DTM Brian Posted November 24, 2003 Report Share Posted November 24, 2003 For the last two years, I have been testing NOS's 05115 dry kit on one primered 86gt. I have concluded that these kits are way overated. NOS claims there dry kit will do 175 flywheel horsepower. I disagree. The most rwhp I have found with this kit is 90 rwhp. The final numbers on the mustang were 322 horsepower and 460 torque. Motor numbers are 230-240 horsepower and 280-290 torque. Here are gains I found which each jetting. NOS 75 shot--->A 50 horse increase at the tires NOS 100 shot---> 60 horsepower gain NOS 125 shot---> 75 horsepower gain NOS 150 shot---> 80 horsepower gain NOS 175+shot---> 90 horsepower gain. RE: 175 shot. A nozzle capable of flowing 400 horsepower and a jet rated for 275 horsepower was used in the 90 rwhp gain. However the stock solenoids and lines that come with the kit were used. Finally Air/Fuel on all these runs were in the 11:1 to 12:1 range. NOS uses fuel pressure to add the additional fuel needed with the nitrous. There is NO control of the pulsewidth of the injectors. Fuel goes from 40 psi to about 60 psi depending on the fuel jetting and with out the shim in the nitrous regulator. With the shim in the regulator will go to about 80 psi, again depending on the fuel jetting. When doubling fuel pressure from 40 psi to 80 psi, you gain a 41% percent in fuel volume. So keeping the pulsewidth a constant. The most horsepower that you could jet a stock mustang safely is about 100 rwhp. Too bad I could not take NOS to court for false claims of their product. Quote Link to comment Share on other sites More sharing options...
Crash1647545504 Posted November 24, 2003 Report Share Posted November 24, 2003 im realy starting to find out what you mean. i orderd my shim today and pump. we will see Quote Link to comment Share on other sites More sharing options...
rl Posted November 24, 2003 Report Share Posted November 24, 2003 The thing is its hard to rate something that is going to be used on a vast number of cars. That kit on a car with a more efficient motor might make the power numbers it claims, it might make more. Blow bye is an issue and the tune is an issue as well. That kit on a high compression 302 with aluminum heads and a cam already making 300rwhp might pick up 100rwhp with the 125 jets. You might be hitting a limiting factor caused by the small exhaust ports on GT40P heads, you can cram a lot of 'air' down its throat, however it is having a hard time getting it out. Using a 19# Injector and raising the FP to 80psi leaves you with an effective 27# injector ((sqrt(80/39.5))*19). This leaves your total fuel flow at 216#/hr, assuming a .5 BSFC this will support 432hp at the crank or about 360rwhp. Quote Link to comment Share on other sites More sharing options...
DTM Brian Posted November 24, 2003 Author Report Share Posted November 24, 2003 Originally posted by rl: The thing is its hard to rate something that is going to be used on a vast number of cars. That kit on a car with a more efficient motor might make the power numbers it claims, it might make more. Blow bye is an issue and the tune is an issue as well. That kit on a high compression 302 with aluminum heads and a cam already making 300rwhp might pick up 100rwhp with the 125 jets. You might be hitting a limiting factor caused by the small exhaust ports on GT40P heads, you can cram a lot of 'air' down its throat, however it is having a hard time getting it out. Rob, I am still using stock heads. I agree that those small exhaust ports can not be helping the situation. However, based on the fuel that I have available, I dont see how I could be getting 175 horsepower worth of nitrous if I am getting rich air/fuel ratios and I am only running 70psi of pressure. Quote Link to comment Share on other sites More sharing options...
rl Posted November 24, 2003 Report Share Posted November 24, 2003 Originally posted by Mobile Chassis Dyno: Rob, I am still using stock heads. I agree that those small exhaust ports can not be helping the situation. However, based on the fuel that I have available, I don't see how I could be getting 175 horsepower worth of nitrous if I am getting rich air/fuel ratios and I am only running 70psi of pressure. That was my point. smile.gif You can throw all the nitrous at it that you want, but you will still be limited by the heads. Are those still stock E6 heads? if so that would explain it. Even stock E7's are not going to allow for much more power than that. You have to be able to get the exhaust out. Quote Link to comment Share on other sites More sharing options...
Guest nevarmore Posted November 24, 2003 Report Share Posted November 24, 2003 The other factor is that you have a chassis dyno not an engine dyno. Thier numbers are based on flywheel HP not RWHP, there will be a discrepancy. Although with the numbers you threw up there shouldn't be THAT much of a difference. Also, there are correction factors for SAE/OEM and aftermarket horsepower rating. NOS may be using a different correction factor, they may be icing the manifold, they may only test on really cold days or with the intake sucking air from the shops A/C system, perhaps even only testing on a 4 banger instead of a nice v8. *I'm just throwing out some ideas. I know that MCD and rl both know a hell of a lot more than I do about this. I'm tryin to help not argue, for once. Quote Link to comment Share on other sites More sharing options...
Guest 1sweet3.4 Posted November 24, 2003 Report Share Posted November 24, 2003 It's pretty easy to calculate flywheel horsepower fairly easily based off of rwhp. Not rocket science. and i don't think he had A/C on. Quote Link to comment Share on other sites More sharing options...
