how much nitrous?

[SpeedSuns]

I have a non-turbo automatic car with 140k mi on it....i just replaced the HG, the valves, and valve springs...what is the biggest shot of nitrous can I use? I seen a thread before saying on a good motor it can handle 125...I was thinkin i really dont need anything higher than 75-100...but idk, I'm just tired of the non-turbo blues....
-kev

 

[MKIIINA]

turbo...N2O will eat up a motor alot faster than a turbo will

 

[Jonnymkiii]

If you go with NOS be very carefull. NOS can burn up a set of factory pistons pretty easily. I have never persoanlly used it, so I can't advise safe limits for you. If it were my car, I wouldn't use NOS without forged pistons.

Good luck with whatever you decide to do.

 

[Anomili]

The only time I would consider NAWZ would be if I had a turbo of a size large enough to warrant it along with the supporting full engine internals. Otherwise I see it more like taking a hammer to the inside of your engine every time you use it.

 

[kaz87supra]

nitrous isnt as bad as ppl make it out to be. but i wouldnt run anything over a 50shot on a stock engine.

 

[Shawndude]

The engine has no idea you're running nitrous, turbo, supercharger or whatever. All it sees is how much air/fuel you burn.

As far as how much? Depends on your setup, and how well you mix and distribute the nitrous and fuel. But whatever you do, your safety of margin is getting smaller and smaller the more Hp you make. There is no "safe" limit, there is just "less dangerous" one.

If you want to go with nitrous, make bloody sure you're getting enough fuel, and it's getting into the right places distributed equally. It won't be cheap in the end, and you could probably do a turbo swap for less.

 

[malloynx]

so guys are so mis-informed. i use to run a 150 shot on my 3.8l camaro.

nitrous doesn't blow motors, people lacking knowledge using n2o blows motors

 

[DEFIANT 7M]

:rant2: :rant2: WT*.....Nitrous in the hands of an idiot is dangerous. A 50-75 shot will be fine. Retard your timing about 3 deg. and have fun. A basic kit will not be expensive at all.

 

[gixxer750]

a basic kit really isn't safe either. A dry shot isn't worth anything, and will probably quickly end you engines life. A well tuned engine with a properly sized wet nitrous setup will last a long time though. Use colder, not platium plugs, retard your base timing 2-3 degrees and give your engine a good tune up. Also do a compression test or even better a leakdown test, and send an oil sample to a lab for examining to see what kind of shape your engine is in. Then, double check everything to make sure it is all proper.

 

[Michael90t]

Dry shot not worth anything??? jees.... all the BS flying around.....

Dry shot is perfectly fine if your fuel system can support the extra fuel needed.... AND the FACTS is if your fuel system is beefy enough to support it a dry shot is a TON safer then a wet shot hell with my 880 cc of available fuel per cylinder(6 stock 440's and 6 more stock 440's one in each intake runner) I wouldnt think twice about running a 150 shot dry if I though the pistons and rods could handle the extra stress) With a wet shot you have to worry about nitrous backfires etc a TON more then when running dry...

NEVER unlesss you want to blow your motor up EVER buy a prefabbed kit hook it up and think your golden..... to safely run nitrous you WILL want in addition to most kits...

TPS sensor of some kind(micro switch or like the zex setup, a switch that runs off the stock tps sensor voltage...) Only allows you to spray at WOT to make sure the fuel is flowing well...

RPM switch(or better yet a window switch) A TON of blown motors is caused when people spray nitrous at WAY to low of an rpm.. Remember horsepower is a factor of torque and RPM so while a 75 shot sprayed at 3500 rpms or so is pretty safe.... the same shot sprayed at 1500 rpms will most likely twist your rods into pretzles...) and rpm switch will only let you spray after the rpm you set it too.. A window switch is even better it turns it on at xx rom and back off again at xxx rpm thus reducing the risk of nitrous backfires caused by rev limits hits etc.....
^^^^^^^^^^^^^^^ are a must

there are other nice to have options like a fuel pressure switch that will shut the nitrous down if fuel pressure drops below xx amount too and is nice to have for extra margin of safety....

Wet shot in my honest opinion are ONLY good for either a vehicle that doesnt have the injector capacity to supply the additional fuel needed OR if you go with a multiport direct injected fogger setup where you dont have nitrous and gas in your entire intake track(oxidiser+fuel=BOOM if you look at it crosseyed)


Dont belive me do a search on the net and look at nitrous applications there is a TON on really good information out there...

 

[Michael90t]

ALSO

you will want to retard your timing based on shot size(look it up there is plenty of reference out there on it..)

Copper plugs are a must.... your plats and irridium plugs have a much finer tip and will heat up very quickly in a nitrouse app... which will cause detonation and the such..... there are pluggs that are made for nitrous with nice big fat tips on them so they can absorbe the extra heat but really any quality copper plugg gapped correctly will work just make sure when your tuning them

 

[gixxer750]

I meant in kit form on a stock engine in my statement. A wet shot would be much safer for the engine than a dry shot on a stock motor. But, I'm not a nitrous expert, I have only ran it on one engine(celica) and blew my 188000 mile engine up. I think it was due to mileage and my getting too happy with the shot size.

 

[DEFIANT 7M]

:3d_frown: I've used nitrous for close to 12 years now on serveral cars..I lost one engine due to MY ignorance!! A 150 shot and 17psi on a stock DSM fuel pump at hits over 120mph! One word LEAN, I melted the #2-3 bores together and snaped the crank. Nitrous is like a gun, care needs to be used to handle it. Ignorance and wrong information will cost you. Some things that have been said are good: Compression test, standard plugs(colder) and reduced timing. There is a ton of information on nitrous. Almost every month some mag has a how to article going. Would I say open up with a 100 plus shot no! Start small and build up reading your plugs. If you want to do extra get a wideban or an egt. To read plugs shut the car of right after you shut the spray off. Pull a plug and check for color or gliter on the electrode. Just my .02

 

[ryans_supra]

This is what happens when you launch a car with nitrous. I don't believe in nitros. Its a cheap way to make power and not very practical. I have seen too many instances at the drag strip of nitrous having its toll on engines.

