Timing retard?
02-28-2004, 09:51 AM
#1
Timing retard?
I was watching HP TV today...they were puttin a Roots blower on a Roadrunner I believe.
But what they said was "every 100+ hp added to a motor, you need to retard the timing about 2-4 degrees."
---Is that on just that type of motor? Or does it apply to all? Do you boosted guys have your timing retarted?
But what they said was "every 100+ hp added to a motor, you need to retard the timing about 2-4 degrees."
---Is that on just that type of motor? Or does it apply to all? Do you boosted guys have your timing retarted?
02-28-2004, 12:34 PM
#3
I was wondering this too. i have a mechanic friend that just got an ecu reprogrammer or something for his shop. he tried to explain it. he said that it cost around $100,000 or something.
does anyone know if that could retard timing?
does anyone know if that could retard timing?
02-28-2004, 01:54 PM
#4
Its not exactly that amount on everycar. It depends on compression and other things.
On a maxima you could be boosting 9psi on the engine and not have any detonation/knock. So then there is no reason to pull back the timing. And yes 9psi added at least 100+ hp if not to the wheels.
After 9psi or so, you are going to want to start retarding timing on a stock compression VQ.
I have a J&S that im using in the meantime while I figure out the Greddy's issue. Got the osciliscope here to see whats going on.
Dixit
On a maxima you could be boosting 9psi on the engine and not have any detonation/knock. So then there is no reason to pull back the timing. And yes 9psi added at least 100+ hp if not to the wheels.
After 9psi or so, you are going to want to start retarding timing on a stock compression VQ.
I have a J&S that im using in the meantime while I figure out the Greddy's issue. Got the osciliscope here to see whats going on.
Dixit
<-Dixit
02-28-2004, 05:01 PM
#6
Originally Posted by BigDogJonx
On a maxima you could be boosting 9psi on the engine and not have any detonation/knock. Dixit
FOCK!!!!! 
but the plan was only to take out 2-3* from 11psi+ ....we shall see 
02-28-2004, 08:07 PM
#7
I was reading an article that you should run 1 psi at a time starting at stock boost 6-7 psi, and run through the powerband and if you start hearing knock from the engine to retard timing 2 degrees and you should be safe.
02-29-2004, 09:11 AM
#8
Yea but spanish, dont rely on hearing knock, you need to either have a J&S to sense the knock from thhe sensor or like an MSD knock sensor hookedup to something to show you the inaudible knocks. Once you hear knock, the damage is already done. Would be best to use the good tools to catch the inaudible ones.
Dixit
Dixit
03-02-2004, 08:08 AM
#10
you should be more than fine on stock timing
Originally Posted by matty
Well if I were to buy a V2 Stillen S/C and run the stock pulley with 9psi will I have to do anything to the timing ??
I dont wanna F anything up
-matt
I dont wanna F anything up
-matt
03-02-2004, 08:52 AM
#13
Originally Posted by matty
how sure are you ???
-matt
-matt
03-02-2004, 08:54 AM
#14
Supporting Maxima.org Member
iTrader: (54)
Join Date: Feb 2001
Location: Northern Jersey
Posts: 10,166
Originally Posted by Stephen Max
I answered you in your other thread, but there are several people here who have run 9-10 psi with stock timing and no problems, myself included. Just be sure your afr is rich enough to suppress detonation. Above 10 psi I would do something about timing.
-matt
03-02-2004, 09:43 AM
#16
The reason we worry about timing, of course, is because of detonation. Likelihood of detonation is influenced by timing advance, compression ratio, afr, fuel octane rating and intake air temperature. Maybe some other stuff too, but these are the important parameters.
Think, then of a 5-dimensional vector space that is bounded by a surface that defines the onset of detonation. Maximum power occurs at the threshold of detonation, therefore the goal in tuning is to optimize engine power by adjusting the independent variables while staying just within the safe operating regime defined by the detonation threshold.
If we had a closed form mathematical expression that defines the detonation threshold and contains the five independent variables, then tuning would be easy. Unfortunately, we don't (yet). So we are forced to adjust one parameter at a time and experiment, either at the track or on the dyno to obtain fuel and timing maps that are a crude approximation to the mathematical expression that is our holy grail.
Think, then of a 5-dimensional vector space that is bounded by a surface that defines the onset of detonation. Maximum power occurs at the threshold of detonation, therefore the goal in tuning is to optimize engine power by adjusting the independent variables while staying just within the safe operating regime defined by the detonation threshold.
If we had a closed form mathematical expression that defines the detonation threshold and contains the five independent variables, then tuning would be easy. Unfortunately, we don't (yet). So we are forced to adjust one parameter at a time and experiment, either at the track or on the dyno to obtain fuel and timing maps that are a crude approximation to the mathematical expression that is our holy grail.
03-02-2004, 09:45 AM
#17
Supporting Maxima.org Member
iTrader: (54)
Join Date: Feb 2001
Location: Northern Jersey
Posts: 10,166
Originally Posted by Stephen Max
Air/fuel ratio.
You have much to learn, grasshopper.
