Nitrous Oxide - N2O timing




View Full Version : N2O timing


mellowyellow
05-21-2007, 06:29 PM
This may be a stupid ? but what is the reason for taking timing out when running N2O ? What can it hurt if you don't ?


Robert56
05-21-2007, 06:39 PM
The cylinder pressures are increased so much that it creates extra heat and leads to deteonation.
Here's the results of to much timing for a given hit.
Busted ringland,
http://www.fquick.com/images/vehicles/full/206333150.jpg?1175222850

Resulting piston melt down,
http://www.fquick.com/images/vehicles/full/206333149.jpg?1175222849

Cylinder damage that ruined block,
http://www.fquick.com/images/vehicles/full/206333151.jpg?1175222850

Head damage, but salvageable,
http://www.fquick.com/images/vehicles/full/206333152.jpg?1175222951

Plug damage, however, just clean them up and re-gap for another dozen passes,
http://www.fquick.com/images/vehicles/full/206333153.jpg?1175222951

Robert

jares99
05-21-2007, 08:23 PM
Are you selling those spark plugs I am looking for a good set....LOL


BayAreaSS
05-21-2007, 08:29 PM
Are you selling those spark plugs I am looking for a good set....LOL
:jest:

mellowyellow
05-21-2007, 09:06 PM
Ok so a buddy is running *31 timing with a 100 shot ...Is he at risk ?

LostCauseZ06
05-22-2007, 01:21 PM
depends on his mods/ if hes detonating... if he detonates on spray he needs to pull timing. i run about 28 degrees on my 200-250 hits. rule of thumb is 2 degrees for every 100 hp shot

mrdragster1970
05-22-2007, 03:50 PM
.

Some use 2 degrees per 50, and some use 3 per 100. Start safe and read plugs every pass to watch the changes.

.

Noyzee
05-22-2007, 05:17 PM
depends on his mods/ if hes detonating... if he detonates on spray he needs to pull timing. i run about 28 degrees on my 200-250 hits. rule of thumb is 2 degrees for every 100 hp shot
28 on 250 wow

LostCauseZ06
05-22-2007, 05:38 PM
28 on 250 wow


haha to be honest the only time my engine has EVER knocked was when i was running out of fuel pump.... ive had my timing upwards of 32-33 degrees on my NA tune with no knock... no power gains... but no knock either :devil:


iron block rocks. ive heard that iron blocks love timing for the most part... but meh, all motors are different

Noyzee
05-22-2007, 05:42 PM
haha to be honest the only time my engine has EVER knocked was when i was running out of fuel pump.... ive had my timing upwards of 32-33 degrees on my NA tune with no knock... no power gains... but no knock either :devil:


iron block rocks. ive heard that iron blocks love timing for the most part... but meh, all motors are different
yhea 32* on na tune fine, but 28* with 250 worth of spray!!
just because it shows no knock doesnt mean much.
get a bore a scope and check out your pistions ect.
thatsalot of timming.
race gas?

brad8266
05-22-2007, 06:12 PM
yhea 32* on na tune fine, but 28* with 250 worth of spray!!
just because it shows no knock doesnt mean much.
get a bore a scope and check out your pistions ect.
thatsalot of timming.
race gas?
:stupid:

28 degrees on a 250 hit is way too much.

Noyzee
05-22-2007, 06:30 PM
:stupid:

28 degrees on a 250 hit is way too much.
its an iron block tho :) :confused:

srsnow
05-22-2007, 06:42 PM
The main reason to retard timing is because nitrous increases the burn rate. So to keep the point where everything is burned completely (around 17 degrees ATDC) you need to pull timing out. Generally 2 per 50 on 100 octane or lower is a good starting point and 3 per 100 on something like C16 or equivalent is pretty safe.

brad8266
05-22-2007, 07:15 PM
The main reason to retard timing is because nitrous increases the burn rate. So to keep the point where everything is burned completely (around 17 degrees ATDC) you need to pull timing out.

:werd: :judge:

Robert56
05-22-2007, 09:28 PM
haha to be honest the only time my engine has EVER knocked was when i was running out of fuel pump.... ive had my timing upwards of 32-33 degrees on my NA tune with no knock... no power gains... but no knock either :devil:


iron block rocks. ive heard that iron blocks love timing for the most part... but meh, all motors are different
Really the Iron block has no bearing on much timing can or should be run. 28* is waaaaaay to much, imo. Just because you haven't had a melt down like above doesn't mean it's correct. On my 408 at 300 I will be starting at around 16* of timing. On my successfull many runs at 200/250 on my ls6 I was running 22* or less and race gas. The above melt down showed no signs of KR, nor did not make any rattling noise, the silent killer.
Anyway, you have any dyno numbers or track times on your combo, very similar to what I am putting together? :drive:
Robert

LostCauseZ06
05-23-2007, 10:25 AM
Really the Iron block has no bearing on much timing can or should be run. 28* is waaaaaay to much, imo. Just because you haven't had a melt down like above doesn't mean it's correct. On my 408 at 300 I will be starting at around 16* of timing. On my successfull many runs at 200/250 on my ls6 I was running 22* or less and race gas. The above melt down showed no signs of KR, nor did not make any rattling noise, the silent killer.
Anyway, you have any dyno numbers or track times on your combo, very similar to what I am putting together? :drive:
Robert


hrmm... thats very interesting, thats like no timing lol :jest: ive sprayed the 200 hit in my car numerous times, hell i even sprayed the 200 on my NA tune once on my old pump but ill admit that i did melt 2 plugs (1 and 7) thanks to my rails being starved. the rest of the plugs looked solidly awesome.


