Safe total timing 50-100 shot?
10-25-2012, 10:21 AM
#41
You are right on the money. My tune is spot on for N/A. I do not want to re-tune for a 50-100 shot of nitrous. I ordered a wet kit, and will pull timing. Non projected plugs will be used for added safety. I am not trying to build a 9-10 sec Nitrous car. Just a reliable fun street car that can hit high 11's with a little spray.
I plan on using a 50 shot with 2 degrees pulled, and use my dashhawk to monitor spark knock. I do not have a A/F gauge, so I will have to pull plugs.
My plugs look light brown, with a tint of white right now
My main question for this thread; is if 26* of total timing, is to much for a 50 shot with 2* pulled (24*). I have seen some LS people talk about using 19* total!
I am just worried because I am not stock anymore, so maybe pulling more timing would be smart.
This car stock had 31* Crazy.....
I plan on using a 50 shot with 2 degrees pulled, and use my dashhawk to monitor spark knock. I do not have a A/F gauge, so I will have to pull plugs.
My plugs look light brown, with a tint of white right now
My main question for this thread; is if 26* of total timing, is to much for a 50 shot with 2* pulled (24*). I have seen some LS people talk about using 19* total!
I am just worried because I am not stock anymore, so maybe pulling more timing would be smart.
This car stock had 31* Crazy.....
Last edited by kinglt-1; 10-25-2012 at 10:56 AM.
10-25-2012, 10:30 AM
#42
Timing advance serves one purpose.
To dictate when the fuel/air mixture is ignited.
The fuel/air mixture(in this case the nitrous makes up part of the air in the mixture) will dictate how much power is made, and timing only serves to light that mixture off.
Your engine has 4 strokes. Intake, compression, power, and exhaust. Ignition happens on the compression stroke. Once the F/A mixture is ignited and combustion happens, the piston is propelled downwards to BDC. The momentum the piston has from the compression stroke is used during the power stroke, the exhaust stroke and the intake stroke. When you end up back to the compression stroke the same cycle is repeated again.
I'm sure you're thinking..."why is this important to timing in a nitrous motor"? Here's why and it's very simple.
Since the momentum from the compression stroke is used for 3 of the engines 4 events it is very important to find the perfect medium of ignition timing and here is why...if you have too little timing, there will not be enough cylinder pressure generated during the compression stroke to carry the same momentum through the remaining 3 strokes of the engine until it returns to the compression stroke. This will show up as a slower e.t., mph or hp/tq. number.
On the other side of the coin, too much timing will carry enough momentum to not slow the piston/rod/crank down, BUT it will create excess heat from starting the combustion event too soon. This excess heat is absorbed by the walls of the cylinder, the piston, the valves and of course...the plug. This shows up as what we know as excess heat on the plug and will take the timing too far down the strap. It will also waste energy by using too much timing to carry the momentum needed to get back to the compression stroke, when a lesser amount would of carried the same amount of momentum needed to not lose power. Basically you end up fighting the natural up and down movement of the piston. End up with too much timing and not only will you lose power, you'll burn the straps off the plugs and maybe even start your own ashtray factory.
Now, all that being said....the perfect amount of timing, not too little not too much will carry the same momentum(piston speed) all the way through the remaining 3 strokes after the compression stroke and not create excess heat and will show as what we refer to as "the perfect plug reading". Not too cold, not too hot, just perfect because not too much or too little timing is being used. It will also not fight the up and down movement of the piston with too much timing, nor will it end up losing piston speed due to too little timing. You're lighting the combustion charge right at the point where the piston would of lost speed(power) if you hadn't lit it at just the right point in time.
That said, it's ALWAYS easier and safer to take more timing out than you know is rational because ALL it will do is lose power. If you don't sneak up on it and take it slow you're asking to dance with the devil....plain and simple.
Fuel/Air mixture determines how much power will be made, not timing. Timing does play a part in the power production, but not as much as you think. It's not some magic power adder that will boost your power output ten fold like a larger nitrous pill or leaning the fuel jet or fuel pressure out will.
Tuning off the knock sensors is just asking for trouble or asking to be slower than the guy next to you that doesn't. I've seen ridiculous things that the knock sensors do, like pulling 5 degrees of timing while I'm on the dyno with 26* total, 13.0 AFR, 10.33:1 static compression and C16 in the tank of my car. There is no reason why they should show knock, but they did. So I turned the damn things off.
