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Old Aug 10, 2005 | 02:19 PM
  #166  
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Originally Posted by propellerhead
Just some additional data... I spoke with the machine shop that did the work on my motor. The dish on the 8.5:1 CR pistons used each have a capacity of 20.5cc. This brings the calculated displacement up to 2,378CC. I've updated my post above where I included the log data.
The dish on a piston goes into the calculations of combustion chamber size, not the displacement of the engine.

Keith
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Old Aug 10, 2005 | 03:06 PM
  #167  
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From: Agrestic
Originally Posted by Fourdoor
The dish on a piston goes into the calculations of combustion chamber size, not the displacement of the engine.

Keith
Hmm, yes. Duh. Displacement doesn't change with piston shape. I'm not sure where my head was at. A little overzealous I guess or perhaps acceleration induced delirium.

Last edited by propellerhead; Aug 10, 2005 at 03:14 PM.
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Old Aug 10, 2005 | 07:55 PM
  #168  
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Originally Posted by propellerhead
Hmm, yes. Duh. Displacement doesn't change with piston shape. I'm not sure where my head was at. A little overzealous I guess or perhaps acceleration induced delirium.
Hmm.. I'm not so sure about this .. you're calculating volume .. so theoritically .. it does affect the overall cc.. minute maybe but it does .. you could be right you know
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Old Aug 12, 2005 | 12:46 PM
  #169  
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From: Agrestic
It does affect combustion chamber volume as well as overall volume but the dish size doesn't change displacement volume. Now if you had some fancy JDM pistons forged of pure Unobtainium-469 that changed dish shape as the piston travelled along it's stroke that might be a different story...
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Old Aug 13, 2005 | 07:31 AM
  #170  
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Originally Posted by propellerhead
It does affect combustion chamber volume as well as overall volume but the dish size doesn't change displacement volume. Now if you had some fancy JDM pistons forged of pure Unobtainium-469 that changed dish shape as the piston travelled along it's stroke that might be a different story...
your dish will affect overall volume if its different from std.. if the dish change shape during travel then it affects overall compression ratio. displacement is measured as a cylinder.. but if the top or botttom of the cylinder is not flat then displacement is changed.. unless cc and volume are 2 separate things
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Old Aug 13, 2005 | 10:04 PM
  #171  
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3037 spool up

Hey

Just wanted to contribute. This is an old datalog (3rd gear pull) of a HKS 3037s wif .87 Exhaust housing, tomei 280 procams, etc....