You have much to learn, grasshopper.
Where do I learn ?? Will I need an a/f gauge ?? (along with Boost, EGT and F/P) used from this deal
-matt
03-02-2004, 09:58 AM
#18
Originally Posted by matty
That last post really confused me...lol....
Where do I learn ?? Will I need an a/f gauge ?? (along with Boost, EGT and F/P) used from this deal
-matt
Where do I learn ?? Will I need an a/f gauge ?? (along with Boost, EGT and F/P) used from this deal
-matt
The only afr gauge worth getting are the ones that use wideband O2 sensors. They are not cheap. I spent about $500.
You can get by cheaper by using an EGT gauge and monitoring EGT closely, along with dyno tuning to establish a safe temperature for your setup.
A fuel pressure gauge is also necessary, it's like a heart monitor.
Boost gauges are fun but not really necessary.
03-02-2004, 10:04 AM
#19
Supporting Maxima.org Member
iTrader: (54)
Join Date: Feb 2001
Location: Northern Jersey
Posts: 10,166
well if i put it in will I have any problems ??
Rebuilt V2 with F/P gauge, EGT, and Boost..the thing is once the car is running good and all I wont know what to look for on the gauges...I will also be getting a S-AFC II
I am very new to all this, like last night new, and I dont know pretty much anything...when monitoring EGT, what do you if it comes in too cold or too hot ?? alos where does the EGT sensor go ?? im having help put it in, but j/w
-matt
Rebuilt V2 with F/P gauge, EGT, and Boost..the thing is once the car is running good and all I wont know what to look for on the gauges...I will also be getting a S-AFC II
I am very new to all this, like last night new, and I dont know pretty much anything...when monitoring EGT, what do you if it comes in too cold or too hot ?? alos where does the EGT sensor go ?? im having help put it in, but j/w
-matt
03-02-2004, 11:07 AM
#20
Senior Member
Join Date: May 2003
Posts: 654
Originally Posted by matty
well if i put it in will I have any problems ??
Rebuilt V2 with F/P gauge, EGT, and Boost..the thing is once the car is running good and all I wont know what to look for on the gauges...I will also be getting a S-AFC II
I am very new to all this, like last night new, and I dont know pretty much anything...when monitoring EGT, what do you if it comes in too cold or too hot ?? alos where does the EGT sensor go ?? im having help put it in, but j/w
-matt
Rebuilt V2 with F/P gauge, EGT, and Boost..the thing is once the car is running good and all I wont know what to look for on the gauges...I will also be getting a S-AFC II
I am very new to all this, like last night new, and I dont know pretty much anything...when monitoring EGT, what do you if it comes in too cold or too hot ?? alos where does the EGT sensor go ?? im having help put it in, but j/w
-matt
To answer you question about EGT. It is basically an indirect tool to gauge what your AFR is. The higher the AFR, the more rich, yet cooler you are running... The lower your lower your AFR, the leaner and hotter you are running.
Like Stephen said earlier... a better form of measuring the AFR, is straight from the O2 sensors... not from the narrowband ones on our cars now, but from a wideband O2 sensor. The exact values of the EGT which correspond to the AFR, I dont know, but im sure some of the members do.
GL, and read through all the threads.. they will answer alot of your questions.
03-02-2004, 11:41 AM
#21
Originally Posted by Stephen Max
The reason we worry about timing, of course, is because of detonation. Likelihood of detonation is influenced by timing advance, compression ratio, afr, fuel octane rating and intake air temperature. Maybe some other stuff too, but these are the important parameters.
Think, then of a 5-dimensional vector space that is bounded by a surface that defines the onset of detonation. Maximum power occurs at the threshold of detonation, therefore the goal in tuning is to optimize engine power by adjusting the independent variables while staying just within the safe operating regime defined by the detonation threshold.
If we had a closed form mathematical expression that defines the detonation threshold and contains the five independent variables, then tuning would be easy. Unfortunately, we don't (yet). So we are forced to adjust one parameter at a time and experiment, either at the track or on the dyno to obtain fuel and timing maps that are a crude approximation to the mathematical expression that is our holy grail.
Think, then of a 5-dimensional vector space that is bounded by a surface that defines the onset of detonation. Maximum power occurs at the threshold of detonation, therefore the goal in tuning is to optimize engine power by adjusting the independent variables while staying just within the safe operating regime defined by the detonation threshold.
If we had a closed form mathematical expression that defines the detonation threshold and contains the five independent variables, then tuning would be easy. Unfortunately, we don't (yet). So we are forced to adjust one parameter at a time and experiment, either at the track or on the dyno to obtain fuel and timing maps that are a crude approximation to the mathematical expression that is our holy grail.
Thread
Thread Starter
Forum
Replies
Last Post
sctludwig
3rd Generation Maxima (1989-1994)
8
09-01-2022 01:32 PM
kjlouis
4th Generation Maxima (1995-1999)
12
10-03-2015 05:29 AM
trungg86
4th Generation Maxima (1995-1999)
7
09-04-2015 04:58 AM