Front mounted gt4202 single turbo START UP VIDEO
07-09-2013, 02:50 PM
#61
Turbo charged engines make significantly more power at high altitude than NA...
However, this does not in any way mean that they make anywhere close to as much power as the same turbo engine would a low altitude or sea level.
Turbos dont recognize PSI, they recognize pressure ratio. Sea level is 14.7psi ambient, if you want to produce 14.7psi boost, the turbo workload is 2.0 pressure ratio. Right now, in Denver CO, my altimeter is saying 12.01psi ambient. For the same turbo to produce 14.7psi boost, the turbo workload is 2.34 pressure ratio ((ambient+boost) / (ambient). It is working significantly harder to produce the same PSI.
The problem is that at altitude the turbo has to work much harder to produce the same PSI it normally would, this creates more heat, which reduces HP.
The altitude also reduces the actual compression ratio the pistons are achieving, which reduces horsepower.
Additionally the intercooler is significantly less efficient as it is surrounded by thinner air molecules and dissipates the already increased heat with less efficiency which reduces horsepower.
Wouldn't make a whole lot of sense to not compensate for the altitude conditions that are unique to Denver, now would it?
So once this new setup is done, it will be corrected per what the professional tuner who tunes cars every day at high altitude thinks is proper.
I am more than happy to take that number vs uncorrected at the low altitude tune/dyno numbers I will get when I go to TX2k14 next year, and since you mentioned betting, hows a friendly wager that they will be within 50WHP of eachother sound?
Do you like apples?
However, this does not in any way mean that they make anywhere close to as much power as the same turbo engine would a low altitude or sea level.
Turbos dont recognize PSI, they recognize pressure ratio. Sea level is 14.7psi ambient, if you want to produce 14.7psi boost, the turbo workload is 2.0 pressure ratio. Right now, in Denver CO, my altimeter is saying 12.01psi ambient. For the same turbo to produce 14.7psi boost, the turbo workload is 2.34 pressure ratio ((ambient+boost) / (ambient). It is working significantly harder to produce the same PSI.
The problem is that at altitude the turbo has to work much harder to produce the same PSI it normally would, this creates more heat, which reduces HP.
The altitude also reduces the actual compression ratio the pistons are achieving, which reduces horsepower.
Additionally the intercooler is significantly less efficient as it is surrounded by thinner air molecules and dissipates the already increased heat with less efficiency which reduces horsepower.
Wouldn't make a whole lot of sense to not compensate for the altitude conditions that are unique to Denver, now would it?
So once this new setup is done, it will be corrected per what the professional tuner who tunes cars every day at high altitude thinks is proper.
I am more than happy to take that number vs uncorrected at the low altitude tune/dyno numbers I will get when I go to TX2k14 next year, and since you mentioned betting, hows a friendly wager that they will be within 50WHP of eachother sound?
Do you like apples?
i am curious though, what were ur uncorrected numbers?
07-09-2013, 03:31 PM
#62
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A good rule of thumb (albeit a vaaaast oversimplification) is that you make an extra 15 horsepower per pound of additional pressure in a Gen III/IV LS-series engine. Assuming that you have everything else in your car upgraded as far as it'll go, you'll wind up with 450 RWHP range for the 364 CID LS2 (N/A). From there, 13 psi x 15 = 195 + 450 RWHP = 655 RWHP. 780 RWHP doesn't pass that sanity check. Not saying it's impossible, but rather, unlikely.
As a further sanity check, we can compare these predictions to S-Cam, who, if memory serves, is making about 775 RWHP with a great 416 CID LS3 motor (60 psi oil pressure hot idle, 85 psi cold idle), 10.5 static CR, meth, phenolic spacer, and a cog overdriven TVS2300 with 18.5 lbs of boost.
Since a nice 416 CID LS3 with good heads will make about 500 RWHP at 10.5 CR, we have 15*18 = 270 + 500 = 770 RWHP. Sanity check passed.
By the way, he went through seven revisions of his fueling system to get that monster working correctly--the final rev, I believe, involved a Walbro GSS 342 or Denso 950-0155 in-tank pump feeding a custom surge tank with twin Bosch 044s. 850cc injectors, -8/-6 AN fuel lines, etc. Fortunately for you, a turbo doesn't have that massive transient kick that a supercharger does, so you probably won't have to worry as much about leaning out your A/F. But you should have had problems a long time ago if you were actually making the power that your tuner is telling you you are.
