Advanced my timing on my 2k2
Senior Member
Joined: Jul 2001
Posts: 306
From: Pittsburgh, PA
Re: I got this one...
Originally posted by IceY2K1
Octane booster is crap. The "best" available ONLY raises it "3-4 points"(NOT OCTANE points!), which means if your running 92-octane and you add the "booster", your only at 92.3-92.4-octane. Trust me, unless you pour several bottles of it for one tank of gas it will NOT make a difference. I've tried EVERYTHING but making my own, which I'm now planning on doing. BTW, this is NOT on the Maxima.
Octane booster is crap. The "best" available ONLY raises it "3-4 points"(NOT OCTANE points!), which means if your running 92-octane and you add the "booster", your only at 92.3-92.4-octane. Trust me, unless you pour several bottles of it for one tank of gas it will NOT make a difference. I've tried EVERYTHING but making my own, which I'm now planning on doing. BTW, this is NOT on the Maxima.
How are you making the octane booster? I just did this for my Mustang 2 weeks ago after finding out I had been mislead by the 104+ octane booster that was raising my octane from 93 to 93.7 at best!!
I use 1 gallon of Toulene mixed with 3 ounces of Marvels Mystery oil. The Toulene has an octane rating of 114, so mixed with 12 gallons of gas it raises the octane from 93 to 94.6. They say you can run up to 10% toulene, which would raise it from 93 to 95.3 (13 gallon tank). They also say Xylene is 117 octane, but for some reason less desirable to use. I paid $25 for 5 gallons of Toulene. When you figure it deplaces one gallon of gas, the real cost would be $3.40 per gallon ($5 per gallon minus $1.60 for the gas it displaces) which is much better than the $7 per bottle of 104+.
--Ray
Ray...
Originally posted by raynist
Hey,
How are you making the octane booster? I just did this for my Mustang 2 weeks ago after finding out I had been mislead by the 104+ octane booster that was raising my octane from 93 to 93.7 at best!!
I use 1 gallon of Toulene mixed with 3 ounces of Marvels Mystery oil. The Toulene has an octane rating of 114, so mixed with 12 gallons of gas it raises the octane from 93 to 94.6. They say you can run up to 10% toulene, which would raise it from 93 to 95.3 (13 gallon tank). They also say Xylene is 117 octane, but for some reason less desirable to use. I paid $25 for 5 gallons of Toulene. When you figure it deplaces one gallon of gas, the real cost would be $3.40 per gallon ($5 per gallon minus $1.60 for the gas it displaces) which is much better than the $7 per bottle of 104+.
--Ray
Hey,
How are you making the octane booster? I just did this for my Mustang 2 weeks ago after finding out I had been mislead by the 104+ octane booster that was raising my octane from 93 to 93.7 at best!!
I use 1 gallon of Toulene mixed with 3 ounces of Marvels Mystery oil. The Toulene has an octane rating of 114, so mixed with 12 gallons of gas it raises the octane from 93 to 94.6. They say you can run up to 10% toulene, which would raise it from 93 to 95.3 (13 gallon tank). They also say Xylene is 117 octane, but for some reason less desirable to use. I paid $25 for 5 gallons of Toulene. When you figure it deplaces one gallon of gas, the real cost would be $3.40 per gallon ($5 per gallon minus $1.60 for the gas it displaces) which is much better than the $7 per bottle of 104+.
--Ray
Sounds like your working from the same receipe I am, but I haven't made a batch yet. I'm trying colder plugs right now and it seems to be working along with the slightly cooler weather. So, I'm probably not going to make any until next summer. Let me know how it works on the Mustang though. The only thing I'm concerned about is the corosive properties of the Toulene and the fuel system components.
[/**THIS IS NOT FOR MY MAXIMA**]
Re: Re: Re: Re: Hey Mini...this sounds interesting because
Originally posted by magnum658
What mods do you have to get 313 horsepower?
What mods do you have to get 313 horsepower?
BTW, he's running N20.