i have had my heads off probably 4 times, popped head gaskets, new valves installed, all sorts of fun stuff but my pistons look like they are brand new minus #1 having a small piece of ground strap embedded in it :jest:



car put down 480 RWHP and 630 RWHP on the 150 hit through the plate kit. Car was running less than optimum with some problems ( 2 dicked up valves you can see my other thread about it)


im trapping 118 MPH with my horrible driving skillz @ 9500 DA naturally aspirated. i havent ran it again with the spray at the track because i dont want a cage. :(

LostCauseZ06
05-23-2007, 10:35 AM
yhea 32* on na tune fine, but 28* with 250 worth of spray!!
just because it shows no knock doesnt mean much.
get a bore a scope and check out your pistions ect.
thatsalot of timming.
race gas?


btw.. to be further flamed.... i have NEVER run race gas in my car :eek2:


heres a vid of my car on the 200 hit (old nozzle kit) pump gas, and i think i was actually running closer to 30 degrees on this run. it was before we tinkered around and found a sweet spot NA @ 28.5. Dont mind the language or the fact i sound like a hillbilly haha i had the flu and was racing my best friend who thought his 383 LE2 LT1 was the fastest car around :jest:

http://s15.photobucket.com/albums/a364/StripedZebra/?action=view&current=ChasevsJason.flv



in other words.. i have never had the need to pull any timing for the most part, my NA tune is my spray tune :mullet:

Noyzee
05-23-2007, 11:04 AM
head gaskets poped? try taking out some timming. lol

weird question here, but 118 at 9500 da with 480 rwhp thats bad!!
i went 128 with my z on spray which is about the same rwhp, i was in about 4000 da
my car is stock as a rock.
we also went 121 with my buddies full weight f-body with 420 rwhp and atleast 300 pounds more then a vett.
sounds strange like somthing isntright on, but its your car you know it better then we would.

CamTom12
05-23-2007, 11:10 AM
Nitrous increases the speed of the flame front, so you're bringing the advance back to properly time the pressure spike to the retreating piston :)

Noyzee
05-23-2007, 11:14 AM
camtom rules!!! come see me again some day bro


sorry, thread hijack

LostCauseZ06
05-23-2007, 11:32 AM
noyzee.... 480 RWHP is corrected... uncorrected thats only like 410-420 RWHP... correction factors up here are roughly 1.13-1.16 depending on the day.


the head gaskets popped because i was running 4.125 fel pro gaskets and when i put the head bolts in i didnt get all the water out. i didnt "blow" a head gasket, they just began weeping a little out of the passenger side.

my car runs good and strong and ive proven that time and time again at the track. 118 Traps at our track are pretty freakin good. the air up here is horrible.

Noyzee
05-23-2007, 11:39 AM
thats better.
i got it. i was going to say somthing is wrong.
and im not doggin you in any way, just saying you may want to try pulling some timming, the car might pick up a bit.

LostCauseZ06
05-23-2007, 12:05 PM
thats better.
i got it. i was going to say somthing is wrong.
and im not doggin you in any way, just saying you may want to try pulling some timming, the car might pick up a bit.


Yeah i mean im still a newbie to nitrous and im sure i will be for quite some time. im always open for suggestions and such. The way i was always taught for nitrous was 2 degrees for every 100 HP of nitrous. What we did when we tuned my car was tuned for max NA power of coarse. while doing so we were seeing upwards of 32-33 degrees of timing with no detonation whatsoever running 91 octane pump gas but the car didnt feel as stong (we were street tuning not dyno tuning) so we bumped it back down to around 30, sprayed the car and it felt solid. plugs looked perfect, and it hit very clean and hard so we left it. I dont have HP tuners personally and the day i was hitting the 200 i didnt have a chance to pull more timing.

i stuck in the bigger jets, went out and raced that camaro i posted the vid of. after that run i pulled into the parking lot and was definately pushing water out of the lower part of the head (stupid fel pros had hardly any gasket right there) so i tore it down and put in MLS 6.0 gaskets. ive never had any problems since then. pistons looked perfect and such.



about 3 or 4 months ago i noticed i had a valve mushrooming on the tip ( i had sprayed many many bottles through the car at this point on the same tune)


pulled my heads and the pistons looked perfect, as did the heads. cylinder walls, everythign still looked in great shape (about 9k miles on everything and lots of spray at this point)


the last time on the dyno where i put down the 480 i was actually only running 28.5 on the 150 shot


anyways... thats my experience with nitrous. so far ive been lucky and only melted a few plugs when i had upped the shot too far and was on stock injectors. :drive:

Noyzee
05-23-2007, 12:48 PM
Yeah i mean im still a newbie to nitrous and im sure i will be for quite some time. im always open for suggestions and such. The way i was always taught for nitrous was 2 degrees for every 100 HP of nitrous. What we did when we tuned my car was tuned for max NA power of coarse. while doing so we were seeing upwards of 32-33 degrees of timing with no detonation whatsoever running 91 octane pump gas but the car didnt feel as stong (we were street tuning not dyno tuning) so we bumped it back down to around 30, sprayed the car and it felt solid. plugs looked perfect, and it hit very clean and hard so we left it. I dont have HP tuners personally and the day i was hitting the 200 i didnt have a chance to pull more timing.

