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Re: How NOT to add NOS [Re: polyspheric] #1554909 12/30/13 12:48 PM 12/30/13 12:48 PM
Joined: Jul 2010 Posts: 1,845 Tampa D DusterDave top fuel
DusterDave top fuel D Joined: Jul 2010 Posts: 1,845 Tampa	Quote: "without fuel to match it stoichiometric ratio" Stoichiometric is irrelevant to tuning an engine for power except as a point of departure: find it, and go lower. 14.7:1 etc. is definitely not what you want to make with nitrous. The real question isn't rich or not, but how rich. Monte, where you at? Gone to the dark side with an LS3 powered '57 Chevy 210

Re: How NOT to add NOS [Re: Monte_Smith] #1554910 12/30/13 12:49 PM 12/30/13 12:49 PM
Joined: Jan 2003 Posts: 8,163 Plymouth, MI Blusmbl master
Blusmbl master Joined: Jan 2003 Posts: 8,163 Plymouth, MI	Quote: Just the dose of pure nitrous is not what hurt it, because without the proper amount of fuel to go with the added oxidizer, you are not doing anything.............BUT.........in this instance, as obviously they were "tuning" on the car, I would bet my bottom dollar the tune was rich. So when they hit it with all the nitrous, the tune got "clean" for a split second(you hear the motor rev)it made some real power, was over timed for that power and pushed a head gasket out. Monte Liquid on a MAF will usually have it read low, but the nitrous had transitioned to gas at that point and was being "counted" by the air meter so the ecu kept adding fuel. I don't think they changed the tune any, I think they just opened up the bottle with the motor at wot and hoped for the best. Unfortunately on a lot of cars timing is modified based on intake temp, so when the intake temp plummeted the ecu thought the motor could handle additional timing. I will say I don't think I've ever seen a head gasket pop that quickly, lol. '18 Ford Raptor, random motorcycles, 1968 Plymouth Fury III - 11.37 @ 118

Re: How NOT to add NOS [Re: Bad340fish] #1554911 12/30/13 01:13 PM 12/30/13 01:13 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Back on Drag Week 10 when the crew was running the Wanbulance, the alt took a dump...so they bought a cheapo gen to hang on the back bumper to run a charger.. on the last night we tried to blow up the gen, hitting it with spray.... never did blow that thing up... but it was fun trying

Re: How NOT to add NOS [Re: MR_P_BODY] #1554912 12/30/13 02:09 PM 12/30/13 02:09 PM
Joined: Jan 2005 Posts: 2,540 Milwaukee WI T TRENDZ master
TRENDZ master T Joined: Jan 2005 Posts: 2,540 Milwaukee WI	Quote: Back on Drag Week 10 when the crew was running the Wanbulance, the alt took a dump...so they bought a cheapo gen to hang on the back bumper to run a charger.. on the last night we tried to blow up the gen, hitting it with spray.... never did blow that thing up... but it was fun trying Thats an example of the timing issue... Generator engines are not tuned for throttle response. They are tuned for max torque. Alot can be taken from this simple example "use it 'till it breaks, replace as needed"

Re: How NOT to add NOS [Re: DusterDave] #1554913 12/30/13 02:42 PM 12/30/13 02:42 PM
Joined: Nov 2004 Posts: 6,890 North Alabama M Monte_Smith master
Monte_Smith master M Joined: Nov 2004 Posts: 6,890 North Alabama	Stoichiometric is a fixed number. It is what it is. NO performance engine will run under power at stoichiometric ratio. Cruise maybe, under power no. It is too lean to make power. Nitrous motors make best power at the same A/F the motor makes best power. So if your engine performs best at say 12:8.1 and you decide you want to spray, THAT is the A/F number you tune to. As for the video, it is easy to see the sequence of events if you watch and listen. When the nitrous first hit, the ECU compensated and it went dead rich. It cleaned up a little, the rpm jumped, it made power, hit the limiter and then pushed a head gasket. Doubt the motor was even hurt other than the head gasket. Monte

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