Xylene does have 117 octane and there is a GN in my neighborhood that uses it all the time to run 28psi of boost. Most of you people would just be better off with mixing in a few gallons of 100 octane street/racing gas (unleaded) with your 93. You can't just look at an octane number and think you've solved all the problems. Gasoline is one of the few fuels that requires a 14.5:1 stochiometric ratio. All of those other chemicals require a much lower ratio which means you have to physically put more of it in the chamber per amount of oxygen present. That and the fact that the BTU # or thermal efficiency of those other fuels arent as good means that they do not make as much HP as regular gasoline.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
Senior Member
Joined: Jun 2001
Posts: 1,015
Way, way, way back when, you were supposed to be able to put moth ***** into your tank to raise the octane 
I don't think it ever worked, but it kept the bugs away.
I always wondered how they harvested those things, moths are sooooo small.
I don't think it ever worked, but it kept the bugs away.
I always wondered how they harvested those things, moths are sooooo small.
Originally posted by SR20DEN
Xylene does have 117 octane and there is a GN in my neighborhood that uses it all the time to run 28psi of boost. Most of you people would just be better off with mixing in a few gallons of 100 octane street/racing gas (unleaded) with your 93. You can't just look at an octane number and think you've solved all the problems. Gasoline is one of the few fuels that requires a 14.5:1 stochiometric ratio. All of those other chemicals require a much lower ratio which means you have to physically put more of it in the chamber per amount of oxygen present. That and the fact that the BTU # or thermal efficiency of those other fuels arent as good means that they do not make as much HP as regular gasoline.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
Xylene does have 117 octane and there is a GN in my neighborhood that uses it all the time to run 28psi of boost. Most of you people would just be better off with mixing in a few gallons of 100 octane street/racing gas (unleaded) with your 93. You can't just look at an octane number and think you've solved all the problems. Gasoline is one of the few fuels that requires a 14.5:1 stochiometric ratio. All of those other chemicals require a much lower ratio which means you have to physically put more of it in the chamber per amount of oxygen present. That and the fact that the BTU # or thermal efficiency of those other fuels arent as good means that they do not make as much HP as regular gasoline.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
Any idea on how corrosive to the fuel system these are?
Guest
Posts: n/a
Well, y'all got my attention enough that I'm going to give it a whirl on my 2k next Wed. I'm going to advance it 3 degrees, but not any more. It's only going to cost me $35 to try it, so what the hell. I don't use my nitrous any more, so I'm not too worried about the problems there, I'll just stop using it.
Originally posted by nc00max
Well, y'all got my attention enough that I'm going to give it a whirl on my 2k next Wed. I'm going to advance it 3 degrees, but not any more. It's only going to cost me $35 to try it, so what the hell. I don't use my nitrous any more, so I'm not too worried about the problems there, I'll just stop using it.
Well, y'all got my attention enough that I'm going to give it a whirl on my 2k next Wed. I'm going to advance it 3 degrees, but not any more. It's only going to cost me $35 to try it, so what the hell. I don't use my nitrous any more, so I'm not too worried about the problems there, I'll just stop using it.
Originally posted by IceY2K1
Too bad I can only buy 91-octane CRAP locally and I have no idea where I could find 100-octane around here. Definitely, no where close.
Any idea on how corrosive to the fuel system these are?
Too bad I can only buy 91-octane CRAP locally and I have no idea where I could find 100-octane around here. Definitely, no where close.
Any idea on how corrosive to the fuel system these are?
76
Citgo
Sunoco (CAM2)
According to the 76 website these gas stations have race gas in Tucson.
Intersection SPEEDWAY/FORGEUS
Corner of Intersection SW
Address 2604 E SPEEDWAY
City TUCSON
State AZ
County PIMA
Phone (520) 323-2354
On Interstate No
Racing Fuel Yes
Intersection FIRST/GLEN
Corner of Intersection SE
Address 2710 N FIRST AVE
City TUCSON
State AZ
County PIMA
Phone (520) 622-8611
On Interstate No
Racing Fuel Yes
Thanks...
Originally posted by SR20DEN
Here are links to find local unleaded race gas.
76
Citgo
Sunoco (CAM2)
According to the 76 website these gas stations have race gas in Tucson.
