timing 150 shot with 104 octane

[LSWHAT!!]

Hey guys im going to be sqeezing a 150 shot through the car here in the next couple of days. I usually squeeze a 100 shout and i pull bout 2 degree with the sunoco 104 just to be safe. my question is do you think that i could leave it at 2 degree with that much octane. i have had pcm for less tune the car but not for n20. So I think that they advanced the timing 2 degrees. my mods are listed below.
95 Trans Am, M6, LTTC coil pack setup ,Pacesetter Lt, electric water pump,custom cold air, Driveline solutions Ford 9 inch 3.89 gears, umi tunel mount adj. torque arm, umi phb, umi lca, umi lca brackets. umi subframe connectors.for the track rear pro stars on some micky thompsons 26, 11.5 E.T. Streets, . 12.7 on motor, 11.72 on a 100 shot of nitrous.

[solga 511]

I am probably gonna get flamed for saying this but, if EVERYTHING on a nitrous set-up is PROPERLY adjusted and dialed in to begin with, you shouldn't have to pull timing. JMHO

[slowdime]

A good rule of thumb is 2 degrees for every hundred hp of nitrous. If the tune is spot on you could get away with only retarding it 2 or 3 degrees.

IMO the above post was the most ignorant statement I have heard in a long time. You may be able to get away with 100 shot at most without any kind of retard, but that does not make it safe. Also I have never seen any fast nitrous cars that do not retard the timing.

Edit: here's what happens when the timing isnt retarded enough

http://i109.photobucket.com/albums/n43/slowdime/DSCN9384.jpg

450 shot without enough retard, turned 4 pistons into ashtrays and melted the heat treating out of the heads

[Chopstix]

Edit: here's what happens when the timing isn't retarded enough



are you 100% positive it was timing related....most of the times when you lift ring lands the car is rich ;)

You retard the timing to make power, not to make it safer. You have to have the spark at the right point. Too early or to late will cause you to lose power and can introduce detonation.

[LSWHAT!!]

so I should retard it six degrees since it was advanced 2 degrees by pcm forless. But i might be able to get away with just pulling 4 degrees if everything is spot on? I thought by running the 104 octane i would be able to very little timing retard am i wrong?

[BLOWNDFIZ]

If I were you I'd pull at least 6 degrees (are you sure the tune is only advanced 2 degrees??) Run it, make sure your A/F is good then start adding the timing back in a degree at a time. All things the same your MPH should pick up by adding back in the timing. Once MPH stops going up then you should be at the optimum timing setting.

That thing only needs to detonate once to cost you some big time $$$.

[slowdime]

are you 100% positive it was timing related....most of the times when you lift ring lands the car is rich ;)

You retard the timing to make power, not to make it safer. You have to have the spark at the right point. Too early or to late will cause you to lose power and can introduce detonation.


Could be a little of both, other ringlands were pushed tighter as well another piston got a hole in it. Pretty sure the ringlands were caused by pre-detonation due to too much timing though.

We were expecting a 250 or 275 shot on that pass, but dad played with the progressive annd it kicked the second stage on accidentally:shame:. Still managed a 9.05 @ 150 while tearing itself apart.

[jakesz28]

I would say to much fuel adds alot of heat to the ring area.


I would also say to start off pulling extra timing. Get a base line reading on how the plugs look then add some timing. A 150 shot isn't much but I think another LT1 with forged pistons hurt it self at that level. It could have been caused by other factors but it is better to pull extra timing then add it as needed by reading the plugs and watching the mph while you add a little timing back.


Also the 2 degrees per 50 hp can get you in trouble real fast. The more power you make the more timing you have to pull. Think if I ran a baseline timing around 38* which is common on the LTx platform and decided to spray 400hp does that mean I only need to pull 16*? That would be a total timing of 22 if the ecm didn't add any to the number in the spark advance table. But then my car this year only wanted about 22* to 24* with a .075 nitrous jet. Which probably falls short of 200hp.

[Twisted Z]

150 with 104? if the A/F is good it won't take much if any.

[solga 511]

IMO the above post was the most ignorant statement I have heard in a long time. You may be able to get away with 100 shot at most without any kind of retard, but that does not make it safe. Also I have never seen any fast nitrous cars that do not retard the timing.


:| Like I said, I seen this one coming. All I really have to say is, look at the title of this thread, go back and reread my previous post word for word and then do it all again.

I personally pushed a "200 shot" through a stock LT1 without pulling any timing for well over 40 passes before I sold the car. As far as I know the person that bought my car drove it for another 60,000 miles before the oil pump went out of it, so I must have either gotten lucky or maybe I had a slight clue of what I was doing.

My previous post had absolutely nothing to do with ignorance and if you haven't seen any fast nitrous cars not pulling timing, I would say that you haven't been around a whole lot of serious N2O cars then.
Although Ray didn't exactly support what I am saying, he didn't cut me down either...........

Anyhow I have personally been around a mid 8 second car that has a purpose built N2O engine pushing over a "450 shot" multi-stage and running it on 36* total timing.

Also, I can point you to a LT1 streetcar that is pushing 1200+ HP through a supercharger, 4L60E, and the 10 bolt rear (granted it has been strengthened) that came with the car, all WITHOUT pulling any timing, and on the LT1 ECM. This car was also built because the general consensus of people said "It can't be done." Yes I know supercharging is not the same as N2O so don't go there. It is pretty close to the same principal however, ie. lots more oxygen, lots more fuel than NA.

I'm done talking about this............

[jakesz28]

I wonder how much timing the ecm was pulling with the knock sensor.

[solga 511]

I wonder how much timing the ecm was pulling with the knock sensor.

If you are referring to my stock LT1 Z28 with the 200 shot, I have no clue. I wasn't data logging the runs that I made, but I did have some help putting the entire N2O system (from electronics to hardware to nitrous and fuel pressures) together and had some very sound advice on picking which parts to use all the way down to the "jet" sizes. I did not go right out and run a 200 shot on the car either, I started at about a 100 and worked my way up. Again, I had help doing this.

If you are referring to the other LT1 car I am talking about, I am not to sure on that either but I can ask if you would like. Something tells me though that with this guy, the computer (KS) isn't much of an issue with him. He is very thorough on everything he does.

[LSWHAT!!]

150 with 104? if the A/F is good it won't take much if any.

So Twisted z your saying with the 104 octane that it i should have to pull to much timing as long as the A/F is good? The reason that i ask this is because this is what i was thinkning becasue 104 octane is alot for a 150 shot. right?

[solga 511]

So Twisted z your saying with the 104 octane that it i should have to pull to much timing as long as the A/F is good? The reason that i ask this is because this is what i was thinkning becasue 104 octane is alot for a 150 shot. right?

No, what he is saying is, that as long as you topped off with 104 in your tank, (assuming that you dont have a dedicated fuel system for your N2O) then you should NOT have to pull any timing. I think this is what you were asking but it is better to be safe then sorry.

[jakesz28]

:| Like I said, I seen this one coming. All I really have to say is, look at the title of this thread, go back and reread my previous post word for word and then do it all again.

I personally pushed a "200 shot" through a stock LT1 without pulling any timing for well over 40 passes before I sold the car. As far as I know the person that bought my car drove it for another 60,000 miles before the oil pump went out of it, so I must have either gotten lucky or maybe I had a slight clue of what I was doing.

My previous post had absolutely nothing to do with ignorance and if you haven't seen any fast nitrous cars not pulling timing, I would say that you haven't been around a whole lot of serious N2O cars then.
Although Ray didn't exactly support what I am saying, he didn't cut me down either...........

Anyhow I have personally been around a mid 8 second car that has a purpose built N2O engine pushing over a "450 shot" multi-stage and running it on 36* total timing.