i stuck in the bigger jets, went out and raced that camaro i posted the vid of. after that run i pulled into the parking lot and was definately pushing water out of the lower part of the head (stupid fel pros had hardly any gasket right there) so i tore it down and put in MLS 6.0 gaskets. ive never had any problems since then. pistons looked perfect and such.



about 3 or 4 months ago i noticed i had a valve mushrooming on the tip ( i had sprayed many many bottles through the car at this point on the same tune)


pulled my heads and the pistons looked perfect, as did the heads. cylinder walls, everythign still looked in great shape (about 9k miles on everything and lots of spray at this point)


the last time on the dyno where i put down the 480 i was actually only running 28.5 on the 150 shot


anyways... thats my experience with nitrous. so far ive been lucky and only melted a few plugs when i had upped the shot too far and was on stock injectors. :drive:
wow, id say you are lucky, either thatthe air up there may just keep the car so fat it doesnt matter. i neverthought of that

1320FEVER
05-23-2007, 02:11 PM
I agree that 28* on a 250 shot is way too much. I wouldn't run any more than 100 shot on 28*. I read somewhere where someone was running 22* on a 200 shot. That seems safe to me. Its not worth risking your motor (or your entire car) just for alittle more hp.

LostCauseZ06
05-23-2007, 03:27 PM
I agree that 28* on a 250 shot is way too much. I wouldn't run any more than 100 shot on 28*. I read somewhere where someone was running 22* on a 200 shot. That seems safe to me. Its not worth risking your motor (or your entire car) just for alittle more hp.


how are you risking your motor/car provided there is no detonation to be seen or heard and the plugs look good? :eyes:

1320FEVER
05-23-2007, 03:40 PM
how are you risking your motor/car provided there is no detonation to be seen or heard and the plugs look good? :eyes:

:jest: All it takes is just one time and you may have a nice red piece of melted down plastic

1320FEVER
05-23-2007, 03:42 PM
how are you risking your motor/car provided there is no detonation to be seen or heard and the plugs look good? :eyes:

Watch, listen, and learn...

http://www.youtube.com/watch?v=xCNs_pOu28A

:jest:

LostCauseZ06
05-23-2007, 05:37 PM
Watch, listen, and learn...

http://www.youtube.com/watch?v=xCNs_pOu28A

:jest:


lol godddammnn i didnt know detonation could do something like that.. i was under the impression a nitrous backfire was the cause of that :jest:

1320FEVER
05-23-2007, 07:26 PM
lol godddammnn i didnt know detonation could do something like that.. i was under the impression a nitrous backfire was the cause of that :jest:

LOL, I suppose your right, but I would still back off from 28 deg on a shot that size regardless whether the motor was pinging or not. But thats just me....you can do what you want to do :)

Robert56
05-23-2007, 11:22 PM
If one person tells ya something, maybe listen, if two people tell ya something maybe you should start listening, if everyone is telling ya something you really should take notice. Sounds like you have had many issues with spray on your car, however, you like to put the blame else where. My opinion is that your motor will not last long at this rate. Good luck though, i hope I am wrong. read, the post by srsnow, there are more than one reason to pull timing, not just safety, but to also make it work at it's peak potential.
On timing, adding the most timing without knock is incorrect way of doing it. The proper way is add timing until your power peak and no more, not until KR, this is n/a timing of course. Try calling all the nitrous companys and ask about your timing, they will tell ya you are on a death warrant.
Robert

Noyzee
05-24-2007, 08:04 AM
how are you risking your motor/car provided there is no detonation to be seen or heard and the plugs look good? :eyes:
the issues with your heads ect could be caused by timing.
also it isnt just for safty, its for performance.
Nitrous, it is not if its going to bite you, it is when :judge:

LostCauseZ06
05-24-2007, 10:01 AM
lol what in the world are you guys talking about??? this forum cracks me up sometimes.


i have had zero problems with my heads and engine. i popped a fel pro 4.125 paper head gasket spraying a 200 shot on a high compression 408..... last time i checked that wasnt exactly a "rare" occurance and was most likely caused by the fact that i didnt get all the water out of the head bolt holes (i didnt realize the bolts went as far down as they do)


what other problems are you guys speaking of that i have? what "issues" with my heads?


i had some old patriots that had the old valves in them. they mushroomed just like everybody elses. just like the AFR's did.

Other than that ive had no problems at all. so would you guys care to explain wtf your talking about ??? :jest:



not that it matters anyways, as ive already said that i have brought the timing down. the timing is now at 28.5 degrees for my NA tune. when i spray on it there is no detonation and car runs smooth as silk. The 28.5 was found ON THE DYNO while making about 10 pulls on/off spray and such. car loved 28.5 even though it didnt detonate upwards of 32-33 degrees.


