wut does 125 at the wheels equal to at the motor thanx guys

 

This brings up an interesting question that I have been thinking about posting for a while now. Let's say an engine makes 200hp at the crank and has a 20% loss for the drivetrain. Now you will have 160hp to the wheel. So we now know that it takes 40hp to spin the drivetrain components. We now add FI of some type that adds 75hp at the crank. Convention wisdom says that our now 275hp motor with 20% drivetrain loss will make 220hp at the wheels. My question is why does it now take 15 additional horsepower (40hp loss vs. 55hp loss) to turn a drivetrain that has not been modified? To me it seems like once you establish the amount of power that it takes to spin the drivetrain that is what is subtracted and not recalculate the loss. What am I missing here?

 

The percentage is an estimate. The only way you will know true HP at the motor is by using an engine dyno. The only way you can truly calculate drivetrain loss is by using an engine dyno, installing the motor in the car, and using a chassis (wheel HP) dyno and doing the calculation for the difference. The original percentage comes from the manufacturers claimed HP rating vs. what the given car dynos to the wheels stock. Notice that all the guys doing dynos after they mod the cars get their wheel HP numbers and reverse calculate to the motor to get their motor HP. It is just an estimate for the motor HP number unless they are using an engine dyno (which they didn't). Drivetrain loss has to be taken at each individual circumastance to be accurate. It seems logical that drivetrain loss would become smaller as power increased. The fact is, you can't tell unless you use both types of dynos (engine and chassis) and caluculate your percentage. Any motor HP claims based on WHP are estimates based on the stock loss percentage. Ok?

Also keep in mind that it takes 20 percent of 100 to make 80 but it takes 25 percent of 80 to make it back to 100.

 

145-150. this would b the case for an nx 125 setup. nos and zex r rated at the crank, so a nos/zex 125 puts around 105 to the wheels.

 

so wut jet # would i use for 125 and 140 at the wheels for a nos kit

 

if u want your nos kit to put 125 to the wheels, u will need to use the jet sizes for a 150 shot. don't know what they r though.

 

I know very little about nitrous. I see people referring to "shot" all the time and I (brilliantly) deduced that the more "shot" the more power you get.

Can someone please explain what "a shot" is? Is this a measurement of the actual volume of NOS you are "shooting" into the engine or what?

 

shot refers to the amount of hp it will add when it is spraying into your intake track. nx rates their shots at the wheels, and nos/zex at the crank.

 

You've got it right! On a wet system like most of us have, I guess you could say the shot size is the amount (volume) of nitrous and additional fuel you're spraying. The "shot size" is adjusted by pill sizes that are located at the end of the fuel & N20 lines.

 

So, when someone says they are spraying "100 shot" using NX nitrous, they will be adding 100 HP to the wheels and if using NOS/ZEX they'd be adding 100 HP at the crank?

 

I know ZEX is not accurate, i had 55 jets in and only put down 28 to the wheels extra........but 90lbs of torque extra.........the best way is to dyno, and if anybody is saying they get 125 to the wheels without a dyno is full of ****, alot of people on this board are full of ****........most i must say.

 

Fluidz said it correctly!! All kits come with their different shot sizes and corresponding N20 & fuel pill sizes to get "their" stated increase in HP. They all give you the impression the increase is at the wheels. BS!! Like fluidz implied , you should be on a dyno when checking out different pill sizes so you know what your A/F is and then make adjustments accordingly. The last Zex/Nos pills I used (73/40) showed an increase of 144 rwhp vs the company's 200 plus statements. If someone on the street asked what I was spraying, I said 150 shot!!

 

Thanks for the Nitrous tutorial guys!

 

Man Doctor.........you post alot here, i love the dedication..........4116.....WHOHOO!!! Go Babe Go!

 

It's just that I have been here about as long as anybody. I was here before THIS particular version of the site existed, waaaaay back in 2001.

 

Bonz your car has everything, I hate you
Just kidding free post

BTW, add a 35 shot to that beast you know you can afford it and it will help your A/F!

 

How is everything

I just wonder what do you mean about "The last Zex/Nos pills I used (73/40)" do you mix some NOS parts with Zex parts? What about that shot that you have 73/40, what was the A/F mix... do you have the stock internals for that time?

Thanks!

 

The pills used by Zex and Nos use the same size of whole in their respective size pills, i.e. a 73 Nos has the same opening as the 73 Zex . It's just the outside of the pills that are different which causes them to not be interchangable. Because Nos pills are easier to find, I bought a $7.00 "Nos Splitter" that connects to the Zex fuel & n20 lines just before they go into the intake tube. This will allow you to use Nos pills on your Zex Nitrous kit. When I was using 73/40 pills (144 rwhp) on the Zex kit, my A/F was in the low 13's from 3000 rpm's to 7000 rpm's on stock internals. I ran like this for about 3 months until one day (on a dyno) my A/F read 17 (lack of fuel going in) and to make a long story short, I now have new internals! The above happened "real fast". I started spraying (on the dyno) @ 3500 rpm's, torque jumped to 465 and @ 4500 rpm's "it was over". I've recently gone to a new n20 kit and have taken the time to do "most" of the safety features that are available! If you take shortcuts and get in a hurry, the experience can be costly! And if you play with the shot size I'm trying next , the words "addictive" and "stupid" come to mind.

 

Yeah you mention something about some NOS Octant Booster... rigth!

I just wondering how much WHP ther car have on highest peak on the NOS pass (compare to the Gas pass) I ask you this because the peak of HP on the NOS passes is on lower RPM's rigth! So you say is 144 (73/40) but that is the peak of the NOS pass less the peak of the gas pass... but at the same Rpm's what is the difference on WHP when you get to the maximun WHP on the NOS pass... and what was your HP on gas and your HP on Nos?
when you say "taken the time to do "most" of the safety features that are available" what are does?

Sorry for all the questions I want to go up on nitrous so I want to make sure I'm doing the rigth thing

Thanks!

 

here i thought mjedens was an n/a freak .