I tune off my plugs, and then reference that reading to my total timing on the bottle, motor, boost whatever and what my AFR reading is in my data log.
Sorry for the long *** post, I just wanted to clear the air and hopefully shed some light in here.
Sorry to the OP.
To dictate when the fuel/air mixture is ignited.
The fuel/air mixture(in this case the nitrous makes up part of the air in the mixture) will dictate how much power is made, and timing only serves to light that mixture off.
Your engine has 4 strokes. Intake, compression, power, and exhaust. Ignition happens on the compression stroke. Once the F/A mixture is ignited and combustion happens, the piston is propelled downwards to BDC. The momentum the piston has from the compression stroke is used during the power stroke, the exhaust stroke and the intake stroke. When you end up back to the compression stroke the same cycle is repeated again.
I'm sure you're thinking..."why is this important to timing in a nitrous motor"? Here's why and it's very simple.
Since the momentum from the compression stroke is used for 3 of the engines 4 events it is very important to find the perfect medium of ignition timing and here is why...if you have too little timing, there will not be enough cylinder pressure generated during the compression stroke to carry the same momentum through the remaining 3 strokes of the engine until it returns to the compression stroke. This will show up as a slower e.t., mph or hp/tq. number.
On the other side of the coin, too much timing will carry enough momentum to not slow the piston/rod/crank down, BUT it will create excess heat from starting the combustion event too soon. This excess heat is absorbed by the walls of the cylinder, the piston, the valves and of course...the plug. This shows up as what we know as excess heat on the plug and will take the timing too far down the strap. It will also waste energy by using too much timing to carry the momentum needed to get back to the compression stroke, when a lesser amount would of carried the same amount of momentum needed to not lose power. Basically you end up fighting the natural up and down movement of the piston. End up with too much timing and not only will you lose power, you'll burn the straps off the plugs and maybe even start your own ashtray factory.
Now, all that being said....the perfect amount of timing, not too little not too much will carry the same momentum(piston speed) all the way through the remaining 3 strokes after the compression stroke and not create excess heat and will show as what we refer to as "the perfect plug reading". Not too cold, not too hot, just perfect because not too much or too little timing is being used. It will also not fight the up and down movement of the piston with too much timing, nor will it end up losing piston speed due to too little timing. You're lighting the combustion charge right at the point where the piston would of lost speed(power) if you hadn't lit it at just the right point in time.
That said, it's ALWAYS easier and safer to take more timing out than you know is rational because ALL it will do is lose power. If you don't sneak up on it and take it slow you're asking to dance with the devil....plain and simple.
Fuel/Air mixture determines how much power will be made, not timing. Timing does play a part in the power production, but not as much as you think. It's not some magic power adder that will boost your power output ten fold like a larger nitrous pill or leaning the fuel jet or fuel pressure out will.
Tuning off the knock sensors is just asking for trouble or asking to be slower than the guy next to you that doesn't. I've seen ridiculous things that the knock sensors do, like pulling 5 degrees of timing while I'm on the dyno with 26* total, 13.0 AFR, 10.33:1 static compression and C16 in the tank of my car. There is no reason why they should show knock, but they did. So I turned the damn things off.
I tune off my plugs, and then reference that reading to my total timing on the bottle, motor, boost whatever and what my AFR reading is in my data log.
Sorry for the long *** post, I just wanted to clear the air and hopefully shed some light in here.
Sorry to the OP.
10-25-2012, 12:23 PM
#46
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Advice taken. With a 100 shot and BR7E plugs gapped@.035" I will start off with 6* (20 total remaining), and work my way up or down from there.
Those were my beginner/misinformed days. 
10-31-2012, 02:14 PM
#49
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Still still waiting a few more parts. Hopefully next month.
I am going to rent dyno time for some WOT pulls so I can read the plugs, adjust timing, and fuel.
Going to start with a 50 shot pulling 4* and work my way up from there.
I am going to rent dyno time for some WOT pulls so I can read the plugs, adjust timing, and fuel.
Going to start with a 50 shot pulling 4* and work my way up from there.
11-30-2012, 07:13 PM
#50
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always pull timing, how much hp do you lose from 26 back to 22 NA? not much. Keep the afrs 12.0 and watch the timing mark and heat range.
