Front mounted gt4202 single turbo START UP VIDEO
07-12-2013, 09:06 PM
#84
Hey Vmapper,
I do have a question for you to explain to me, my builder dynoed his 4th gen LT1 Camaro on the same dyno as me, corrected I think he made 801 at 20PSI on a stock longblock LT1 UNCORRECTED was 630. Car weighs 3800lbs with driver, he ran a 9.85. How does a 630WHP car run 9's?
Just trying to understand things...
I do have a question for you to explain to me, my builder dynoed his 4th gen LT1 Camaro on the same dyno as me, corrected I think he made 801 at 20PSI on a stock longblock LT1 UNCORRECTED was 630. Car weighs 3800lbs with driver, he ran a 9.85. How does a 630WHP car run 9's?
Just trying to understand things...
07-12-2013, 09:15 PM
#85
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Lots of cars have run 9s with less than 630whp. I didn't read this whole thread so sorry if I'm jumping into an argument.
Also, I have to say 170hp due to correction factor has me scratching my head, that's a lot.
Also, I have to say 170hp due to correction factor has me scratching my head, that's a lot.
07-12-2013, 11:49 PM
#88
What I try to explain is, turbos alleviate that elevation air density difference (elevation equalizers so to speak), so using a NA correction factor does not provide a good representation of actual power.
Last edited by vmapper; 07-13-2013 at 12:15 AM.
07-12-2013, 11:50 PM
#89
No worries,
As mentioned, Uncorrected is a closer representation of power for turbo w/wastegate than using any correction factors supplied. All be it, you could and should add 5% as discussed. so ~660 or even maybe 9% (upper end) considering Denver has a high D.A. = 687rwhp (but that is a guess based on very limited information - including which CF used, or what dyno). 9% is sure closer to Uncorrected than 26% with xx CF.. and you even said yourself, turbos compensates for elevation, but then you cant turn around and 'add' all the correction factors used for NA engine adjustments. This is not rational. Some CF is needed of course, and we went over that.
You could look at it another way obtaining a close representation by taking the CF and reducing by 16% for example.
This example is implying that SAE (all 26% of the correction added gives a true representation of a turbo setup. This does not make sense as that is like saying a turbo has no advantage over NA. And conveniently, ~800 hp is guestimated needed to move a 3800 lbs vehicle under 10sec based on interweb calculators.
Without knowing the heap of other variables about the car,
more important what was the MPH? @ What DA?
It was said you 'think' for the correction number hp it was, but certain for the Uncorrected? what is the ME setup for the drum?
Someone said the weight or was that scaled weight on a CAT scale for example? between run and track, no mods?
These are all questionable as they are not verified.
Sorry, just too much missing side information here so unfortunately I cannot comment on the 1/4 mile vs approx hp required vs measured hp.
As mentioned, Uncorrected is a closer representation of power for turbo w/wastegate than using any correction factors supplied. All be it, you could and should add 5% as discussed. so ~660 or even maybe 9% (upper end) considering Denver has a high D.A. = 687rwhp (but that is a guess based on very limited information - including which CF used, or what dyno). 9% is sure closer to Uncorrected than 26% with xx CF.. and you even said yourself, turbos compensates for elevation, but then you cant turn around and 'add' all the correction factors used for NA engine adjustments. This is not rational. Some CF is needed of course, and we went over that.
You could look at it another way obtaining a close representation by taking the CF and reducing by 16% for example.
This example is implying that SAE (all 26% of the correction added gives a true representation of a turbo setup. This does not make sense as that is like saying a turbo has no advantage over NA. And conveniently, ~800 hp is guestimated needed to move a 3800 lbs vehicle under 10sec based on interweb calculators.
Without knowing the heap of other variables about the car,
more important what was the MPH? @ What DA?
It was said you 'think' for the correction number hp it was, but certain for the Uncorrected? what is the ME setup for the drum?
Someone said the weight or was that scaled weight on a CAT scale for example? between run and track, no mods?
These are all questionable as they are not verified.
Sorry, just too much missing side information here so unfortunately I cannot comment on the 1/4 mile vs approx hp required vs measured hp.
Last edited by vmapper; 07-13-2013 at 12:16 AM.
07-13-2013, 11:56 AM
#90
Let’s look at this another way:. (Perhaps Im not good at explaining) and again, sorry for the huge write-up.
So forget we are turbocharged for a moment.
Let’s pretend this is a NA vehicle, managed 630rwhp uncorrected with an extremely high DA, the software wants to apply a 1.26 CF. (this means, the air is off by 26% from the SAE Reference of Air Temperature: 77F Absolute Pressure: 29.23 inches Hg Relative Humidity: 0%.