C. Temp AFR RPM TPS (%) Boost Speed Knock Air Temp

85 14.2 2,600.00 102 1.3 31 0.1 24
85 14.1 2,600.00 102 1.3 31 0 24
85 14 2,650.00 102 1.3 31 0.1 24
85 14 2,650.00 102 1.3 31 0 24
85 14 2,650.00 102 1.3 32 0.1 24
85 13.9 2,700.00 102 1.3 32 0.1 24
85 13.7 2,700.00 102 1.3 32 0.1 24
85 13.7 2,700.00 102 1.3 32 0.1 24
85 13.6 2,750.00 102 1.6 32 0 24
85 13.6 2,750.00 102 1.6 32 0.1 24
85 13.6 2,750.00 102 1.6 33 0.1 24
85 13.6 2,800.00 102 1.6 33 0 24
85 13.6 2,800.00 102 1.9 33 0.1 24
85 13.6 2,800.00 102 1.6 34 0.1 24
85 13.5 2,850.00 102 1.9 33 0.1 24
85 13.4 2,850.00 102 1.9 34 0.1 24
85 13.2 2,850.00 102 1.6 34 0.1 24
85 13.1 2,900.00 102 1.9 34 0.1 24
85 13.1 2,900.00 102 1.9 34 0.1 24
85 13.2 2,950.00 102 1.9 35 0.1 24
85 13.2 2,950.00 102 2.2 35 0.1 24
85 13.2 3,000.00 102 2.2 35 0.1 24
85 13.2 3,000.00 102 2.2 35 0.1 24
85 13.2 3,000.00 102 2.2 36 0.1 24
86 13.2 3,050.00 102 2.2 35 0.1 24
86 13.2 3,050.00 102 2.2 36 0.1 24
85 13.4 3,050.00 102 2.2 36 0.1 24
86 13.4 3,100.00 102 2.2 36 0.2 24
85 13.4 3,100.00 102 2.6 37 0.1 24
86 13.4 3,150.00 102 2.6 37 0.1 24
86 13.6 3,150.00 102 2.6 38 0.1 24
86 13.6 3,150.00 102 2.9 38 0.1 24
86 13.7 3,200.00 102 2.6 38 0.1 24
86 13.7 3,200.00 102 2.9 38 0.1 24
86 13.7 3,250.00 102 2.9 38 0.1 24
86 13.7 3,250.00 102 2.9 38 0.1 24
85 13.7 3,300.00 102 2.9 39 0.1 24
86 13.7 3,300.00 102 2.9 39 0.1 24
86 13.7 3,350.00 102 2.9 39 0.1 24
86 13.7 3,350.00 102 3.2 40 0.1 24
86 13.7 3,350.00 102 2.9 40 0.2 24
86 13.7 3,400.00 102 2.9 40 0.1 24
86 13.7 3,400.00 102 3.5 40 0.1 24
86 13.7 3,450.00 102 3.5 41 0.1 24
86 13.7 3,450.00 102 3.5 41 0.2 24
86 13.7 3,500.00 102 3.8 41 0.2 24
86 13.9 3,500.00 102 3.8 42 0.1 24
86 13.7 3,550.00 102 3.8 42 0.1 24
86 13.7 3,550.00 102 3.8 42 0.2 24
86 13.6 3,600.00 102 4.5 42 0.1 24
86 13.6 3,600.00 102 4.5 43 0.1 24
86 13.5 3,650.00 102 4.5 43 0.1 24
86 13.4 3,700.00 102 4.5 43 0.2 25
86 13.4 3,700.00 102 4.5 43 0.1 24
86 13.4 3,750.00 102 4.5 44 0.1 25
86 13.2 3,750.00 102 4.8 44 0.1 25
86 13.2 3,750.00 102 5.1 44 0.1 25
86 13.1 3,800.00 102 5.4 45 0.1 25
86 13 3,850.00 102 5.8 45 0.1 25
86 13 3,850.00 102 5.8 45 0.1 25
86 12.7 3,900.00 102 5.8 46 0.1 25
86 12.9 3,950.00 102 5.8 47 0.1 25
86 12.7 3,950.00 102 6.4 47 0.2 25
86 12.7 4,000.00 102 6.4 47 0.2 25
86 12.6 4,000.00 102 6.4 48 0.2 25
86 12.7 4,050.00 102 7 48 0.1 25
86 12.6 4,100.00 102 7.4 48 0.3 25
86 12.6 4,100.00 102 7.7 48 0.1 25
86 12.6 4,150.00 102 8.3 49 0.2 25
86 12.5 4,150.00 102 8.3 50 0.2 25
86 12.4 4,200.00 102 9 49 0.5 25
86 12.2 4,250.00 102 9.3 50 0.3 25
86 12.1 4,300.00 102 9.6 51 0.4 25
86 12 4,300.00 102 10.2 51 0.2 25
86 12 4,350.00 102 10.9 51 0.4 25
86 11.9 4,350.00 102 11.2 52 0.2 25
86 11.7 4,450.00 102 11.8 52 0.2 25
86 11.7 4,450.00 102 13.1 53 0.4 25
86 11.6 4,500.00 102 13.4 53 0.3 26
86 11.5 4,550.00 102 14.7 54 0.2 26
86 11.5 4,550.00 102 16.3 54 0.2 26
86 11.5 4,650.00 102 17.3 55 0.4 26
86 11.4 4,700.00 102 18.6 55 0.4 26
86 11.4 4,700.00 102 19.8 56 0.6 26
86 11.4 4,800.00 102 22.1 56 0.4 26
86 11.2 4,800.00 102 22.1 57 0.3 26
86 11.4 4,900.00 102 24 58 0.4 26
86 11.2 4,950.00 102 24.6 58 0.4 26
86 11.4 5,000.00 102 25.3 59 0.4 26
87 11.4 5,050.00 102 24.6 60 0.4 26
86 11.4 5,150.00 102 25.6 61 0.4 26
87 11.4 5,200.00 102 25.3 61 0.7 26
87 11.4 5,250.00 102 26.2 62 0.5 26
87 11.4 5,300.00 102 25.6 63 0.6 26
87 11.4 5,400.00 102 25.9 63 0.4 27
87 11.4 5,450.00 102 26.2 64 0.7 27
87 11.4 5,500.00 102 25.9 65 0.6 27
87 11.4 5,550.00 102 25.6 66 0.7 27
87 11.4 5,650.00 102 25.3 67 0.5 28
87 11.4 5,700.00 102 25.3 68 0.6 28
87 11.6 5,750.00 102 25.9 68 0.5 28
87 11.5 5,800.00 102 25 69 0.7 28
87 11.5 5,900.00 102 25.3 70 0.9 28
87 11.4 5,950.00 102 26.2 71 0.7 28
87 11.2 6,050.00 102 26.2 71 0.6 29
87 11.2 6,100.00 102 25.6 72 0.5 29
87 11.2 6,150.00 102 25.6 73 0.5 29
87 11.4 6,200.00 102 25.6 73 0.7 30
87 11.2 6,300.00 102 25.3 75 0.9 30
87 11.2 6,350.00 102 25.3 75 0.8 30
87 11.1 6,400.00 102 25.3 76 0.7 30
87 11.2 6,450.00 102 25.3 77 0.7 31
87 11.2 6,550.00 102 25.3 77 0.5 31
87 11.4 6,600.00 102 25.3 78 1.1 32
87 11.4 6,650.00 102 24.6 79 1 32
87 11.4 6,700.00 102 24.6 79 0.9 32
87 11.5 6,800.00 102 25.3 80 0.9 32
87 11.4 6,850.00 102 25.3 81 0.7 33
87 11.5 6,900.00 102 25.3 82 0.8 33
87 11.4 6,950.00 102 24 83 0.7 34
87 11.4 7,050.00 102 24.3 84 0.8 34
87 11.4 7,100.00 102 24 84 0.9 34
87 11.5 7,150.00 102 24 85 0.8 35
88 11.5 7,200.00 102 24 85 1.1 35
88 11.5 7,250.00 102 24.6 86 0.9 36
88 11.5 7,350.00 102 23.7 86 0.8 36
88 11.5 7,400.00 102 24 87 1.2 37
88 11.6 7,450.00 102 24 88 1 37
88 11.6 7,450.00 102 24 89 0.8 38
88 11.5 7,550.00 102 23 89 0.8 38
88 11.4 7,600.00 102 24 89 0.9 38
88 11.4 7,650.00 102 23.7 91 0.7 39
88 11.2 7,700.00 102 23.4 91 0.9 39
88 11.1 7,750.00 102 23.4 92 0.8 39
88 11.2 7,800.00 102 24 93 1 40
88 11.2 7,850.00 102 23.7 93 0.9 40
88 11.2 7,900.00 102 23.7 94 0.8 40
88 11.4 7,950.00 102 24 94 0.8 40
88 11.4 8,000.00 102 23.7 95 1.2 41