11-30-2012, 08:05 PM
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I'm not sure why some of these guys are talking about retuning a car for nitrous? Dial in the tune on motor. Pull 2-3* for every 50 hp of nitrous. All of your fueling for nitrous should be controlled/adjusted with the fuel jet based off of plug reading and not in the tune. Just my 2 cents. I'm always had better ET and trap speed pulling the correct amount of timing for nitrous. The out of the box jetting for most kits are known to be conservative. My car would even make a pass on a 100 shot without loading up on fuel with the old nitrous outlet 53/33 jetting. They changed all of their jetting because is was too conservative. Guys like Camscam proved that so I would suggest you guys listen to the guys that have had great success with nitrous.
12-01-2012, 10:02 AM
#53
Been a busy topic here lately I see. 87silverbullet seems to have a good handle on this one. Read this when you get a chance as well:
https://ls1tech.com/forums/nitrous-o...ng-intune.html
https://ls1tech.com/forums/nitrous-o...ng-intune.html
12-02-2012, 01:12 AM
#54
I tune mine on our Eddy Current Dyno Jet all the time along with our shop car that makes 1000rwhp on spray, but we are able to control the load cell and put as much heat in the plugs as we need. I'm also conservative with the tune on the dyno compared to what we'd run at the track and mainly use it to get a good baseline tune.
12-02-2012, 05:52 PM
#55
Unless it's a Mustang Dyno or a Eddy Current Dyno Jet or a Dyno Dynamics I wouldn't either.
I tune mine on our Eddy Current Dyno Jet all the time along with our shop car that makes 1000rwhp on spray, but we are able to control the load cell and put as much heat in the plugs as we need. I'm also conservative with the tune on the dyno compared to what we'd run at the track and mainly use it to get a good baseline tune.
I tune mine on our Eddy Current Dyno Jet all the time along with our shop car that makes 1000rwhp on spray, but we are able to control the load cell and put as much heat in the plugs as we need. I'm also conservative with the tune on the dyno compared to what we'd run at the track and mainly use it to get a good baseline tune.
Nitrous needs to be looked at as a HOT NA setup. Run it lean and add the heat incrementally with the timing. No timing = no heat no matter what the fuel mixture (to an extent).
12-04-2012, 08:17 AM
#56
Unless it's a Mustang Dyno or a Eddy Current Dyno Jet or a Dyno Dynamics I wouldn't either.
I tune mine on our Eddy Current Dyno Jet all the time along with our shop car that makes 1000rwhp on spray, but we are able to control the load cell and put as much heat in the plugs as we need. I'm also conservative with the tune on the dyno compared to what we'd run at the track and mainly use it to get a good baseline tune.
I tune mine on our Eddy Current Dyno Jet all the time along with our shop car that makes 1000rwhp on spray, but we are able to control the load cell and put as much heat in the plugs as we need. I'm also conservative with the tune on the dyno compared to what we'd run at the track and mainly use it to get a good baseline tune.
With your statement of " I run it conservative", you already know that a dyno doesn't do as good as the track. So you know what to do to compensate. Alot of people don't, they get on the dyno and tune it like if it was at the track. Then when they go to the track. BOOM!
Here is what a 200 shot on pump gas with only 5* pulled on a 95* day did to some bearings. It ran fine on the dyno with 5* pulled. The detonation killed the bearings.
12-20-2012, 10:36 AM
#59
I have the " If it aint broke, don't fix it" attitude on this subject. I have been tuning at the track for years and have never ran into problems so I try to stay that way. Plus, I don't have access to a dyno all the time.
With your statement of " I run it conservative", you already know that a dyno doesn't do as good as the track. So you know what to do to compensate. Alot of people don't, they get on the dyno and tune it like if it was at the track. Then when they go to the track. BOOM!
Here is what a 200 shot on pump gas with only 5* pulled on a 95* day did to some bearings. It ran fine on the dyno with 5* pulled. The detonation killed the bearings.
With your statement of " I run it conservative", you already know that a dyno doesn't do as good as the track. So you know what to do to compensate. Alot of people don't, they get on the dyno and tune it like if it was at the track. Then when they go to the track. BOOM!
Here is what a 200 shot on pump gas with only 5* pulled on a 95* day did to some bearings. It ran fine on the dyno with 5* pulled. The detonation killed the bearings.
Last edited by LSxPwrDZ; 12-20-2012 at 10:41 AM.