As a further sanity check, we can compare these predictions to S-Cam, who, if memory serves, is making about 775 RWHP with a great 416 CID LS3 motor (60 psi oil pressure hot idle, 85 psi cold idle), 10.5 static CR, meth, phenolic spacer, and a cog overdriven TVS2300 with 18.5 lbs of boost.
Since a nice 416 CID LS3 with good heads will make about 500 RWHP at 10.5 CR, we have 15*18 = 270 + 500 = 770 RWHP. Sanity check passed.
By the way, he went through seven revisions of his fueling system to get that monster working correctly--the final rev, I believe, involved a Walbro GSS 342 or Denso 950-0155 in-tank pump feeding a custom surge tank with twin Bosch 044s. 850cc injectors, -8/-6 AN fuel lines, etc. Fortunately for you, a turbo doesn't have that massive transient kick that a supercharger does, so you probably won't have to worry as much about leaning out your A/F. But you should have had problems a long time ago if you were actually making the power that your tuner is telling you you are.
My dyno tuning/ numbers was done on 91 octane in Calgary AB. And we did keep the timing conservative ( we pulled no timing with no meth, then added the meth just for insurance). With enough octane and very aggressive timing I think we could add another 50-75 hp but for me its a street car and a once in a life time dyno number means nothing to me so we never filled the tank with 112 or better fuel and put more timing to the car.
The biggest factor I had was the fuel system. I could make 580ish hp on the stock fuel system with a BAP. it was my limiting factor. So I tried many different things to get to the next level and a surge tank with dual bosch 044 pumps, with a full return system and a denso in tank pump to feed it seemed to work.
I have a shelby gt500 in my garage as a daily driver car with some mods-approx. 600 crank hp car and the difference between the 2 cars is night and day- people laugh when I tell them the Shelby is the weekday car and the cts-v the Saturday night car.
I wish you the best of luck on your build and I hope you hit the power numbers that your expecting. I know I never could come close to 700 rwhp at 13 lbs of boost with a cathedral headed, stock fuel systemed, stock short blocked car.
07-09-2013, 03:53 PM
#63
Thanks for the info s-cam.
It was not a stock fuel system tho, a walbro 400 with 70lb injectors running at 95%duty cycle is flowing a ridiculous amount compared to stock. Add in the meth and114 octane and you all might begin begin to understand how numbers like that can be achieved?
Also there's a big difference in SC vs turbo, there's a lot more to it than comparing psi to psi, its in the cfm flowed.
Theres a reason all the huge company's trying to make ridiculous hp do it with turbos (lingenfelter, Hennessey, heffner, ugr)
It was not a stock fuel system tho, a walbro 400 with 70lb injectors running at 95%duty cycle is flowing a ridiculous amount compared to stock. Add in the meth and114 octane and you all might begin begin to understand how numbers like that can be achieved?
Also there's a big difference in SC vs turbo, there's a lot more to it than comparing psi to psi, its in the cfm flowed.
Theres a reason all the huge company's trying to make ridiculous hp do it with turbos (lingenfelter, Hennessey, heffner, ugr)
07-09-2013, 04:39 PM
#64
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Dude , Awesome build! keep up the good work.
LMFAO at the Radiator and intercooler hate mail.
Haters had me at mid 10's and blowing up.
Year and a half later Im mid 9's fkn around , and driving it every day.
Never pay them attention. Attention is what the drama queens strive for.
LMFAO at the Radiator and intercooler hate mail.
Haters had me at mid 10's and blowing up.
Year and a half later Im mid 9's fkn around , and driving it every day.
Never pay them attention. Attention is what the drama queens strive for.
07-09-2013, 05:11 PM
#65
No problem, and NOT everyone does this incorrectly.
Its simple, they apply a CORRECTION FACTOR when they shouldnt be (turbo - wastegate)
Why is that?
That would be because if you looka t J1349 or ANY of the correction factors, they are used for NA ambient air calculating.
what does a turbo with a wastegate do?
well, it attempts to reach the same kpa of air (atmosphere) into the manifold regardless of where the air is being collected from (high or low elevations). what does this mean?
It means that since air is actually comprised of 20.916% oxygen regardless of where it comes from (exception is troposphere and upper).
If you get 200kpa of air, it will contain xxx amount of oxygen.
The higher the altitude means per cube of space there is simply LESS Air, but per MOLE, still the same 20.916% of oxygen. Elevation is out the window the second your manifold goes beyond ambient.
200kPA REGARDLESS if it is collected at 4000ft or 200ft will have the same amount of oxygen. (that is your power).
Since wastegates obtain the same PSI regardless what does this mean?
