IWGF

iTrader: (6)

We had a dyno day today and I put the car up on the rollers to get it dyno'd.
Originally, my tuning passes a few months ago, the car made 574/612 with 950psi bottle pressure.
Today, it made 565rwhp, down 10 from last time. That was from the ridiculously high DA and correction factor today along with high heat. No worries, AFRs were fine.
2nd pass, car went REALLY fat on the dyno, 10.0. Made 523. I'm wondering if maybe it was due to a bad fill?
Both passes bottle pressure was over 1000psi
I still need to look at my plugs and see if they're fouling out. And no, I can't read these ones since I had to drive home after the dyno day (didn't have any tools on me.)
Thoughts? Opinions? I'm not the most experienced nitrous guy, but I'm learning.

Gary Z

How much over 1000 psi? You may have been flowing gas rather than liquid.

IWGF

iTrader: (6)

That's very possible. It was at like 1100, but it was higher (1200+ YIKES I know!) because I accidentally left the heater on too long and purged it down to that.

Gary Z

When nitrous oxide pressure is above 1100 the nitrous is above it's critical temperature, the temperature above which it cannot be liquid. When only gas is flowing, a lower mass is flowing. This explains why you were so rich and probably also explains why power was down.

IWGF

iTrader: (6)

I didn't know that... Guess I've got some more research to do. Thanks mang.
Any other opinions?

dnkynrbk

iTrader: (34)

I would say either the bottle was low on you just got all air comming out. Was this a brand full bottle. Before I have my bottles refilled I alway try to empty it out or try to let out as much air as possible before I get a new fill.

IWGF

iTrader: (6)

dnkynrbk,
It was a brand new fill. However, the shop that I've been going to seems to have bad fills quite often. My friends shop just got a fill station, so I'll be going to his shop from now on.
I didn't empty it all the way, but it was almost empty to begin with.

dnkynrbk

iTrader: (34)

man that sucks. This day in age we cant afford bad fills lol. What was the AF on the 1st pass?

IWGF

iTrader: (6)

Both passes today dropped to 10.0, which is definitely not good. Prior to that, it's always been right around 11.4-11.5

magnum-gto

I agree with GaryZ.......you were above the supercritical pressure and temp.
Your A/F went rich because you were flowing gas instead of liquid.

Keep the pressure below 1050 and the temp below 85* and you will reduce
your problems with "a bad Fill".

Oldsmobility85

iTrader: (1)

What do you mean by bad fill? if the bottle weighs out correctly (24.5-25lbs) there shouldn't really be a problem. Air doesn't weigh anything.

magnum-gto

Were you sending that question to the OP?

IWGF

iTrader: (6)

I believe he was. And he may be right, but I didn't weigh the bottle as I was in a hurry.

BAKED

iTrader: (14)

Truth^^^^