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Twin Turbo 928 fixed and back out there terrorizing the streets!

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Old 05-16-2018, 03:26 PM
  #1921  
Carl Fausett
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This chart was just made by us today. Engine dyno of our 6.54L motor. Shows 900 HP at the crank (OK, 897.7 ) She was running real smooth, too.

I will post the video just as soon as I can.

Old 05-16-2018, 03:49 PM
  #1922  
ptuomov
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Thanks for posting that. What fuel and what manifold pressure?
Old 05-16-2018, 03:56 PM
  #1923  
Carl Fausett
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We use only gas and boost. No other additives. Gas was Sunnoco 110.

Peak manifold pressure was 186 Kpa, Boost pressure would be 12.3 psi.
Old 05-19-2018, 02:19 AM
  #1924  
ptuomov
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Default Figuring out the fueling

John’s executing his research program and this is where he is now on pump gas:



Old 05-19-2018, 11:50 PM
  #1925  
andy-gts
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so Carl is crank and 110 octane with supercharger and Johns is rwhp on pump gas and turbo........hmmmm
coooool
Old 05-20-2018, 04:51 PM
  #1926  
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Originally Posted by andy-gts
so Carl is crank and 110 octane with supercharger and Johns is rwhp on pump gas and turbo........hmmmm coooool
The blue engine in my car has almost all stock or lightly modified stock components. Stock valve sizes with minor porting. Stock pistons with dish machined into them. Stock crankshaft with done oiling improvements. Stock ppf rods. Stock intake manifold with some porting. Modified S3 cams with new profiles. Stock throttle body element. Stock 5L displacement. Stock computers with ST2 software. So the two engines are quite different in terms of what they are and what design philosophy they are based on.

Another thing is that we're asking LH, EZ-K, and ST2 to do things that nobody else has ever asked them to do. In the process, we're finding all sorts of engine control issues at 500 crank hp and 600 crank hp levels that nobody else has uncovered. For example, we're hitting the Super MAF voltage of 5.11V at 3500 rpm, hands up if someone else has done that? And then a follow up question what happens when you do that? ;-) As a reference, 5.11V from SuperMAF corresponds to approximately 1800 kg/h and 600 crank hp. C'mon, the answer to this question should be known to everyone who claims to be making 600hp or more at the crank with stock computers!




Last edited by ptuomov; 05-21-2018 at 12:28 PM.
Old 05-21-2018, 10:50 AM
  #1927  
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Compare boost pressures. We made ours on 12.3 psi of boost. What was John's?

I expect he's running more boost, but curious how much more.
Old 05-21-2018, 11:02 AM
  #1928  
ptuomov
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Originally Posted by Carl Fausett
Compare boost pressures. We made ours on 12.3 psi of boost. What was John's? I expect he's running more boost, but curious how much more.
About 16.7 psi at peak power, give or take, for that particular run. That’s measured from the intake manifold, not compressor outlet.

Last edited by ptuomov; 05-21-2018 at 11:25 AM.
Old 05-23-2018, 11:32 PM
  #1929  
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More details of what's going on at the 720 rwhp level, these are 6000-6250rpm range averages from another run today:

Pressures:
Barometer 14.80
Turbocharger Suction Pressure (ABS) 13.85
Intercooler Pressure Delta (DIFF)1.30
Intake Manifold Pressure (ABS) 30.69
Downpipe Pressure (ABS) 15.97

Tempratures:
Turbo Comp. Discharge Temp (3) 321.50
Pre-Intercooler Temp. (4) 292.53
Post-Intercooler Temp. (6) 121.84
Intake Manifold Temp. (7) 117.91
Old 05-24-2018, 10:05 PM
  #1930  
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Unless I am misreading or missed other info -

IATs post intercooler will pose problems with detonation if you look at similar platforms. On a road course those would rise possible (balancing more air flow, but also more heat) to 130. You would need meth there to cool post IC pre port.

You will need to increase the fuel's detonation resistance or reduce IATs.
Old 05-24-2018, 11:17 PM
  #1931  
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wouldnt the FINAL TUNE be on actual road course.....to help the need for reduced IAT or fuel detonation.....
Old 05-24-2018, 11:52 PM
  #1932  
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Originally Posted by andy-gts
wouldnt the FINAL TUNE be on actual road course.....to help the need for reduced IAT or fuel detonation.....
What do you mean? More air flow thru the various heat exchangers? The dyno has three large fans blowing air simulates those decently well, although of course not perfectly.

99/100 people tuning these cars only tuned the highest load cells at high rpms. In contrast, John tunes basically every cell to the extent that it can be tuned.
Old 05-24-2018, 11:57 PM
  #1933  
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What is the stock IAT?
Old 05-25-2018, 08:23 AM
  #1934  
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Originally Posted by worf928
What is the stock IAT?
Stock engine intake manifold air temperature is very close to ambient temperature at WOT. Seems like the small effects of heat in the engine bay, friction in the flow causing turbulence, and small pressure drop because of flow resistance don't make much of a difference.

This test was done on a hot and sunny day, with ambient temperature over 90 inside the hangar. There's no AC in there, that would be very expensive facility to cool.

The intercoolers are working incredibly well, minimal pressure drop at 1.3 PSI and 170F coming off the charge air temperature. John got those right, only took six months to design! ;-)
Old 05-25-2018, 02:21 PM
  #1935  
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ptuomov,
I thought the car was meant for road racing and you would do final tune at each course at elevation and temp to optimized tune for each course......sorry I thought this was racer only.....!!!!!


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