Guest 1sweet3.4 Posted November 24, 2003 Report Share Posted November 24, 2003 whoops misread previous post. however the statement about calculating flywheel hp from rwhp. still stands Quote Link to comment Share on other sites More sharing options...
stolen 5.0 Posted November 24, 2003 Report Share Posted November 24, 2003 NX wet kit, 75 shot equaled bout 70 rwhp and 120 rwtq. it was running a lil rich too Quote Link to comment Share on other sites More sharing options...
OGRE Posted November 24, 2003 Report Share Posted November 24, 2003 Fowlers car getting 70 on a 75 shot NX is teh first NX graph i've heard or seen below it's rating. Although all except his were kits, whereas he did a good job of putting his together himself. propane bottle warmer > * Quote Link to comment Share on other sites More sharing options...
stolen 5.0 Posted November 25, 2003 Report Share Posted November 25, 2003 mine is under cause it's running a lil rich. i have a bottle heater now Quote Link to comment Share on other sites More sharing options...
Mensan Posted November 25, 2003 Report Share Posted November 25, 2003 NOS adds torque. How much power is added is dependent on RPM. Think about it. Quote Link to comment Share on other sites More sharing options...
mjeosu27 Posted November 25, 2003 Report Share Posted November 25, 2003 You think NOS is fucked up- remember when we dyno'd my car Brian? I had the jet in for what Compucar claimed to be a 40 shot, and I picked up 80rwhp and 120rwtq. Then put in the jet for what Compucar claimed to be a 55 shot, and I picked up 120rwhp and 180rwtq. graemlins/eek2.gif Quote Link to comment Share on other sites More sharing options...
desperado Posted November 25, 2003 Report Share Posted November 25, 2003 I guess I still have questions about running a dry kit. Scares me really. Is it really that big a deal to run a wet kit on an injected car. I realize that there is a cost savings, and if you aren't really looking to go big then it's an option, but to me, unless you have a fuel pressure gauge and watch it close. I could see the motor going lean really quick if the fuel pump went dry for a second or something. But I suppose that it could happen with a wet kit as well, but you can put a pressure switch on th fuel line on a wet kit and kill the spray if the fuel pressure drops. If you are going higher pressure on the dry kits, then I am not sure that is doable. Also, how does running your rail pressure up effect your gas milage and the fuel mixture when not spraying?? Quote Link to comment Share on other sites More sharing options...
OGRE Posted November 25, 2003 Report Share Posted November 25, 2003 the problem with wet kits is they have a bad reputation for tearing up intakes when people don't use them right. I would only use a wet kit, but you have to have the right safety equip. ie. WOT switch (obviously) and a window switch so that you cannot spray below or above a prescribed RPM. Most people recommend not spraying a wet kit below 3000rpm. I personally don't like a dry kit for 2 reasons, they typically don't reach advertized hp and i don't like the idea of leaning out a particular cylinder. But that is just my preferance. Quote Link to comment Share on other sites More sharing options...
stolen 5.0 Posted November 25, 2003 Report Share Posted November 25, 2003 i dont like WOT switchs, i like to have control of the system, not the pedal Quote Link to comment Share on other sites More sharing options...
desperado Posted November 26, 2003 Report Share Posted November 26, 2003 Originally posted by Stolen 5.0: i dont like WOT switchs, i like to have control of the system, not the pedal I have seen several setup's that used a WOT and a pushbutton, it's wired in such a way that you can't get the system to fire unless the button is pushed AND the WOT switch is activated. I have seen guys run with a WOT switch and NO other switch, not even an arming switch, that I would never recomend, switches can stick, and especially with a wet kit, you can fire the system with the throttle plates closed and spin the motor apart, and never touch the throttle. Not having at least an arming switch is just being stupid, and a good way to get killed. If the car's it gear, the brakes aren't gonna hold it if the system comes on, and if it sticks when the car is running down the track, road or what ever, it's like having the gas pedal stick only worse, at a certain point, even if you kill the spark to the motor by shutting the key off, the motor will run on because of the preignition that all sprayed motor are prone to, you might not even realize that you are experiencing it, but it's there and without a way to kill the spray, it will hurt you. Quote Link to comment Share on other sites More sharing options...
OGRE Posted November 26, 2003 Report Share Posted November 26, 2003 "... and window switch" Quote Link to comment Share on other sites More sharing options...
Dweet Posted November 27, 2003 Report Share Posted November 27, 2003 Originally posted by *** : the problem with wet kits is they have a bad reputation for tearing up intakes when people don't use them right. I would only use a wet kit, but you have to have the right safety equip. ie. WOT switch (obviously) and a window switch so that you cannot spray below or above a prescribed RPM. Most people recommend not spraying a wet kit below 3000rpm. I personally don't like a dry kit for 2 reasons, they typically don't reach advertized hp and i don't like the idea of leaning out a particular cylinder. But that is just my preferance. +1 Quote Link to comment Share on other sites More sharing options...
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