AME_VIP

iTrader: (2)

Some of you may know I have an NX wet nitrous kit . 150 shot. liquid filled NX pressure gauge, downtube and TPS switch are the only accessories.

92 SC400 auto
NGK BKR7E plugs (NGK 6097)
K&N drop in filter
94 octane fuel
walbro 255lph fuel pump
B&M fuel pressure gauge (reads 44psi at idle)
Full bottle. Filled up the day before. Bottle pressure only reaches 600 psi.

No nitrous I dynoed at 171.6 HP with A/F ratios about 11.0:1

With 150 shot I dynoed at 267.6 HP with A/F ratios about 10.1:1 !

These #s are very dissapointing. My a/fs are wayyyy rich!
btw this was done on a Dyno Dynamics Dynamometer with intertial dyno compensation factor (*1.17)

One problem is that I don't have a bottle warmer and my gauge was reading 600psi.

My next move is to get a SAFC and possibly a fuel pressure regulator to lean out the mixure.

Any advice from you guys would be great! Thanks.

BigManne

iTrader: (3)

get that bottle presure up to about 900-1000 and it will change your numbers. it will hit alot harder too

AME_VIP

iTrader: (2)

thanks. A bottle warmer is definitely first on the list.

A local DSM tuner is telling me that its the higher fuel flow of the 255 fuel pump. Its a common problem on dsm's that the return oriface on the stock regulator is too small to return all the fuel. Therefore, I'm having the same issue and thats why its so rich without and with nitrous.

codetoad

iTrader: (2)

the bottle pressure is definitely the problem. You should be making at least 40+ whp more than that once its at the right psi (950-1050)

Do you still have factory exhaust?

mkorsu

TT:

What was the mileage of your engine when you installed the NO2? Condition of the internals?

Mikethe1st

I had no idea these cars ran sooooo rich stock.

AME_VIP

iTrader: (2)

It shouldn't run that rich. I think its the 255 fuel pump. Anyone put the pump in with no big power adder mods and gone to the dyno?

150 shot is fine.

111,000 miles on the motor. Still on factory exhaust.
I have a B&M fuel pressure gauge as well thats under the hood.

Codetoad, I know I need a warmer but it still doesn't explain the richness with no N20.

Jimbo2828

thats weird my car i dyno and got 203 at the wheels with no nitrous hmm i might consider getting nitrous now then hahahahahaha

mkorsu

What year is your car?? You definately didn't get 203rwhp out of a 92-94!!

AME_VIP

iTrader: (2)

what do most people get from a 92-94 ? I remember reading someone that got 190 whp on the dyno.

mkorsu

From what I recall, bone stock, no mods, roughly in the 165-175 range. RWHP. I forget who on here got it up to 211 or 214 rwhp with BFI, exhaust and a few other BPU's.

PHLSingle

I can tell you...with a doubt in my mind...your lower nitrous pull is directly related to your bottle pressure.

600psi is a near empty bottle @ almost any temperate - I'm assuming you didnt dyno in 0deg weather?

Go get it filled now, then redyno.

The other week, I was able to get up to *almost* 900psi w/the bottle warmer on full blast...there was only 2lbs of nitrous in the bottle and the hit was WEAK.

Filled it up & saw 1050psi....hit HARD.

AME_VIP

iTrader: (2)

Thank you.
The bottle was filled the day before the dyno run. I did not have a warmer installed.

Could low pressure in the bottle cause a rich condition because too much fuel was being added? 10:1 is way too rich.

SCV8

I would get rid of the "Y" in the stock exhaust, replace with an X pipe, or just twin pipes w/crossover tube(cheaper), and get a larger air filter before tweaking the mixture.
Those two mods will cost less than an AF/C anyways, unless you already have one.
You can make an aluminum plate that replaces the panel filter, and cut off the front of the airbox, mount new filter onto the plate. If you get a cone kit, make sure it's actually larger than the stock one, and has a good radius into the MAF.

Jimbo2828

my car is a 93 with intake and exhaust only heres the dyno sheet