Nitrous HP Dilema

[1Slow90coupe]

I recently installed a NX wet kit on my car. I ran it at the track a couple of times. Then I took the car and put it on a dyno. Here is what I have.

Stock 90 efi 302
150 wet shot
other minor bolt ons
Dyno N/A was 205HP/320fttq to the wheels
stock plugs timing set at 10deg

No changes just 150 shot
306hp/455tq to the wheels

I talked to the guys at NX and they said that the timing should be set at approx 8deg and to use NGK UR6 plugs which are two steps colder than stock.

I talked to a friend that works at ford and knows far more about these cars than I do, and he says to run 1 step colder with the timing set at 10 deg.

I am trying to pick up the extra 50 or so HP that I am not getting the the 150 shot, but still want to stay fairly safe on the block.

Why is it that you run colder plugs than stock? Why back off the timing? Please be more specific than saying "because your supposed to"

Thanks for the help.

 

[ECU5.0]

you run colder plugs and retard the tiiming to prevent detonation which is very dangerous to your blocks health when running nitrous. i would listen to the nx tech guy and run the ngk plugs and run 8 degrees timing. he works for the company and knows more than your friend about nitrous. not saying your friend is dumb....but why not listen to someone who works for the company?

 

[1Slow90coupe]

I understand that detonation can cause serious damage. Detonation occurs when the motor is leaned out as I understand it. And on the dyno I ran rich the whole time. I think he may be telling me to play it a little too safe, and it's costing me HP. Am I wrong?

 

[Speeds8erM-1]

Nitrous doesnt always like timing, sometimes turning it back is not only safer but also makes more power. What was your bottle pressure? NX Kits are jetted rich and pick up quite a bit when they have a good bit of pressure.

 

[Grn92LX]

What was your bottle pressure and how was the a/f ratio? 8-10* timing should be fine.

 

[1Slow90coupe]

Bottle pressure was 1050-1100. A/F ratio was 11.25 to 10.25 at the end of the run

 

[2002BLGT]

what jets are you running ?

 

[FORCED2DV8]

Like others have said check your jet sizes to make sure you have the matching nitrous jet with the correct fuel jet, 8 degrees of timeing sounds about right, when you spray the rate at which the fuel burns is much quicker therefore timing is adjusted to make up for this. Go with the colder plugs, heat you nitro bottle, and check your normal fuel pressure, does the car run rich normally??

 

[1Slow90coupe]

The car does run a little rich normally. The fuel pressure stays constant, even while spraying. The jets are 62 Nitrous and 38 Fuel

 

[2002BLGT]

try a 65 nitrous jet , 36 fuel jet , 10 degrees should be fine with 93 octane and some octane boost , keep it at 8 if you arent sure ......and stock fuel pressure 38 psi ...... should keep the AF at 11.2 all the way to redline ( I have my own wideband , they are nice to have ) and that is plenty rich and safe .........a friend of mines running the same setup and netted a 7.68 at 90 mph the other night at a local eighth mile track ......

 

[fiveohGT]

nothing like nitrous on a daily driver....so much fun