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wow that looks like a good deal, isn't that the kit that's usually 500 or so?
 

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Discussion Starter #3
This guy has had these kits up for awhile at 350, they might have been more in the past. I don't know much about nitrous so I was hoping the more experienced will chime in and let me know what there thoughts are on the price and quality.
 

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Looks like a good deal. The standard kits, ones that don't use a "control" box like Zex, are pretty basic really. Not a whole lot to be made of "bad" quality.
Here is something you might wanna consider http://www.speedshop.org/store/scripts/prodList.asp?idCategory=96

I've purchased a decent amount of stuff through them and they have always been great, and their purge kit I has worked flawlessly.
 

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Discussion Starter #6
nice, thanks for the link Aaron, with there 8 cylinder kit, and no control box, how does your car know how to add more fuel to compensate for nitrous? I'm only planning on running a 50 shot to start.
 

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Texas Chapter Director
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I called the place that is selling that setup on Ebay and they seem legit. I have seen them advertise on local forums in Houston and have had nothing but good comments. If I get a chance and am in the area Ill ask some questions if you want.
 

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Dim Bulb
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Aaron_T said:
The nozzle goes before the MAF, so the MAF "tells" the computer to add more fuel.
Not sure how it works safely, but it does.
Simple... the MAF senses how much air is coming into the engine. Nitros condenses the air, the MAF senses there's more air coming through the intake, and adds more fuel to compensate
 

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Discussion Starter #10
speed95 said:
I called the place that is selling that setup on Ebay and they seem legit. I have seen them advertise on local forums in Houston and have had nothing but good comments. If I get a chance and am in the area Ill ask some questions if you want.
Thanks, I'm learning all I can right now about nitrous and set-ups before I take the jump. If I think of anything ill let you know. I've seen ALOT of nitrous set-ups with the nozzle right before the TB, actually all systems I've seen so far. How is that possible? I'm assuming it's due to the kit having a "control box" like zex?
 

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Whining Intakes Rock
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Falcon5783 said:
Simple... the MAF senses how much air is coming into the engine. Nitros condenses the air, the MAF senses there's more air coming through the intake, and adds more fuel to compensate
That is partially correct. The MAF senses air mass by how much voltage it has to use to keep the hot wire 200 degrees Celsius above the surrounding air temperature as measured by the Intake Air Temp (IAT) sensor. Condensing the air (increasing volume) wouldn't effect that if the condensed air was also at the same temperature. Nitrous shot into the air stream will cool the air and the hot wire causing the MAF to use more voltage to keep the operating temperature of the wire. Interestingly enough, it wouldn't matter if the IAT sensor was part of the MAF or separate as is the case of MN12s.

The second part of the equation would be the o2 sensors. As the nitrous is compressed, oxygen is released. The o2 sensors will pick that up and the eec will compensate by adding more fuel.
 

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Whining Intakes Rock
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Big_Irish said:
...I've seen ALOT of nitrous set-ups with the nozzle right before the TB, actually all systems I've seen so far. How is that possible? I'm assuming it's due to the kit having a "control box" like zex?
Zex's controller box hooks up to your fuel pressure regulator. It increases fuel pressure which will cause a little bit more gas to be injected during the injectors cycle.
 

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Big_Irish said:
I've seen ALOT of nitrous set-ups with the nozzle right before the TB, actually all systems I've seen so far. How is that possible? I'm assuming it's due to the kit having a "control box" like zex?
Wet kits will go right before the TB due to the fact that nitrous and fuel are sprayed through the nozzle, thus no need for use of the maf to add it.
 

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Al_Florida said:
That is partially correct. The MAF senses air mass by how much voltage it has to use to keep the hot wire 200 degrees Celsius above the surrounding air temperature as measured by the Intake Air Temp (IAT) sensor. Condensing the air (increasing volume) wouldn't effect that if the condensed air was also at the same temperature. Nitrous shot into the air stream will cool the air and the hot wire causing the MAF to use more voltage to keep the operating temperature of the wire. Interestingly enough, it wouldn't matter if the IAT sensor was part of the MAF or separate as is the case of MN12s.

The second part of the equation would be the o2 sensors. As the nitrous is compressed, oxygen is released. The o2 sensors will pick that up and the eec will compensate by adding more fuel.
TY :thumbsup:
 

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Discussion Starter #15
Aaron_T said:
Wet kits will go right before the TB due to the fact that nitrous and fuel are sprayed through the nozzle, thus no need for use of the maf to add it.
So would that make a wet kit safer due to less less chance of running lean and blowing something, as long as theres no puddling in the intake?
 

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IMO I would say so, atleast on the running lean part. Also it's easier tune for a wet kit since the fuel is gonna be added in a more consistent amount. Basically you know there is gonna be x amount of fuel based on the size fuel jet and fuel pressure. It's kind of nice to know that there will always be atleast some fuel added with the nitrous, unless something drastic happens, but I would think it would be likelier to run lean on a dry kit. Not saying it's likely to happen when correctly setup btw.
Kits like NX, TNT, etc... normally make more power than most dry kits, so there is a risk factor there. These kits normally will make more or atleast the same wheel hp as the shot size you use, and almost always more wheel torque than the shot size.
Dry kits like NOS I have seen that normally they make pretty close to there shot size at the wheels, but the torque does "usually" increase a higher number than the shot size.
Zex I think has a bit lower gains than a standard dry kit.

