NOS vs. NX myth BUSTER
 

NOS rating their horsepower gains at the crank is hereby declared a myth. I know many members using the NOS dry kit refuted the claim, but I thought I'd offer some solid evidence.

Jetting for 85 shot, I gained 94.69 hp and 137.7 ft-lbs. tq over my baseline run today on the dyno. I'm running the NOS #5124 kit.

250.61 hp - 309.34 tq - 1996 GXE Auto

http://members.cox.net/akrug/Dyno532003.jpg

Mods:
- NOS dry kit (jetted for 85 shot) @ 900 psi
- NOS purge kit
- NOS hi-flo bottle valve
- Bottle heater (generic)
- NGK 1-step colder copper plugs (gapped to .037)
- Walbro GSS342 255lph high pressure fuel pump
- SARD fuel pressure regulator
- Custom Upper Intake Pipe w/ JWT Cone Filter
- Unorthodox Racing UDP
- Cattman Y-pipe
- Random Tech Cat
- Warpspeed B-pipe
- Stillen Muffler
- Mobiletek Valvebody Recalibration
- Hayden Tranmission Cooler 403
- 205/65/15's with stock "saw blades"

Good gains with the nitrous!..but I can't help but notice that your baseline run is pretty low with all your other bolt-on mods (even with your colder plugs). My baseline dyno with similar mods and the same NGK 1-step colder plugs was 167hp. With stock heat range plugs, I dynoed one seventy something. I guess colder plugs affect each car in different ways...

Your baseline run was taken BEFORE the nitrous run, correct?

Yeah the baseline was the first run and I have no idea why my N/A hp numbers are so low although a couple Maximas on this board with n20 setups have run in the 150 range off the bottle which makes me feel a little better.

My baseline hp a couple months ago was 163.3 before I added the Walboro/SARD combo. There really could be a million reasons for the loss in power N/A. Different dyno tech, warmer temps, etc, etc.

Nice results. But this only works ina few cases. The 70 shot I had on my '98 Maxima actually gave me a true 70hp at the wheels. Exhaust has alot to do with the actual nitrous gains.

True, but I wasnt trying to say that the NOS kit gives more than it's rated power, just not less as has been discussed. In other words, IN THEORY, a NX jet rated at 70 hp = a NOS jet rated at 70 hp.

I was backing up your inital statement. Why are you trying to defend it?



Trying to compare the ratings from the manufacturers is pointless. A jet is a jet. A .042 from NOS won't make any more or elss power than a .042 from NX or anyone else so long as the rest of the car is setup right.

GREAT numbers:bowdown1:

I see that now after reading it a couple of times, I just thought that you may have been misinterpreting what I was trying to say.

You're right, and yes it is pointless to compare, I removed the statement a couple minutes before your reply.

Andrew- Do you think it might be that leak in your intake? I noticed that you were blowing Nitrous all over your engine bay. My N/A run was so low because I had no FPR, the Dyno guy did speculate that at THAT time I might have been loosing up to 15fwhp due to the rich A/F mixture and the 18" lead sinkers I was driving on.

Also your an auto, that has some thing to do with the lower numbers.

I dont think the leak is causing my low N/A numbers. The hole is like a pin sized opening and I think I probably just need to get some cement or solder or something to close it up. My N/A numbers were down about 7 hp from the last time I went to dyno which was in February. So it being warmer coupled with the traffic i sat in coupled with the Walboro making me run a little richer than last time could all have contributed to my lower numbers.

EDIT: I was looking at the wrong view on my Dynojet viewer, my actual numbers were 250.61 hp and 309.34 ft-lbs tq. so I was off by a fraction but it looks cooler :D.

http://members.cox.net/akrug/Dyno532003.jpg

You've got a strong max:nod:, Especially for an 85 shot@900psi. I gained about what you have, but it took 100shot@1100psi. What's your mixture(A/F) through the RPM band?

Thanks. A/F was pretty much exactly the same as what it was off the bottle. Except for the onset of n20 around 3800 (where I was lean due to the quick change in fuel pressure) and when n20 was stopped around 6000 (where I was rich due to fp build up during spray) the A/F stayed in the 12-13:1 range. I could probably lean out a little.

Blue is N20
Red is N/A

http://members.cox.net/akrug/af.jpg

I'm not trying to be argumentative, but according to the power scale he pressed the red button at 3800, your cars a/f mixture doesn't level off till 1000rpms later. Is it safe to assume that it takes the ECU that long to adjust the fuel/injecter maps to the increased fuel pressure? I see that it gets richer after he stopped spraying because you have to burn off the increased pressure.

I still think that with an ecu that adjusts its trims can use less fuel pressure with with the same a/f mixture, because it took so long for the computer compensate for the increased fuel pressure.

I lost you on your conclusion, what are you saying exactly?

Niiiiiiiiiiiiiice... :thumbsup:

Glad to see you are having good results from the dry NOS kit. You did not dispel any myths though, because you didn't test an NX kit at the same time.

For every 1 that may have gotten the advertised HP rating or higher there are probably a 100 that saw less than advertised gains with NOS.