Intersection SPEEDWAY/FORGEUS
Corner of Intersection SW
Address 2604 E SPEEDWAY
City TUCSON
State AZ
County PIMA
Phone (520) 323-2354
On Interstate No
Racing Fuel Yes
Intersection FIRST/GLEN
Corner of Intersection SE
Address 2710 N FIRST AVE
City TUCSON
State AZ
County PIMA
Phone (520) 622-8611
On Interstate No
Racing Fuel Yes
Here are links to find local unleaded race gas.
76
Citgo
Sunoco (CAM2)
According to the 76 website these gas stations have race gas in Tucson.
Intersection SPEEDWAY/FORGEUS
Corner of Intersection SW
Address 2604 E SPEEDWAY
City TUCSON
State AZ
County PIMA
Phone (520) 323-2354
On Interstate No
Racing Fuel Yes
Intersection FIRST/GLEN
Corner of Intersection SE
Address 2710 N FIRST AVE
City TUCSON
State AZ
County PIMA
Phone (520) 622-8611
On Interstate No
Racing Fuel Yes
I started a location database, everyone please add to it if you know of any locations to buy 100 octane fuel.
http://forums.max-world.org/index.php?act=ST&f=29&t=295
http://forums.max-world.org/index.php?act=ST&f=29&t=295
Senior Member
Joined: Jul 2001
Posts: 306
From: Pittsburgh, PA
Originally posted by SR20DEN
Xylene does have 117 octane and there is a GN in my neighborhood that uses it all the time to run 28psi of boost. Most of you people would just be better off with mixing in a few gallons of 100 octane street/racing gas (unleaded) with your 93. You can't just look at an octane number and think you've solved all the problems. Gasoline is one of the few fuels that requires a 14.5:1 stochiometric ratio. All of those other chemicals require a much lower ratio which means you have to physically put more of it in the chamber per amount of oxygen present. That and the fact that the BTU # or thermal efficiency of those other fuels arent as good means that they do not make as much HP as regular gasoline.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
Xylene does have 117 octane and there is a GN in my neighborhood that uses it all the time to run 28psi of boost. Most of you people would just be better off with mixing in a few gallons of 100 octane street/racing gas (unleaded) with your 93. You can't just look at an octane number and think you've solved all the problems. Gasoline is one of the few fuels that requires a 14.5:1 stochiometric ratio. All of those other chemicals require a much lower ratio which means you have to physically put more of it in the chamber per amount of oxygen present. That and the fact that the BTU # or thermal efficiency of those other fuels arent as good means that they do not make as much HP as regular gasoline.
I recently found out about the fuel additives too, when they rate an additive as 7 points or 10 points that means they raise the octane by 0.7 or 1.0 . Who knows how or why they can legally get away with this but the crap just doesn't work. Or I should say most of it is crap. There are some brands availible that are quite expensive that do work as they should and do make power too. Some of them have real nitromethane. But even nitromethane isn't the best additive for a street driven vehicle because Nitro doesn't make power the same way as gasoline does. Nitro burns much slower so it has a much longer and slower flame front. One of the best additives for a street car is something that burns about as fast or faster than gasoline such as Alcohol or Methanol. Im not exactly sure if those burn any faster but they do generaly have a higher octane but a lower stochiometric ratio. Alcohol tends to make alot more peak power than Nitro because of it's faster burn.
--Ray
Originally posted by raynist
I don't really use the Toulene to create more power, just to let it run safely with more boost to prevent detonation.
--Ray
I don't really use the Toulene to create more power, just to let it run safely with more boost to prevent detonation.
--Ray
You knew that and I knew that. But everyone didn't.
Exactly...
Originally posted by raynist
I don't really use the Toulene to create more power, just to let it run safely with more boost to prevent detonation.
--Ray
I don't really use the Toulene to create more power, just to let it run safely with more boost to prevent detonation.
--Ray
Damn GA16DE
Originally posted by ewood420
going to sears point tonight to test the timing advanced. I will also
put some 100 octane race gas in
with a 1/8 tank of 91 octane. see if i can better my best time
going to sears point tonight to test the timing advanced. I will also
put some 100 octane race gas in
with a 1/8 tank of 91 octane. see if i can better my best time
Senior Member
Joined: Mar 2002
Posts: 285
i called up courtesy to see if they would do it, the tech really was confident in knowing how to use consultII. So he told me he would ask around and call me back.
