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Why a 76? Compressor map question...

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Old Jul 5, 2006 | 08:22 AM
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Default Why a 76? Compressor map question...

So, I am starting to think about going turbo.

I keep seeing everyone using gt76s. People are making great power with them but it seem like an inefficent choice.

The GT4088 is the one I have my eye on...seems like even this is border line efficent.



I have been using this a a way to figure out air flow...

Code:
PSI 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
rpm\PR 1.00 1.07 1.14 1.20 1.27 1.34 1.41 1.48 1.54 1.61 1.68 1.75 1.82 1.88 1.95 2.02 
3400 20 21 22 24 25 26 28 29 30 32 33 34 36 37 38 40 
3500 20 22 23 24 26 27 28 30 31 33 34 35 37 38 39 41 
3600 21 22 24 25 26 28 29 31 32 34 35 36 38 39 41 42 
3700 21 23 24 26 27 29 30 32 33 34 36 37 39 40 42 43 
3800 22 23 25 26 28 29 31 32 34 35 37 38 40 41 43 44 
3900 23 24 26 27 29 30 32 33 35 36 38 39 41 42 44 45 
4000 23 25 26 28 29 31 33 34 36 37 39 40 42 44 45 47 
4100 24 25 27 29 30 32 33 35 37 38 40 41 43 45 46 48 
4200 24 26 28 29 31 32 34 36 37 39 41 42 44 46 47 49 
4300 25 27 28 30 32 33 35 37 38 40 42 43 45 47 48 50 
4400 25 27 29 31 32 34 36 38 39 41 43 44 46 48 50 51 
4500 26 28 30 31 33 35 37 38 40 42 44 45 47 49 51 52 
4600 27 28 30 32 34 36 37 39 41 43 45 46 48 50 52 54 
4700 27 29 31 33 35 36 38 40 42 44 46 47 49 51 53 55 
4800 28 30 31 33 35 37 39 41 43 45 47 48 50 52 54 56 
4900 28 30 32 34 36 38 40 42 44 46 48 49 51 53 55 57 
5000 29 31 33 35 37 39 41 43 45 47 49 50 52 54 56 58 
5100 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 
5200 30 32 34 36 38 40 42 44 46 48 50 52 55 57 59 61 
5300 31 33 35 37 39 41 43 45 47 49 51 54 56 58 60 62 
5400 31 33 35 38 40 42 44 46 48 50 52 55 57 59 61 63 
5500 32 34 36 38 40 43 45 47 49 51 53 56 58 60 62 64 
5600 32 35 37 39 41 43 46 48 50 52 54 57 59 61 63 65 
5700 33 35 37 40 42 44 46 49 51 53 55 58 60 62 64 66 
5800 33 36 38 40 43 45 47 49 52 54 56 59 61 63 65 68 
5900 34 36 39 41 43 46 48 50 53 55 57 60 62 64 67 69 
6000 35 37 39 42 44 46 49 51 53 56 58 61 63 65 68 70 
6100 35 38 40 42 45 47 50 52 54 57 59 62 64 66 69 71 
6200 36 38 41 43 46 48 50 53 55 58 60 63 65 67 70 72 
6300 36 39 41 44 46 49 51 54 56 59 61 64 66 69 71 73 
6400 37 39 42 44 47 50 52 55 57 60 62 65 67 70 72 75 
6500 38 40 43 45 48 50 53 55 58 61 63 66 68 71 73 76 
6600 38 41 43 46 48 51 54 56 59 61 64 67 69 72 74 77 
6700 39 41 44 47 49 52 54 57 60 62 65 68 70 73 76 78 
6800 39 42 45 47 50 53 55 58 61 63 66 69 71 74 77 79
Basically, I am wondering why the 76 is a more popular choice then an 88 or even bigger...
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Old Jul 5, 2006 | 09:02 AM
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That turbo's too small....2PR = 60lb/min...
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Old Jul 5, 2006 | 09:16 AM
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The 88 is?