Meaning, if you could run uncorrected with those air values existing, you would match what SAE CF applied elsewhere. So, you found a near sea level place, with 29.23 in of mercury and relative dew. The Uncorrected dyno Run would be 800rwhp and SAE would have a CF of 1.00 so also 800rwhp. They would be the same. Uncorrected = SAE Corrected.
Okay, so at sea level (ideal for SAE) you uncorrected (actual power) 800rwhp, as you increase altitude, you expect to lose power... and one does, its 630rwhp by the time you obtain (xxxx whatever the weather station values are) (in this case the weather measurements are off by 26% from SAE reference.
So far, everything is fine....
You’re back at sea level, this time but is turbo charged w/gate. Again, lucky to run at 77°F, 29.23 inHg (98.98kpa) and zero humidity. You whack out 800rwhp same as the NA car uncorrected Apply the SAE correction, it’s also 800rwhp due to 1.00 CF.
These cars should run similar mph/et (of course, lots of variables) but this is to make a point. They should, same power (omit curves, drivers etc).
Turbo man heads for the highest dyno in North America where NA car measured actual 630.... [Pause]
Does the turbo man (Actual power - uncorrected) dyno higher than the NA car or same or lower?
Obviously not lower, that would not make sense to lose more power than NA.
The same? Again, turbos reduce that elevation change, giving an advantage.
They hit the race track, turbo car clearly wins... (This is expected).
So, uncorrected must be a higher value... and let’s say for all intents and purposes it dynos 728 uncorrected. If you apply the correction used for the NA guy being 1.26 the software would give a peak of 917 (sofware math is designed for NA applications it has no way of knowing your FI). (Meaning, IF you were at reference SAE altitude, the car would expect to put down 917. But it only put 800 when we were there! This doesnt make sense (hmm) (actual - uncorrected is the actual). This goes Visa Versa (800rwhp uncorrected at high elevation would NOT expect to drop as much as a NA car down to 630rwhp)
So, how could both cars be identical at referenced altitude but turbo is advantaged at higher altitude?
It means that the 1.26 CF over inflates the turbo car (applying correction factor (which is really bringing the values to a standardized reference)... so the next question is, well by how much?
*assume the dyno is properly calibrated, properly maintained.
The test I had done a decade ago was run uncorrected in two different cities (one low elevation close to where IF one applied SAE it was 1.00 (little to no difference) and the other which varies from 1.10-1.14 but averages 1.13CF. The turbo vehicle only changed ~3-4% of uncorrected power, not 13. Most dyno shops are not usually in places where DA is up towards 7000ft. (or elevations over 3500ft) so for those, I 'expect' based on experience that percent to increase 5-or maybe Denver having extremely high DA 9% tops (lenient). I don’t know for certain, I have never tested that much of a difference. Perhaps you can, make a trip of it!
Do an uncorrected run where SAE is roughly 1.00 (so no difference). Compare the two Actual power curves (uncorrected runs) to give an approximate delta. This of course, requires minimizing other variables, such as tire spin, weather station maintenance, drum maintenance etc… (many variables).
So, back to the red herring (or is it?)...
you were told, Im assuming, not witnessed, as you would have hit the sea level track with them.(couple days trip as there is nothing in Colorado) or trust that the time slip is indeed for that vehicle, having no changes mods wise (including weight) that a turbo car Uncorrected, applies SAE (which is against everything) gave a value which then surprisingly reflects the 10 sec run for a car that weighs 3800lbs.
OR is it possible that the weight it actually 3600lbs, tracked at sea level and only requires 680rwhp to get under 10? Not 800rwhp? so this is all irrelevant.
The above example would indicate:
The dyno was done at an extremely high DA and the track run was done at sea level with air conditions close to SAE values to even make this (what is incorrect anyway) SAE correction appear correct. And this whole discussion is around attempting to show that SAE is proper for turbo correction because the car went under 10s and that reflects the expected hp, so it has to be. This is circumstantial information, and asking these questions will find out where the lie is embedded or simply incorrect information.
So first question is: Where was the dyno run performed and which TRACK was the run done at. (Road trip anyone?). If this answer alone doesn’t make sense, then one need not go further.
If one ran a time such as 9.8 sec then did an uncorrected run in relatively the same DA showing 800rwhp similarities then showing its 630 Uncorrected (actual) up higher, and SAE corrected for that run shows 800, that contradict everything said, then well, ill have to re-evaluate everything I understand thus far, but nothing of the sort has happened and for me would not make rational sense in the first place (turbos....)