I was able to get 10psi @ 4100rpm and 20psi @ 4500rpm after changing the exhaust housing to a .73.

Ben

Last edited by woobos; Aug 13, 2005 at 10:08 PM.
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Old Aug 13, 2005 | 10:07 PM
  #172  
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Sorry guys...

i copied and paste from excel and it looks terrible.
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Old Aug 15, 2005 | 07:08 AM
  #173  
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From: Rosedale, IN
Originally Posted by gunzo
your dish will affect overall volume if its different from std.. if the dish change shape during travel then it affects overall compression ratio. displacement is measured as a cylinder.. but if the top or botttom of the cylinder is not flat then displacement is changed.. unless cc and volume are 2 separate things
It does NOT effect cc's of displacement (volume) at all of the engine, just the volume of the combustion chamber. Displacement is a real simple calculation with only three factors. Number of pistons, piston diameter, and stroke length. There is no factor for piston shape.

Keith
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Old Aug 15, 2005 | 07:26 AM
  #174  
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Originally Posted by Fourdoor
It does NOT effect cc's of displacement (volume) at all of the engine, just the volume of the combustion chamber. Displacement is a real simple calculation with only three factors. Number of pistons, piston diameter, and stroke length. There is no factor for piston shape.

Keith

err why not??
you're calculating volume in displacement aren't you?
8.8cmx4.25cm^2xpi is a cylindrical shape.. in an induction cycle, don't you draw in the volume of air equal to the volume of each cylinder?? if thats the case a 5cc dish warrants a 5cc increase in volume..

geez getting really confused now
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Old Aug 15, 2005 | 07:51 AM
  #175  
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From: Rosedale, IN
Finally have some new data from the difference having a tune from a professional makes over my un-tuned boost response.