So what exactly do you suppose im doing wrong that i need to take advice about???



this isnt rocket science. if the car detonates, your gonna have problems. If its not detonating and the plugs look good then your good to go. i dunno WTF you guys are talking about. Just because you have it stuck in your head that thats too much timing is total BS. every motor is different, every setup is different. detonation kills motors, not nitrous itself or timing. Its the detonation that is CAUSED by those things but so long as the detonation is not happeneing there is no problems running the car the way that i do.



anyways.... im done argueing about this.

1320FEVER
05-24-2007, 10:25 AM
All I can say is that you certainly picked the right name
for your LS1tech username: Lost Cause :jest:

Just kidding! :)

Noyzee
05-24-2007, 10:39 AM
lol what in the world are you guys talking about??? this forum cracks me up sometimes.


i have had zero problems with my heads and engine. i popped a fel pro 4.125 paper head gasket spraying a 200 shot on a high compression 408..... last time i checked that wasnt exactly a "rare" occurance and was most likely caused by the fact that i didnt get all the water out of the head bolt holes (i didnt realize the bolts went as far down as they do)


what other problems are you guys speaking of that i have? what "issues" with my heads?


i had some old patriots that had the old valves in them. they mushroomed just like everybody elses. just like the AFR's did.

Other than that ive had no problems at all. so would you guys care to explain wtf your talking about ??? :jest:



not that it matters anyways, as ive already said that i have brought the timing down. the timing is now at 28.5 degrees for my NA tune. when i spray on it there is no detonation and car runs smooth as silk. The 28.5 was found ON THE DYNO while making about 10 pulls on/off spray and such. car loved 28.5 even though it didnt detonate upwards of 32-33 degrees.


So what exactly do you suppose im doing wrong that i need to take advice about???



this isnt rocket science. if the car detonates, your gonna have problems. If its not detonating and the plugs look good then your good to go. i dunno WTF you guys are talking about. Just because you have it stuck in your head that thats too much timing is total BS. every motor is different, every setup is different. detonation kills motors, not nitrous itself or timing. Its the detonation that is CAUSED by those things but so long as the detonation is not happeneing there is no problems running the car the way that i do.



anyways.... im done argueing about this.
heat is the issue, detonation isnt as much an issue, but your right. throw timming at it and call it a day.
good luck with the car :chug:

SS Blazer 07
05-24-2007, 11:11 AM
Having used nitrous I do not understand why would you ever try to run max timing? Pulling timing depends on where you tune started at. Not only pulling timing makes you run a lot faster it is also the safe way to run. Why would you run max timing even if you get by with it? Again pulling timing & running higher octane makes you run much faster? I would for sure keep it below 25 degrees on bigger shots. If you have a fixed tune with lots of advance get the new MSD Timing Twister it lets you adjust timing pulled when the nitrous is activated then return to normal for motor run's. New product. Anyone not running a good wide-band A/F (Innovate) with the gauge at eye level so you can see it when running the 1/4 mile also is your best friend. I sure see some living on the edge thinking by some. This is free advice so some will still find out the hard way.
http://s85.photobucket.com/albums/k73/SSTBLS2/?action=view&current=P1000405.jpg

LostCauseZ06
05-24-2007, 11:20 AM
heat is the issue, detonation isnt as much an issue, but your right. throw timming at it and call it a day.
good luck with the car :chug:


I will admit, the car runs hotter on spray than id like, i have seen temperature spikes up to around 220 degrees instead of my usual 190 degree running temps. but i still have not gotten any detonation from the increased heat (im guessing thats what your getting at)


keep in mind. im guessing your mostly a track car that hot laps at the track spray after spray after spray. in that case then id totally agree about running less timign and more safety.


my car is a street car, used pretty much solely for roll racing on the freeway. Keep that in mind, it needs to be tuned for max NA power that i can do and then every now and then throw some spray into the mix when its necesarry (not very often) and its usually 1 single run from 40-140.


im guessing thats where the discrepency in your and my beliefs is the way we drive and race our cars. all my runs on spray are generally at 1 in the morning when its super cold outside and optimum conditions. which im sure is helping with heat issues as im not running in the hot sun at the track and hot lapping all day long.



anyways.. glad we had a decent little conversation, i hope i havent offended you as im just trying to give some in put on what has worked with my engine. every setup is different and thats mainly what im trying to get at is all. i dont doubt you in the least bit Noyzee :chug:

LostCauseZ06
05-24-2007, 11:21 AM
Having used nitrous I do not understand why would you ever try to run max timing? Pulling timing depends on where you tune started at. Not only pulling timing makes you run a lot faster it is also the safe way to run. Why would you run max timing even if you get by with it? Again pulling timing & running higher octane makes you run much faster? I would for sure keep it below 25 degrees on bigger shots. If you have a fixed tune with lots of advance get the new MSD Timing Twister it lets you adjust timing pulled when the nitrous is activated then return to normal for motor run's. New product. Anyone not running a good wide-band A/F (Innovate) with the gauge at eye level so you can see it when running the 1/4 mile also is your best friend. I sure see some living on the edge thinking by some. This is free advice so some will still find out the hard way.
http://s85.photobucket.com/albums/k73/SSTBLS2/?action=view&current=P1000405.jpg


if you read closely you will see that the car is not being ran at max timing. never did we hit "max timing" its about 4 degrees under the highest timing point we ever hit (we still had no detonation therefore it wasnt max timing)

