Dynamometer Results & Comparisons - First Dyno Experience... :(

went to dyno day at the shop in town saturday and came out pretty dissappointed from my first dyno with my T/A. over all it ended up doing 256hp/314tq...:barf: and ITS A 2001 LS1..WTF it ran so lean that by the time it got to 6000rpm the ratio was at 18:1.. does it just need a good tune or is this something more serious?

wow.... something is really off, just by looking at what you have in your sig i dont think any of those would effect it so much to throw it off that far, im guessing you dont have a check engine light correct? It would be wise to have a tuner hook up and see what is going on with your car.

my SES light is on but it is for an O2 sensor. and i had the cutout closed on the runs bc it hurt it by about 14hp

Front O2 or rear O2 sensor?

one of the front WILL screw everything up

how would it effect it? by 50 or so horsepower though?

It tells the computer HOW MUCH fuel to spit. 18:1 sounds like you need to fix your car before dynoing and hurting the engine

An 02 sensor should not cause you to go lean at WOT. When in PE, STFTs cut out and LTFTs only alter fueling if they are positive.

OP, was this a tailpipe sniffer giving you 18:1?

whoa that seems way off?

Why would you dyno a car with a known 02 problem? I would think you'd want the car in as nice of mechanical shape as possible for your dyno run.

Retunes/dyno time are much more expensive than an 02 sensor.

Well o2 sensors do not come into play at WOT, there it depends on a predetermined loop. Now the o2 sensor will screw up normal driving wwhich should be corrected before the dyno. Also if its going that lean ONLY up top then I suggest you take a good look at fuel pressure get a gauge and strap it to you car and do go some street pulls if it drops below 55psi for longer than a couple seconds while your in it then the fuel pump is toast. an o2 will not cause it to go lean if anything it will cause it to run rich.

Around 3500 rpm the ratio was at 14 or so. If it doesn't matter at wot then is it my fuel pump?

02 sensors feedback is only used in part throttle situations - not WOT. Thus a bad O2 sensor will not affect WOT performance since WOT is in open loop mode, not closed loop. I'm going to go with fuel pump as well. Considering your torque is significantly higher, I would say the pump leans it out as the RPMs climb, and hence the drastic difference between the two numbers.

Does it have a KN, sounds like a oily MAF to me.

my main concern is the health of the car. i have to fix the o2 censor this month anyway because its inspection month. if i also need a fuel pump to correct the problem i want to go ahead and get that done before spring.

yeah i have a k&n filter

just sell your car before you ruin it .

went to dyno day at the shop in town saturday and came out pretty dissappointed from my first dyno with my T/A. over all it ended up doing 256hp/314tq...:barf: and ITS A 2001 LS1..WTF it ran so lean that by the time it got to 6000rpm the ratio was at 18:1.. does it just need a good tune or is this something more serious?


sounds about right for a stock LS1 that has never been touched and its 11 years old

sounds like your AFR may be correct...for that tailpipe..
I've found that you can get different AFR readings from different tailpipes...
at low rpm they both tend to flow similar, but as rpm goes up and pressures rise, you get the problem that the exhaust doesnt want to make a 180* turn to go back to the other side, so it comes out of one pipe more than the other.

usually one will read correct, and the other will read way lean.

and noticing your signature... you have a cutout... does it seal all the way? does it seal correctly at WOT and high rpm's?
that could be skewing your readings as well.

you can also look at your narrowband readings to get an idea if the dyno wideband is in the right area
if its really 18:1, you will see your narrowband o2's below 450mv by quite a bit
if its richer than 14.7 it should be above 450mv..
most people equate 13's being somewhere in the 800~900mv range(its not correct, but its a ballpark guess at best that will at least tell you that you are on the rich side of 14.7)
it is not accurate, and you cannot use it for tuning WOT, but it can tell you if you are really lean like the dyno wideband is showing

also, 18:1 naturally aspirated wont hurt anything, its just not gonna make good power..
the stock settings will see knock, and pull timing...it will be fine..
people have run around for years on a stock tune being lean with no issues.