I hope he can figure it out. It seems extremely simple.
I hope he can figure it out. It seems extremely simple.
Senior Member
Joined: Aug 2002
Posts: 1,280
Ok, I'm confused. Advancing the timing should only increase power at higher engine speeds. At lower engine speed, you would actually lose power. So how did this advancing work, did it shift the timing map for the whole RPM range? or just higher RPM? Anyone know?
And what is all this talk about higher octane fuel? Advancing the timing should not affect fuel compression. Actually, you are sparking earlier, so the fuel is actually less compressed when the fuel first starts to burn. So why higher octane?
And what is all this talk about higher octane fuel? Advancing the timing should not affect fuel compression. Actually, you are sparking earlier, so the fuel is actually less compressed when the fuel first starts to burn. So why higher octane?
Senior Member
Joined: Aug 2002
Posts: 1,280
I think some of you need to read up on this stuff before jumping on the timing advance bandwagon.
The Basics
More detail about adjusting timing/ignition systems
I think the only people who could possibly benefit from this are SC'd people.
The Basics
More detail about adjusting timing/ignition systems
I think the only people who could possibly benefit from this are SC'd people.
Maxima Pilot
Joined: Oct 2001
Posts: 1,467
From: Beaverton, Oregon
Kojiro, u obviously did not read this yourself...
how can you read this and opine that this can only be beneficial to supercharged angines?
Please help me here for I see no way u can read all this and reach that conclusion. In real life, most forced-induction systems require a RETARDATION of ignition timing along with intercooling, water injection & other ways to REDUCE combustion chamber temperatures, not to increase them by adding advance.
Please help me here for I see no way u can read all this and reach that conclusion. In real life, most forced-induction systems require a RETARDATION of ignition timing along with intercooling, water injection & other ways to REDUCE combustion chamber temperatures, not to increase them by adding advance.
Senior Member
Joined: Aug 2002
Posts: 1,280
Re: Kojiro, u obviously did not read this yourself...
Originally posted by Galo
how can you read this and opine that this can only be beneficial to supercharged angines?
Please help me here for I see no way u can read all this and reach that conclusion. In real life, most forced-induction systems require a RETARDATION of ignition timing along with intercooling, water injection & other ways to REDUCE combustion chamber temperatures, not to increase them by adding advance.
how can you read this and opine that this can only be beneficial to supercharged angines?
Please help me here for I see no way u can read all this and reach that conclusion. In real life, most forced-induction systems require a RETARDATION of ignition timing along with intercooling, water injection & other ways to REDUCE combustion chamber temperatures, not to increase them by adding advance.
Point was, why are we playing with the initial timing? I could see potentially advancing the curve, but I don't understand why we are playing with the initial timing. Also, why are we assuming that Nissan didn't set the timing optimally? And won't the computer just change the timing on the fly anyways, depending on emissions and intake and rpm? So this advance will be overridden anyways. Please verify or disprove if you know more specifics of the engine's ECU.
Maxima Pilot
Joined: Oct 2001
Posts: 1,467
From: Beaverton, Oregon
First off, the article confirms that all the
initial static advance you can add is good for performance in the low-mid RPM ranges -because you have added advance until the point in time the distributors' (in our case, the ECU) advance curve takes over.
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
Senior Member
Joined: Jun 2002
Posts: 131
Re: Re: Kojiro, u obviously did not read this yourself...
Originally posted by Kojiro_FtT
Also, why are we assuming that Nissan didn't set the timing optimally?
Also, why are we assuming that Nissan didn't set the timing optimally?
Senior Member
Joined: Aug 2002
Posts: 1,280
Re: First off, the article confirms that all the
Originally posted by Galo
initial static advance you can add is good for performance in the low-mid RPM ranges -because you have added advance until the point in time the distributors' (in our case, the ECU) advance curve takes over.
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
initial static advance you can add is good for performance in the low-mid RPM ranges -because you have added advance until the point in time the distributors' (in our case, the ECU) advance curve takes over.
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
Maxima Pilot
Joined: Oct 2001
Posts: 1,467
From: Beaverton, Oregon
Kojiro...oh, yeah, it's still running perfect -
and yes, the added torque is still noticeable!
