what is it about nitrous the makes it break stuff?
04-28-2009, 08:25 PM
#21
The post above is for the one that say im crazy ,The first post that i put up sound reasonable. But i guess you all know best. But nitrous need less timing, more fuel, lower heat range plugs and a good tune. and a WB to watch air to fuel mixture. Thats all i said.
04-28-2009, 10:04 PM
#22
How can you tell someone to take out 4* of timing for every 50hp if you don't even know what cylinder head, valve angle, compression ratio, camshaft timing, quench, etc...? Who ever came up with the equation for taking a certain amount of timing out per 50hp should be slapped. Every engine is not the same, and does not take the same formula. Contrary to popular belief, nitrous also does not need more fuel. If you are tuning nitrous by reading the a/f ratio, you are pissing up a rope. A/F ratio is meaningless with nitrous. The N/F ratio is what matters. The only way to correctly tune nitrous is reading the plugs. Smaller single systems are typically not as critical. You will always burn a piston from being rich and/or over timed before you will from being lean. I personally can't say I have ever seen a piston that was burnt from a lean condition. Every one I've seen have either been melted from too much timing, or had lifted ring lands from too much fuel, just to name a few scenarios. They all typically result from over timed, or overly rich.
04-28-2009, 10:17 PM
#24
There is no optimal a/f ratio. Kind of like n/a, you feed it unitl it stops making power. Tune by the plugs. Whatever the engine likes, it likes. Once you get the tune-up close, you can monitor the a/f after that as a reference. I have some tune-ups that ended up in the 14's. My personal car is in the low 14's, and spraying between 4-500.
04-28-2009, 10:25 PM
#26
Well, 99 out of 100 of us dont have the time nor money to be sitting on a dyno to find all this out and pull plugs...
My wideband has helped me out alot in tuning for N/A (~13.0) , then I just throw in the recommended nozzles and hit the ~12.0 range and pull some timing and call it a day. You follow a few "general" rules and it help you spray safe.
Ive went lean pretty bad one time and thought I got off the gas pretty quick, when I got back and pulled plugs 4 out of the 8 had no ends left.. Im sure if I wouldnt of had the wideband in and saw it when I did it could have went alot worse. So, I dont think your statement of A/F on nitrous is accurate.
My wideband has helped me out alot in tuning for N/A (~13.0) , then I just throw in the recommended nozzles and hit the ~12.0 range and pull some timing and call it a day. You follow a few "general" rules and it help you spray safe.
Ive went lean pretty bad one time and thought I got off the gas pretty quick, when I got back and pulled plugs 4 out of the 8 had no ends left.. Im sure if I wouldnt of had the wideband in and saw it when I did it could have went alot worse. So, I dont think your statement of A/F on nitrous is accurate.
04-28-2009, 10:30 PM
#27
Well, 99 out of 100 of us dont have the time nor money to be sitting on a dyno to find all this out and pull plugs...
My wideband has helped me out alot in tuning for N/A (~13.0) , then I just throw in the recommended nozzles and hit the ~12.0 range and pull some timing and call it a day. You follow a few "general" rules and it help you spray safe.
Ive went lean pretty bad one time and thought I got off the gas pretty quick, when I got back and pulled plugs 4 out of the 8 had no ends left.. Im sure if I wouldnt of had the wideband in and saw it when I did it could have went alot worse. So, I dont think your statement of A/F on nitrous is accurate.
My wideband has helped me out alot in tuning for N/A (~13.0) , then I just throw in the recommended nozzles and hit the ~12.0 range and pull some timing and call it a day. You follow a few "general" rules and it help you spray safe.
Ive went lean pretty bad one time and thought I got off the gas pretty quick, when I got back and pulled plugs 4 out of the 8 had no ends left.. Im sure if I wouldnt of had the wideband in and saw it when I did it could have went alot worse. So, I dont think your statement of A/F on nitrous is accurate.
04-28-2009, 10:34 PM
#28
But don't take my word for it, I'm nobody.
Read up on this guy, or send him an email, and he'll tell you the same thing I just did. His name is Monte Smith, and is the Technical Director for Nitrous Oxide Systems (NOS).
http://www.montesmithperformance.com/
Read up on this guy, or send him an email, and he'll tell you the same thing I just did. His name is Monte Smith, and is the Technical Director for Nitrous Oxide Systems (NOS).
http://www.montesmithperformance.com/
04-28-2009, 10:35 PM
#29
Running 100 octane, had 5* pulled via timing tuner.. ran 175 shot when later I found out that my fuel system was tapped out at 80 shot. I went lean. On top of that my NANO bottle went to ~1500psi due to the regualtor was fucked up on the fill up. Call it what you want, I changed plugs and ran ET below next time out.
I would also imagine your block is built for spray... So, you have a bigger window for error.
I would also imagine your block is built for spray... So, you have a bigger window for error.
04-28-2009, 10:53 PM
#32
Running 100 octane, had 5* pulled via timing tuner.. ran 175 shot when later I found out that my fuel system was tapped out at 80 shot. I went lean. On top of that my NANO bottle went to ~1500psi due to the regualtor was fucked up on the fill up. Call it what you want, I changed plugs and ran ET below next time out.
I would also imagine your block is built for spray... So, you have a bigger window for error.
I would also imagine your block is built for spray... So, you have a bigger window for error.
I also have a 3600lb race weight f-body, cam only with a 6 speed with a .062 nitrous jet that runs 9.80s.
