Juicedz

I am going to the dyno tomorrow and I am going to be spraying a 200 shot on a builr bottom end. I have 1/2 tank of 114 gas. I don't have a controller for timing, so I will just go into the computer and pull it out. How much timing should I be running at wot? Also, will pulling out the time be safe and give me more power, or will it just give me more power if I have detonation?

GM Muscle

iTrader: (9)

If your doing mutiple pulls I think 20-22* would be a safe starting point. From there you should beable to go up alittle.

NXJeremy

I would say pull 2 degrees from what ever timing you run N/A.

Robert56

iTrader: (2)

I have run 22 and 24 on a 200 shot, and no problemo.
Robert

Patrick G

iTrader: (14)

Don't you want to pull 2-3 degrees for every 50 shot? If so, then you'll want to pull 8-12 degrees. If you're at 28 degrees N/A, then that would mean 16-20 degrees right?

rg42284

iTrader: (4)

Sorry to hijack the thread but
with a 150-200 wet shot and 22-24 degrees of timing, would a 50/50 mix of 91 octane and 100 octane be enough?

Robert56

iTrader: (2)

Well that's the general rule considering safety and no dyno. The best way to set timing is on a dyno for max power, of course without knock. Often, people that follow that rule really need no timing pulled and end up comprimising power. Now size of shot, fuel and other things have to be considered, that's why dyno tuning is the best. also, the other end of this is the misconception that the most timing without detonation equals best power. Untrue, often highest power will be reached at less timing, so the rule of advancing timing till some noise then back off, just isn't the right way.
Robert

necrocannibal

iTrader: (5)

I run a 200 wet shot with a stand alone fuel system running 116 octane and I run 26* timing with no issues.

NX_CaGEdApE00

iTrader: (7)

falcon listen to these guys... look at there setups and times.. they really know there ****....

id say start at 20-22 and go from there..

good luck buddy

Loudmouth LS1

iTrader: (10)

I ran 150 shot with 22 degrees of timing on 93 octane with almost 11.5/1 compression w/o any problems.

Y2K2LS1

Guys, please post what fuel you are using. And if you had a wideband what afr for that combination.

NX_CaGEdApE00

iTrader: (7)

good thought

Robert56

iTrader: (2)

Innovate LM1 WB, 11.5 a/f and 92 octane.
Robert

Patrick G

iTrader: (14)

I think some of you think that you want as much timing as the motor can take before detonating to make the most power on the spray. This is simply not true. Because nitrous burns so much faster than fuel/air alone, your optimum point of ignition lead will be a lot less.

Internal combustion engines make peak combustion pressure at about 15 degrees ATDC. In a naturally aspirated engine, we move the ignition timing to allow enough lead to give the burn peak pressure at 15 degrees ATDC. If you have 30 degrees of advance to make best power with your NA motor, that means it takes about 45 degrees for the combustion process to reach it's peak pressure.

When you add a 200 shot of nitrous, your burn rate is a lot faster. Probably only 33-37 degrees of rotation to reach peak combustion pressure. If you don't retard the timing, your peak combustion pressure will occur at 3-7 degrees ATDC. This is way before the sweet spot. The piston doesn't have as much leverage on the crank at 3 degrees ATDC as it does at 15 degrees. If you don't retard your timing, it's costing you power PERIOD! Don't think it's just about avoiding detontation.

One of the reasons detonation occurs is if you get peak cylinder pressure at TDC, the piston is deadlocked. Guess what happens? Major damage! Retard that timing on the juice and watch your power increase!

tuff

iTrader: (15)

Id start at 22 and adjust according. I would run 104 unleaded fuel with a colder plug gaped at about 0.30.Thats a safe tuneup and just go more agresseve as you get data.If you have no data and are happy with the car leave it alone because it will just like be like playing with a bomb.

Ben R

Don't trust your wideband. They're not all accurate. There is only one thing that will tell you what your engine wants, and that's the spark plug. Spark plugs don't lie. And don't use a chassis dyno to tune N20. Especially you guys with low-pressure, stand-alone fuel systems.

Ben R

Patrick,

there is so much science in tuning N20 it's not even funny. N/A tuning methods and theories does not apply. It's like tuning an alcohol carburetor the way you'd tune a gasoline carburetor. It doesn't work.

If you're serious about getting max HP out of your nitrous system, you need to hire the services of a professional and reputable tuner.

tuff

iTrader: (15)

Reading plugs is huge as ben r said.BTW i never been dyno tuned even on horsepower.But i do have a wideband.

Loudmouth LS1

iTrader: (10)

Ok, probably a dumb question, but what do I look for when reading the plugs, cuz I have no clue, never done it before, so what should they look like if everything is runnin perfect? And what are bad signs?

tuff

iTrader: (15)

Reading a plug means you have to shut the car down in the big end.Not so easy for some people.