Sorry if it's worded all fuct up like, but I'm at work and trying to hurry :D
 

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Big_Irish said:
So would that make a wet kit safer due to less less chance of running lean and blowing something, as long as theres no puddling in the intake?
Yes...safer than this kit anyhow. I don't care how much cooler the intake charge is, the EEC can not add enough additional fuel to compensate for a 100 HP shot of nitrous.

I imagine the reason this kit is so cheap as compared to others out there is there is alot of stuff missing...like relays, fogger nozzel, nitrous filter, provisions for adding additional fuel, bottle mounting brackets and probably more.

I think your better off going with Zex if you want a dry kit and NX or NOS if you want a wet kit.

David
 

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Discussion Starter #18
The dry kit thats available through Aaron_T's link looks complete. Once you hit WOT doesn't the computer go into a loop anyways and adds X amount of fuel without compensating? If I hit WOT then hit the button for a 75 dry shot, wouldn't the fuel be there or will the maf have to adjust? Relying on the maf to control how much gas to add with nitrous running through it doesn't seem like that good of an idea to me. Does anyone here run this type of setup?
 

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IMO, that kit is not safe at all. Its a dry kit, but as Dave stated, there is no way to enrich fuel.

Quick overview,

On the ZEX dry kit, they add additional fuel pressure using a small amount of nitrous to push harder on your fuel pressure regulator. This added pressure pushes on the internal diaphram inside. 1psi boost=1 psi increased fuel pressure. Zex does it nicely and everything is contained in a box.

An NOS dry kit works almost the same way. The kit uses two solenoids. One for nitrous, the other for fuel enrichment using the same technique as ZEX.

In this kit, they give you only a nitrous solenoid. There is no way to increase fuel. You'd have to do this yourself. The only real way to do it on a EFI car is to get into the computer and command it to dump in lots of fuel during WOT. You'd have to have two programs, one for street and one for nitrous use.

Yes your car does go into open loop during WOT, but that doesn't mean much. All it means is that the o2 sensors are ignored and that the car uses load vs RPM to guess as to how much fuel to add by looking at a table. Load is a function of airflow and displacement, and the airflow values are taken from the MAF table. The MAF does not control fuel enrichment. All it does is tell them computer the amount of air entering the engine. The computer uses these values to determine load, and then it looks under a table at WOT to determine fuel. You'd be spraying after the MAF anyways, so the car never knows that you have started spraying, or that there is any additional airflow/oxygen into the intake track. Its very accurate until you start making airflow mods on your car and its flowing a lot more air than stock. This is where a tune comes into play and you adjust your transfer fuctions.

Another myth is that you can run an adjustable regulator and crank up fuel pressure and under WOT and nitrous use, it'll even out. WRONG.

The factory computer is designed to run on a fuel pressure of 39psi static. IF you crank this up to 50psi or whatever, the computer will "see" this increase pressure from the 02 sensors during closed loop. The car will automatically compensate for this increased pressure by making the injector pulse width smaller, providing less fuel, and you're back where you started again.

So people ask, "Well the car is in open loop during WOT, and doesn't look at o2 sensors...". Well that are right and wrong. The car doesn't look at your 02's under WOT, but it still uses your KAM, or Keep alive memory. It remembers any changes that were made using the computers adaptive control, and it uses these changes under WOT as well. So if it sees a huge increase in fuel pressure it'll trim it out under part throttle, but under WOT, it will remember the decrease in injector pulse.

Basically, thats a bandaid fix, and it'll work for about 5 min, and then the car will trim it out, and you're back to where you started.

SOOOOOOO.......to sum it all up, your best bet is going with either a ZEX or NOS kit if you're set on using a dry kit. If you like a wet kit, then go with NX. A lot of this stuff is from personal experience. I run a zex dry kit and I'm pretty happy with it. However, since I'm running a SC car, the fuel enrichment jetting charts do not apply. I have my own wideband set-up, so seeing what the exact ratio is and making changes is easy.

Spraying before your MAF with a dry kit will not give enough fuel enrichment. Sure it might see some aditional airflow, but I'm almost certain that it'll peg the MAF. The MAF can only see a max of 4.7 volts. Under WOT as is, I'm sure you see around 4.1-4.2 volts. Once you peg that meter, the car uses a stored fuel table and guess as to how much fuel to add using no sensors to get its information from. So basically, the computer is driving blind.

On a side note, I agree, Dynotune is a great place. They are actually my local dyno as well. I got their purge kit and the rest of their stuff is top notch. However, just knowing how the ECU's on theses cars work, I'd never spray before the MAF. Its not the correct way and its not a safe way at all.

I hope I answered some of your questions.
 
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