The fact that you are getting less than normal HP N/A is probably explaned by the fact that you upgraded your Fuel Pump and Fuel Pressure Regulator which could have been producing less than optimal results. You should have did one run N/A the same time you did the NOS run at least that would give a little more credence to the claim.

You will never see an NX kit put out less than advertised HP, it is guaranteed to be within 2%, NOS would never make a claim like that.

I swapped from NOS to NX in one weekend, same shot no other changes and ran .5 seconds quicker in the 1/4, which equates to 50 HP or more. I was also running faster times than most people with Max's with my NOS kit, but the NX is just that much better.

Regardless if you like NOS and get good results, consider youself lucky but you aren't dispelling any myths.

I see you re-wrote your original post. :thumbsup:

When you say it was the same shot are you talking about the same Jet size or the same advertized hp rating? We all know each manufacturer rates them differently and that NOS rates their kits higher than NX does. Thats why I say the only thing comparable is exact same nitrous jet sizes granted each kit is tuned properly. The fact that you ran quicker somewhat proves your NX was making more average power. It would be nice to see someone do an actual test of both kits with the same jet sizes and lets see it on a dyno chart.

I used the same size jet for a 100 shot both kits, .047. When someone else tries both kits and dynos both then I guess there will be actual proof of what they do.

What I do know is what I stated earlier, I tried both kits within the same week same car same size jet and ran a full .5 second faster and that is a MEGA difference. Also my setup was virtually duplicated by David6601 and he ran exactly the same time as me so mine is not one in a 100 like DCMax.

When you compare something you have to do everything the same except for that one item, otherwise you don't know for sure where and what is causing the change. I think I did that.

What was the MPH difference?

What's up Jim. First off, I want to make it clear that I respect you and your posts on this forum as much as anyone and I'm glad you've entered this healthy discussion.

I wasnt trying to discredit your claim that NX is better than NOS. I'm not biased towards NOS, it just happens to be the setup that I run. Maybe in the future I'll run a NX setup, it just hasnt happened yet. So to make it crystal clear, I'm not making a claim that either is better than the other.

The purpose of my initial post was to target the claim that NOS's jet hp gain ratings are made at the crank and not the wheels. When your very informative post on NX vs. NOS made the Nitrous board FAQs, the claim of NOS crank ratings began to spread like wildfire and it's still going on.

That stated, yes I gained more than NOS's rated power, it was power at the wheels, and this was at a constant 900 psi. As for me being 1 in 100. I don't think that's true either. Iron Lung and CalsonicSE are two frequent posters on this board running NOS kits and they both have also experience similar numbers. This may be rare as far as overall satisfaction vs. NX, but you have to factor in a lot of people that run NOS kits, don't upgrade their fuel pumps or purchase a FPR, items you don't need for a NX setup. So as far as NOS setups with the addition of a upgraded FP and FPR, the satisfaction rate and hp gains are probably much more consistent than you think.

As far as quarter mile times go, that's basically the factor that most people would look at as far as gains go. I havent run the quarter with my current setup so I can't discuss that aspect but I know you (Jim) run slicks and I'd be curious as to your times with NX and NOS with street tires.

Again, I'm not saying NOS is better than NX or visa versa, but I definitely don't see your statement that NOS rates their hp gains at the crank as absolute by any stretch.

SR20DEN I ran 13.6@100 on NOS and 13.1@104 on NX

DCMAX nothing I say is absolute. Mostly I am just speaking from my experience and what I have read on numerous other boards and pit talk which is that NOS is crank HP. You would never get NOS to admit that, they just don't say. However NX does and they also guarantee it. Most dynos I have seen though for NOS do not live up to claims and I think yours is one of the exceptions.

Its not really all that important to me either way I just couldn't get over the difference between the two and it is very easy to tell without a dyno, it was that huge. Also I was happy with the NOS I thought I was doing very well compared to most folks.

Main reason I went to NX was because my Son was sponsored by them and I got a great hookup because of that, I didn't really expect there to be that great a difference that was just bonus, plus I sold my old kit for a good price.

I have never tried running the 1/4 without slicks even N/A but I know what would happen with nitrous, (either kit) it would be no traction big time. Next time I'm there though I will try and remember to try it out, maybe this weekend. I think I am finally ready to tryout the 95 GXE, have been working on it for about 2 months now. Don't know why its taking so long I am not doing anything really special but I like to take my time and being as old as I am means slow anyways.

Going to try a few runs at the 125-150 HP setup to see what it will do but really I am setting up to run Import Bracket and will probably run a 35-50 shot or whatever I can get to run consistant times.

PS Do you have a JWT ECU still? I noticed you have one listed on the 1/4 forum.

No, I went back to the stock ECU when I installed the NOS kit in January. I sold the JWT a couple weeks ago to another member.

Jim thats why I would like to see the differences on the dyno chart. I have noticed that going from dry to a wet/dpi on my SE-R made a huge different at the same supposed hp rating. Although I can't factually prove it since the jetting scenarios were much different. I do believe the wet systems hit harder and make you go down the track quicker. I just want to see exactly why. And I do not beleive it's really as plain as NX vs. NOS vs. Zex vs. whoever.