Noyzee
05-24-2007, 11:35 AM
I will admit, the car runs hotter on spray than id like, i have seen temperature spikes up to around 220 degrees instead of my usual 190 degree running temps. but i still have not gotten any detonation from the increased heat (im guessing thats what your getting at)


keep in mind. im guessing your mostly a track car that hot laps at the track spray after spray after spray. in that case then id totally agree about running less timign and more safety.


my car is a street car, used pretty much solely for roll racing on the freeway. Keep that in mind, it needs to be tuned for max NA power that i can do and then every now and then throw some spray into the mix when its necesarry (not very often) and its usually 1 single run from 40-140.


im guessing thats where the discrepency in your and my beliefs is the way we drive and race our cars. all my runs on spray are generally at 1 in the morning when its super cold outside and optimum conditions. which im sure is helping with heat issues as im not running in the hot sun at the track and hot lapping all day long.



anyways.. glad we had a decent little conversation, i hope i havent offended you as im just trying to give some in put on what has worked with my engine. every setup is different and thats mainly what im trying to get at is all. i dont doubt you in the least bit Noyzee :chug:
when i said heat, yes the motor runs a little hotter, but also exhaust gas and the chambers ect produce more heat causing melted pistions. if you melt a pistion 80% of the time you will not see any knockretard ect.

but like i sadi, if you where to look for your best times or racing a car on the street that was close.
pulling a couple degrees on spray will make you go better if the rest of the tune up is correct.
again, your saving grace could be that air you have in your town that you could cut with a knofe.
if you raced when i race (cold days here) DA is in the negitive, do that with all your timming and you will see what i meen. lol

LostCauseZ06
05-24-2007, 11:44 AM
when i said heat, yes the motor runs a little hotter, but also exhaust gas and the chambers ect produce more heat causing melted pistions. if you melt a pistion 80% of the time you will not see any knockretard ect.

but like i sadi, if you where to look for your best times or racing a car on the street that was close.
pulling a couple degrees on spray will make you go better if the rest of the tune up is correct.
again, your saving grace could be that air you have in your town that you could cut with a knofe.
if you raced when i race (cold days here) DA is in the negitive, do that with all your timming and you will see what i meen. lol


lol yeah its kinda a double edged sword having shitty air. we still get to claim corrected numbers and say we make as much HP as you guys but out track times suck.

but at the same time i can say im making 500 RWHP and launching at 5k RPM's on my stock rear with slicks and a mcleod street twin with no problems when in fact im only launching with about 420 RWHP :jest:

1320FEVER
05-24-2007, 12:09 PM
Anyone not running a good wide-band A/F (Innovate) with the gauge at eye level so you can see it when running the 1/4 mile also is your best friend.[/url]

I agree with that. An A/F wideband is an excellent investment and well worth the money if your running a big shot of nitrous.

tunedbytad
05-24-2007, 01:05 PM
Thought I would check out this thread for some nice technical timing info. After reading the Lost Cause debate, I was wrong. :lurk:

Robertt56 - I couldn't agree more with your timing levels for your power level, looks like it cost you some money to obtain that info?

MRDragster1970 - good rules of thumb practical application, You wouldn't be a Robert or a Bobby would you?

just some info on my exp.
I have tuned more then a few lsx cars
Stock LS1s on Cali 91 fuel in 100 heat will just start pinging @ 26 deg. :bang:

IMHexp. back to back dyno and track results have proven;
Less timing will always make more power on spray than NA timing.

FACT. Detonation @ BTDC makes massive negative torque.

The point to internal combustion is to expand or detonate the fuel ATDC to send the piston and rod in the direction it is ALREADY going...DOWN. Spark advance is lead time for the burn event to happen. There is another technology out there that uses glow plugs that have no spark advance and it make gobs of low end torque.

FACT. Pre detonation is happening before you can see or hear it. If you are making a minor 15-25 foot pounds of negative tq due to mild pre detonation that you can not hear yet, it is hard...impossible... to realize this minor power loss when your adding 200 hp to the motor.

Anyone want to do the math on how much total heat energy the piston head and valve have to endure with 20 HP worth of detonation **20hp is like 4% of total output on a 200ish shot LS1** with a 11 second run. Watching a nice calibrated aftermarket temp gauge crank over to the right during and after a run is a good indication that too much timing is present.

mrdragster1970
05-24-2007, 04:12 PM
.

No, that is my real license ! ! !

.

tunedbytad
05-24-2007, 04:51 PM
:thinker: Oh duh~ my bad

Robert56
05-24-2007, 07:08 PM
Thought I would check out this thread for some nice technical timing info. After reading the Lost Cause debate, I was wrong. :lurk:

Robertt56 - I couldn't agree more with your timing levels for your power level, looks like it cost you some money to obtain that info?

MRDragster1970 - good rules of thumb practical application, You wouldn't be a Robert or a Bobby would you?

just some info on my exp.
I have tuned more then a few lsx cars
Stock LS1s on Cali 91 fuel in 100 heat will just start pinging @ 26 deg. :bang:

IMHexp. back to back dyno and track results have proven;
Less timing will always make more power on spray than NA timing.

FACT. Detonation @ BTDC makes massive negative torque.

