is a 100 shot safe on my motor?

[98COBRA281]

right now im making 310rwhp, hoping to be about 320ish when fine tuned, and im going to be spraying it very soon, i have a zex wet kit, and im wanting to spray a 100 shot, but i worried about it because i have stock pistons, so the 100 shot will put me about 420ish rwhp, and 450ish rwtq, and it will be getting a nitrous dyno tune, so will it be safe on the 100, or should i just stay with the 75 shot?

 

[98stangv8]

right now im making 310rwhp, hoping to be about 320ish when fine tuned, and im going to be spraying it very soon, i have a zex wet kit, and im wanting to spray a 100 shot, but i worried about it because i have stock pistons, so the 100 shot will put me about 420ish rwhp, and 450ish rwtq, and it will be getting a nitrous dyno tune, so will it be safe on the 100, or should i just stay with the 75 shot?

There is no real "good" answer to your question....I wouldn't do it...you are really starting to push it on the stock internals...I know others may say it is safe...but I wouldn't do it...not after you had all that other work done...

Get some PI Heads and some forged internals and put a blower on it...then you will be around 500 rwhp....

I know it is a lot more cash to do that...but it will be even more if you overdo it with the nitrous..

 

[bhuff30]

Always work your way up slowly. Start with a 50 shot, then a 75, carefully checking the plugs for signs of detonation and of course the AF ratio. Then, if everything is clean pull a degree or 2 of timing and try the 100 shot.

I wouldn't worry too much about the bottom end falling apart from 'too much power'. There are plenty of people running more rwhp than that using a supercharger, and the supercharger sucks an extra 50+hp. That's an extra 50+ hp that the engine is making already, but is sucked away from the crank. If they were making power using a turbo or nitrous, their safe limit would be higher. Think back to the 60s when engines were rated at gross horsepower, and remember it is gross horsepower you should be worried about and not rwhp. No blower robbing 50+hp for you.

 

[Stan Weiss]

Lets get a few things straight. A 100 HP shot will give you 100 HP at the flywheel not the rear wheels. A 100 HP shot will give you 150 increase in torque at 3500 RPM and 131 at 4000 RPM at the flywheel. In other words the lower you start the nitrous the higher the torque increase.

Computer simulation of stock engine with 100 HP shot

 

[98stangv8]

Good call on the crank vs rwhp...totally missed that!

Nice graph too BTW...that is good info there!

 

[98COBRA281]

Always work your way up slowly. Start with a 50 shot, then a 75, carefully checking the plugs for signs of detonation and of course the AF ratio. Then, if everything is clean pull a degree or 2 of timing and try the 100 shot.

I wouldn't worry too much about the bottom end falling apart from 'too much power'. There are plenty of people running more rwhp than that using a supercharger, and the supercharger sucks an extra 50+hp. That's an extra 50+ hp that the engine is making already, but is sucked away from the crank. If they were making power using a turbo or nitrous, their safe limit would be higher. Think back to the 60s when engines were rated at gross horsepower, and remember it is gross horsepower you should be worried about and not rwhp. No blower robbing 50+hp for you.

I AM NOT GOING TO SPRAY IT UNTILL ITS ON THE DYNO!!, the firts time the car will be sprayed it will be on the dyno, so we will be watching everthing like afr, detonation ect....

 

[parrish5o]

You should be safe with a 100hp shot.

 

[bhuff30]

Most companies rate the nitrous shot at the rear wheels. In actuality, the gain at the crank is very close to the gain at the wheels. Consider 2 identical GT mustangs, one is NA making 225hp at the crank and another is supercharged making 450hp at the crank, with the exact same drivetrain. If the drivetrain losses are 35hp on the NA car, you might think it is 70hp on the blown car... This is not the case at all. There are losses due to friction, viscosity of the fluid and several other sources. A large portion of the losses are present, no matter how much power is going through the drivetrain. In reality, if the NA car is loosing 35hp in the drivetrain, given the same drivetrain, the supercharged car may be loosing only 40-45hp in drivetrain losses. Again, most of the losses are present no matter what the load is.

So, if you add a 100 shot, you likely only loose 5hp of the 100 you added to drivetrain losses. It is no where near the 15-25% you commonly see as overall losses. This is why no matter who makes the kit, the gains on a nitrous shot will be very close to the gains you see at the rear wheels.

Good call on the crank vs rwhp...totally missed that!

Nice graph too BTW...that is good info there!

 

[98stangv8]

Most companies rate the nitrous shot at the rear wheels. In actuality, the gain at the crank is very close to the gain at the wheels. Consider 2 identical GT mustangs, one is NA making 225hp at the crank and another is supercharged making 450hp at the crank, with the exact same drivetrain. If the drivetrain losses are 35hp on the NA car, you might think it is 70hp on the blown car... This is not the case at all. There are losses due to friction, viscosity of the fluid and several other sources. A large portion of the losses are present, no matter how much power is going through the drivetrain. In reality, if the NA car is loosing 35hp in the drivetrain, given the same drivetrain, the supercharged car may be loosing only 40-45hp in drivetrain losses. Again, most of the losses are present no matter what the load is.