 

[silver88turbo]

Use it right and its the most cost effective power adder just without the streetability of FI.

 

[PynkEye]

Think we should restart this post and say at the beginning, IF YOU DONT KNOW WHAT YOUR TALKING ABOUT, DONT BOTHER POSTING !!!!!

I dont know shit about NOS exept for the common shit peoeple say about it, but what the fuck do people know right, personnal experience is the real answer. So only listen to people with personnal experience...non of that my friends fathers mothers son in law used blah blah up his ass.

Please people, lets keep this forum professional and only post if we are 100% sure of the answer, Thank you

 

[MisterTurbineTwister]

I have used nitrous oxide and it can be maintaned responsibly, but if you don't know what a safe HP level of use is, you don't understand enough about nitrous oxide to use it correctly.

The best thing to do with a nitrous system is to invest in a controller like Jacob's Electronics Nitrous Mastermind or something equivelant. A controller makes the use of an electronicly metered valve and automaticly adjusts timing along with the amount inducted and when it's inducted per each combustions condition. Very much like an EFI system, only for nitrous injection.

It should only be used at WOT and with the correct fuel pressure and timing retardation. I would never use nitrous oxide with a cast piston.

It all comes down to the money=HP equation. Yes, you can do it, but it's usually not worth it in the long run.

Top fuel 800+ cubic inch nitro-methane dragsters pushing 2000hp can run 3.4 seconds in a 1/4 mile. Anything is possible, but they rebuild the engine after 3 runs IF they are lucky enough to make 3. It's usually 1 or 2 passes.

How can they do this? It's called a bottomless pile of $$$,$$$ made possible by corporate sponsorship.

Nitrous oxide IS a lot like a gun. I like that analogy, but the truth told, even with correct use it does take thousands of miles off of the lifespan of the engine.

Nitrous Oxide was first used in world war 2 fighter plane engine development for temporary added oxygen induction at higher altitudes and for climbing without stall. It has been around in automobiles since the first nut case decided to take an allison v12 from a P51 mustang and put it in his '23 roadster, nitrous system still intact and all...

The reason I say no on the idea is for 2 reasons:
1- You can spend your money in better places on a stock, cast piston engine and get more life and fun out of it. a safe 50HP shot is all you should do and it's hardly worth the work and $ envolved.

2- The idea of using Nitrous Oxide itself. I think it's wallet HP and not smart HP. There is nothing impressive about nitrous oxide. Anyone can throw money at a nitrous system and go fast, but it's temporary in the short run, needing to refill it all of the time AND it's temporary in the long run because it destroys engines, even when it's correctly used by an experienced perosn.

Anyone that disagrees, I suggest to pull an engine apart after 40,000 miles that used nitrous oxide and compare it to the same 40,000 mile engine without the use and prove to tell me different.

Let the babies have their bottles.

 

[drunk_medic]

You don't need nitrous with a Supra.. and even if you FEEL that you need it, using a "small shot" [50< but <100 shot] is all you should venture, and you need to make sure that you DO get a "smart" system.
Hell, the guys with larger turbos only use a 50-75 shot just to help them get spooled.

Buying n2o is wasted money - money you could be using to restore your MkIII to pristine condition, or money to make your MkIII faster by other means.

 

[siman]

yep...."the bottle is for babies"....

spend your money on a turbo upgrade or boost controller. For a $400 nitrous system you could have the Lex AFM, 550's and a boost controller and have another 50-100hp extra right off the bat, with the same amount of "time" spent tuning.

I have seen horrer stories with using nitrous...yes it works..but its not good for the long run....

-Jonathan

 

[DEFIANT 7M]

Like I said at least one mag will have a nitrous article at any given time. In this months Popular Hot Rodding, the article is "Mr. Nitrous ". Some of the things I knew already and some I did not. Mike Thermos the man behind NOS is being interviewed by David Vizard. One thing that hit me is the timing retard issue. I've always done it because it was the "right" thing to do when using nitrous. The reason to do it is this....
Quote:
David Vizard: Bearing in mind the number of magazine articles that have categorically stated the timing must be retarded for best results, I am suprised that it's even an issue.

Mike Thermos: I think many readers feel that info was to give a safety margin rather than maximum power. After all, "throwing advance" at an engine, sounds like it ought to do something postive. Unfortunately, too many racers are "catchy phrase" driven while reality is something else. If we look at the pressure rise in a cylinderof an engine having optimum advance, we find that, give or take a degree or so, peak combustion pressue occurs at about 15 degrees after TDC. This figure seems to stay relatively constant whether the engine is normally aspirated, supercharged or turbo'd and nitrous is no different. Any time we add nitrous, with optimum amountof additional fuel, the rate of combustion speeds up. That is because the overall ratio of oxygen to nitrogen has increased. I have seen nitrous injected into an engine where the timing was not changed and the point of peak pressure moved to just one or two degrees after TDC. At TDC, no amount of pressure in the cylinder will turn the motor over because the crank is deadlocked; the piston/rod assembly has no leverage on the crank. At two degrees after TDC the situation is hardly any better. By retarding the ignition so that peak pressure once again occurs at about 15 degrees after TDC, power goes up to a maximum. My experience here is if you violate this 15 degree rule,as I like to call it, it will cost you parts and power.