Just yesterday I romped on it a bit harder than usual in third gear (from about 2500 rpms to maybe 4000) going up a hill that I travel every day home from work and it really surprised me how torquey the engine feels now...definitely noticeable!
Just yesterday I romped on it a bit harder than usual in third gear (from about 2500 rpms to maybe 4000) going up a hill that I travel every day home from work and it really surprised me how torquey the engine feels now...definitely noticeable!
Re: First off, the article confirms that all the
Originally posted by Galo
initial static advance you can add is good for performance in the low-mid RPM ranges -because you have added advance until the point in time the distributors' (in our case, the ECU) advance curve takes over.
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
initial static advance you can add is good for performance in the low-mid RPM ranges -because you have added advance until the point in time the distributors' (in our case, the ECU) advance curve takes over.
Secondly, when I did this to my car, the tech and I CONFIRMED that the ECU maintained the added 3 degrees of advance at least up to 3k RPMs, we did this by just simply setting up a timing light and looking at how the timing shifted as we added or reduced advance.
It stands to reason that this would be the case -that the timing change would hold throughout the rev range- because Org members have had to use this process to REDUCE their timing to reduce detonation, knock, etc
From my OBD-II scans, it looks like as soon as you touched the accelerator the ECU would begin ADVANCING the timing up to ~40-50 degrees and even to 60 degrees depending on the rate of change of the TPS. However, what I'm seeing is NOT actual timing, but ECU target timing, so I couldn't confirm whether or not the ECU compensated for the base idle timing adjustment once under load.
BTW, I think I MIGHT know why the 3-degree "wall" was stopping the advancing, but I don't know YET how to get around it. The only thing I can figure trying is to back down the idle rpms, then try and advance more. I'm thinking that since your advancing the timing, your also increasing the rpms and the ECU is seeing that increase and backing back the idle speed and/or timing. If that doesn't work, then you must perform an "Idle Air Volume Learning" procedure to allow the engine to stay within the specified range with the higher advance. Takes about 20-seconds, but you need to have the car warmed-up and certain conditions satisfied for it to work properly. If you get to this point I can help.
It's all theory right now, but I've seen this happen before.
Maxima Pilot
Joined: Oct 2001
Posts: 1,467
From: Beaverton, Oregon
Hey, Ice...I think ur on to something here...
dat might explain why when we attempted to go +4 the timing looked to get erratic...if you recall my post about -ohh, forty posts before this one (LOL!!!) that's exactly what we observed, almost like we reached a 'wall' and the ECU was attempting to advance further -but could not.
Anyway, I'm perfectly happy now and will NOT go where ur going but let me know if your theory holds.
After all, if three is good, five must be better, eh??!!
Anyway, I'm perfectly happy now and will NOT go where ur going but let me know if your theory holds.
After all, if three is good, five must be better, eh??!!
Senior Member
Joined: Jul 2001
Posts: 306
From: Pittsburgh, PA
Originally posted by Kojiro_FtT
Ok, I'm confused. Advancing the timing should only increase power at higher engine speeds. At lower engine speed, you would actually lose power. So how did this advancing work, did it shift the timing map for the whole RPM range? or just higher RPM? Anyone know?
And what is all this talk about higher octane fuel? Advancing the timing should not affect fuel compression. Actually, you are sparking earlier, so the fuel is actually less compressed when the fuel first starts to burn. So why higher octane?
Ok, I'm confused. Advancing the timing should only increase power at higher engine speeds. At lower engine speed, you would actually lose power. So how did this advancing work, did it shift the timing map for the whole RPM range? or just higher RPM? Anyone know?
And what is all this talk about higher octane fuel? Advancing the timing should not affect fuel compression. Actually, you are sparking earlier, so the fuel is actually less compressed when the fuel first starts to burn. So why higher octane?
Maxima Pilot
Joined: Oct 2001
Posts: 1,467
From: Beaverton, Oregon
raynist: Correct. And many months of detonation,
pinging, knocking and other assorted -and very noticeable- ills and loud noises will precede a blown piston, bent rod, blown gasket and other assorted malaise u describe.