Summary:
Suggesting SAE reflects a turbo w wastegate actual power - this contradicts why turbos are advantageous in the first place to suppress elevation power loss, it contradicts the math, and it contradicts what dynojet themselves state, it contradicts what Society of Automotive Engineers state and it’s a miss-use of their correction factor. It also does not reflect uncorrected runs done at sea level vs uncorrected runs at higher elevations.
So forget we are turbocharged for a moment.
Let’s pretend this is a NA vehicle, managed 630rwhp uncorrected with an extremely high DA, the software wants to apply a 1.26 CF. (this means, the air is off by 26% from the SAE Reference of Air Temperature: 77F Absolute Pressure: 29.23 inches Hg Relative Humidity: 0%.
Meaning, if you could run uncorrected with those air values existing, you would match what SAE CF applied elsewhere. So, you found a near sea level place, with 29.23 in of mercury and relative dew. The Uncorrected dyno Run would be 800rwhp and SAE would have a CF of 1.00 so also 800rwhp. They would be the same. Uncorrected = SAE Corrected.
Okay, so at sea level (ideal for SAE) you uncorrected (actual power) 800rwhp, as you increase altitude, you expect to lose power... and one does, its 630rwhp by the time you obtain (xxxx whatever the weather station values are) (in this case the weather measurements are off by 26% from SAE reference.
So far, everything is fine....
You’re back at sea level, this time but is turbo charged w/gate. Again, lucky to run at 77°F, 29.23 inHg (98.98kpa) and zero humidity. You whack out 800rwhp same as the NA car uncorrected Apply the SAE correction, it’s also 800rwhp due to 1.00 CF.
These cars should run similar mph/et (of course, lots of variables) but this is to make a point. They should, same power (omit curves, drivers etc).
Turbo man heads for the highest dyno in North America where NA car measured actual 630.... [Pause]
Does the turbo man (Actual power - uncorrected) dyno higher than the NA car or same or lower?
Obviously not lower, that would not make sense to lose more power than NA.
The same? Again, turbos reduce that elevation change, giving an advantage.
They hit the race track, turbo car clearly wins... (This is expected).
So, uncorrected must be a higher value... and let’s say for all intents and purposes it dynos 728 uncorrected. If you apply the correction used for the NA guy being 1.26 the software would give a peak of 917 (sofware math is designed for NA applications it has no way of knowing your FI). (Meaning, IF you were at reference SAE altitude, the car would expect to put down 917. But it only put 800 when we were there! This doesnt make sense (hmm) (actual - uncorrected is the actual). This goes Visa Versa (800rwhp uncorrected at high elevation would NOT expect to drop as much as a NA car down to 630rwhp)
So, how could both cars be identical at referenced altitude but turbo is advantaged at higher altitude?
It means that the 1.26 CF over inflates the turbo car (applying correction factor (which is really bringing the values to a standardized reference)... so the next question is, well by how much?
*assume the dyno is properly calibrated, properly maintained.
The test I had done a decade ago was run uncorrected in two different cities (one low elevation close to where IF one applied SAE it was 1.00 (little to no difference) and the other which varies from 1.10-1.14 but averages 1.13CF. The turbo vehicle only changed ~3-4% of uncorrected power, not 13. Most dyno shops are not usually in places where DA is up towards 7000ft. (or elevations over 3500ft) so for those, I 'expect' based on experience that percent to increase 5-or maybe Denver having extremely high DA 9% tops (lenient). I don’t know for certain, I have never tested that much of a difference. Perhaps you can, make a trip of it!
Do an uncorrected run where SAE is roughly 1.00 (so no difference). Compare the two Actual power curves (uncorrected runs) to give an approximate delta. This of course, requires minimizing other variables, such as tire spin, weather station maintenance, drum maintenance etc… (many variables).
So, back to the red herring (or is it?)...
you were told, Im assuming, not witnessed, as you would have hit the sea level track with them.(couple days trip as there is nothing in Colorado) or trust that the time slip is indeed for that vehicle, having no changes mods wise (including weight) that a turbo car Uncorrected, applies SAE (which is against everything) gave a value which then surprisingly reflects the 10 sec run for a car that weighs 3800lbs.
OR is it possible that the weight it actually 3600lbs, tracked at sea level and only requires 680rwhp to get under 10? Not 800rwhp? so this is all irrelevant.