So why do people run 76s all the time?
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Old Jul 5, 2006 | 09:42 AM
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70stang, the GT4088 is only a 63mm. Its quite a bit smaller then a big 76mm.
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Old Jul 5, 2006 | 11:00 AM
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hmmmm

Can you post a link to a map for the 76 people are using?

THANKS!

Are these GT42 76s or what? I must be confused...
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Old Jul 5, 2006 | 01:41 PM
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Originally Posted by 70Stang
hmmmm

Can you post a link to a map for the 76 people are using?

THANKS!

Are these GT42 76s or what? I must be confused...


I was using a GT42-76... no one has a compressor map for it...... from what we know about it it will work very well with a 346ci LS1.... in the upper RPM it will run out of steam...on a 370.
I wouldnt use it though........ im a little pissed at Precision right now

Kyle
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Old Jul 5, 2006 | 02:06 PM
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Originally Posted by NA$TY-TA
I was using a GT42-76... no one has a compressor map for it...... from what we know about it it will work very well with a 346ci LS1.... in the upper RPM it will run out of steam...on a 370.
I wouldnt use it though........ im a little pissed at Precision right now

Kyle
Jose has a Map for it I think... think I saw it on his site. I wish I could use a GT42-76 but I dont have enough room for that big *** housing. That is why I am going with a 76MPS
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Old Jul 5, 2006 | 02:26 PM
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Here is a host of maps on the site.

http://www.forcedinductions.com/compressormaps.htm
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Old Jul 5, 2006 | 02:37 PM
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Originally Posted by NA$TY-TA
I was using a GT42-76... no one has a compressor map for it...... from what we know about it it will work very well with a 346ci LS1.... in the upper RPM it will run out of steam...on a 370.
I wouldnt use it though........ im a little pissed at Precision right now

Kyle
Man I hear ya bro Did your new toy come in?
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Old Jul 5, 2006 | 02:40 PM
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Originally Posted by JMBLOWNWS6
Man I hear ya bro Did your new toy come in?

Ask the guy above you to ask JZ if it did?????

Kyle
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Old Jul 5, 2006 | 02:43 PM
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Kyle the core units arrived today, we are waiting on more compressor wheels to arrive.
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Old Jul 5, 2006 | 02:45 PM
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Originally Posted by DrTurbo
Here is a host of maps on the site.

http://www.forcedinductions.com/compressormaps.htm

BTW the GT42 is there but its only the 70mm version and the 74mm version... none for the GT42-76.

Kyle
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Old Jul 5, 2006 | 02:56 PM
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For reference, a standard Garrett part number like GT4088, GT4202, etc lists the size of the compressor wheel EXDUCER.

you need to know the compressor wheel trim, and you can find the size of the inducer on the compressor.

IE, my GT4202's are 74mm inducer, 102mm exducer. Thus the 02 in the part number.
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Old Jul 5, 2006 | 03:20 PM
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Originally Posted by DrTurbo
Kyle the core units arrived today, we are waiting on more compressor wheels to arrive.

Awsome news......
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Old Jul 5, 2006 | 03:34 PM
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Originally Posted by NA$TY-TA
Awsome news......
He said wheels? Twin turbo action
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Old Jul 5, 2006 | 03:59 PM
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Originally Posted by JMBLOWNWS6
He said wheels? Twin turbo action

No Jose and Jason order several hundred wheels at a time.
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Old Jul 5, 2006 | 04:05 PM
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DrTurbo,

You have any GT42 76 journal bearing turbos in stock?

PM me a price!
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Old Jul 5, 2006 | 04:24 PM
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Originally Posted by longrange4u
Jose has a Map for it I think... think I saw it on his site. I wish I could use a GT42-76 but I dont have enough room for that big *** housing. That is why I am going with a 76MPS
I'm going with two 76mps's on the new engine.
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Old Jul 5, 2006 | 04:40 PM
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Originally Posted by sr71
I'm going with two 76mps's on the new engine.

That is going to be a sick Vette indeed.
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Old Jul 5, 2006 | 05:21 PM
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Originally Posted by DrTurbo
That is going to be a sick Vette indeed.

Are there any plans for compressor maps of the ""S"" Series Turbo's???
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