ScottStaypuff
Active member
Hi guys, I'm a newb here and will probably have a ton of questions about getting max power out of 250/300 I6s (for my Maverick). I also have a Neon and have nitrous on it, controlled by an NX Maximizer. The Ford I6 is a different animal but many of the concepts should crossover from this FAQ I wrote. Just thought I'd share what I know...
LOTS of Nitrous
Scott Kornish wrote:
You're looking at start percent of 20-30% in 1st w/ build time of 2 seconds or so.
30-45% start percent in 2nd gear.
40-65% in 3rd gear.
50-80% in 4th gear
Start with long build times and low percentages and work your way to faster build times and higher nitrous start percentages.
NX conservatively states that a typical stock 4 cylinder engine can handle a straight 75 shot with no problems. At 3000 rpms the torque added would be 75hp*5252rpm/3000rpm = 131.3 ft-lbs. So to be conservative we'll say your engine can handle making 230ft-lbs of torque without bending a rod. (Assuming you're hitting the nitrous while already accelerating the car). You want to set up you nitrous controller so you don't exceed this torque limit. At 6000rpms a 125 shot would add 125*5252/6000 = 109.4ft-lbs. You're way safe as long as you set the time on the controller to be hitting full nitrous by the time you're at 6000rpm. I use Desktop Dragstrip to help figure out time in each gear so I know how long to set the build time for. Its kind of a guessing game, but just work your way up and input your data as you go to match your real world runs as closely as possible.
Here's a basic "How To: Not Break your Engine with Nitrous" I wrote...
"From my experience and what I've researched on the subject I believe that an engine will live a long and healthy life with nitrous use if you just don't exceed certain limits. Pretty much all common sense...
1) You can't ask the engine to make too much torque, you'll bend the rods
a)You can use more nitrous at higher rpm and in higher gears, the converse is also true.
2) You can't overrev the motor, rods will fly apart.
3) You have to have enough fuel
4) You can't have too much ignition advance or too low of octane
5) You can't run nitrous for too long with stock internals, rings will butt together and pistons may get a hole in them.
6) Any detonation with stock internals is BAD. Cast/hypereutectic pistons will crack pretty easy under these conditions.
example 1:
Neon guy decides he wants to see what nitrous does if you shoot from idle. I saw some nice pics of bent rods...
example 2:
Neon guy has a 2.4 with bolt ons, shoots a 75 shot for awhile with no problems. Moves up to a 100 shot and blows up his engine in a month. Why though? This guy was doing a couple no-no's. He had a stock fuel pump (only good to about 225hp), AFX pcm which advanced timing, no timing retard, stock internals, and raced a Mustang Cobra to over 140mph when he got a big hole in one of his pistons.
example 3:
Civic guy w/ a d16 hatch, stock internals, did everything right, had a 3 stage nitrous system and shoots a 150hp NOS shot, even 180 a few times. Never had a problem in the couple years he had it set up like that. The car was still running strong when he sold it.
I've been thinking the most important thing to consider for me is to not exceed the torque limit of the engine since i have the other things covered. I may try my theory out with more nitrous but longer build times sometime soon..."
LOTS of Nitrous
Scott Kornish wrote:
You're looking at start percent of 20-30% in 1st w/ build time of 2 seconds or so.
30-45% start percent in 2nd gear.
40-65% in 3rd gear.
50-80% in 4th gear
Start with long build times and low percentages and work your way to faster build times and higher nitrous start percentages.
NX conservatively states that a typical stock 4 cylinder engine can handle a straight 75 shot with no problems. At 3000 rpms the torque added would be 75hp*5252rpm/3000rpm = 131.3 ft-lbs. So to be conservative we'll say your engine can handle making 230ft-lbs of torque without bending a rod. (Assuming you're hitting the nitrous while already accelerating the car). You want to set up you nitrous controller so you don't exceed this torque limit. At 6000rpms a 125 shot would add 125*5252/6000 = 109.4ft-lbs. You're way safe as long as you set the time on the controller to be hitting full nitrous by the time you're at 6000rpm. I use Desktop Dragstrip to help figure out time in each gear so I know how long to set the build time for. Its kind of a guessing game, but just work your way up and input your data as you go to match your real world runs as closely as possible.
Here's a basic "How To: Not Break your Engine with Nitrous" I wrote...
"From my experience and what I've researched on the subject I believe that an engine will live a long and healthy life with nitrous use if you just don't exceed certain limits. Pretty much all common sense...
1) You can't ask the engine to make too much torque, you'll bend the rods
a)You can use more nitrous at higher rpm and in higher gears, the converse is also true.
2) You can't overrev the motor, rods will fly apart.
3) You have to have enough fuel
4) You can't have too much ignition advance or too low of octane
5) You can't run nitrous for too long with stock internals, rings will butt together and pistons may get a hole in them.
6) Any detonation with stock internals is BAD. Cast/hypereutectic pistons will crack pretty easy under these conditions.
example 1:
Neon guy decides he wants to see what nitrous does if you shoot from idle. I saw some nice pics of bent rods...
example 2:
Neon guy has a 2.4 with bolt ons, shoots a 75 shot for awhile with no problems. Moves up to a 100 shot and blows up his engine in a month. Why though? This guy was doing a couple no-no's. He had a stock fuel pump (only good to about 225hp), AFX pcm which advanced timing, no timing retard, stock internals, and raced a Mustang Cobra to over 140mph when he got a big hole in one of his pistons.
example 3:
Civic guy w/ a d16 hatch, stock internals, did everything right, had a 3 stage nitrous system and shoots a 150hp NOS shot, even 180 a few times. Never had a problem in the couple years he had it set up like that. The car was still running strong when he sold it.
I've been thinking the most important thing to consider for me is to not exceed the torque limit of the engine since i have the other things covered. I may try my theory out with more nitrous but longer build times sometime soon..."