Old data:

RPM ------- 2nd ---------3rd ----------4th
2500 ---------.1 --------- .6 ------------ 1.0
3000 --------1.0 ------- 1.6 ------------ 1.9
3500 ------- 1.9 ------- 2.9 ------------ 3.4
4000 ------- 3.8 ------- 6.5 ------------ 8.1
4500 ------- 7.5 -------12.0 ---------- 15.4
5000 ----- 11.7 -------18.5 ---------- 18.5
5500 ----- 17.7 -------19.2 ---------- 19.3
6000 ----- 20.1 ------ 20.1------------ 19.8
6500 -------------------20.9 ------------ 20.6
7000 -------------------21.0 ------------ 21.2
7500 -------------------21.8 ------------ 22.2

New Data:

RPM ------- 2nd ---------3rd ------------4th
2500 ---------.4 -------- 1.3 ------------ 1.8
3000 --------1.2 ------- 2.3 ------------ 3.0
3500 ------- 2.1 ------- 4.0 ------------ 5.1
4000 ------- 4.8 ------- 7.8 ----------- 11.4
4500 ------- 8.5 -------13.9 ---------- 21.8
5000 ----- 14.3 -------24.0 ---------- 23.9
5500 ----- 20.8 -------24.0 ---------- 23.9
6000 ----- 25.0 ------ 24.0----------- 25.0
6500 ----- 25.5 -------25.6 ---------- 26.0
7000 ----- 25.2 -------25.3 ---------- 26.0
7500 ----- 25.2 -------25.6 ----------------

Wastegate is fully open at 4600 RPM in 4th gear now!

Later,

Keith
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Old Aug 15, 2005 | 08:01 AM
  #176  
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From: Rosedale, IN
Originally Posted by gunzo
err why not??
you're calculating volume in displacement aren't you?
8.8cmx4.25cm^2xpi is a cylindrical shape.. in an induction cycle, don't you draw in the volume of air equal to the volume of each cylinder?? if thats the case a 5cc dish warrants a 5cc increase in volume..

geez getting really confused now
The cylinder is perfectly cylindrical with no top or bottom.... the piston has a shape. The "swept area" is the amount that matters. From the top of the pistons stroke upward to the extent of the head is the combustion chamber. Changing the shape of the pistons crown is no different than adding or removing material from the head inside the combustion chamber. It effects combustion chamber volume, and compression ratio... but has zero effect on displacement.

Keith

PS: This is totally off topic, and as a Mod I sugest you start a new thread about it if you have any more questions

Keith
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Old Aug 15, 2005 | 04:07 PM
  #177  
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The cylinder is perfectly cylindrical with no top or bottom.... the piston has a shape. The "swept area" is the amount that matters. From the top of the pistons stroke upward to the extent of the head is the combustion chamber. Changing the shape of the pistons crown is no different than adding or removing material from the head inside the combustion chamber. It effects combustion chamber volume, and compression ratio... but has zero effect on displacement.
off topic you're right!

Last edited by gunzo; Aug 15, 2005 at 04:10 PM.
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Old Aug 15, 2005 | 04:15 PM
  #178  
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fourdoor,

can you please list your mods? also, what is the elevation like where you live?

Last edited by TwStDeVo; Aug 15, 2005 at 08:38 PM.
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Old Aug 15, 2005 | 08:39 PM
  #179  
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looking for advice from everyone,

i live in an area that is 6000ft above sea level. i want the 35r but worried about spool up. i have been following the other thread closely. a local person bought a 3076 and says he gets full boost around 4500, so i figure the 35r would be around 5000. would it still be worth buying the 35r or should i just stick with something like the buschur 20g? i will be using the utec for tuning.
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Old Aug 16, 2005 | 12:57 AM
  #180  
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Originally Posted by bolsen
****Remember people, 15psi on a gt35 is ALOT different than 15psi on a 16g!!!! Just because you aren't at full boost doesn't mean you aren't making power!****
Was just thinking the same myself...and was wondering why more people aren't concerned about what power they are making at a certain RPM, rather then just what they boost is at at a given RPM.

Last edited by KevPSR; Aug 16, 2005 at 01:30 AM.
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