It means per pass of the impeller, at higher elevation, less air is gathered, so to reach 200kpa, more impeller passes are required... this means, your dyno CURVE changes, but the peak does not. Same at sea level, takes less passes of the impeller to reach that SET 200kpa by the wastegate, obtaining the kpa quicker (rpm curve shift)...
There are other factors at play.
1. Turbo MAP, if at higher altitude the higher rpm required to reach that kpa pushes the efficiency off
2. heat generated by that change..
But guess what? thats no WHERE NEAR what the correction factors put in place. (unless one has chosen an incorrect A/R or turbo size in the first place - and uses a **** intercooler)
Otherwise, if one THINKS their build is done well and chosen parts correctly, then no. this is no excuse.
Ive went through the math for DIN, STD and SAE.
Here is an email right from the VP at Dynjet when I asked about Turbos
You are correct, the J1349 should not be used on forced induction
applications. I've attached some details on how our correction factor is
actually circulated, so feel free to review the details.
Currently we do not have a "forced induction" specific correction factor,
but we should soon.
Regards,
----------------
Dan Hourigan
VP Dynamometer Sales
Dynojet Research Inc.
Its simple, they apply a CORRECTION FACTOR when they shouldnt be (turbo - wastegate)
Why is that?
That would be because if you looka t J1349 or ANY of the correction factors, they are used for NA ambient air calculating.
what does a turbo with a wastegate do?
well, it attempts to reach the same kpa of air (atmosphere) into the manifold regardless of where the air is being collected from (high or low elevations). what does this mean?
It means that since air is actually comprised of 20.916% oxygen regardless of where it comes from (exception is troposphere and upper).
If you get 200kpa of air, it will contain xxx amount of oxygen.
The higher the altitude means per cube of space there is simply LESS Air, but per MOLE, still the same 20.916% of oxygen. Elevation is out the window the second your manifold goes beyond ambient.
200kPA REGARDLESS if it is collected at 4000ft or 200ft will have the same amount of oxygen. (that is your power).
Since wastegates obtain the same PSI regardless what does this mean?
It means per pass of the impeller, at higher elevation, less air is gathered, so to reach 200kpa, more impeller passes are required... this means, your dyno CURVE changes, but the peak does not. Same at sea level, takes less passes of the impeller to reach that SET 200kpa by the wastegate, obtaining the kpa quicker (rpm curve shift)...
There are other factors at play.
1. Turbo MAP, if at higher altitude the higher rpm required to reach that kpa pushes the efficiency off
2. heat generated by that change..
But guess what? thats no WHERE NEAR what the correction factors put in place. (unless one has chosen an incorrect A/R or turbo size in the first place - and uses a **** intercooler)
Otherwise, if one THINKS their build is done well and chosen parts correctly, then no. this is no excuse.
Ive went through the math for DIN, STD and SAE.
Here is an email right from the VP at Dynjet when I asked about Turbos
You are correct, the J1349 should not be used on forced induction
applications. I've attached some details on how our correction factor is
actually circulated, so feel free to review the details.
Currently we do not have a "forced induction" specific correction factor,
but we should soon.
Regards,
----------------
Dan Hourigan
VP Dynamometer Sales
Dynojet Research Inc.
Last edited by vmapper; 07-09-2013 at 06:27 PM.
07-09-2013, 05:21 PM
#66
Either you are not able to choose the proper intercooler for your setup or delusional thinking this affects numbers by 22%.
The molecules are not 'thinner', the space between them is greater as you elevate, the molecules do not change. I would agree, there would be some variances here. again, from my tests and discussions, not 22%, no where near what the SAE correction factor does.
Wouldn't make a whole lot of sense to not compensate for the altitude conditions that are unique to Denver, now would it?
So once this new setup is done, it will be corrected per what the professional tuner who tunes cars every day at high altitude thinks is proper.
I am more than happy to take that number vs uncorrected at the low altitude tune/dyno numbers I will get when I go to TX2k14 next year, and since you mentioned betting, hows a friendly wager that they will be within 50WHP of eachother sound?
So once this new setup is done, it will be corrected per what the professional tuner who tunes cars every day at high altitude thinks is proper.
I am more than happy to take that number vs uncorrected at the low altitude tune/dyno numbers I will get when I go to TX2k14 next year, and since you mentioned betting, hows a friendly wager that they will be within 50WHP of eachother sound?
Feel free to argue with Dynojet VPs.
Ive already done the dyno at sea level and again at upper elevations, and I do recognize that using SAE or STD or DIN OVER-INFLATES a PROPERLY setup turbo waste-gate setup.
I like apples and apple pie.
