what's the minimum size turbo???

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Aug 10, 2007 | 02:03 PM
  #1  
what is the smallest size turbo that could push between 5-10 pounds of boost on a 305? just a little project, doesn't have to last all that long, 6 months for all i care, just thought it would be an interesting way to kill the 305 to make way for the 350.
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Aug 10, 2007 | 04:59 PM
  #2  
Re: what's the minimum size turbo???
I would think that a T3 would be sufficient for those kind of boost numbers.... Personally I would go with a T70 single... they have some on ebay.....for a decent price..
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Aug 10, 2007 | 11:11 PM
  #3  
Re: what's the minimum size turbo???
any suggestions as to about what size t3?
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Aug 11, 2007 | 12:24 AM
  #4  
Re: what's the minimum size turbo???
A turbine A/R of .82 and a compressor with a super 60 trim wheel.

For what it is worth, I put a small set of T3s on a 305ci. 45 trim compressor, .48 A/R turbines on both banks.

It would be more effective to put some N2O on it if you are looking for short term. Boost only pays off in the long term.
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Aug 11, 2007 | 06:45 AM
  #5  
Re: what's the minimum size turbo???
60-1 or a mpt70 is the way to go IMO.
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Aug 18, 2007 | 11:00 AM
  #6  
Re: what's the minimum size turbo???
Got a T04B / H-P TRIM .84 ar turbine[borgwarner] new for 350 + shipping.
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Aug 18, 2007 | 11:31 PM
  #7  
Re: what's the minimum size turbo???
Quote: Got a T04B / H-P TRIM .84 ar turbine[borgwarner] new for 350 + shipping.
That would be a good unit. It amazes me how cheap BW can sell a quality turbo. I wonder where they are manufactured. For $200 more you can get a 1000 HP turbo.
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Aug 19, 2007 | 01:06 AM
  #8  
Re: what's the minimum size turbo???
Quote: That would be a good unit. It amazes me how cheap BW can sell a quality turbo. I wonder where they are manufactured. For $200 more you can get a 1000 HP turbo.
yes sir t6 fram s400 FTW...they make the t4 flange version now, but its $1100
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Aug 19, 2007 | 01:50 AM
  #9  
Re: what's the minimum size turbo???
Quote: yes sir t6 fram s400 FTW...they make the t4 flange version now, but its $1100
you kidding me? the PTE 71 gtq im saving for is 1500.
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Aug 19, 2007 | 01:58 AM
  #10  
Re: what's the minimum size turbo???
gt 67 was enough to put an Ls1 in the 10s
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Aug 19, 2007 | 06:38 AM
  #11  
Re: what's the minimum size turbo???
Quote: yes sir t6 fram s400 FTW...they make the t4 flange version now, but its $1100
I don't see a T4 being all that useful on a V8 unless the turbo was installed only to make 500 - 600 HP. Maxing out that compressor requires the big turbine housing to keep exhaust back pressure in check. Using the T4 would require most of the energy dumped through the WG at the high end of the compressor potential.

The Garrett GT45 and GT47 series has a turbine wheel that is close in size to the standard S400 wheel. Looking at the turbine maps show that it can flow a lot more efficiently at the high end of the S400 compressor potential. Using something like the GT42 turbine wheel reduces the flow by a large amount. You can get the S400 with the smaller wheel like the GT42 for under $600. I wouldn't go any smaller than that for a V8. I wouldn't even think about a T4 frame using that big of a compressor.
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Aug 19, 2007 | 06:45 AM
  #12  
Re: what's the minimum size turbo???
Quote: gt 67 was enough to put an Ls1 in the 10s
Many turbos will put an LS1 in the 10s. They range in price from free to $2000. The BW units seem to be a better buy than the PTE stuff.
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Aug 19, 2007 | 07:58 PM
  #13  
Re: what's the minimum size turbo???
Quote: That would be a good unit. It amazes me how cheap BW can sell a quality turbo. I wonder where they are manufactured. For $200 more you can get a 1000 HP turbo.
Borgwarner packaged a Schwitzer to4b / masterpower turbine and it appears to be a high quality unit.
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Aug 19, 2007 | 08:09 PM
  #14  
Re: what's the minimum size turbo???
Quote: For what it is worth, I put a small set of T3s on a 305ci. 45 trim compressor, .48 A/R turbines on both banks.
How did that work out?
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Aug 20, 2007 | 12:34 AM
  #15  
Re: what's the minimum size turbo???
Quote: How did that work out?
I am not sure yet. I backed the rig out of the garage and did the exhaust heat cycle to cure the paint and check for leaks today. It is the first time it has been out of the garage in almost 2 years.

After everything looked OK, I took it for short ride with the 4 gallons of 2 year old 87 octane which is probably 80 - 85 octane by now. I rolled on the throttle and it started to ping so I backed out. It looks like boost was coming in at around 2000 RPM.

I have some body work to finish up and plan to get it inspected by the end of the week. I will post more in the thread I started years ago for the build. The plan is to tune it running 87 octane full time and add alky under boost. Not sure if I can get there with it, but I am going to try. It is a stock 305ci with 9.3:1 or 9.5:1. I forget which it is........
The goal is to run 87 octane and 12 PSI of boost for about 350 - 400HP. The lower RPM torque is what I am really after.
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