NOS Nelson..thanks for the insight. Sounds good to me. Hope youll hang around the boards and add to the discussion.

 

I just had a nitrous backfire myself this past thurs. I have been puzzled as to how it happened. My car always runs very rich on motor and on spray the A/F meter on the usually can't read it because it gets so rich. I blew my MAF off and caught my air lid and filter on fire. I did have the bottle pressure around 1100 psi and did spray around 2800 rpms. It also killed my battery when it happened though I guess it was about time for a new battery anyways. My plugs were gapped at .040. I haven't really seen anything in this thread that answers my questions. Anybody have an other insights as to why mine may have backfired.

 

There is no way for unburnt fuel to remain in a cylinder long enough to ignite the intake charge. A pig rich engine will pop and sputter all the way down track and will not ignite the intake charge. In order for the exhaust charge to ignite the intake charge the engine would have to be running as if the timing were set at 30 ATDC which we all know is impossible for an engine to remain lit on. I have tuned thousands of systems that were running way too rich and they never backfire out the intake. The answers are all here. I don't know how else to explain it for you.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NOS Nelson:
<strong> Nitrous in itself is absolutely non flammable. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">THANK YOU!!! I have heard SO MANY people try to tell me that nitrous is highly flammable, which is why it adds power. I raise my glass to you! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by pimpmaro:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NOS Nelson:
<strong> Nitrous in itself is absolutely non flammable. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">THANK YOU!!! I have heard SO MANY people try to tell me that nitrous is highly flammable, which is why it adds power. I raise my glass to you! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Next time someone tells you that you have my permission to call them an a**clown. After all if the car in the F&F exploded in a blue cloud it must be true. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

The only time you would get an explosion is if the bottle has been modified. For example plugging the pressure release valve. The standard valve is preset to blow at 3000psi. So if you heat the bottle too much the little cap pops releasing 3000 psi of expensive nitrous. The only other thing I've heard of happening is someone holding the torch in one spot too long and creating a weak spot in the bottle. Then eventually the bottle breaks or explodes, however I've never seen this happen, just rumor.
As long as you use it properly your in no real danger of a "Fast and Furious" explosion.

Jeffrey

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by B18B1LS1:
<strong> The only time you would get an explosion is if the bottle has been modified. For example plugging the pressure release valve. The standard valve is preset to blow at 3000psi. So if you heat the bottle too much the little cap pops releasing 3000 psi of expensive nitrous. The only other thing I've heard of happening is someone holding the torch in one spot too long and creating a weak spot in the bottle. Then eventually the bottle breaks or explodes, however I've never seen this happen, just rumor.
As long as you use it properly your in no real danger of a "Fast and Furious" explosion.

Jeffrey </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well said. Nitrous oxide is non flammable. By heating the bottle with a torch it weakens the aluminum and it loses it's ability to handle pressure.

Also yes an engine that is flooded with fuel at a low rpm will tend to want to detonate which may cause a backfire. Most however are caused by a lean mixture. We've all seen dyno pulls at the proper RPM range end up backfiring.

 

The only backfires I have seen have been at low RPM's. None of the cars in question had window switches. First one, six speed car sprayed and bogged, then pop(only MAF, intake, and lid, etc.). Second six speed car, guy was on and off the gas to get traction, pop(cracked block and head). Third car was a buddy's LT1, he sprayed at approx. 2000-2500RPM's, pop. Last one was a mustang spraying off the line, no window switch, pop.
Seems to me low RPM's or getting on and off the gas are the causes of the backfires I have seen.

One question, if nitrous is not flammable, then what causes the explosion when someone heats a nitrous bottle with a blowtorch? Maybe I'm missing something.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XAntivenomX:
<strong> One question, if nitrous is not flammable, then what causes the explosion when someone heats a nitrous bottle with a blowtorch? Maybe I'm missing something. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">My guess would be the big increase in pressure causes the explosion. Its not like the fire is actually touching the nitrous if the nitrous is inside the bottle anyway.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by B18B1LS1:
<strong> As long as you use it properly your in no real danger of a "Fast and Furious" explosion.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">It would wind up being much worse if the bottle popped.

Aluminum schrapnel flying in every direction.

Just hope you dont drop the bottle and break the valve off... youve got a missle on your hands then.

 

NOS Nelson...

sent you mail <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

Response sent. ( Mills Lane voice ) Let's get it on. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Tony TNT:

Fuel puddling was proganda come up by NOS to sell dry kits. [/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That is a pretty bold and dare I say ignorant statement. Do you have any facts to back up such claims or are you just making things up. There has been quite a few reasons why fuel would "puddle" and not be evenly distributed. What proof do you have that it won't. You have been awfully quite since that statement. Just wondering if you cared to back it up, or if by your silence you're admitting you were wrong. Here is your chance to set the record straight.

 

Hey Snow...welcome over to LS1Tech.
Just to clarify, and correct me if Im wrong, Snow is a tech for NOS.

Please give us your thought on the subject.

