XKR Super G... Going for Mach 1
...Too wild for me 
You told me that if your new setup doesn't make 1,000+whp... ^ you'll try one of those in an STS style rear mount location.
09-12-2009, 04:32 PM
#1107
I went and measured my turbo housings today. They are 3071R turbos with a 0.64 A/R.
Long story short, as we suspected, the A in Garrett's A/R formula does NOT stand for the area of the turbine inlet.
Using Garrett's drawing and my actual turbo housing, R measures to be about 50 mm. (Raj, you were right, the wall was 4 mm). Thus, A should be 50 * 0.64 = 32 mm^2.
I measured the diameter of the inlet area where indicated in Garret's drawing. The diameter measured approximately 34 mm. I was using a paper ruler which was bending a bit, so this value is probably a bit smaller, and may actually have been closer to 32 mm.
The opening is not perfectly circular, but we'll use this measurement just to get an approximation of the inlet area, which turns out to be approximately 804 mm^2. In actuality, the inlet area is probably a good 10%-20% larger than this due to the inlet shape.
Now, using Garrett's definition of A/R, my A/R = 16.1. The housings are specified as 0.64. So we can safely assume that their formula is way, way off. In other words, A is NOT the area of the inlet as they state on their website. Instead, A is the diameter of the turbine inlet.
I have not yet heard back from Garrett, but I believe that when I do, they will confirm this. Hopefully they will correct the tutorial on their website.
I will now compute the Approximate turbine areas for various turbochargers for comparison to the flange area, which is how this all started. I'll post the results.
Long story short, as we suspected, the A in Garrett's A/R formula does NOT stand for the area of the turbine inlet.
Using Garrett's drawing and my actual turbo housing, R measures to be about 50 mm. (Raj, you were right, the wall was 4 mm). Thus, A should be 50 * 0.64 = 32 mm^2.
I measured the diameter of the inlet area where indicated in Garret's drawing. The diameter measured approximately 34 mm. I was using a paper ruler which was bending a bit, so this value is probably a bit smaller, and may actually have been closer to 32 mm.
The opening is not perfectly circular, but we'll use this measurement just to get an approximation of the inlet area, which turns out to be approximately 804 mm^2. In actuality, the inlet area is probably a good 10%-20% larger than this due to the inlet shape.
Now, using Garrett's definition of A/R, my A/R = 16.1. The housings are specified as 0.64. So we can safely assume that their formula is way, way off. In other words, A is NOT the area of the inlet as they state on their website. Instead, A is the diameter of the turbine inlet.
I have not yet heard back from Garrett, but I believe that when I do, they will confirm this. Hopefully they will correct the tutorial on their website.
I will now compute the Approximate turbine areas for various turbochargers for comparison to the flange area, which is how this all started. I'll post the results.
09-12-2009, 05:33 PM
#1108
EDIT EDIT EDIT: Garrett finally got back to me, which changes the entire analysis...
Essentially A is the inlet area, but the formula only works in INCHES, while all of their dimensions are specified in mm.
OK, using A as the area of the inlet (in inches), I have computed the following turbine inlet areas:
GT3071R 0.64 A/R: 800 mm^2
GT3071R 0.86 A/R: 1143 mm^2
GT3076R 0.64 A/R: 834 mm^2
GT3076R 0.84 A/R: 1156 mm^2
GT3582R 0.76 A/R: 1117 mm^2
I computed using the same formula previously posted, but converted everything to inches to perform the calculations to make it work with Garret's inch-based A/R values, then back to mm.
The flange areas are as follows:
T25: 1735 mm^2
T3: 2412 mm^2
T4: 3623 mm^2
EDIT EDIT EDIT EDIT: The T25 flanges will work perfectly fine.
Essentially A is the inlet area, but the formula only works in INCHES, while all of their dimensions are specified in mm.
OK, using A as the area of the inlet (in inches), I have computed the following turbine inlet areas:
GT3071R 0.64 A/R: 800 mm^2
GT3071R 0.86 A/R: 1143 mm^2
GT3076R 0.64 A/R: 834 mm^2
GT3076R 0.84 A/R: 1156 mm^2
GT3582R 0.76 A/R: 1117 mm^2
I computed using the same formula previously posted, but converted everything to inches to perform the calculations to make it work with Garret's inch-based A/R values, then back to mm.
The flange areas are as follows:
T25: 1735 mm^2
T3: 2412 mm^2
T4: 3623 mm^2
EDIT EDIT EDIT EDIT: The T25 flanges will work perfectly fine.
Last edited by ttg35fort; 09-14-2009 at 11:26 AM.
09-13-2009, 04:20 AM
#1109
interesting.
29psi? that about what GTM said that the 3076's needed to run to see about 900, so that falls within reason. THats alot of boost and I dont think Sharif has even tuned passed the internal MAP sensor of a Haltech at 22 psi.
