How big of an effect does bottle pressure have on your times? I've seen discussion of preffered pressure levels but I have a simple setup with no bottle heater and am pretty much stuck with whatever the outside temp allows me to have.

Last time I went to the track (first and only time with nitrous) I ran a 14.8 best on the night. NA I run 15.5. I am running a 65hp shot. Seems like everyone is seeing a full second or more drop with 50+ hp shots. I know it was a cold night, I think in the 50s, so the bottle was cold and pressure down. It also dissapeared fast, my times climbed up in a hurry, getting to 15.3 only 3 runs after the 14.8

Since the track in now closed for the winter, I was just curious what I could have done with optimal pressure. Thanks for any input.

 

I don't know about actual times because I've never been to the track before, but I am a witness of what bottle pressure can do for actual power levels. I had an 80-shot jet (NOS rates their jets at the crank, right?), dynoed it at 1200+ psi and got 100hp and 150 tq at the wheels over baseline. It's amazing what a few hundred psi can do...that's why I think a bottle heater is a necessity.

 

Bottle pressure is as crucial to power output as fuel pressure is. Both will determine the amount of power that a given setup will put out. A change in temp of only 100 psi either way can make as much as as 50% diff. in power output. In other words, if you have your system tuned for say 60 shot and you run the temp 100 psi lower than the optimal 900-1000psi, it is then only putting out 40-45hp.

Bottle temp is very critical to both tuning and accurate power output. A heater only costs about $100 thru outlets like ebay, so there is really no really good reason not to have one. It is also impossible to properly tune your system w/o having constant/predictable bottle pressures.

 

Hopefully I will be able to get a heater by the time the track opens up again in the spring. I guess if I had normal pressure I probably could have ran mid 14s easy then. I had a feeling that the pressure was way down and hurting me. Oh well, I'll find out for sure next spring, thanks for the info guys.

 

One good product of low nitrous pressure though is that it probably won't do any damage, you will just run rich. Much better than lean. As long as you have a gauge you can just put your bottle under your heater outlet to bring the pressure up, I have watched many guys do that, cheap bottle warmer and it cools the engine at the same time.

 

I have seen guys also use a torch to heat the bottle up. This is not such a good idea since there is little control as to how quick the bottle warms up once the metal starts to heat up.

I still suggest that you go with the heater since it's really inexpensive and reliable.

 

Hey thats a great idea, I never thought about that. I do have a pressure gauge, just haven't put it on yet. (of course, I got it after I went to the track so I don't know what the pressure was that night). As soon as it warms up a bit and drys off I'll try that, thanks.

 

which bottle heater do you guys recommend? some are temp controlled or psi controlled..

whats the difference and is there one better than the other? or all the same?

 

I personally use the NOS brand heater. I haven't used the NX one which is psi controlled. Only difference between the two is how they come on. One uses two little metal probes that go between the heater and the bottle (works like a thermostat), and the other is connected to the bottle's valve and senses pressure.

To be honest that's really the only difference between the two. The heater elements and electrical connections are pretty much the same. Both are set up to help you get 900-1000 psi optimum w/o you having to do anything but turn it on.

IMO one is not "better" than the other since they both do the exact same thing and have the same basic factory settings. You should probably choose one based on either price or preference. Some people like to keep their entire system one brand, others don't care.

You can get a baseline price guide by browsing thru ebay. They usually have several for sale of each. I've seen them be had off ebay, brand new, for less than $100. That's about $50-75 off reg. retail price.

 

If you believe that no matter how much nitrous is in your bottle that the same temperature will give the same pressure, then OK the NOS will do it.

Personally I want it regulated by the pressure because I don't believe that 85 deg or whatever NOS regulates it to will give the same pressure for all bottle levels.

Regulating by pressure is more accurate. We are trying to keep the same pressure not temp, I think NOS got a deal on those regulators.

 

so what do you recommend?

 

I am using the NX (pressure regulated). Remember that with less n2o in the bottle it'll take more heat to bring it up to the right pressure so the NOS might not be as effective.

And concerning running without a warmer on a cool day: I've noticed lately that when I purge and it's cool outside sometimes I don't get that white gaseous plume. I filled the bottle and it still had six pounds in it. (pressure in bottle was about 650-750 psi) But on warmer days with the heater on and pressure right about 900 psi I can blow almost a whole tank of n2o and see that cool cloud rising up!

So yes you'll get more nitrous out when the bottle is at the right temp (this explains the quick fall off in ET when you do multiple runs on a cold bottle)

 

I have noticed that the temp outside does have an effect on the size of the plume. I think its just the difference between the temp of the nitrous and the outside temp. Seems to be a much larger plume in hot weather.