View Full Version : Upgrades for Nos?

06-17-2003, 10:58 PM
I've decided im probably gonna get a Nitrous setup, but i was just wondering if anyone would be able to tell me what kind of upgrades i would want to do first, i hear the sly has a nitrous setup... or maybe it was someone else, jsut wondering who has got it, and what kind of setup you got.


06-17-2003, 10:59 PM

06-17-2003, 11:49 PM
i heard nos is pointless to get in a bmw .. dont ask me why though

06-18-2003, 12:01 AM
yes sly is running nos, but i would suggest getting the ZEX nitrous kit for your car. its an easy install, and safe to run unlike NOS wet systems. you wont need any upgrades

06-18-2003, 12:58 AM
whats so safe about the ZEX kit, i heard they are the safest to run too, but what is different, does it kick in at certain RPM or what??? and that whole thing about nos not workin on bimmers is rediculous.

06-18-2003, 08:44 PM
some people will tell you ZEX isn't as safe on our cars as they claim, but from the stories I heard, it sounds like they were just pushing the car too hard.

That aside, if you want a safe setup, go with a wet-system.
I've also seen direct port systems that inject into each cylinder on the intake plenlum, but I'm not sure how safe that is compared to a wet setup.
There are all sorts of gadgets you can install for safety which should shut off the nitrous if things go wrong as well.
A purge kit is a good thing to install so I've been told as well.

(everything I said was from reading, not first hand experience, so I'm not an expert with nos....just letting you know beforehand! :))

06-18-2003, 10:26 PM
the drty setup is more safe, i would suggest 50 shot as the highest to go with no engine modifications

06-18-2003, 11:00 PM
A dry nitrous ( nos is a brand name) system is far from being as safe as a wet system. If your stock fuel system can't keep up with the fuel demand for the nitrous the mixture will lean out and detonate( this is where you run into melted pistons and engine failure).

Here are some guidelines( I have tuned nitrous motors and have first hand experience)

- First find out what your stock engine components are made of.

cast iron crank and rods will safely handle a 30-50hp shot

cast steel 50-80hp shot

forged steel (rare in stock applications) up to 125 shot

For a small hp boost I would recomend going with a single fogger nozzle (mixes N20 and fuel in a single nozzle) to find the best jetting for it go to the NOS website and as a rule of thumb always run the fuel 1 jet larger than recomended.

More fuel will not have any negative side effects other than a richer mixture and black exaust smoke and then you can tune the jet sizing down from there but if you dont run enough fuel and it leans out your pistons can melt.

06-20-2003, 12:45 AM
so what does an '89 325i have? cast iron or cast steel???
and i was only planning on gettin a 50 shot zex kit anyways

06-20-2003, 06:53 PM
ZEX rules get ZEX. My friend has it on his Civic (yeah I know). But it's a nice and simple system. There are no silenoids, everything is in one purple box that you mount in the engine bay. Also Zex can be hooked up for throttle respone, so instead of hitting a button when you want the juice, you just floor it and the nitrous kicks in ( I don't know if Nos or NX does this too).

06-20-2003, 07:48 PM
Originally posted by msifashion
There are no silenoids,

you have no idea what you are talking about....

damn. maybe a little research would be of some help here guys...

here is a little starter information:
all nitrous kits have solenoid(s)
the zex kit only has one solenoid while the NOS kit has two just incase the first one fails.
Some kits are rated at the wheels and others at the crank so when somebody is running a 50 shot they could mean either depending on brand.
The two major upgrades you need for you car involve the fuel system and the spark.. you need to change the gap on your spark plugs and change your fuel pressure to add more fuel when you spray... you may need a better fuel pump.
You will want an EGT gauge to make sure you're not running too lean or rich.
There are also many things you can do for safety suck as a window switch that will only operate between a set RPM range to ensure you don't find the car spraying after fuel cut during a close race.

as you can see there is a lot to study if you want to be smart about using nitrous on a car... my advice is to start reading and play it safe and you should have no problem tuning with it.

The Sly
06-21-2003, 01:39 AM
WooHoo Well said theblue....

From experience on a M20 engine, i would say get a wet system single jet in the intake boot and do not go over 75HP

Safety would be a well running strong engine, good plugs, new cap and rotor ....start shooting at 3000rpm or "2000 in my case... up to the 6500rpm limit...

NOS needs free flow of air in and exhaust out.....
No aftermarket chip and highest octane fuel possible...I use aviation fuel..

Make sure your fuel delivery is working good cause if you run lean ...You burn your pistons..You can get a Fuel pressure switch..if fuel pressure drops below a certain level,,,NOS is disable

You will replace lots of motor mounts and guibo...

I was able to do 13.85sec on a stock engine, a few mods and 70hp NOS....

Have Fun

06-21-2003, 03:33 AM
I thought ZEX had all the stuff in that purple box. Anyways, I admit I know nothing of nitrous, was just saying Zex seemed pretty cool. No reason to put people down, but you're just that cool, right.

Dave 325i
06-21-2003, 01:18 PM
I think he was just trying to keep the discussion technical - I doubt anyone is going to buy a nitrous kit based on the fact that someone said "it's pretty cool". :)

06-21-2003, 03:39 PM
i wouldn't, i'd buy it cause it was in a civic

06-22-2003, 03:30 PM
thanks alot sly, the info helps me alot, i think i probably will be goin with the 50shot zex kit, it is a single jet wet system, and they are supposed to be very easy to install, and not a bad price either, and from what i hear it can be programmed so it kicks in at any RPM you want when its on, anyways i gotta do a bit more research on it still, but thanks

06-22-2003, 11:24 PM
I was thinking about getting a Nitrous Express kit, and also a Zex kit about two months ago after talking about it on forums, going to places, talking with racers i found that NOs is crap that i wouldnt let touch my engine.

1. all racers that ive met, who use or have used nos systems, ranging from dry to wet, have had major problems with their engines. The worst of which is a guy that changed his motor 3times in one year on a nearly indestructable base (VR6).

2. never buy dry, as pointed out before it`s not as good as wet, but also in wet system the NO is mixed in with gas to provide a more even flow of power.

3. nos runs out, and each time you fill up it`s 50bucks per pound, 6 pound bottle = 300bucks for about 2days of night driving, or a couple runs down the track.

if you dont care about these things, one myth you need to undestand that the movie Fast/furious did is that you will have no button to squirt the gas in, the Nos is injected only at the time there is pressure in the exhaust, while at full throttle, also it only comes on at certain RPMs, and sometimes only in certain gears if programmed that way. the computer stops spray when you release the pedal creating less, or no pressure.

For the install price i guess you cant beat it, but you may end up paying more then if you got a decent 8psi junkyard turbo setup... plus you have that power always.