 

hey guys. im not an expert on N2O or anything, i have some knowhow. i have a buddy and a neighbor that owns 2 prostock cars, and they both run big shots of N20. well my buddy was tuning his car, turned the bottle on w/o purging the fuel and boom, all the butterflies in the carb were bent into a U. that seems like it would be from a lean mixture. as of N20 being flamable, its not. all it is nitrogen and oxygen. nitrogen is a nonflamable gas and oxygen is an oxidizer(inceases the ease and speed of combustion) that all nitrous really is. and if someone tells you that N20 or oxygen is flamable, u can call them a moron. i work with the stuff every day, so i know what it can and cant do.

 

Ok, so how about a system like Venom that pulses your injectors for added fuel?

It's sort of like a wet system, but better.

What about the new NX kit where it replaces your fuel rails?

I'd love to hear your opinions.

Thanks.

 

ok, here is my 02 since no one has really hit on a few important instances... the first and foremost has to do with Lobe separation of the camshaft. the second is timing.. too much timing with too much overlap and time bomb potentioal. carbed cars have more Lobe separation typically than FI engines to increase cylinder scavenging under higher RPM.. this is when a few degrees of crank rotation both valves are open at the same time to create a vacucum in the exhaust and to draw more air into the cylinder.. .this is what creates the "lope" with an aftermarket cam. some of the cyl pressure is actually released into the exhuast and creates flow pulses. Now when at low RPMS and you spray it under 3K you are increasing your chances of bogging when the spray is activated plus the potential for too much timing... keep in mind the added fuel with NOS increases cyl pressure DRASTICALLY very fast.. so if the car bogs (which is where 90% of backfires occur) you are in effect "stopping" the engine for a minute second which creates a backfire (remember in at least one cyl both valves are open and if the spark fires before they are fully seated ( timing to advanced)or the exhaust gas heat itself (or a hot ex valve if lean)is enough to ignite the vapors in the intake from both valves being open at hte end of the exhaust stroke and beginning of the intake stroke).. now add fuel puddling in the intake ( which is a REAL scenario i don't care what ANYONE says) and you have a potential time bomb waiting to go off. 5 liter mustangs were notorious for this ( remember the brass freeze plugs in the upper of a 5 liter? yep the fuel puddles there and when a back fire occurs BOOM and out go the freeze plugs and possibly the upper manifold with it) which created the need for a safer system which NOS developed the dry kit to minimize puddling which minimizes back fire potential... remember NOS by itself is inert.. it needs fuel and fire to make a bang... this is why the Pro Mod guys run cams with up to 118 Lobe centers... to minimize back fire potential.. 250 hp and up systems are not recommended on a 112 Lobe center... does it work? sure.. but the potential is there... 200 shot and up i run a 114 minimum.. but this is my preference and it works for me.. there are lots of reasons back fires occur and it is FACT wet "NON" direct port systems have a higher potential for backfire than do ANY dry systems.. you can experience it with both however.. there are no golden setups to completely do away with backifre potential... but rule of thumb is DON'T spray under 3K.. the more HP the higher the rpm... 2 DONT run timing too far advanced this creates and EARLY plug fire and then we go back to lobe separation agin.. make sense? hope this helps guys... the typing sucks but i hope i got he point accross...

Wes

 

383LQ4SS you are correct I am an NOS tech. The whole wet or dry thing is always being debated. I personally don't care for wet kits I have seen and talked to too many people that have had problems on all diffrent kinds of cars, some of these guys had been running them for months with no problem others didn't get 10 feet before they had a backfire. Most every problem I've seen with dry kits stem from one of two things, too big of a jet or incorrect install. Dry kits on LS1's tend to be limited to around 100hp due to the fact that they are a non bypass fuel system . So if people want more power they either go wet or direct port. I've talked to plenty of people who say they run bigger then 100HP without running lean but from the tests we did on the '98 test car 100hp was the safe limit. On my personal car I put 36's (about 125hp) in and the A/F ratio was 13.5:1. Like Nelson said he has built dry kits over 300HP. I've seen it. I've been at the dyno when it's happened. Wet kits have there place and with a few precautions the chance of a backfire can be lowered but there is always a chance no matter what. Like ChicagoZ06 said when the fuel injected mustangs first came out we said great single nozzle ahead of the throttle body slam dunk. How much easier could it be? Well after we got a bunch of calls with guys blowing up air boxes we thought maybe we should rethink this. Hence the birth of the dry kit. What better place to get fuel then from the injector. Isn't that where the factory wanted it to come from? It would have been real easy for us to just keep selling wet kits in fact we could have made allot more money if we did. We could have had a kit for new Mustangs along time ago along with allot of other cars. I don't bash other companys every bodys just trying to make a buck so I take offense other companys do. To say fuel puddling is "propaganda" seems un-professional which is why I ask Tony TNT once again do you have proof to back that statement up? Sorry for the long post but I just wanted to clear things up. It all boils down to this nitrous is fun anybody who has dealt with knows that any way you do it as long as you have fun. I will try to help where I can and will probably need help when it comes to other asspects of LS1's. So if any one has questions let 'em rip.

ChicagoZ06 good post lots of good points.

Shaun

 

Just wanted to add this is why i really enjoy ls1tech.com, this is excellent information and we even have big dogs chimming in with their info. <img border="0" alt="[worship]" title="" src="graemlins/gr_hail.gif" />