If you have no detonation, pinging, knocking or any other evidence of pre-ignition (which is what really drives up cylinder pressure, BTW) you have no chance of the situation you're describing actually happening.
If you have no detonation, pinging, knocking or any other evidence of pre-ignition (which is what really drives up cylinder pressure, BTW) you have no chance of the situation you're describing actually happening.
Senior Member
Joined: Jul 2001
Posts: 306
From: Pittsburgh, PA
Re: raynist: Correct. And many months of detonation,
Originally posted by Galo
pinging, knocking and other assorted -and very noticeable- ills and loud noises will precede a blown piston, bent rod, blown gasket and other assorted malaise u describe.
If you have no detonation, pinging, knocking or any other evidence of pre-ignition (which is what really drives up cylinder pressure, BTW) you have no chance of the situation you're describing actually happening.
pinging, knocking and other assorted -and very noticeable- ills and loud noises will precede a blown piston, bent rod, blown gasket and other assorted malaise u describe.
If you have no detonation, pinging, knocking or any other evidence of pre-ignition (which is what really drives up cylinder pressure, BTW) you have no chance of the situation you're describing actually happening.
When I advance the timing on my vehicles (2 89 Mustang Gt's and Ford Truck) I advance them from 10* base in 2* increments until I hear a slight ping and then back it off 1*. I usually end up advancing them 3-4 degrees
Slight pinging under load is NORMAL = better fuel economy = better emissions...
If you drive around with your windows down out here in the AZ desert with the crap 91-octane they sell, you'll hear detonation from MOST vehicles coming out of a stop light. Apparently, it's NOT catostrophic as most people think, since your average driver wouldn't even notice with the A/C, radio, and wind/engine noise.
OT, but my '93 Sentra has been plagued with detonation ever since ~60K. I've seen EVERY Nissan dealer in the TRI-State area and all have first said it's normal and when I persist to fix it, they just retard the timing further than the OEM recommended 10°±2° BTDC to 4-5° BTDC. So, it runs like a dog during the summer. I've always used PREMIUM fuel(was 92, now 91) and since ~75K Chevron Premium exclusively. The Chevron fuel helped noticeably and has been the ONLY good advice I've gotten yet from a dealer.
Now that the warranty is long gone and with 135K+ on the OD, I adjust the timing on a weather-by-weather basis, but I definitely lost 2 or 3° due to the downgrade from 92 to 91 octane. Everyone tells me to ignore it, but I can't. I've run enough fuel cleaners to turn the plugs a redish color and the last resort is to perform a combustion chamber cleaner, but with 135K+ miles I think it would do more harm then good. I'll just milk it along until I drive it into the ground or it blows up and I'll drop in a SR20DE motor to use for a toy car.
OT, but my '93 Sentra has been plagued with detonation ever since ~60K. I've seen EVERY Nissan dealer in the TRI-State area and all have first said it's normal and when I persist to fix it, they just retard the timing further than the OEM recommended 10°±2° BTDC to 4-5° BTDC. So, it runs like a dog during the summer. I've always used PREMIUM fuel(was 92, now 91) and since ~75K Chevron Premium exclusively. The Chevron fuel helped noticeably and has been the ONLY good advice I've gotten yet from a dealer.
Now that the warranty is long gone and with 135K+ on the OD, I adjust the timing on a weather-by-weather basis, but I definitely lost 2 or 3° due to the downgrade from 92 to 91 octane. Everyone tells me to ignore it, but I can't. I've run enough fuel cleaners to turn the plugs a redish color and the last resort is to perform a combustion chamber cleaner, but with 135K+ miles I think it would do more harm then good. I'll just milk it along until I drive it into the ground or it blows up and I'll drop in a SR20DE motor to use for a toy car.
Senior Member
Joined: Jul 2001
Posts: 306
From: Pittsburgh, PA
Galo, good point on the colder plugs. I did this with my Supercharged 89 Mustang GT. Pinging/detonation, while never good is much less of a problem on a non supercharged vehicle, the supercharged raises compression in the cylinder and magnifies detonation problems. I have an 86 Ford F150 that has pinged since I got it, I really don't care as I only paid $800 for it and it has run for 5 years. I still use 87 octane in it.
--Ray
--Ray