Could you post the actual dimensions of the various flanges. I couldnt find that data. I am also interested in seeing how you came up with the measurements for the other turbos if you didnt actually measure them.
Interesting data, now we just need real world #s
. 30 psi here we come!
29psi? that about what GTM said that the 3076's needed to run to see about 900, so that falls within reason. THats alot of boost and I dont think Sharif has even tuned passed the internal MAP sensor of a Haltech at 22 psi.
Could you post the actual dimensions of the various flanges. I couldnt find that data. I am also interested in seeing how you came up with the measurements for the other turbos if you didnt actually measure them.
Interesting data, now we just need real world #s
. 30 psi here we come!
09-13-2009, 06:18 AM
#1111
Registered User
Like I tell anyone thats been in my car, and is amazed by pump gas powe.....
"LIFE BEGINS AT 30PSI"
At least on mine the power difference once you get up above 22-25psi is BRUTAL.
The car is almost violent at 25-30psi......**** be happenin FAST!!!!!!!
Tom
"LIFE BEGINS AT 30PSI"
At least on mine the power difference once you get up above 22-25psi is BRUTAL.
The car is almost violent at 25-30psi......**** be happenin FAST!!!!!!!
Tom
interesting.
29psi? that about what GTM said that the 3076's needed to run to see about 900, so that falls within reason. THats alot of boost and I dont think Sharif has even tuned passed the internal MAP sensor of a Haltech at 22 psi.
Could you post the actual dimensions of the various flanges. I couldnt find that data. I am also interested in seeing how you came up with the measurements for the other turbos if you didnt actually measure them.
Interesting data, now we just need real world #s. 30 psi here we come!
29psi? that about what GTM said that the 3076's needed to run to see about 900, so that falls within reason. THats alot of boost and I dont think Sharif has even tuned passed the internal MAP sensor of a Haltech at 22 psi.
Could you post the actual dimensions of the various flanges. I couldnt find that data. I am also interested in seeing how you came up with the measurements for the other turbos if you didnt actually measure them.
Interesting data, now we just need real world #s
. 30 psi here we come!
09-13-2009, 09:06 AM
#1113
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Thanks for the info Terry....
Making the power was not a worry for us....the Carbonetic clutch is the only worries FP,GTM and I have. It's rated at 900+whp.... That's why I don't want Sharif to push it on his dyno....850+ on FP dyno and the rest on a DJ...
I am not willing to give up the Carbonetics for a race only setup....remember this car is setup for multi use.
Making the power was not a worry for us....the Carbonetic clutch is the only worries FP,GTM and I have. It's rated at 900+whp.... That's why I don't want Sharif to push it on his dyno....850+ on FP dyno and the rest on a DJ...
I am not willing to give up the Carbonetics for a race only setup....remember this car is setup for multi use.
09-13-2009, 09:42 AM
#1117
Thanks for the info Terry....
Making the power was not a worry for us....the Carbonetic clutch is the only worries FP,GTM and I have. It's rated at 900+whp.... That's why I don't want Sharif to push it on his dyno....850+ on FP dyno and the rest on a DJ...
I am not willing to give up the Carbonetics for a race only setup....remember this car is setup for multi use.
Making the power was not a worry for us....the Carbonetic clutch is the only worries FP,GTM and I have. It's rated at 900+whp.... That's why I don't want Sharif to push it on his dyno....850+ on FP dyno and the rest on a DJ...
I am not willing to give up the Carbonetics for a race only setup....remember this car is setup for multi use.
09-13-2009, 09:47 AM
#1118
There is a Japtrix build/tuned RB26 (2.6L) motor pushing over 30 psi and getting over 600 whp on 93 octane. That's over 230 hp/L on pump gas. 
I beleive that the compression on that motor is 8:1, and it is all cast iron. Both of those things help alot.
I beleive that the compression on that motor is 8:1, and it is all cast iron. Both of those things help alot.
09-13-2009, 09:53 AM
#1119
Registered User
I dd it at 14psi, when out with "friends" on pump I'll go to 17psi....have seen 18psi, but the last plug change showed some speckles....so keeping it below that for safety. If we touched the tune could go higher....
But 14psi is 530rwhp (SP's mustang dyno), so figure 18-20hp per lb of boost, so somewhere right at 590-600rwhp at 17psi (have to dyno it at 17psi on pump one day to see)
basically pump gas is more than enough for 99.99% of the stuff out there......but Vlad's crazy G35 sedan just made 597rwhp at 12psi through a TH400.......I'll need a whole lot more for that lol.
tom
But 14psi is 530rwhp (SP's mustang dyno), so figure 18-20hp per lb of boost, so somewhere right at 590-600rwhp at 17psi (have to dyno it at 17psi on pump one day to see)
basically pump gas is more than enough for 99.99% of the stuff out there......but Vlad's crazy G35 sedan just made 597rwhp at 12psi through a TH400.......I'll need a whole lot more for that lol.
tom