With the K&N Air filter, its also a possibility that you have a Dirty MAF as the oils tend to get sucked off of the filter and dirty the MAF making it read incorrectly...
you may just need to clean the MAF...
buy a couple cans of MAF cleaner form the parts store and go to town on it..


also, take out the K&N and look at it...if you can touch it and oil comes off on your fingers, then it is far too much oil on it...which is typical if you pulled it out of the box and just put it in

I always start by buying teh K&N kit, and cleaning all the oil off of it, and then spraying on a much lighter coat than what it came with out of the box...


Does the car have fresh plugs in it? new oil? or did you just buy it and take it to the dyno without doing normal maintenance items..


I cant tell you the number of tunes I've done that started off like yours...with a little maintenance and cleaning, it picked up 20 or 30 HP

also, what brand of dyno...all of them read different...
I have one locally that we call the heartbreaker... a stock LS1 will barely do 240HP..LOL...but we all know differently...its good for solid state tuning and its the only eddy current dyno in town, and it lends to being able to add a load to do a longer pull on a really short gear car to get proper data to be able to make an informed change to the tune. spark mapping also tends to translate better to the street/track for that reason.

if I want big #'s, theres a really really old dynojet within an hour drive that will make even the slowest car a dyno queen..


unfortunatley, theres just not enough data in your first post to say what is wrong...

I would bet on the simple fixes I mentioned above...
clean MAF, less oil on the K&N, new plugs, fresh oil, try the other tailpipe to check AFR.

just sell your car before you ruin it .


worst advice ever...:gtfo:

just sell your car before you ruin it .

why would i sell a true ws6....

the k&n filter does have a good amount of oil on it from past times taking it out. im getting fresh plugs in today and i will clean the maf if that will help. oil was changed on january 28, 2012. i just got the cutout about a week ago and it seems to be fine. i definitely want a tune because i want to make more power later down the road. thanks for the help.

went to dyno day at the shop in town saturday and came out pretty dissappointed from my first dyno with my T/A. over all it ended up doing 256hp/314tq...:barf: and ITS A 2001 LS1..WTF it ran so lean that by the time it got to 6000rpm the ratio was at 18:1.. does it just need a good tune or is this something more serious?


LEAN at high rpm can be many things. stick to basics first.....check your fuel filter, and pump. next would be be the fuel lines. often the stock fuel lines won't handle many modifications, and may need to be enlarged.
anything at all that restricts the fuel flow, can and will cause a lean condition at higher rpms. also, check your fuel pressure regulator.

The car still has a catalytic converter on it, yes? Tailpipe wideband readings are worthless if so.

Go over the basics man. Fix your check engine light issues. Clean all of that excess oil out of the MAF and K&N. Give the car a tune up. Check for excessive backpressure in the exhaust. Check the clutch out etc.

yes it still has stock exhaust except for the e cutout after the y pipe

is the fuel really holding back about 50 horsepower though?

very highly possible

The car still has a catalytic converter on it, yes? Tailpipe wideband readings are worthless if so.



Catalytic Converter doesnt change air fuel by that much on the dyno....

both dynos locally that I use, I've verified that AFR is within .2 of being correct comapred to one in the pipe pre catalytic converter

and I've done this comparison multiple times....every time I do a car I get the customer an A/F reading from the dyno, but use my wideband in the front o2 bung to do the tuning


your Myth has been dispelled by hard cold facts and physically proof.:cool:

Catalytic Converter doesnt change air fuel by that much on the dyno....

both dynos locally that I use, I've verified that AFR is within .2 of being correct comapred to one in the pipe pre catalytic converter

and I've done this comparison multiple times....every time I do a car I get the customer an A/F reading from the dyno, but use my wideband in the front o2 bung to do the tuning


your Myth has been dispelled by hard cold facts and physically proof.:cool:

Beat me to it.... Correct sir :) Yes, pre cat to aft cat was .02-.03, seen this over and over...

Catalytic Converter doesnt change air fuel by that much on the dyno....

both dynos locally that I use, I've verified that AFR is within .2 of being correct comapred to one in the pipe pre catalytic converter

and I've done this comparison multiple times....every time I do a car I get the customer an A/F reading from the dyno, but use my wideband in the front o2 bung to do the tuning


your Myth has been dispelled by hard cold facts and physically proof.:cool:

Ok, how about you back that "I saw it on my dyno" truck up a little bit and explain to my ignorant, stupid ass how catalytic converters and oxygen sensors work then?

Ok, how about you back that "I saw it on my dyno" truck up a little bit and explain to my ignorant, stupid ass how catalytic converters and oxygen sensors work then?


the narrow band O2 sensor does not actually measure oxygen concentration, but rather the difference between the amount of oxygen in the exhaust gas and the amount of oxygen in air. Rich mixture causes an oxygen demand which creates a voltage...

catalytic converters do not change the oxygen content in any way..... it converts the three main pollutants in automobile exhaust. It converts carbon monoxide (CO) and unburned hydrocarbons (HC), and a reduction reaction converts oxides of nitrogen (NOx) to produce carbon dioxide (CO2), nitrogen (N2), and water (H2O)

it doesn change the oxygen content...
it reduces the Demand for more oxygen to "balance the equation" so to speak

in your pre cat o2 it see's all the pollution gasses mixed in and the oxygen demand changes, creating a swing in voltage
at stoich, the pollution gasses are at a minimum..so the oxygen demand is "ideal" and you get a voltage in the 450mv range

when the Catalytic converter processes those pollution gasses...and converts them to other things, the oxygen demand is "ideal" again...creating a voltage in the 450mv range

when your cats fail and can no longer correct those pollution gasses, your rear o2's start to swing due to the new change in oxygen demand..when they go past a certain range a certain # of times, it sets an SES light to let you know



A wideband O2 is An electronic circuit containing a feedback loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas

It will show the same oxygen content before and after the catalytic converter as it measures Actual Oxygen Content

typically you get just a few tenths of a point leaner at the tailpipe due to fresh air contamination from being so close to the exit point..


and I can repeat the example on any dyno in the country assuming their wideband is not old and out of calibration.


When you have done several hundred tunes...you tend to notice these things a little more than the end user who only knows what he has read on the internet where freedom of speech tends to let myths fly rampantly.

most people dont even know that their dual exhaust that comes from a Y pipe to a dual outlet, has tailpipes that will see different flows at different RPM's and one will read lean compared to the other.(next time you are on the dyno with your car... try a back to back pull in each pipe and notice the difference between the two)

From a Y-Pipe, a single outlet exhaust will typically do the exact same as a dual tip exhaust, and sometimes it will do better at higher rpm's... less turns inside the muffler = less restriction = more power..

I'm a little sorry I asked, didn't mean for you to go and type that much. This is what I wanted, really:



catalytic converters do not change the oxygen content in any way..... it converts the three main pollutants in automobile exhaust. It converts carbon monoxide (CO) and unburned hydrocarbons (HC), and a reduction reaction converts oxides of nitrogen (NOx) to produce carbon dioxide (CO2), nitrogen (N2), and water (H2O)

it doesn change the oxygen content...
it reduces the Demand for more oxygen to "balance the equation" so to speak



Now, I need to know, how do you make CO and HC into CO2 and H2O without using up O2? This is the most awesome chemical reaction I have ever heard of.

I'm a little sorry I asked, didn't mean for you to go and type that much. This is what I wanted, really:



Now, I need to know, how do you make CO and HC into CO2 and H2O without using up O2? This is the most awesome chemical reaction I have ever heard of.

you realize it doesnt change the Oxygen content.. its still there, just bonded to other items...the amount of total O2 is still the same


just because you have carbon dioxide, doesnt mean that the oxygen has dissappeared...its still there... cO2

it means that the catalytic converter has allowed bonding and break down of pollutants..when they bond to other chemicals, they are no longer toxic to our environment...

like an acid neutralizing a base...all the chemicals are still there...just re-arranged

the more HC and CO it makes, the more O2 your narrowband thinks it needs to balance the equation....

