For those that like to be drug free, Co2 over the intercooler helps with air intake temps a ton = more hp.

 

A single dry shot of N20 right into the intake elbow won't hurt a thing. Nitrous cannot hurt a diesel like a gasser. When a gasser goes lean on Nitrous, that is when things begin to melt, Since diesels don't have spark plugs, if there is a lean condition, it simply does not light. Also there is no throttle to have backfires, in this sense, Nitrous is more suited to a diesel engine than any gasser. I'm going to put a single fogger on mine w/ a .62 jet and try it out on the dyno. Alot of local "non-sanctioned" diesel pulls will allow it, and I want to see what it does on the dyno as well...

 

WhiteSport600,

Using can and does hurt things..... You must o-ring your head at a minimum to keep things together. Also you can have a nitrous backfire, I have seen and done it twice. I destroyed a dyno shop's exhaust system from a nitrous backfire!

Doug

 

An O-ringed head is not necessary if you're running a mild shot. If you go and throw a big orifice in on top of a heavily over fueled truck... You bet you need it. Since almost everyone I've heard of is running a dry manifold kit (except for 1 or 2 I've heard are experimenting with wet kits), I'll assume we're talking dry manifold systems...

99.9% of n2o backfires are through the intake, on wet manifold kits and on vehicles with ignitions, but on occasion you'll get a considerably smaller dry manifold intake back fire... Once again on a vehicle with an ignition. I'd like to hear the logistics of ruining a dyno exhaust evac system from a nitrous induced backfire through the exhaust . An extreme EGT igniting unburnt fuel & air perhaps??? Most common reason for a backfire is on wet systems and when the motor lays down off of the line or the driver back pedals... The fuel may or may not fall out of suspension in the air due to instant reduction in MAP and intake flow, may or may not puddle in the intake, the driver get's back in it, the ignition goes from an extreme retarded state to an extreme advanced state and during this time the intake valve opens with a residual burn left over from the inefficient ignition event and boom... You just lit off all of the n2o and fuel in the intake... On a dry kit the explosion would only be dictated by the amount of fuel there was left if the combustion chamber. Throttle bodied vehicles compound this effect as when the throttle valve is closed during this event, the volume between it and the cylinder act as a secondary combustion chamber until the throttle valve is forced or bent open. I've dumped the second stage of a 250hp shot independant bottle two stage system at the 60 foot line WITHOUT the second bottle in the car... It literally split the fiberglass hood in the center and felt like someone threw a concussion grenade in the car.

As the ignition event on a diesel is self created from the cylinder pressure during the compression event and all valves are long since closed, the likelyhood of a n2o backfire on a diesel is EXTREMELY unlikely.

 

azcrawler,

I have to disagree on a small shot of nitrous being OK. I have played with nitrous on diesel for over 4 years now and again and again I see guys try and run a "small shot" without an o-ringed head. Eventually they fail..... Normally guys use their trucks for everyday use so if it lets go it will not be convenient and will be much more of a problem then doing it right from the start. Its kinda like having an auto tranny and putting in injectors and a comp box, it will last awhile but not forever.

Normally the backfire on a diesel is caused by dumping the nitrous into the intake prior to enough boost. The explosion is pretty impressive! as for your question on the exhaust evac system, we use it on all diesels due to the excessive smoke they produce. It is nothing more than 5" flexpipe hooked to the exhaust and vented outside, most dyno shops use this type of setup.

 

I can tell you for a fact,from my truck,if you spray it without enough boost,it will backfire back through the intake and at night when it does it,it will shoot about a 3 foot flame out from under the truck,both with one nozzle and a .063 jet dry,and with twin nozzle and .100 jet dry,so if you hook up spray take Jetpilots advice,and hook up a boost switch to not allow it to come on to soon,I've popped mine about 5 times,and have a new gasket and studs laying on the bench,I know this gasket is on borrowed time!!!!

 

I wasn't saying that spraying it before boost is built wouldn't cause a backfire, that's a no-brainer... Diesels have no vacuum to draw the N20 into the cylinder, the turbo HAS to be there to "push" it in, it's still hard to explain why they backfire though, because anytime there is fire in the cylinder, the valve MUST be closed...unlike a gasser. I was simply saying that when N20 isn't abused, it doesn't cause problems on a diesel. Raised cylinder pressures are the only downside, but that happens with everything you do to raise HP. Headstuds, probably gonna need 'em.... O-rings, probably not necessary unless you are way too serious.

 

I'd just like for someone to explain exactly what occurs when you're getting these dry manifold back fires... Residual burn left over after the exhaust valve closes and then the intake valve opens? That's the ONLY thing I can rationalize it as. I'd honestly like to see a 3-foot dry manifold back fire through an intercooler and turbo. I only had MAYBE a 6 +/- foot flame through a NA intake with a lake of Turbo Blue sitting in the bottom. Anyway, interesting dialogue .

Jet'- Yeah I know all about the evac systems . I've had my fair share of test & tune pulls. I was just suprised that the hose or system could be ruined. Sounds like they might have been using a flimsier flex pipe. The two shops I use out here have thick silicon/rubber type material 6 inch evacs & I've seen them take some serious abuse 900+ hp cars. I can't even imagine it getting damaged.

 

Even if a Diesel had a severe nitrous backfire, there is nothing to hurt. It will blow/shred an intercooler hose before doing damage to anything. Pressure will definitely go back toward the I/C and blow a hose before blowing a head gasket. The head gasket seals against insane cylinder pressures (even stock) and the I/C hoses are designed to hold to around 60-70psi... Which do you think will go first?

 

I'd guess it more like this: Severely over-fueled truck, residual fuel left in the cylinder and an exhaust valve that is somewhere in the vicinity of 1600 degrees. This will not ignite diesel at all, but when you add enough Nitrous...anything could happen

 

Well I wish I still had the pic of the 5" SS flexpipe that was pretty much shredded like a slinky when mine went bang one day.....

WhiteSport600,

Diesels do have vacuum. The cylinder pressures are also much higher running nitrous, thus the need for o-ringed head. Some of the guys running the MLS gasket are having better luck with headgasket integrity but they still are failing. Using o-rings/firerings and studs are really necessary for guys who want reliability. If someone doesn't care whenwhere their headgasket lets go then I say go ahead and run nitrous without the headwork. But, if you want to drive to and from the track/dyno without the probability of failure then I would recommend making the proper mods.

My first time I played with nitrous in early 2000 I was able to make 5 dyno runs before the headgasket went. Once it was o-ringed I was able to push the motor over 760 RWHP and I drove it all over the country to race. In 2003 I installed nitrous on a 2001.5 truck and made over 900 uncorrected RWHP, but even with studs and an o-ringed head I blew the headgasket! Yes these trucks were extreme but I have seen a headgasket blow with a resonable boost level, wastegated and a really small shot, you just never know.

Doug

 

Ooooooooof!

 

Well then, I guess I can't argue with that... Pretty impressive experience there man, I wish I could've seen something like that.

 

I guess my stock HG is doomed......

 

mine is right behind you