The point to internal combustion is to expand or detonate the fuel ATDC to send the piston and rod in the direction it is ALREADY going...DOWN. Spark advance is lead time for the burn event to happen. There is another technology out there that uses glow plugs that have no spark advance and it make gobs of low end torque.

FACT. Pre detonation is happening before you can see or hear it. If you are making a minor 15-25 foot pounds of negative tq due to mild pre detonation that you can not hear yet, it is hard...impossible... to realize this minor power loss when your adding 200 hp to the motor.

Anyone want to do the math on how much total heat energy the piston head and valve have to endure with 20 HP worth of detonation **20hp is like 4% of total output on a 200ish shot LS1** with a 11 second run. Watching a nice calibrated aftermarket temp gauge crank over to the right during and after a run is a good indication that too much timing is present.

Good explanation. Yea that pre ignition can lead to detonation. 30 guys were standing around my car and it didn't make any noise or sign of something wrong. Was watching for KR on the laptop, it was ZERO. My car held up well with over 200 sprayed passes, then went to a 285rwhp and decided to pull an additional 4* of timing, well I added the 4* instead of pulling it, and ended up with about 26* total. Way too much for that level, that's why I caution running a high timing on the big shots. (on my dry, timing can be pulled in the tune automatically when spraying only)

Anyway, Lostcause, what plugs are you running. Is this how you have been checking for detonation, reading plugs? Really the best way I am finding out, can't count on the Tuner Programs to let us know. Once again, good luck on your combo, i am hoping my 408 will also be a beast. :cheers:

Remember what Brad said, (to all reading along) it's not a matter of if you hurt something, but rather a matter of when, at least on the big hits.
Robert

jmalibuss
05-24-2007, 07:22 PM
just some info on my exp.
I have tuned more then a few lsx cars
Stock LS1s on Cali 91 fuel in 100 heat will just start pinging @ 26 deg. :bang:

IMHexp. back to back dyno and track results have proven;
Less timing will always make more power on spray than NA timing.

FACT. Detonation @ BTDC makes massive negative torque.

The point to internal combustion is to expand or detonate the fuel ATDC to send the piston and rod in the direction it is ALREADY going...DOWN. Spark advance is lead time for the burn event to happen. There is another technology out there that uses glow plugs that have no spark advance and it make gobs of low end torque.

FACT. Pre detonation is happening before you can see or hear it. If you are making a minor 15-25 foot pounds of negative tq due to mild pre detonation that you can not hear yet, it is hard...impossible... to realize this minor power loss when your adding 200 hp to the motor.

Anyone want to do the math on how much total heat energy the piston head and valve have to endure with 20 HP worth of detonation **20hp is like 4% of total output on a 200ish shot LS1** with a 11 second run. Watching a nice calibrated aftermarket temp gauge crank over to the right during and after a run is a good indication that too much timing is present.

Could Not agree more! :)

jmalibuss
05-24-2007, 07:37 PM
In addition, Everyone on here who is serious about making safe power wither it be N/A or forced induction should have a WB in their car. Reading plugs is not always as accurate as one might think. Not to say don't read plugs but they will not always tell you the whole story. If I had my way I'd put one in every header tube!
I wonder if anyone can give me a price break for buying 8 WB's? :thinker:

Noyzee
05-25-2007, 08:11 AM
In addition, Everyone on here who is serious about making safe power wither it be N/A or forced induction should have a WB in their car. Reading plugs is not always as accurate as one might think. Not to say don't read plugs but they will not always tell you the whole story. If I had my way I'd put one in every header tube!
I wonder if anyone can give me a price break for buying 8 WB's? :thinker:
wide band are good, but not always right on. like computers. never put all your eggs in one basket.
always read plugs no mater what the wb says.

1936FordPU
05-25-2007, 09:18 AM
In addition, Everyone on here who is serious about making safe power wither it be N/A or forced induction should have a WB in their car. Reading plugs is not always as accurate as one might think. Not to say don't read plugs but they will not always tell you the whole story. If I had my way I'd put one in every header tube!
I wonder if anyone can give me a price break for buying 8 WB's? :thinker:Dude...plug reading has been around WAY before WB's were invented. He may be old school....If he is, id bet he knows what hes looking at under that 10X magnifier.

jmalibuss
05-25-2007, 10:26 AM
I Agree Plug Reading has been around for much longer and it is a another way to look inside the combustion chamber. However, unless you make a pass wide open, immediately shut off the engine and then read the plugs there is a good chance that they will not show you what you need to see. Idling and part throttle time will change the way the plugs look and what they show.
On the same token, if something is going south in the motor, a WB will NOT show you signs of detonation!

bjamick
05-25-2007, 10:35 AM
28 on 250 wow
Ya thats what i was thinking.... :eek: isnt our cars stock with 28 degrees timing??

I've heard that 2 degrees per 50hp but i was running stock timing on my 100 shot with no problems but i had a bigger fuel jet then i was supposed to so that away it was "safe" :jest:

LostCauseZ06
05-25-2007, 12:07 PM
I Agree Plug Reading has been around for much longer and it is a another way to look inside the combustion chamber. However, unless you make a pass wide open, immediately shut off the engine and then read the plugs there is a good chance that they will not show you what you need to see. Idling and part throttle time will change the way the plugs look and what they show.
On the same token, if something is going south in the motor, a WB will NOT show you signs of detonation!



yes and no... you have to shut it off immediately to know where your A/F is at. but if you were detonating/leaning out your plugs are going to be pretty hammered (speckled and/or melted ground straps) even if you let the car idle for a while afterwards.