04-28-2009, 11:02 PM
#33
Running 100 octane, had 5* pulled via timing tuner.. ran 175 shot when later I found out that my fuel system was tapped out at 80 shot. I went lean. On top of that my NANO bottle went to ~1500psi due to the regualtor was fucked up on the fill up. Call it what you want, I changed plugs and ran ET below next time out.
I would also imagine your block is built for spray... So, you have a bigger window for error.
I would also imagine your block is built for spray... So, you have a bigger window for error.
Pulling a set amount of timing would all depend on where you started. Most tune NA by putting in as much timing as they can get away with until the get KR. A lot of folks on this board could pull 5 degrees of timing NA and barely notice a loss in MPH, if any. You should pull at least 2 degrees per 50hp for the first few 50hps. With more nitrous you should increase that ratio, then pull a little more just for the hell of it. You can always add timing later to get more power, but you can't take it away from the motor you just melted down.
If you've got to waste a few sets of perfectly good plugs, that's chump change compared to what it costs for even the smallest nitrous **** up.
04-28-2009, 11:10 PM
#34
Had you not have been running so rich, the fuel system would have been better for a little bit bigger shot, and you wouldn't have had as much timing which would lessen the chance for failure during a lean scenario (although that's not the point of pulling timing).
Pulling a set amount of timing would all depend on where you started. Most tune NA by putting in as much timing as they can get away with until the get KR. A lot of folks on this board could pull 5 degrees of timing NA and barely notice a loss in MPH, if any. You should pull at least 2 degrees per 50hp for the first few 50hps. With more nitrous you should increase that ratio, then pull a little more just for the hell of it. You can always add timing later to get more power, but you can't take it away from the motor you just melted down.
If you've got to waste a few sets of perfectly good plugs, that's chump change compared to what it costs for even the smallest nitrous **** up.
Pulling a set amount of timing would all depend on where you started. Most tune NA by putting in as much timing as they can get away with until the get KR. A lot of folks on this board could pull 5 degrees of timing NA and barely notice a loss in MPH, if any. You should pull at least 2 degrees per 50hp for the first few 50hps. With more nitrous you should increase that ratio, then pull a little more just for the hell of it. You can always add timing later to get more power, but you can't take it away from the motor you just melted down.
If you've got to waste a few sets of perfectly good plugs, that's chump change compared to what it costs for even the smallest nitrous **** up.
I dont know what you mean by running so rich... I never said I ran rich, I ran lean. Run out of fuel = lean.
And to be honest, I cant remember if it was a 150 or a 175 shot I was running at the time. It was over a year ago.
04-28-2009, 11:16 PM
#35
You've got to know which set of general rules that you should be following. There's a right set and a wrong set.
04-28-2009, 11:21 PM
#36
12.0 is just a number I shoot for and generally a safe one on the spray. Sometimes it ends up 11.5, sometimes 12.3.. I have a stand alone in the works (to fix the fuel issue) and it should be done this weekend. PLan on running the 116 octane, that should help.
Let me ask you this, so with running 100 octane in the tank and 116 in the stand alone, what would be the advantage? Less timing, running a leaner A/F??
Last edited by waterbug1999; 04-28-2009 at 11:26 PM.
04-28-2009, 11:28 PM
#37
Gotcha.. I thought you were talking about my melt down being rich. I was like
12.0 is just a number I shoot for and generally a safe one on the spray. Sometimes it ends up 11.5, sometimes 12.3.. I have a stand alone in the works (to fix the fuel issue) and it should be done this weekend. PLan on running the 116 octane, that should help.
12.0 is just a number I shoot for and generally a safe one on the spray. Sometimes it ends up 11.5, sometimes 12.3.. I have a stand alone in the works (to fix the fuel issue) and it should be done this weekend. PLan on running the 116 octane, that should help.
Contrary to popular belief, nitrous also does not need more fuel. If you are tuning nitrous by reading the a/f ratio, you are pissing up a rope. A/F ratio is meaningless with nitrous. The N/F ratio is what matters. The only way to correctly tune nitrous is reading the plugs. Smaller single systems are typically not as critical. You will always burn a piston from being rich and/or over timed before you will from being lean. I personally can't say I have ever seen a piston that was burnt from a lean condition. Every one I've seen have either been melted from too much timing, or had lifted ring lands from too much fuel, just to name a few scenarios. They all typically result from over timed, or overly rich.
Safe AFR is the correct AFR, which isn't rich or lean. You can hurt the motor with too much of either. You can't hurt anything with too little timing.
04-28-2009, 11:35 PM
#38
But running a mix of race fuel it is important that you always keep the mix the same or check the state of tune after changing fuels. They all have different burn characteristics which will have an effect on the timing that you have/need.
04-28-2009, 11:40 PM
#39
150-175 isn't that big of a shot. I think you could get away with less fuel, assuming cold plugs and correct timing. It's up to you to figure out what plugs and what timing it will end up being.
But running a mix of race fuel it is important that you always keep the mix the same or check the state of tune after changing fuels. They all have different burn characteristics which will have an effect on the timing that you have/need.
But running a mix of race fuel it is important that you always keep the mix the same or check the state of tune after changing fuels. They all have different burn characteristics which will have an effect on the timing that you have/need.
04-28-2009, 11:51 PM
#40
Well, thats as big of a shot I think my stock block will handle... I always run 100 octane in the tank (easy to get ahold of)) when racing and 91 when around town and plan on just filling a 5 gallon can of some 116 race gas to top of the stand alone when needed. Higher octane should lesson detonation/KR, right?