Nitrous and tunning
 

My son and I just installed a ZEX dry kit - 75 shot - on our 88GT project car. We're going to the track for some test&tune sessions. All the ZEX instructions said was to return timing to the stock 10 degrees that's it.

I've read some posts about guys tunning for nitrous - what should we do at the track? Is there any unwritten wisdom or magic in tunning with nitrous?

The thing about returning you timing to base is that the stock timing is already retarted from making peak power so you don't need to retard it more with only a 75 shot htat the ZEX is giving you . Once you get it all sorted out you may even be able to put a little timing back into it but i wouldn't risk it until you are sure that everything is working good then maybe adcance it one degree at a time.

Stock 10 degrees is fine for a dry 75 shot...

Re: Nitrous and tunning
 

I don't believe it is unwritten, but bottle pressure is an important aspect to nitrous tuning that is often overlooked by many beginners. In order to maintain consistent performance while getting the most out of your nitrous system, keep a close watch on your bottle pressure... keep it consistent, around 1000psi is what I prefer; however, the most common 'safe' range to work within is 900-1050psi. If you don't have a good bottle heater, get one (I prefer Nitrous Express products).

Oh, and start reading your plugs... you want them to be a charcoal grey color on the ground electrode.

-Ryan

Ryan - thanx for the info on the plugs, I do have a question. If the plugs aren't charcoal gray as you say - what colors are bad and what does these other colors indicate, I would assume one condition is lean?

You want to stay away from turning the ground electrode white, which is a lean condition... or too much timing advance.

Black, obviously, would be really rich. If you get them to turn a light chocolate/tan, that's right in the ball park for a good tune as well... that would be considered more of a safe tune that'll still make good power.

Also worth mentioning: the best way to get an accurate reading on the plugs, is to shut the motor down right after you cross finish line and coast over to the return road and pull a couple plugs there to get an idea of what direction you should move towards with the tune.

Hope that helps... I imagine it will when the time comes to jet the system up past 75hp. :)

10* is WAY safe...you shouldn't need to go lower than that...however if you ever upgrade to a timing retard ignition, then the unwritten rule says to retard the timing 2* for every 50 Hp of nitrous...(assuming you advance the timing)...