I'm still relatively new around Nitrous, but after understanding basic concepts it seems that the wet may run faster IRL is because of the way nitrous and fuel are distributed.

Opinion:Personally I'd rather not run fuel through the intake manifold since it's designed for a gas not a liquid, but who knows I may retract that statement in the future.

Regardless, in the wet/DPI setup since you're putting in the nitrous and fuel together you should be getting close to the correct ratio. Since the dry setup just bumps the fuel pressure and we know that cylinders 5 and 6 get the most nitrous, the far cylinders (1 and 2) are getting more fuel than needed so the power should drop off since the A/F is really rich. The effect is probably even more exaggerated in high hp shots, so you end up with the right amount of fuel in the close cylinders and even more rich in the far cylinders. Overall it seems to me that the close cylinders and injectors would be (more) overworked and would have lower compression sometime in the future. My goal with nitrous was a modest shot (50-70) so wet/dry really didn't make a huge difference to me. After researching though, if I do decide to go higher I'll probably be converting to a wet setup.

Cliff Notes: The wet may make more power than dry since the fuel/nitrous gets where it needs to be, while in a dry kit the cylinders with less nitrous lose power from the incredibly rich mixture. My .02
-hype

I am well aware of the dispersion issues. I stated several times that I want to see why on the dyno charts.

NX claims that they achieve up to 50% more HP wet than dry. How much of that is advertising claims and how much is truth I don't know, I just know it does make more.

Sure would be interesting to see the same car dyno both and it would be very easy to switch over too, using same bottle etc.

Although now that NOS and ZEX have a wet kit I am sure they achieve similar results. It did take them a while though, I guess they thought NX was taking too much business so they had better jump in there. I wonder what they say about spraying gas into a dry manifold now?

XHypex if you saw one of the NX nozzles in action you wouldn't say they run a liquid through the manifold. It is virtually a gas when it leaves the nozzle, its not like you are spraying liquid fuel in there. You would have to see it to believe how well it works. Probably why it took so long for Zex and NOS to get a wet nozzle out that worked. (If it does, haven't seen much on them yet)

Jim, I bet it really is a fine atomization, but it's hard enough to design a good intake manifold for air let alone whatever else we put down the runners. I really find flow dynamics and thermo interesting, but I wouldn't want the responsibility for coming up with some of these designs on paper.

Maybe you can answer a question while we're talking about wet/dry. After looking at NOS wet/dry kits I've been wondering why the solenoids are different :gotme: I had a thread about it a while ago, but no one really commented. It seems to me that you may need a larger solenoid to get enough flow from the fuel since it's flowing at a much lower psi, but is that the only reason? While I'm a 60 shot and below I'm definitely staying dry, but I (and others) would be interested in a NOS dry-> wet conversion kit.
-hype

The fuel solenoids don't really need to be any larger. Infact it needs to be the largest at 7psi. Look at the NOS and NX jetting charts and you will see that the jet sizes at a carburated 7psi are the same for both nitrous and fuel. At 52psi I will have to run some of the smallest fuel jets made just to start at a lowest 125hp shot. You'll have to calculate more than just the fluid dynamics invloved to compare the sizes for fuel orifices. The chemical reactance needs to be added in as well in the form of the stochiometric ratio which is 14.7 parts fuel to 1 part oxygen.

pretty good numbers.....

Nice numbers. I'm hoping to get decent numbers out of the my wet setup.

hmm.. nitroussss

Why'd you choose a dry shot? Isnt' a wet shot safer and more controllable? That what I was running in mine and I never had a problem but I thought dry shots were a little more difficult to deal with...

so is it safe to say the NX has the best set-up for the money? the last question i think would be if money is not the factor, which is better wet or dry setups? good post guys very informative.

Always go with Wet! dont care what anyone says. if your going with dry you have to depend on your injectors to keep up with the additional fuel. and yes NX is probably the best out there, you also have lifetime warranty on the solenoid, which should be sent every so often to get cleaned up and inspected

The only way I would go dry, is if I had an extra map dedicated for nitrous. For example, when the nitrous arm switch is activated it switches to the nitrous map. Then the ecu adds the added fuel and retards the timing.
It would be exactly like hondata's nitrous control:
http://hondata.com/featuresnitrous.html

I wish we had something like this available for our cars.
Other than that, wet all the way!

Well with the EU, you can do that. you can set the lil switches for different maps.

I like it wet!


:D

If I decide to run nitrous again, it will be a NX wet system.

If I got a screaming deal on a NOS dry system though, I also would not hesitate to run it. :D

^^Thats good news, bc I believe I have youre old NOS kit sir! Bought it from Matt Calder a few months ago but havent actually run it yet. After what Ive read I think if I bump the shot at all (im at 50 right now) I will probably buy the NX wet kit solenoids. I went ahead a threw in 2 step colder plugs even though at this point its a bit overkill. Probably going to do this first run here in a week or two bc I lost the jet :banghead:

Grant