So, if you add a 100 shot, you likely only loose 5hp of the 100 you added to drivetrain losses. It is no where near the 15-25% you commonly see as overall losses. This is why no matter who makes the kit, the gains on a nitrous shot will be very close to the gains you see at the rear wheels.

we have already covered this:

http://forums.stangnet.com/772004-rwhp-loss-through-drivetrain.html

 

[bhuff30]

Wow, thanks. That thread said a LOT of NOTHING. There was no conclusion and barely any factual data.

Yes, you can think of the drivetrain losses as being a percentage of the power you make. If you keep the same drivetrain and increase the power, then the percentage loss goes down. There are certain losses that are present no matter what the load is... and no, doubling the load does NOT double the total losses.

Again, if the drivetrain losses with a 225hp engine are 35hp, then the losses with a 450hp engine are NOT 70hp (the same percentage). It is something between 35 and 70hp. Really, this is absolutely true and proven in engineering gearing text books and show by MM&FF. I clearly remember reading and article stating that a T5 transmission has about 30hp of losses, no matter how much power you are making. Yes, more power means more losses, but the percentage of losses goes down.

we have already covered this:

http://forums.stangnet.com/772004-rwhp-loss-through-drivetrain.html

 

[98COBRA281]

^ i toltally agree witht you, so a 1000 crank hp car will loose 130-150hp throught the drivetrain? thats just

 

[fast97gt]

^ i toltally agree witht you, so a 1000 crank hp car will loose 130-150hp throught the drivetrain? thats just

rightO bippy, d/t loss is the same no matter what. the percentage conspericy that was used can only apply to na engines. as far as being safe yes it is with a good tune, but not if you are going to use the nitrous everytime you crank the car up and go some where. its designed for racing and bragging rights so to answer your question only relies on how much youll use it.

 

[Stan Weiss]

Wow, thanks. That thread said a LOT of NOTHING. There was no conclusion and barely any factual data.

Yes, you can think of the drivetrain losses as being a percentage of the power you make. If you keep the same drivetrain and increase the power, then the percentage loss goes down. There are certain losses that are present no matter what the load is... and no, doubling the load does NOT double the total losses.

All I have seen posted so far is hearsay and no factual data. How about some links?

Again, if the drivetrain losses with a 225hp engine are 35hp, then the losses with a 450hp engine are NOT 70hp (the same percentage). It is something between 35 and 70hp. Really, this is absolutely true and proven in engineering gearing text books and show by MM&FF. I clearly remember reading and article stating that a T5 transmission has about 30hp of losses, no matter how much power you are making. Yes, more power means more losses, but the percentage of losses goes down.

 

[bhuff30]

I spent a while making a long reply with more information and examples, but I'm not going to post it. I don't want to further drive the thread off topic. You can do as I did long ago and pull out some mechanical engineering textbooks and journals and look for this kind of information. My only point is, that quite a few of the losses are parasitic, and present no matter what the load is. It takes a minimum amount of power to turn a drivetrain at 60mph without any load, just because of frictional losses, pumping losses and losses of the gears meshing. The only additionals loads are from the extra frictional resistance on the bearings and gears to keep everything streight and true when power is applied.

 

[32ValveRom]

I'm thinking you should be safe with the 100 shot as long as you have the tune. But like, one of your replies if i were you I'd get the PI heads before i got into nitrous.

 

[98COBRA281]

I'm thinking you should be safe with the 100 shot as long as you have the tune. But like, one of your replies if i were you I'd get the PI heads before i got into nitrous.

why pi heads?, i make more power them most pi swapped cars, and have the same compression as pi swapped motors, if i were to put pi heads on my car id probably lose power..............

 

[roundboy]

I was making 310rwhp with a head, cams stock bottom end 2v pi motor.. I put a wet kit 100 shot on it and made 403 rwhp on the n2o tune.. the motor will be fine if tuned right.. i have a all motor tune and a n2o tune..

 

[fast97gt]

I was making 310rwhp with a head, cams stock bottom end 2v pi motor.. I put a wet kit 100 shot on it and made 403 rwhp on the n2o tune.. the motor will be fine if tuned right.. i have a all motor tune and a n2o tune..

not to be a smarty but its no2

 

[98COBRA281]

I was making 310rwhp with a head, cams stock bottom end 2v pi motor.. I put a wet kit 100 shot on it and made 403 rwhp on the n2o tune.. the motor will be fine if tuned right.. i have a all motor tune and a n2o tune..

yes, i will have 2 tunes also...

 

[roundboy]

not to be a smarty but its no2

NO n2o is right!!!
Nitrous oxide, commonly known as "laughing gas", is a chemical compound with the chemical formula N2O.

Nitrous oxide - Wikipedia, the free encyclopedia