the wideband just says...oh... that much exists in this packet of gas

o2 demand vs actual O2

you realize it doesnt change the Oxygen content.. its still there, just bonded to other items...the amount of total O2 is still the same


just because you have carbon dioxide, doesnt mean that the oxygen has dissappeared...its still there... cO2

it means that the catalytic converter has allowed bonding and break down of pollutants..when they bond to other chemicals, they are no longer toxic to our environment...

like an acid neutralizing a base...all the chemicals are still there...just re-arranged

the more HC and CO it makes, the more O2 your narrowband thinks it needs to balance the equation....

the wideband just says...oh... that much exists in this packet of gas

o2 demand vs actual O2
but it is not seen as o2.

Ok E=MC^2 and a^2 + b^2=C^2

Anyways, first order of business, a simple tune-up (plugs, wires, fuel filter, PCV, and air filter) Then clean your MAF with some electrical parts cleaner, or alcohol and cotton swab (just don't break the little wires) See how she does.

Then see what kind of fuel pressure you are getting at WOT like stated above to be positive you don't have a weak fuel pump.

I should have said actual molecules of oxygen instead of 02 for the wideband

while a narrow band looks for missing 02 to complete the equation

the wideband looks for actual total molecules of oxygen remaining

Co2 has two molecules of oxygen that were not consumed during combustion


I'm done with trying to teach you chemistry

The real question should be why the hell did the dyno operator make a full pull with it that lean? Hopefully you didn't hurt anything in the motor.

I'm done with trying to teach you chemistry

Why is that? Did you just realize that your argument is ridiculous? Never mind catalytic converters, O2 readings would never change at all no matter how rich or lean an engine was run if you were correct. The oxygen from the combustion process would still be there, just attached to Hydrogen, Carbon and Nitrogen molecules. Humans would be able to breathe under water too, lol. :jest:

Anyways, first order of business, a simple tune-up (plugs, wires, fuel filter, PCV, and air filter) Then clean your MAF with some electrical parts cleaner, or alcohol and cotton swab (just don't break the little wires) See how she does.

Yes!

i wish i'd have recorded the waveforms from the mercury sable that was running stupidly lean, thanks to the typical intake leak those 3.0's got. i had before and after.

Clogged cats , oliy MAF , Bad fuel pump .

Sad to see that your 1st dyno experience is a bad one..
I dynoed 332rwhp 339rwtq with 98 Z28 A4 K&N Filter ,cutout and LS6 Intake stock tune.
13:4 A/F ratio.

Why is that? Did you just realize that your argument is ridiculous? Never mind catalytic converters, O2 readings would never change at all no matter how rich or lean an engine was run if you were correct. The oxygen from the combustion process would still be there, just attached to Hydrogen, Carbon and Nitrogen molecules. Humans would be able to breathe under water too, lol. :jest:



Yes!


our lungs dont have the ability to unbond oxygen from complex Molecules
the oxygen is still there... Fish(and some amphibians) have Gills that can filter our and breathe the dissolved o2 in the water...not the O2 in the H2O


In the case of hydrogen and oxygen gas, if you react them together one way you get liquid water (H2O). The reason we cannot breathe liquid water is because the oxygen used to make the water is bound to two hydrogen atoms, and we cannot breathe the resulting liquid. The oxygen is useless to our lungs in this form.

The oxygen that fish breathe is not the oxygen in H2O. Instead, the fish are breathing O2 (oxygen gas) that is dissolved in the water. Many different gases dissolve in liquids, and we see an example all the time in carbonated beverages. In these beverages, there is so much carbon dioxide gas dissolved in water that it rushes out in the form of bubbles.

Fish "breathe" the dissolved oxygen out of the water using their gills. It turns out that extracting the oxygen is not very easy -- air has something like 20 times more oxygen in it than the same volume of water. Plus water is a lot heavier and thicker than air, so it takes a lot more work to move it around. The main reason why gills work for fish is the fact that fish are cold-blooded, which reduces their oxygen demands. Warm-blooded animals like whales breath air like people do because it would be hard to extract enough oxygen using gills.

Humans cannot breathe underwater because our lungs do not have enough surface area to absorb enough oxygen from water, and the lining in our lungs is adapted to handle air rather than water. However, there have been experiments with humans breathing other liquids, like fluorocarbons. Fluorocarbons can dissolve enough oxygen and our lungs can draw the oxygen out


and ... there is actually a Fluid that has enough o2 dissolved in it for us to breathe it....
they use it in the medical field...it is especially useful for a very undeveloped premature baby who's lungs are not ready to breathe oxygen from the Air. the fluid carries enough Oxygen that it can be absobed thru an undeveloped lung until it can grow far enough to support life from air based breathing.(my mom worked in a hospital that did this treatment to extremely premature babies)

for the life of me I cant remember the name of it, but I remember its a tongue twister..LOL




I wish I had a good example is something you could understand for the difference of how a narrowband o2 works and how a wideband o2 works and why the catalytic converter doesnt change the amount of oxygen Atoms total......but until you take a Chemisty class...you will never understand how it works at a molecular level.



and hey...look...wikipedia can tell you exactly what I have already said..
http://en.wikipedia.org/wiki/Oxygen_sensor

im going to start by saying what ive been told then i need some feedback on what to do next. I was told that the cig/accy fuse also operated part of the ecm?

That fuse was blown at the time of the dyno.

I have since replaced the fuse with a higher 30 amp.

Now that i can plug in the obd reader it says SECONDARY AIR which is the air pump?

ive also been told the air pump is an emissions device, but does it effect the power?
OR will replacing that fuse that supposedly also runs the ecm fix my air/fuel problems and loss of power problem?

this is all in question form and im only stating what has been told to me.

im going to start by saying what ive been told then i need some feedback on what to do next. I was told that the cig/accy fuse also operated part of the ecm?

That fuse was blown at the time of the dyno.

I have since replaced the fuse with a higher 30 amp.



it doesnt control anything in the pcm... but you wont be able to connect to the pcm with a scanner if that fuse is blown... the pcm data port shares power with that fuse



Now that i can plug in the obd reader it says SECONDARY AIR which is the air pump?

ive also been told the air pump is an emissions device, but does it effect the power?
OR will replacing that fuse that supposedly also runs the ecm fix my air/fuel problems and loss of power problem?

this is all in question form and im only stating what has been told to me.

the Secondary Air pump is only active when the engine is cold...
above a certain temperature, it is shut off by the pcm...
it should not cause any differences on the dyno.

"to do next" would be to go back to the dyno
do pulls with the wideband in each exhaust pipe to see which one reads the richest, then check your HP/TQ Graphs... and decide if you want to spend thecash on a tune to re-dial the fuel and spark in to make the most power possible as your setup currently sits.

do you think its worth the $ to replace the secondary air pump then? if it doesnt effect the dyno number or anything. and ive read where a lot of people delete them

Nope.. just have somebody tune it out...and then physically remove it...unless you live in California....

thanks for all the help man i appreciate it

Did anyone catch he replaced the fuse with a larger one. You never do that as it will cause more problems.

Nope.. just have somebody tune it out...and then physically remove it...unless you live in California....

or nj or any other state with an I/M program.

Did anyone catch he replaced the fuse with a larger one. You never do that as it will cause more problems.

Yeah I caught that, fuses are sized to prevent melting wires or damaging circuits... OP, go back and replace with the original size. If it blows again, find your ground and fix.

Any update on your car buddy? i just read through ur entie thread cause i really want to hear that your car has a functional heart. I dont want to believe there is an fbody out there that is putting down the #s u ave with those mods. dont say its true brotha!!!

Any update on your car buddy? i just read through ur entie thread cause i really want to hear that your car has a functional heart. I dont want to believe there is an fbody out there that is putting down the #s u ave with those mods. dont say its true brotha!!!
cleaned MAF sensor and the intake/filter. Replaced all spark plugs. Going to order a Walbro Fuel Pump tomorrow and then take her back to the dyno to see how she does. And ive never heard of that with the fuses but ill replace it with the correct size

update op???

In for update

Did you change your fuel filter before dropping the cash on a new fuel pump?