpm. Of course a cyl will hold a known cubic inch, but how fast can it re-fill and go through it's four strokes, that is the real measurement of volumetric efficancy. An engine is just an air pump and the better you can get air in and out the better it will make HP. So, stating that a cylinder can only hold so much tells nothing about its ability to make HP. NOS company makes an adjustable kit from 150 to 1000+ Horse Power. Two engines with the same cubic inches (cly vol) can certainly run different amounts of Nitrous for different hp readings and it's limiting factor is not how much a cylinder holds, but things like rpm's, ported heads, headers, ign timing and so on. Nobody has been able to put together a NA gasoline engine that is 100% efficient(volumetric efficiency), I think they can only get into the 80+% range. NOS calls the kit "The Worlds Most Powerful Nitrous Oxide System". Well that's enough rambling for now.
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08-13-2003, 06:37 PM
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Re: huge shot limit??
A motor will reach a critical point where you can stuff as much oxygen into it as you can and nothing will happen. You will have maxed out, volumetric efficiency comes to mind as the term we are looking for here. Take a 76mm turbo and replace it with a 101mm, at some point you will simply not be able to produce any more horsepower with it. It's not a function of buy a bigger blower or turbo when you reach this point. It's the ability to fit enough oxygen into the cylinder before the explosion. That is known as 100% volumetric efficiency, and no superchargers and turbochargers will not give you extra credit. They can only reach 100%, hence the equation (Volume of air admitted to cylinder / volume of air equal to piston displacement) * 100.
At some point the cylinder just becomes cramped and it won't take any more. You can put your boost pressure through the roof if you want, it simply won't help. Same thing with nitrous, once you reach the point where the cylinder just doesn't take it you're done. Granted I believe that turbo and supercharger applications can get higher efficiencies, by how much is not really easy to quantify because they ultimately suffer the same demise.
For the guys that spray through or underneath their blower, it's typically done in the absence of an intercooler and can reduce the temperature substantially and lead to better combustion. This is where things get interesting. A bit overboard for anything we even get into with these cars yet.
At some point the cylinder just becomes cramped and it won't take any more. You can put your boost pressure through the roof if you want, it simply won't help. Same thing with nitrous, once you reach the point where the cylinder just doesn't take it you're done. Granted I believe that turbo and supercharger applications can get higher efficiencies, by how much is not really easy to quantify because they ultimately suffer the same demise.
For the guys that spray through or underneath their blower, it's typically done in the absence of an intercooler and can reduce the temperature substantially and lead to better combustion. This is where things get interesting. A bit overboard for anything we even get into with these cars yet.
in regards to volumetric efficiency, forced induction can create higher than 100% volumetric efficiency because if you compress the air enough you can fit more air into a given space simply because it has been compressed.
also, i thought there was a guy on this board who was spraying through his intercooled procharger. if i remember correctly he sprayed on the intercooler and a 50hp shot yielded 70-100hp or something like that.
now if were talking overboard and you have the internals anddrivetrain to do this, you could maybe spray nitrous before the charger and if your theroy of only being able to up the psi so much holds true then you can still make more power because now instead of air being compressed and shoved into the cylinder it's nitrous so while you dont end up with more "air" in the cylinder you do have more oxygen which = more power
edit: added paragraphs
08-13-2003, 06:40 PM
#9
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Re: huge shot limit?? also on a 422ci motor the sidewalls may not be thick enough to hold up to the crazy amounts of cylinder pressure they would be put through. even a built iron motor can only take so much abuse especially when it is bored almost to the max.
08-14-2003, 08:27 PM
#13
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Re: huge shot limit?? the amount of N2O you can put though a engine is mainly dependent on the HP level it already has. you ususally can only double you HP level with N2O but that is it and you will have a hard time not blowing it up. you can easily spray %50 of your currant HP level though and %75 is very possible with good tuning.
08-15-2003, 10:28 PM
#14
Re: huge shot limit?? V/E on a NA engine imo would have a tough time reaching 100% wouldn't it. The reason being, as RPM increases you have less time to fill cylinder. For example, if mixture were drawn in very slowly, a full measure could get in. However, the mix (as rpm increases) must pass very rapidly through a series of restricting openings and bends in the intake. In addition, the mix is heated (engine heat) and then expands. The two conditions rapid movement and heating, reduce the amount of mix that can get into cylinder. A full mix can not enter because time is to short and the air becomes heated. Therefore, Volumetric Efficiency is the ratio between the amount of air/fuel mix that could enter under ideal conditions and what actually enters. VE can drop as low as 50% at very high RPM's on many engines. So, on a N/A engine it would be almost impossible to maintain 100% through out the RPM range, so it usually averages out to about 80% on stock engines and maybe 90+% on an Hi-Po engine, but not 100%. At least this is what I think I was taught. Hope to hear more on this debate.
08-15-2003, 10:33 PM
#15
TECH Senior Member
Re: huge shot limit?? I agree, you won't see a VE of 100% thoughout the RPM range on any NA engine. You can, however, see it through some range of RPMs (due to excellent exhaust scavenging and intake pulse timing.)
:p
08-19-2003, 10:15 AM
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Re: huge shot limit?? I'm in the process of adding all of the parts required to run the levels of hp in your thread. Forget about anything above 700 rwhp w/o O-ringing the block, changing to a 9/16" stud, using a tr 9 or 10 plug, and various other mods.
