Are you standing up? ok, sit down for this one...
06-09-2005, 01:12 PM
#101
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Originally Posted by gq_626
800 degrees C or F? I am really confused now.
Are you saying you are at 800 degrees F at WOT at 10psi? That is what my car idles at.
If you are saying that you are at 800 degrees C...that is incredibly hot EGT level...especially when the sensor is mounted on your test pipe.
Please clarify
Are you saying you are at 800 degrees F at WOT at 10psi? That is what my car idles at.
If you are saying that you are at 800 degrees C...that is incredibly hot EGT level...especially when the sensor is mounted on your test pipe.
Please clarify
06-09-2005, 02:09 PM
#102
At a cold idle....about 800F...warm idle...about 900F
WOT 1250-1350. My sensor is mounted 1 inch from the turbo exhuast housing, on the downpipe. With cast manifolds, and heat coatings, I doubt the temp is much hotter at the exhuast manifold flange...mayb 100F at most.
This should give you an idea of your actual EGT's...hope it helps.
Careful with the EGT's....too much timing retard, and the EGT's skyrocket after 5500rpm..and very very quickly. With your water injection system, you should be fine.
WOT 1250-1350. My sensor is mounted 1 inch from the turbo exhuast housing, on the downpipe. With cast manifolds, and heat coatings, I doubt the temp is much hotter at the exhuast manifold flange...mayb 100F at most.
This should give you an idea of your actual EGT's...hope it helps.
Careful with the EGT's....too much timing retard, and the EGT's skyrocket after 5500rpm..and very very quickly. With your water injection system, you should be fine.
06-09-2005, 07:16 PM
#104
Originally Posted by tonio
timing retard raises the EGT's? I know mine skyrocketed once to about 1200 degrees and hasn't done it since.. I was a little nervous about that.
If you saw 1200F with the sensor mounted on the test pipe, it must have been a freak thing...because that temp...measured at your test pipe...would easily be enough to melt your pistons.
06-10-2005, 08:58 AM
#105
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Originally Posted by gq_626
Yes, timing retard, higher octane fuel, and lower compression all will raise EGT's.
Not necessarily. Sounds your like talking about unburned fuel going through the exhaust.
Certain conditions have to be met for any of the above to apply, and rarely are they. And if you think about it, that's sort of a false alarm anyway because the cylinder isn't absorbing that much heat.
06-10-2005, 10:43 AM
#106
Originally Posted by SpeedDreamTuner
Not necessarily. Sounds your like talking about unburned fuel going through the exhaust.
Certain conditions have to be met for any of the above to apply, and rarely are they. And if you think about it, that's sort of a false alarm anyway because the cylinder isn't absorbing that much heat.
Certain conditions have to be met for any of the above to apply, and rarely are they. And if you think about it, that's sort of a false alarm anyway because the cylinder isn't absorbing that much heat.
SpeedDreamer, you are completely wrong..and I respectfully disagree with what you are saying.
It's a basic tuning priciple, and automotive engineering principle, that my orginal statement is true.
Too much timing advance or too much timing retard can also raise EGT's. Tuning is much more then setting A/F ratios. Assuming a car is perfectly tuning at WOT, then retarding the timing after the trq peak (peak cylinder pressure) will definately raise EGT's...all things being equal. This is the reason many top tuners will retard timing excessely in the lower and midrange, which results in a very large trq increase, and then gradually advance timing after the trq peak, in order to flatten the trq curve, increase WHP, and reduce EGT's as redline approaches.
The reason for this, is the flame front starts closer to TDC, and hence, gets a late start....a late finish...and more unburned superheated fuel is left behind. It is not optimum or complete combustion...hence..higher EGT's. We've demonstarted this numerous times on the dyno, and any good tuner will understand this principle clearly.
Lower pressure and higher octane as the same effect. Slower burns....
I simple experiment for you, is to run a car on a load based dyno...part throttle at normal timing. Then retard timing to 10 degrees total advance, and watch the effect on EGTs.
06-10-2005, 11:52 AM
#107
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Sharif, you don't have a sound arguement. And you basically reworded what I said.