Btw robert i dont think it was 100% the timing that killed your motor... the stock pistons are junk and you were running power levels similar to what most guys run before the ring lands give up. id say yours looks like it finally just cracked or got a little melted then just went to hell. Forged nitrous pistons are a alot more forgiving and can handle alot more actual HP than the stock pistons.


its all in the tune up till a point... that point is the actual physical constraints the motor itself has on it. you can have a tune spot on but stock pistons are not going to like over 550 RWHP for very long :(

Noyzee
05-25-2007, 12:31 PM
I Agree Plug Reading has been around for much longer and it is a another way to look inside the combustion chamber. However, unless you make a pass wide open, immediately shut off the engine and then read the plugs there is a good chance that they will not show you what you need to see. Idling and part throttle time will change the way the plugs look and what they show.
On the same token, if something is going south in the motor, a WB will NOT show you signs of detonation!
after every pass i run threw the traps, throw it in N shut it right down and cost to the end. i pull over, shut off my bottle, purge, then pull a few plugs throw some warmup plugs in the car drive back to the trailer. read the plugs, put them back in, pull the rest of the plugs be sure all looks ok, reinstall mke adjustments as needed. thats how you do it. :chug:

mrdragster1970
05-25-2007, 06:17 PM
.

If you're not towing back then you have to pull the plugs at the big end ^^^^. Even the 1/2 mile drive back will alter the true read. I have a Professional style data recorder, on my Pro-Modified and we still pull plugs. All the data you can get, is better for making changes, or catching something going away on you.

For the guys running more timing than the specs say, or people say you should. More timing is not going to make more power in every case. As said, there is a specific relationship between burn, timing, compression, efficiency ect ect. You might actually be hurting your power by going more & more timing. Just because you aren't blowing up, doesn't mean you won't. Maybe soon, maybe never. Example on BBC. The better the head, the less timing we run. My Profiler & Pro-Stock heads run much less timing, and make more power. I'm not a rocket scientist, but there is a real reason for more efficient motors with & without N2O to like less timing.

.

jmalibuss
05-25-2007, 07:06 PM
.

The better the head, the less timing we run. My Profiler & Pro-Stock heads run much less timing, and make more power. I'm not a rocket scientist, but there is a real reason for more efficient motors with & without N2O to like less timing.
.
All in all timing is just what is states, Timing. You are timing when you have max cylinder pressure at a given crank angle. All the number is, is your lead time. More efficent engine will want less lead time.

Lythropus
05-28-2007, 01:52 PM
I wish there was an easy answer to this. Say I'm running 28 degrees on a NA tune, I can bump it up to 32 with no knock on hot days and also no gain in power...so wouldn't spraying a 150 at 28 just be like running 28 and saying I'm pulling 4 degrees...???

So what do most people do? So say I'm running 28 degrees and want to spray a dual stage 300 shot. 93 in tank and 116 in stand-alone. One guy said he was at 25 degrees and a dual stage 300 shot. If I check plugs (right heat range and good reading) at that level, have no KR, read fat on a wideband, and only use fresh race gas that wouldn't be safe? If not then why the hell not? It seems like running the timing up until I get some kr and then backing it off is just running it close to the edge...

mrdragster1970
05-28-2007, 05:06 PM
.

I'm probably not saying what I mean correctly, but I'll try. If you increase timing and don't increase HP why do it. Max timing without detonating is not automatically max power. Like it was said, peak power has a sweet spot in timing. If my motor runs the exact same from 22-26 degrees, I run 22 degrees. On conventional heads, same thing, 32-36 degrees, I use 32. Just because you can run more timing without knock, doesn't mean you have to.

.

CamTom12
05-29-2007, 11:24 AM
this isnt rocket science. if the car detonates, your gonna have problems. If its not detonating and the plugs look good then your good to go. i dunno WTF you guys are talking about. Just because you have it stuck in your head that thats too much timing is total BS. every motor is different, every setup is different. detonation kills motors, not nitrous itself or timing. Its the detonation that is CAUSED by those things but so long as the detonation is not happeneing there is no problems running the car the way that i do.


If you've bumped timing up on a dyno you'll notice that as you add degrees you make more power to a certain point, then you really won't make much more even as you add timing to it. This is probably where you're sitting. if you then continue to add timing you'll then hit detonation.

All spark advance does is timing the flame front, or pressure spike, to the downward motion of the piston. This is good for the motor. You can add too much advance and have the pressure spike hit during the piston's dwell time at the top of its motion. This is when you'll be able to add timing without making more power. This isn't that great for your motor. When the peak pressure hits as the piston is on it's way up is when you'll hear the actual ping, though. That's the sound of your bearings making contact with each other. This is bad for your motor.

brad8266
05-29-2007, 11:57 AM
The proper way is add timing until your power peak and no more, not until KR, this is n/a timing of course.

Oh so true. There is no need to advance till it knocks, juts till youre at peak power.