Also, I can point you to a LT1 streetcar that is pushing 1200+ HP through a supercharger, 4L60E, and the 10 bolt rear (granted it has been strengthened) that came with the car, all WITHOUT pulling any timing, and on the LT1 ECM. This car was also built because the general consensus of people said "It can't be done." Yes I know supercharging is not the same as N2O so don't go there. It is pretty close to the same principal however, ie. lots more oxygen, lots more fuel than NA.

I'm done talking about this............


Whats funning is a nitrous tuner that is well known and works for NOS has told me on more then one occasion that he has cars that run as low as 0-5* total timing. :shame: I'll keep advising others to pull extra timing and add it back while watching the plugs and mph. Hell my stock shortblock motor was hit with 250 and ran fine when I pulled it out. But I run them a little leaner then most and pull extra timing.

[Chopstix]

Whats funning is a nitrous tuner that is well known and works for NOS has told me on more then one occasion that he has cars that run as low as 0-5* total timing. :shame: I'll keep advising others to pull extra timing and add it back while watching the plugs and mph. Hell my stock shortblock motor was hit with 250 and ran fine when I pulled it out. But I run them a little leaner then most and pull extra timing.

:claps::claps::claps::claps::claps::claps::claps:: claps::claps::claps:

[Tony Shepherd]

:| Like I said, I seen this one coming. All I really have to say is, look at the title of this thread, go back and reread my previous post word for word and then do it all again.

I personally pushed a "200 shot" through a stock LT1 without pulling any timing for well over 40 passes before I sold the car. As far as I know the person that bought my car drove it for another 60,000 miles before the oil pump went out of it, so I must have either gotten lucky or maybe I had a slight clue of what I was doing.

My previous post had absolutely nothing to do with ignorance and if you haven't seen any fast nitrous cars not pulling timing, I would say that you haven't been around a whole lot of serious N2O cars then.
Although Ray didn't exactly support what I am saying, he didn't cut me down either...........

Anyhow I have personally been around a mid 8 second car that has a purpose built N2O engine pushing over a "450 shot" multi-stage and running it on 36* total timing.

Also, I can point you to a LT1 streetcar that is pushing 1200+ HP through a supercharger, 4L60E, and the 10 bolt rear (granted it has been strengthened) that came with the car, all WITHOUT pulling any timing, and on the LT1 ECM. This car was also built because the general consensus of people said "It can't be done." Yes I know supercharging is not the same as N2O so don't go there. It is pretty close to the same principal however, ie. lots more oxygen, lots more fuel than NA.

I'm done talking about this............

Sorry........I am not believing any of this either. 450 shot should be in the 15-18 degree timing range. If the guy is at 36 degrees he will not have pistons, heads, and block left after about 5 seconds. And yes I have been around nitrous for a long long time. I would love to be his engine builder because he would come back on a monthly basis!:D

[Twisted Z]

Hey as long as he is done talking about it ;)

BTW I was at 26* with a 250 shot ;)

A/F was good as were the plugs

[NitrousJunkie]

I don't see why you would need to pull the timing on 104 octane, I don't think the A/F will be bad at all.

[96lt1m6]

i ran a NX 150 hit NO TIMING pulled in the tune, pump gas(91) octane with tr55s never so much as burned a plug,did i rely on the knock sensor to pull timing possibly...EFI cars can get away with it better than a carb car and that is where the 2* per 100 came from . anything more than 150 i would definately pull timing on EFI..... read your plugs,feel and listen to the car

[Chopstix]

Guys...you do not pull timing just to make it safer, it is done so you make more power.

You need to have the plug firing at the right time. ;)

[jakesz28]

The more power you make and the more efficent the motor the less timing you need.


You start losing a little power before the plugs burn( most of the time)

I've sprayed a 150 shot on a cam only car without pulling timing. Then I got the mallory 685 and pulled some timing for safety but the car went faster so I just pulled more timing and sprayed more. :cool: