Bottle Pressure

[FAT460]

Hey Guys...

Most systems recommend running bottle pressue at 900 to 950 PSI...

Has anyone played with bottle pressure?????

We played around a bit, running up to 1100PSI and with the appropriate jetting made more power on a dyno.... But we found on the track, the higher bottle pressure wasn't as quick... and i suspect that this is because the bottle pressure difference from the start of the 1/4 to the end of the 1/4 was much greater using a higher initial pressure....

Any thoughts???

[Steve-UK]

Could well be the drop in pressure causing the car to run rich at the end when you need the power, how long did you run the car for on the gas on the dyno? Did you measure the pressure drop when you ran it on the dyno?

[FAT460]

Could well be the drop in pressure causing the car to run rich at the end when you need the power, how long did you run the car for on the gas on the dyno? Did you measure the pressure drop when you ran it on the dyno?

Gday Steve....

When we tuned it on the dyno, we were really only tuning the A/F and as you would expect with a higher bottle pressure you can add some more fuel and make more power......

As you say, at the end of the track it felt as if it was nosing over slightly as it fattened up.....

After our little experiment, i've gone back to running 950psi, with absolute consistency on the track.....

[Nate]

I did a simple experiment yesterday with some larger solenoids. What I found out was around 1000 psi, the output of nitrous from the solenoid decreases. As pressure increased (around 1050), output continued to be slightly decreased, and then at around 1100, there was too much pressure and the solenoid no longer worked.

The solenoid must overcome the 950 pound pressure in order to lift. Most solenoids are made to stop working at about 1000psi. I have seen instances where it still works at 1100, but that's about it. So, as your pressure increases, your solenoid struggles more and more to lift the plunger that's inside it, therefore creating less output.

It is wise to run your bottle no greater than 1000.

[FAT460]

thanks nate....

[ZoomZ]

I run a consistant 1200 psi through my system spraying 2 kits setup 150/150 and have never had a problem like nate said , but i also run twin bottles and have jetted my setup acordingly .
The main thing is to be consistant , if you jet at 950 , race at 950 .

On one kit the car went 10.5 but i havnt sprayed the 2nd kit at the track yet .
On a 200 shot , my setup dropped 1000 psi from the tree to the traps .

Ive run 950 before but my pressures dropped before i crossed the line every time , so now i jet/run at 1200 psi .

[mrr23]

hey russ, glad you made it over. i usually run 1000 psi myself. IMO, 150 and under, stay with what the manufacturer of the kit says to run. when you start running large amounts of nitrous, bottle pressure is going to drop quickly. so, compensating with higher pressure to slow the amount of drop is one way. another would be to run two bottles "Y"ed together or a larger capacity bottle. i know of one guy that runs 1500 psi over on ls1tech.

[Nate]

What kind of solenoids are you using to run 1200-1500 psi?

[mrr23]

ZoomZ has NX last time i saw pics of his car. i'll check on the guy running 1500 psi.

[srsnow]

Actually the higher the bottle pressure you start with the faster you will lose pressure. So if you were having pressure drop issues due to an inadequate amount of nitrous volume for the amount you are running and you were limited to a certain bottle size you would want to start at a lower pressure. I've known of people setting up their system around 700psi to try and fight pressure drop. Although the best way would still be to increase the volume of nitrous through either one large bottle or multiple smaller ones.

[Helmsdini]

I have noticed that alot of companies including zex and some others are releasing nitrous regulators now, to keep the nitrous pressure constant through the entire run.
Here is an example:
http://www.mpsracing.com/products/MPS/PressurePro.asp

[srsnow]

There are a couple of problems with regulators, which is why they have never really caught on. When you try and regulate the nitrous it phase changes after the regulator and freeze everything also because of the phase change the density can change dramatically which will change the overall flow. Another problem is that because most nitrous kits are setup to run around 900-1000psi getting a high enough pressure to regulate back down with out hitting the critical point of the nitrous can be difficult. I know Dave Koehler did some testing on a regulator (not positive which one) and found that it did an adequate job on smaller HP settings but that didn't work on larger settings. I think an accumulator or gas bladder in side the bottle would be a better way of trying to maintain pressure than a regulator.

[Helmsdini]

good info! i wasnt sure how those things were working out and havent ever seen anyone use them.

[slopoke]

When you try to regulate liquid nitrous it can phase change back to gaseous nitrous and lose some of its cooling effect which may increase chances for detonation. They seem to work but there are risk involved. Nitrogen push/boost may be a better alternative. Anybody here use a nitrogen push system ?

[hookemup32]

i dont know alot about n20, you katts know alot more then i do but i had many times of havein too much bottle press over 1000+ psi and my solenoid would not work.