The above example would indicate:
The dyno was done at an extremely high DA and the track run was done at sea level with air conditions close to SAE values to even make this (what is incorrect anyway) SAE correction appear correct. And this whole discussion is around attempting to show that SAE is proper for turbo correction because the car went under 10s and that reflects the expected hp, so it has to be. This is circumstantial information, and asking these questions will find out where the lie is embedded or simply incorrect information.
So first question is: Where was the dyno run performed and which TRACK was the run done at. (Road trip anyone?). If this answer alone doesn’t make sense, then one need not go further.
If one ran a time such as 9.8 sec then did an uncorrected run in relatively the same DA showing 800rwhp similarities then showing its 630 Uncorrected (actual) up higher, and SAE corrected for that run shows 800, that contradict everything said, then well, ill have to re-evaluate everything I understand thus far, but nothing of the sort has happened and for me would not make rational sense in the first place (turbos....)
Summary:
Suggesting SAE reflects a turbo w wastegate actual power - this contradicts why turbos are advantageous in the first place to suppress elevation power loss, it contradicts the math, and it contradicts what dynojet themselves state, it contradicts what Society of Automotive Engineers state and it’s a miss-use of their correction factor. It also does not reflect uncorrected runs done at sea level vs uncorrected runs at higher elevations.
Last edited by vmapper; 07-13-2013 at 12:31 PM.
07-13-2013, 12:43 PM
#91
Here is a link to build thread and video, it is a stock bottom end with horrible cams and the head is NOT ported.
The run was done at Bandimeere the DA was 8200'.
https://ls1tech.com/forums/lt1-lt4-m...ds-inside.html
The run was done at Bandimeere the DA was 8200'.
https://ls1tech.com/forums/lt1-lt4-m...ds-inside.html
07-13-2013, 01:35 PM
#92
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Bullitt mustang at a mile high 7.7sec.
Lower HP/TQ and around the same weight
Range Rover Evoque at a mile high 7.3s
I also think that turbos will make up for some of the loss due to altitude.
Lower HP/TQ and around the same weight
Range Rover Evoque at a mile high 7.3s
I also think that turbos will make up for some of the loss due to altitude.
Last edited by DougNuts; 07-13-2013 at 01:46 PM.
07-13-2013, 02:02 PM
#93
Bullitt mustang at a mile high 7.7sec.
http://youtu.be/65O3gDOF54Y
Lower HP/TQ and around the same weight
Range Rover Evoque at a mile high 7.3s
http://youtu.be/A-asNbRU6rg
I also think that turbos will make up for some of the loss due to altitude.
http://youtu.be/65O3gDOF54Y
Lower HP/TQ and around the same weight
Range Rover Evoque at a mile high 7.3s
http://youtu.be/A-asNbRU6rg
I also think that turbos will make up for some of the loss due to altitude.
07-13-2013, 02:57 PM
#94
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B-rock. Sell me your turbo kit for half price and I will provide you with as much dyno graphs as you need. Close to sea level(seattle). Corrected and uncorrected on a dyno jet dyno 
then we will have a proper comparrison
then we will have a proper comparrison
07-13-2013, 04:06 PM
#96
07-13-2013, 04:07 PM
#97
07-13-2013, 04:43 PM
#99
Anyways, impressive out of a LT1 for sure. (I never questioned it though).
Everything aligns...
135MPH, requires ~680rwhp
Weight? all girls lie, so do shops! You say 3800, he says 3700. I smell a few hundred less, more like 3500 or lessSorry going to need that DOT scale slip or the vid of 350lb fat man driving down the strip.
The screen shot of the dyno doesn't show anything, no CF, if its used or not, which one, weather measurements.
This doesnt change the basics or the fact SAE is an over-inflated number on a turbo w/wastegate.
Im not sure if what I said made sense, it is what it is...
Everything aligns...
135MPH, requires ~680rwhp
Weight? all girls lie, so do shops! You say 3800, he says 3700. I smell a few hundred less, more like 3500 or lessSorry going to need that DOT scale slip or the vid of 350lb fat man driving down the strip.
The screen shot of the dyno doesn't show anything, no CF, if its used or not, which one, weather measurements.
This doesnt change the basics or the fact SAE is an over-inflated number on a turbo w/wastegate.
Im not sure if what I said made sense, it is what it is...
07-13-2013, 05:21 PM
#100
Numbers or not, I applaud B ROCKS for doing this. I am definitely not even close to being as versed as some of the guys in this thread about engines, but I still think its ******* awesome to watch the build, and the fact that he is being innovative is great. Mad props man.