Nitrous on a 5S Options

[94celicadude]

Hello all,

Its been a while since I have posted anything up... got both of my girls running like dreams and of course the projects just keep coming on.

I finally got the 7A sorted out, basically ended up rebuilding it a second time because of crappy piston rings from the shop that put the short block together... and after two bolts fell out of my shift forks, i finally got her back up and driving again... now just have to put the new S-AFCII back in it after the original was stolen... oh and get a tune.... damn i guess i really had some **** happen to me lol

Oh well anyways... this topic is about my GT Hatch.


Over the summer I ordered a set of Webcams 294 regrinds... installed them and I absolutely LOVE them! I really should have made a post about the installation and the results after tuning.

Basically... the cams bumped me up to 132 WHP.. and i forgot the torque #... sorry I would post the dyno chart but I am in Spain studying abroad and dont have it with me.

Well to get to my real question, I bought a Zex Wet Nitrous kit for my car.. and have not yet installed it considering my motor has 245K miles on it. So i am going to rebuild the motor, do some NA mods to it as the same time... Extrude Hone and such... and then i would love to hook up this nitrous kit.

My questions are... has anybody ever put a nitrous kit on the 5S?

Can the 5S take a 75 wet shot? (After a rebuild of course)

Has anybody had any bad experiences putting nitrous on the 5S?


I hope to get some feedback, positive or negative. I am doing this in order to make sure that i dont cost myself a second motor rebuild againlol

Hope to hear from all of you.

Thanks
Matt

PS I figured id post up a few pics of the car as she sits now... just for fun





This post has been edited by 94celicadude: Nov 9, 2009 - 11:17 AM

[Dr_Tweak]

I've worked with nitrous a few times, personally I think it's a fun option. It's very important to buy the right kit and to make sure you take all of the precautions when running it.

MSD makes a great programmable window switch which I highly recommend. That combined with the usual safeties (full throttle switch, low pressure switch, etc) makes for a reliable option. Also you need to do your research as to the type of nitrous system to get. The best is direct port which injects exactly the same amount of nitrous AND fuel into each cylinder. Of course this is the most expensive but it's the most reliable and is what I would personally run.

The other type is the dry system which increases fuel pressure to compensate for the nitrous which is being spraying into the intake, this is the type you would normally run on an EFI engine. The downside is that the stock fuel injectors can only compensate so much, so you're limited on how much nitrous you can use. Someone wanting to go this route might want to look into some larger injectors and an adjustable fuel pressure regulator to make sure there is plenty of fuel on tap.

You want to stay away from wet systems which spray both nitrous and fuel into the intake, the fuel will not flow evenly to all cylinders (because EFI engines have intake manifolds that are designed to flow air only and not fuel... they have different flow characteristics) which will often result in one lean cylinder. (The obvious exception to this is if you have a carburated engine, since those manifolds are designed to properly flow both fuel and air).

Finally, don't forget how nitrous works. Nitrous Oxide, N20, is 1/3rd oxygen, vs. the atmosphere which is 1/5th oxygen. The additional oxygen must be mixed with the appropriate amount of fuel in order to maintain a proper air/fuel mixture. In addition it increases power by it's cooling effect which increases air density. The gas itself is not flammable, nor does it "increase fuel octane".

Other precautions you should take include using 92 or 93 octane fuel at all times to prevent detonation, as well as using one step colder spark plugs so that they don't become a "hot spot" and cause pre-ignition.

One last word of advice. Depending on how often you fill the gas cylinder and how often you use it, and how much that costs (it's been a while since I checked), you may find yourself spending quite a bit every month keeping your car on the gas. I once saw someone do some calculations and figure out that after 1 year of using nitrous, he spent as much on it as he would have on a good-quality turbo system. In other words, up to 1 year it was cheaper to go with nitrous.... after the 1 year the turbo system would have paid for itself. Choose wisely.

-Doc