Lots of fuel, and lot's of timing make torque. Period. When you have an engine that's at a constant RPM, yes you would want to retard the timing because the volumetric efficiency goes up, the spark requirements of the engine go down. This is because the higher cylinder pressure from more air in the engine being forced in will result in a faster combustion process. Essentially, you need less timing for the air to be combusted. Now that's with a engine with a VE greater than 100 because thats what forced induction is. Additionally, as I said earlier that's with a constant RPM which rarely will you have unless your pulling up a hill.
Now with an variable RPM pull, the ignition timing needs to go (advance) up as volumetric effiency increases (more boost). . This is because the engine is spinning faster and it needs to start the combustion process earlier so it's at the so called right posistion when the piston heads downward. This is on variable, the correct way, and your arguing a constant.
Another error in your post is horsepower makes heat. There can't be any arguement there as more fuel for higher RPM and air is required. Additional burned fuel creates heat so contrary to your beleif, EGT's raise and should raise as redline approaches. If EGT's do not, your not making any more power. More fuel and RPM makes more heat.
Less timing, less compression, and more octane, only and I repeat ONLY raise EGT's if you've got unburned fuel in the exhaust burning. You would never want a scenario like this as it would totally hinder performance. Unburned fuel is loosing power any way you look at it.
Lots of fuel, and lot's of timing make torque. Period. When you have an engine that's at a constant RPM, yes you would want to retard the timing because the volumetric efficiency goes up, the spark requirements of the engine go down. This is because the higher cylinder pressure from more air in the engine being forced in will result in a faster combustion process. Essentially, you need less timing for the air to be combusted. Now that's with a engine with a VE greater than 100 because thats what forced induction is. Additionally, as I said earlier that's with a constant RPM which rarely will you have unless your pulling up a hill.
Now with an variable RPM pull, the ignition timing needs to go (advance) up as volumetric effiency increases (more boost). . This is because the engine is spinning faster and it needs to start the combustion process earlier so it's at the so called right posistion when the piston heads downward. This is on variable, the correct way, and your arguing a constant.
Another error in your post is horsepower makes heat. There can't be any arguement there as more fuel for higher RPM and air is required. Additional burned fuel creates heat so contrary to your beleif, EGT's raise and should raise as redline approaches. If EGT's do not, your not making any more power. More fuel and RPM makes more heat.
Less timing, less compression, and more octane, only and I repeat ONLY raise EGT's if you've got unburned fuel in the exhaust burning. You would never want a scenario like this as it would totally hinder performance. Unburned fuel is loosing power any way you look at it.
06-10-2005, 12:07 PM
#108
You are taking my comments out of context. Engines that produce more horspower generate more heat. I though it was obvious that you needed more fuel and air to accomplish this, so I didnt even point it out.
By defination, this is pricely what happens when you run less timing, less compression, and more octane...so higher EGT's are inevitable. But too much timing retard can and will destroy a motor ask some other tuners that you trust for their commentary on this.
Too much advance, or too much retard, are equally dangerous, IMHO.
Less timing, less compression, and more octane, only and I repeat ONLY raise EGT's if you've got unburned fuel in the exhaust burning.
Too much advance, or too much retard, are equally dangerous, IMHO.
06-10-2005, 12:47 PM
#109
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Originally Posted by gq_626
You are taking my comments out of context. Engines that produce more horspower generate more heat. I though it was obvious that you needed more fuel and air to accomplish this, so I didnt even point it out.
By defination, this is pricely what happens when you run less timing, less compression, and more octane...so higher EGT's are inevitable. But too much timing retard can and will destroy a motor ask some other tuners that you trust for their commentary on this.
Too much advance, or too much retard, are equally dangerous, IMHO.
By defination, this is pricely what happens when you run less timing, less compression, and more octane...so higher EGT's are inevitable. But too much timing retard can and will destroy a motor ask some other tuners that you trust for their commentary on this.
Too much advance, or too much retard, are equally dangerous, IMHO.
It's been my experience that too litte timing doesn't hurt a motor. It may run bad, but I can't see the point in retarding timing to the point it hurts the motor, can you?
Too much timing is only dangerous if it detonates. That's what a good tune is for. And I do a damn good job of doing that.
06-10-2005, 12:55 PM
#110
Ive been street tuning my G35 with a Vortech SC . With out touching the A/F [ its high 11 at 4000rpm and goes down to high 10 at redline ] I had 9 degree's of retard at 6500rpm and 12.5psi of boost . My EGT's [ probe 1 in. from exhaust port ] was 815 C. thats right at 1500 degree's . I then reduced the retard to 8 degree's and the EGT's dropped to 773 C. and that is 1425 degree's . Im going to let a real tuner finish my tuning .
Just trying to add a little fuel to the fire.....lol
Just trying to add a little fuel to the fire.....lol
06-10-2005, 01:21 PM
#111
Thanks for sharing that booger.
There are general rules to follow when tuning a car...these are the rules I am referring to.
Every tune will reponse differently, based on boost, CR, fuel, timing...etc.
This is why tuning takes many many hours of practice and experiences. As mentioned earlier, depending on where you in the pressure spectrum, increasing timing can increase EGT's or reduce them. When retarding timing, EGT's can be reduced (if you are near the knock threshold, or increased (if you are far from the knock threshold).
In my illustartion, I am saying that EXCESSIVELY low timing for a given pressure/RPM level will result in higher EGT's. Just as EXCESSIVELY high timing will result in higher EGT"s and then eventually detonation.
Tuning is an imprecise artform, and that's why it takes a few hours at least...to properly tune a car on a dyno. And I am by no means a master guru tuner....we're always learning more about how to extract safe power from these cars, and what are the next limitation and bottlenecks when it comes to tuning. I have an open mind, and listen to other experienced tuners theories and tuning tactics....that's how we'll ALL get better at this.
In booger's example, he advanced his timing just 1 degree, and his EGT's down almost 75 degrees F. If he was near the knock threshold, his EGT's would have gone up. Of course, just before the onset of detonation, and as detonation is occuring, EGT's actually go down.......kinda tricky...isnt it.
There are general rules to follow when tuning a car...these are the rules I am referring to.
Every tune will reponse differently, based on boost, CR, fuel, timing...etc.
This is why tuning takes many many hours of practice and experiences. As mentioned earlier, depending on where you in the pressure spectrum, increasing timing can increase EGT's or reduce them. When retarding timing, EGT's can be reduced (if you are near the knock threshold, or increased (if you are far from the knock threshold).
In my illustartion, I am saying that EXCESSIVELY low timing for a given pressure/RPM level will result in higher EGT's. Just as EXCESSIVELY high timing will result in higher EGT"s and then eventually detonation.
Tuning is an imprecise artform, and that's why it takes a few hours at least...to properly tune a car on a dyno. And I am by no means a master guru tuner....we're always learning more about how to extract safe power from these cars, and what are the next limitation and bottlenecks when it comes to tuning. I have an open mind, and listen to other experienced tuners theories and tuning tactics....that's how we'll ALL get better at this.
In booger's example, he advanced his timing just 1 degree, and his EGT's down almost 75 degrees F.
If he was near the knock threshold, his EGT's would have gone up. Of course, just before the onset of detonation, and as detonation is occuring, EGT's actually go down.......kinda tricky...isnt it.
Last edited by Sharif@Forged; 06-10-2005 at 01:24 PM.
06-10-2005, 05:40 PM
#112
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Originally Posted by SpeedDreamTuner
I'm taking your comments out of the context you set them in. I'm just reading what your wrote.
It's been my experience that too litte timing doesn't hurt a motor. It may run bad, but I can't see the point in retarding timing to the point it hurts the motor, can you?
Too much timing is only dangerous if it detonates. That's what a good tune is for. And I do a damn good job of doing that.
It's been my experience that too litte timing doesn't hurt a motor. It may run bad, but I can't see the point in retarding timing to the point it hurts the motor, can you?
Too much timing is only dangerous if it detonates. That's what a good tune is for. And I do a damn good job of doing that.
Good discussion here...but SPEEDDREAMTUNER:...Why do you have to be such an a$$? Engage in a discussion without your ego getting all bent out of shape..I see exactly why WE had such a hissy fit back and forth...even if you really think you do know everything (I'll say it again-"think")...try to display it in a humble manner...
06-10-2005, 06:07 PM
#113
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Originally Posted by 350zDCalb
Good discussion here...but SPEEDDREAMTUNER:...Why do you have to be such an a$$? Engage in a discussion without your ego getting all bent out of shape..I see exactly why WE had such a hissy fit back and forth...even if you really think you do know everything (I'll say it again-"think")...try to display it in a humble manner...
06-10-2005, 06:44 PM
#114
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Originally Posted by SpeedDreamTuner
Read what you want, your pointless talking too.
06-10-2005, 09:44 PM
#115
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Originally Posted by 350zDCalb
ok, do you mean to say "you're pointless talking to"?....dude, for the sake of all of us understanding what concept you are attempting to convey, take a summer school english class.
Your getting added on the ignore list.
06-11-2005, 06:44 AM
#116
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Originally Posted by SpeedDreamTuner
Sad, your insulting me over one e and I don't think you've ever capitolized one thing. Your getting added on the ignore list.
Your getting added on the ignore list. but i'm good at the ... (dot, dot, dot)
dude, just go away...this thread is to discuss technical issues, not whether or not you got attention as a child.
06-13-2005, 07:24 PM
#117
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Update
So,
I just got home, after a 12 hour day of work getting my car back together..
We started the motor at about 8pm. Sounded great, started immediately, let it idle for about 3 minutes, then shut her down
Put her up in the air and noticed a huge puddle of oil under the car.
At this point, almost too exhausted to lift my head and look under the car, I grabbed a flashlight, hoping not to see any oil from the rear main seal....
The verdict:
Oil appears to be coming from both turbos...
My assumption:
I had both turbo feed lines replaced with better quality lines, since both turbos were dropping oil, I assume that the lines/fittings are off...I paid top dollar for these lines from a place that does this solely (make lines for auto and hydrolic equip)
So, at this point, I am exhausted and frustrated, because I know that tomorrow, more than likely, both turbos need to come out...again!!!
We'll just swap back in the standard lines and I'll go try to take back the new lines and find out what was wrong (and hopefully get some money back-more than likely not) This is about 4 hrs of work when all said and done, and frankly, I', tired of connecting/disconnecting my turbos and wastegates..it is a pain in the a$$ with the motor out..and now we got to do it with the motor in the car
anyway, i should be breaking in the motor tomorrow night, i'll keep you updated
TODD
I just got home, after a 12 hour day of work getting my car back together..
We started the motor at about 8pm. Sounded great, started immediately, let it idle for about 3 minutes, then shut her down
Put her up in the air and noticed a huge puddle of oil under the car.
At this point, almost too exhausted to lift my head and look under the car, I grabbed a flashlight, hoping not to see any oil from the rear main seal....
The verdict:
Oil appears to be coming from both turbos...
My assumption:
I had both turbo feed lines replaced with better quality lines, since both turbos were dropping oil, I assume that the lines/fittings are off...I paid top dollar for these lines from a place that does this solely (make lines for auto and hydrolic equip)
So, at this point, I am exhausted and frustrated, because I know that tomorrow, more than likely, both turbos need to come out...again!!!
We'll just swap back in the standard lines and I'll go try to take back the new lines and find out what was wrong (and hopefully get some money back-more than likely not) This is about 4 hrs of work when all said and done, and frankly, I', tired of connecting/disconnecting my turbos and wastegates..it is a pain in the a$$ with the motor out..and now we got to do it with the motor in the car
anyway, i should be breaking in the motor tomorrow night, i'll keep you updated
TODD
06-13-2005, 07:27 PM
#118
Stay the course Todd...you are almost there.
I am pretty sure your guy that made the lines used the wrong fitting, or didnt include the adaptor. These arent standard 4ANS lines. They are a metric pipe fitting of some type...I personally havent seen this before.
I am pretty sure your guy that made the lines used the wrong fitting, or didnt include the adaptor. These arent standard 4ANS lines. They are a metric pipe fitting of some type...I personally havent seen this before.
06-13-2005, 07:31 PM
#119
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Originally Posted by Sharif@Forged
Stay the course Todd...you are almost there.
I am pretty sure your guy that made the lines used the wrong fitting, or didnt include the adaptor. These arent standard 4ANS lines. They are a metric pipe fitting of some type...I personally havent seen this before.
I am pretty sure your guy that made the lines used the wrong fitting, or didnt include the adaptor. These arent standard 4ANS lines. They are a metric pipe fitting of some type...I personally havent seen this before.
Why must these turbos be soooooooooo hard to get to?!?!?!?!?
I want to drill/cut a hole in my engine bay for easy access to the turbos through the wheelwells!!!
I need to perfect this, this could be a useful mod