LostCauseZ06
05-29-2007, 03:42 PM
Oh so true. There is no need to advance till it knocks, juts till youre at peak power.


lol there is so much more to that statement its insane though... there is another HUGE piece to this puzzle.... a/f ratios.


until you mess around with your a/f ratio at the higher timing levels you will never really know if your at "max power"

mellowyellow
06-21-2007, 01:05 AM
What do you guys think about 29.5* with a 150shot ? Ive tried it and logged it with no KR and A/F was fine ????

mellowyellow
06-21-2007, 01:43 AM
Finally my post shows up...LOL...^^^^^

Robert56
06-21-2007, 09:22 PM
What do you guys think about 29.5* with a 150shot ? Ive tried it and logged it with no KR and A/F was fine ????
Most in the industry will say that stock timing is fine upto 150 shot, running highest octane available. Your cylinder pressures will be no where near what a 200 plus hit will see.
Robert

mellowyellow
06-21-2007, 10:42 PM
Thanks for the reply Robert...

BayAreaSS
06-21-2007, 11:21 PM
I dont know if this has been asked already but what is stock timing on an ls1?

And what should the timing be for a 75-100 shot?

WizeAss
06-22-2007, 09:33 AM
What do you guys think about 29.5* with a 150shot ? Ive tried it and logged it with no KR and A/F was fine ????

where do you engage the nitrous? 3500 rpm,....... 3000 rpm? this makes a difference. If you are wanting to get it down the 3000 rpm.... my suggestion is that the volume of nitrous your engine is injesting and digesting..... might want to tune it for less timing at 3k, then raise it 2 degrees at 3500.... then raise another degree or two at 4k+...

so if you are running 29 degrees at 5k rpm.... I would only run around 25 degrees at 3k rpm......

Too bad most run NA tunes as nitrous tunes. Noyzee... your thoughts?

WizeAss
06-22-2007, 09:35 AM
Most in the industry will say that stock timing is fine upto 150 shot, running highest octane available. Your cylinder pressures will be no where near what a 200 plus hit will see.
Robert
Come on Robert... tell the real story. At 3000 to 3500 rpm..... the cylinder pressue on a 150 shot is greater then that of a 225 shot at 6k rpm. RPM has a huge impact on the amount of nitrous you can run.

jakesz28
06-22-2007, 06:40 PM
In my car I wasn't noticing any knock and the plugs looked fine. But when I installed the mallory 685 my car picked up 2-3 tenths. This was on a 150 shot.


Now I just put a two stage system on so I will 200 RWHP (100 + 100). I run 36 degrees timing for the N/A tune and plan on pulling 10 degres timing when the second stage comes in.
Does that sound like a good strarting point?

Robert56
06-22-2007, 09:23 PM
Come on Robert... tell the real story. At 3000 to 3500 rpm..... the cylinder pressue on a 150 shot is greater then that of a 225 shot at 6k rpm. RPM has a huge impact on the amount of nitrous you can run.
Not sure the point, or what your getting at? The fact of the matter is the torque of a 150 can do more damage at 3000rpm, compared to a 225 shot at 6000rpm. Why is this, the time the high clyinder pressures remain in the clylinder. So, comparing a 150 at 3000 to a 225 at 6000 is not an apples to apples comparison.

Why you bring this up not sure, did I state something wrong? My comment was about comparing a big hit and timing, what we have been kinda talking about (just trying to clarify). Do you know how much progressively greater the clyinder pressures are when comparing a 150 @ 3000 and a 250 @ 3000?
Robert

WizeAss
06-23-2007, 11:47 AM
Not sure the point, or what your getting at? The fact of the matter is the torque of a 150 can do more damage at 3000rpm, compared to a 225 shot at 6000rpm. Why is this, the time the high clyinder pressures remain in the clylinder. So, comparing a 150 at 3000 to a 225 at 6000 is not an apples to apples comparison.

Why you bring this up not sure, did I state something wrong? My comment was about comparing a big hit and timing, what we have been kinda talking about (just trying to clarify). Do you know how much progressively greater the clyinder pressures are when comparing a 150 @ 3000 and a 250 @ 3000?
Robert


you are right.... I was asking for you to clarify....... basically that you dont have to pull as much timing out if you get a progressive controller. since you can run less nitrous at lower rpms and more at higher rpms.... you can keep your timing up by running less nitrous down low. It really is not the problem with timing and nitrous over 4500 or more rpm.... it is spraying the car from 3k to 4500 that creates those high cylinder pressures and detonation potential with NA timing.

SILVERZZ28
06-24-2007, 11:51 PM
lol godddammnn i didnt know detonation could do something like that.. i was under the impression a nitrous backfire was the cause of that :jest:

What a tool!!!

Remember this post?

http://www.ls1tech.com/forums/showpost.php?p=7111371&postcount=19

Maybe this will help you understand why it happened :chug:

SILVERZZ28
06-24-2007, 11:57 PM
lol what in the world are you guys talking about??? this forum cracks me up sometimes.


i have had zero problems with my heads and engine. i popped a fel pro 4.125 paper head gasket spraying a 200 shot on a high compression 408..... last time i checked that wasnt exactly a "rare" occurance and was most likely caused by the fact that i didnt get all the water out of the head bolt holes (i didnt realize the bolts went as far down as they do)


Hmmm I have never had an issue with head gaskets! Must be rare :bang:

Water in the bolt holes had nothing to do with it. However.......... the water in your head probably did :jest: