Nitrous tune on dyno or street???

[obengston]

I just recently installed a nitrous system.

Elderbrock RPM 100-250 shot system.

I added the following:

1. Digital RPM window switch
2. MSD mechanical retard switch (can pull timing before use)
3. Lean shut down switch (detects if going lean then shuts system off)
4. remote bottle opener
5. heater with pressure switch
6. digital tank pressure gauge (so I can see the pressure while driving)
7. wot switch

I do have a digital AEM A/F gauge

I put a "t" -an fitting before fuel log on carb and run line to fuel solenoid. I have the new holley mechanical (flows 175gph) with out needing a regulator.

I have 8an gas line from tank to fuel log.

So i will use the lowest pills 1st (100 shot). My question is it better to do this on a dyno or on the track (test) first.

I'm thinking dyno 1st so I can do the NA pull 1st then on the juice. Any comments or suggestions...

Engine is 383 forged internals, Dart Pro 1 215 worked heads. AED 750 Carb. Custom ground cam, 1 3/4 stepped to 1 7/7 headers, 3" exhaust, MSD ignition system, compression 10-8

Plugs AR3933 should I change these??

[sam 74]

you need to go 1 step colder on the plugs for every 50 hp gain in nitrous, if i remember correctly, but without a lot of nitrous jets to test out or an adjustable fuel system for the nitrous you won't be able to tune the nitrous per say, just check what actual hp your getting at the wheels, also you'll need to use a small plug gap, i had best results with a .035 gap

[obengston]

So since I'm currently running AR3933 (I believe is in the middle as far as heat range) you say go with a AR#3932? , and gap around .035, Sounds good. Again I have the pills to go from 100, 150, 200, and 250. Is this plug good to stay with or should I get a different kind, probably more of a personal preference I'm sure.

[sam 74]

you're probably good with that plug up to 150 shot then i'd take another step colder when you go above 150. you can tune your nitrous with an adjustable fuel regulator, i found mine liked 5 psi of pressure with the solinoid open. sometimes even though the rateings are 100, 150 and so on thats not what you actually get at the wheels. if you're going to have someone tune it for you make sure they know what they are doing, i've seen people lose their motor on dynos trying to tune nitrous setups.

[obengston]

How do you know what psi the system likes? What do it do or don't do? Man I'm already regretting this dyno tomorrow bitting my nails..., but I have murphy on my side so I'm sure it will blow in the morning....

[sam 74]

quarter mile time and mph, i did my tuning on the track. it took a while but i slowly dialed it in. you can actually change the hp output of the rated shot through your fuel pressure, its not a giant gain but when you're looking for every bit you can tuning is your best friend. i've been using nitrous for 10+ years and i haven't had a blow up yet, knock on wood, if your tuner is good you shouldn't have any issues.

[obengston]

I took it to the Dyno today. NA was about 383 rwhp, then started with a 100 shot then to 150. After tuning it was almost at 500 rwhp, but had to let off because it was blowing through the hughes 3500 stall. So now I'm pulling the converter to have it worked. Other than that it did really good. So the NA of 383 rwhp did pretty good 11.7 in the quarter without tuning the suspension. Can't wait to see what the extra 140 plus hp will give me as far as 1/4 mile times. Plus the converter was flashing up to around 4300rpm, and then blow through at around 6100rpm.