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Discussion Starter · #1 ·
How much nitrous is safe to run with a GT. When i mean safe, i dont mean like i could do it a few times and then worry. I mean pretty consistantly down the track. I know the tranny would probably be the weak point. Anyone know how much to run?
 

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Discussion Starter · #3 ·
i already have a CAI, and DP

by the time i get a nitrous kit, ill have a GT2 cam, 105# valve springs, upgraded pushrods, custom tune DHP and maybe PEMs.
 

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If you get a custom tune PCM then I would suggest getting a happy knob to retard timing. This will allow you to step up to 75-100 shot easily.
 

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Discussion Starter · #5 ·
im not worried about the engine, im worried about my non HD tranny.

Also, to my understading, a HD will bolt up to a L36 but you need a longer driver axle, right? anything else i'd need to do this?
 

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Im running a shift kit and gen 1 LSD as my only tranny mods and its non-HD.
I have 55k miles on my 2000 monte and no problems yet. When I go WOT I get a nice bark in the 1-2 shift, and it seems to drive and shift perfectly. I guess it depends on the way you drive. You should be fine with only adding and LSD. Why fix it if it aint broke :D
 

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Abysalone said:
If you get a custom tune PCM then I would suggest getting a happy knob to retard timing. This will allow you to step up to 75-100 shot easily.
That is good advice. If you are concerned about your tranny, set up a window switch and only spray between 3500 - 5800 RPM. That way, you won't bounce off the rev limiter and spray through your shifts. I found that my GT would rev up so fast in 1st that the tach would fly by the shift point and bounce off the rev limiter before it could shift. If your shift point is at 6000, have the nitrous stop at 5800 and move your rev limiter up to 6500.
 

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I ran 75 dry on my GT and it felt pretty good. I had a CAI, -ubend and TR6's at .035. Looking back I wish I had set it up to come on after the launch (better control and less likely to break something.) I was able to run a 14.800 :) with a 2.4 60ft :mad:

Good Luck
 

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Unless you have a progressive nitrous controller then I would not recommend kicking it on at less than 3k rpm. Bad things can happen when you throw a full shot in there at too low of an RPM. I think pector already mentioned this, but a window switch is an almost needed addition unless you manually hit a spray button.
 

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Abysalone said:
Unless you have a progressive nitrous controller then I would not recommend kicking it on at less than 3k rpm. Bad things can happen when you throw a full shot in there at too low of an RPM.

Why is that ? Are you saying any size shot at low RPMs? How do you control when the nitrous squirts when your using a wide open throttle switch? As soon as it is triped out comes the nitrous.
 

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From what I've read it is typically recommended that you spray nothing under 2500 RPM, however most people go by 3000 RPM for a small safety margin. As far as I've heard there are 2 main problems at low RPM.
The first problem is with fuel puddling (obviously only w/ a wet system-probably a wet kits main disadvantage), when air going through the manifold is moving slowly at low RPM, the fuel in the fuel-nitrous spray tends to fall out of suspension and puddle up. Supposedly this is more of a problem in the case of a vehicle that has a "dry" manifold from the factory (ie fuel injected at ports) b/c there are some spots in the intake where air will slow down quite a bit at low rpms. This promotes the puddling as well. The problems with these fuel puddles are first that the fuel didn't make it to the cylinder w/ its respective nitrous, so the cylinders are running leaner, and also in the case of a backfire you have liquid gasoline in your manifold ready to ignite.
The other problem I've heard is about the engine being under high load anyway (called lugging) being at WOT at low rpm, then adding significant extra stress through a sharp hit of nitrous, IIRC I thought it made the engine more prone to detonation although I could be wrong.

When using a throttle activated switch (in a non computerized nitrous setup), you place a mechanical switch that will only make contact when the gas pedal is depressed 100%. You then ground the one lead of your fuel and nitrous solenoids (or just nitrous w/ a dry), and run your positive lead to the WOT switch, so the circuit can only be completed at WOT, then run the same wire to a master arming switch, so the WOT switch then solenoids only get 12v when the system is armed, then run the wire to a 12volt source. This way you have to have the master switch on and be running WOT to give the solenoids 12v to open up. One other possible addition is a fuel pressure safety switch that can also be wired inline, so that if fuel pressure falls below a certain amount (such as if your fuel pump dies), it will break the circuit, this way you don't go dumping a huge stream of nitrous in w/o any fuel. Maybe someone else will chime in and add to this, I'm not a nitrous expert by any means.
 

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dayday said:
I ran 75 dry on my GT and it felt pretty good. I had a CAI, -ubend and TR6's at .035. Looking back I wish I had set it up to come on after the launch (better control and less likely to break something.) I was able to run a 14.800 :) with a 2.4 60ft :mad:

Good Luck
I was able to hit a 13.95 @ 102 with a 2.2 60ft with my Zex 75shot. In hindsight, I was not very smart about usage. I should have been scanning, should have upgraded my injectors to 36#, and gone with the happy knob/PCM combo to retard the timing. Opening up your exhaust is a huge benefit for a nitrous setup as well. You could build a car completely around the principles of using nitrous wisely. It wouldn't necessarily be the best setup for a street N/A or power adder.

Here is a great writeup..
http://www.grapeaperacing.com/GrapeApeRacing/tech/nitrousoxide.pdf
 
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