Turbo experts: need some input.

Zack

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Im starting to gather parts for my upcoming turbo project.

Problem is, I have no idea how to properly select the correct A/R.
Im definitely using a 76mm precision (or comp) billet wheel turbo.
Both sides will be 2.5" piping merged together, and a 4" downpipe.
Then it will split into the stock dual exhaust.

Since its a 4500lb car, I was thinking the .82 A/R is what I should go with, but then I heard I may have backpressure issues at the top end.
Since im totally clueless, any advice is appreciated.
 

Yaj Yak

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I would almost have posted this in a general car thread because this irks a lot more towards turbo knowledge than direct Marauder know how. Especially because there are so many turbo guys on the site that are so knowledgeable that may not see this here.
 

Yaj Yak

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Ps I currently have a boner over the thought of a turbo Marauder. That is all
 

1MEANGT

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A lot depends on how much power you want to make? Also how fast you want the turbo to spool. Plus there are way more factors, compressor maps, ect. But that is getting deep into it.

I run a .96 AR on my Precision 78mm. Spools fast and makes awesome power. Pulls hard all the way through the top end and I see full boost at about 3500 RPM. Though I have more cubes which makes a difference.

What are you looking to do with this setup?
 

Zack

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I drive the car everywhere, and the engine is already built with 9.5:1 compression.
Also, the fuel system is setup for big power already.

So, I just need to make 12-13psi on 93 then turn it up when I put E85 in it.

Nothing fancy, just want a turbo...bad.

Oh, Im not after a power number, I already know it will make a lot. LOL
 

Jon01

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Does the motor have stock cams?
What converter?
281"?
Why fuck around with E85? Put meth on that bitch and have ludicrous speed available whenever you want it.
 

Zack

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Does the motor have stock cams?
What converter?
281"?
Why fuck around with E85? Put meth on that bitch and have ludicrous speed available whenever you want it.
I cant stand extra tanks, lines, pumps etc.
That is one the main reasons for going turbo.
 

Jon01

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How about all the other info I asked about?
 

1quick

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Yeah it's not really all that close, I just punched the info from my car and it said I'd need a 93mm turbo at 34 psi to make 600 at the crank, but I run a 67mm at 17 to make that
 

Zack

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How about all the other info I asked about?
4.6, stock cams/heads.

I will have a good converter for the build....not sure of stall though.

Im not looking to set records, just have some serious fun.
 

Jon01

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My $.02, I'd stick with the 82 for a street beater. It'll spool instantly with a good converter and make enough power to get things done nicely.
 

hotford

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Zack give Harry a call at Percesion Tubro, he'll have the turbo you need and all the info that will require to go with it.
 

1MEANGT

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The .82 A/R will more then likely work out perfect for what you want to do. If it becomes a restriction then just swap it out to a .96 housing.

Precision told me the smallest turbo I should go with is a 88mm. Which is probably true on my combo but my 78 works perfect and is awesome on the street. Does not take long to spool at all and easily got me to where I want to be for now.
 

Spoolin D Dub

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Im starting to gather parts for my upcoming turbo project.

Problem is, I have no idea how to properly select the correct A/R.
Im definitely using a 76mm precision (or comp) billet wheel turbo.
Both sides will be 2.5" piping merged together, and a 4" downpipe.
Then it will split into the stock dual exhaust.

Since its a 4500lb car, I was thinking the .82 A/R is what I should go with, but then I heard I may have backpressure issues at the top end.
Since im totally clueless, any advice is appreciated.
what size motor do you have?
 

Eagle

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Call your preferred turbo vendor and ask them to spec a turbo for your application. Best advise that anyone could give you. I bought from precision and they were VERY helpful in helping me select the correct turbo.
 

Pressure Ratio

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The .82 A/R will more then likely work out perfect for what you want to do. If it becomes a restriction then just swap it out to a .96 housing.

Precision told me the smallest turbo I should go with is a 88mm. Which is probably true on my combo but my 78 works perfect and is awesome on the street. Does not take long to spool at all and easily got me to where I want to be for now.
Did you order a 88mm for a winter upgrade yet? Lol
 

Pressure Ratio

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Mike needs a 91 or 94 mm turbo. He has a way better motor than I do.





Op, twins are easier to package usually. And usually better suited for a street car. Better boost response and such. But call a pro for recommendations for sure. There is A LIT that goes into picking a correct turbo for a combo.
 

1MEANGT

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Mike needs a 91 or 94 mm turbo. He has a way better motor than I do.





Op, twins are easier to package usually. And usually better suited for a street car. Better boost response and such. But call a pro for recommendations for sure. There is A LIT that goes into picking a correct turbo for a combo.
Would need to re-do the hotside of my kit to put an 88 on it. And how do I have a way better motor then you..........lol

I love my 78 on the street. Sees boost almost instantly when I nail it and I have plenty of power with room to grow. Besides, it is a street car. :smile:
 

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