new to nos! when they say retard timing.back off from factory timing are actually 4deg after top dead center?ran 14.82 on motor added a 75 shot ran 14.07. i bought plugs 1 heat range colder and would like to set timing for 150 shot. nx system wet.87 iroc true 350 all stock except screens taken out mass and flowmaster and trans work.9bolt bg rear.

 

Make sure you have good bottle pressure and a bottle warmer. Pressure should be around 900 to 1100 psi.

You would usually retard timing 2 degrees from base per 50 hp. You should actually be at 0* at base with a 150 shot. Stock base timing is 6* Before Top Dead Center(BTDC). Also go one more degree colder on the spark plug with the 150 shot. (AC Delco R43TS)

 

okay i think u just really cleared my problems of findin colder plugs. is that plug number 2 degrees colder or what? becuz im planing on runnin about a 125-150 shot with my N.O.S. superpowershot set up and im having trouble findin the right plugs. so is that number u listed the number i would need for 2 degrees colder plugs or no?

 

yeah that's 2 degrees colder than stock. stock is R45TS

 

Check out MSD and Jacobs, both sell fairly inexpensive timing retard controls that make this ALOT easier. It will automatically retard the timing, or you can use a **** to accomplish the same thing.


Too much timing advance and nitrous make big boom....



HTH

 

Leave timing at stock for 150 hp shot...The general rule of thumb is to retard 2* from what runs well on your car for every 50 hp.

Example:
My car runs well N/A with 12* initial. I backed off 6*(for 150 shot) back to 6* (which is factory) and ran a 12.9@109.25 with no problems (I also ran 2 plug ranges colder). If you back timing to 0* your car will run like crap

 

Considering that his car is basically stock and the stock base setting is 6* (as specified on his Catalyst sticker under the hood) his base should be 0* for the 150 shot. This is what lead me to that conclusion.

 

I can see how you came to your conclusion (sound reasoning), I came to the same conclusion 4 months ago before my Nitrous setup came along. I learned the truth, however, by talking to NX tech support and getting replies from people with similar nitrous experiences. I'm not saying you're wrong, just that it is unnessecary to take out as much timing as you suggest.

I have stock heads, lower end, and cam...the only notable modifications made to my engine are intake, 1.6 roller rockers, and header-back exhaust - nothing major. The way his motor reacts to nitrous should be no different than mine, or any other thirdgen owner who runs nitrous on a stock - from the heads down - engine. I run 6* with a 150 shot, a few others run 8*. It works. You should tune your car based on performance, not what the catalyst sticker sayes (ie: retard 6* from that which your car likes initial). Ask 12secGTA, or do a search - it will confirm what I said.

On a side note, don't worry about emissions with 12 or even 15* initial timing N/A. I passed (with 12* initial timing, no smog pump, 50 psi of fuel pressure, and only a 3" Dynomax Superconverter cat) the driving test with 0.38 PPM HC (0.8 PPM limit) and 6 PPM CO (15 PPM limit).

 

thanks alot!for the info. I will get r43ts plugs and retard to 0 for safety!!!! want to have fun! not a tow truck bill.thanks joseph. working on getting bottle warmer now!sorry about confusion i had it at 4btdc on a 75 shot over safety right!Instead of 6 like sticker says.