In the end, feel free to run on a loaded dyno (either the 224xLC ) that I run on, or a mustang eddy dyno.
But your output WILL be closer to the uncorrected than using J1349 correction with the weather station values and your inflated values are exaggerated with higher elevations, e.g. denver that probably has a D.A. of 7000.
Last edited by vmapper; 07-09-2013 at 06:29 PM.
07-09-2013, 05:26 PM
#67
Thanks for the info s-cam.
It was not a stock fuel system tho, a walbro 400 with 70lb injectors running at 95%duty cycle is flowing a ridiculous amount compared to stock. Add in the meth and114 octane and you all might begin begin to understand how numbers like that can be achieved?
Also there's a big difference in SC vs turbo, there's a lot more to it than comparing psi to psi, its in the cfm flowed.
Theres a reason all the huge company's trying to make ridiculous hp do it with turbos (lingenfelter, Hennessey, heffner, ugr)
It was not a stock fuel system tho, a walbro 400 with 70lb injectors running at 95%duty cycle is flowing a ridiculous amount compared to stock. Add in the meth and114 octane and you all might begin begin to understand how numbers like that can be achieved?
Also there's a big difference in SC vs turbo, there's a lot more to it than comparing psi to psi, its in the cfm flowed.
Theres a reason all the huge company's trying to make ridiculous hp do it with turbos (lingenfelter, Hennessey, heffner, ugr)
also, meth does allow advanced timing which in turn adds tons of power.
Arun is a guy that know all about this.
Last edited by vmapper; 07-09-2013 at 05:31 PM.
07-09-2013, 05:31 PM
#68
Anyways, I in no way meant to 'flood' your thread here B_ROCKS_IT,
Nothing personal. Merely understanding.
I do enjoy your ideas and builds you are a man that gets **** done.
Nothing personal. Merely understanding.
I do enjoy your ideas and builds you are a man that gets **** done.
Last edited by vmapper; 07-09-2013 at 05:49 PM.
07-09-2013, 09:46 PM
#73
Appreciate the encouragement as well.
I need to find the most recent dyno I did and see what correction factor was used on that one.
07-10-2013, 12:00 PM
#74
Ask your local shop to provide you with the .drf file, you can install winpep7 at home and tinker with the recorded run (just a tabular file with all the information of uncorrected AND of logged sensors and weatherstation values). Though, you will not be able to adjust the DA adjustments (dyno itself calibrations) or the weatherstation information.
http://www.dynojet.com/downloads/software.aspx
I am always in 'learn mode' as well. But Ive really beat the dyno subject hard as I wanted to know why there were so many variances from shop to shop (eddy current vs inertia) etc., as well as I merely wanted to know the closest representation of my runs. Its a tool.
I rarely get the chance to make work of what i consider cool projects like you are doing here, fabing and new ideas! Please continue!
http://www.dynojet.com/downloads/software.aspx
I am always in 'learn mode' as well. But Ive really beat the dyno subject hard as I wanted to know why there were so many variances from shop to shop (eddy current vs inertia) etc., as well as I merely wanted to know the closest representation of my runs. Its a tool.
I rarely get the chance to make work of what i consider cool projects like you are doing here, fabing and new ideas! Please continue!
07-10-2013, 03:36 PM
#75
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Being a mechanic for quite a while I still leave system designing to the pros because certain aspects I just can't grasp... Lots of good info here... And in the end I'm sure B's car will be badass
07-11-2013, 11:49 AM
#76
Ask your local shop to provide you with the .drf file, you can install winpep7 at home and tinker with the recorded run (just a tabular file with all the information of uncorrected AND of logged sensors and weatherstation values). Though, you will not be able to adjust the DA adjustments (dyno itself calibrations) or the weatherstation information.
http://www.dynojet.com/downloads/software.aspx
I am always in 'learn mode' as well. But Ive really beat the dyno subject hard as I wanted to know why there were so many variances from shop to shop (eddy current vs inertia) etc., as well as I merely wanted to know the closest representation of my runs. Its a tool.
I rarely get the chance to make work of what i consider cool projects like you are doing here, fabing and new ideas! Please continue!
http://www.dynojet.com/downloads/software.aspx
I am always in 'learn mode' as well. But Ive really beat the dyno subject hard as I wanted to know why there were so many variances from shop to shop (eddy current vs inertia) etc., as well as I merely wanted to know the closest representation of my runs. Its a tool.
I rarely get the chance to make work of what i consider cool projects like you are doing here, fabing and new ideas! Please continue!
Where are you located, I take it you have a shop? THanks
07-11-2013, 11:49 AM
#77
