Twin Turbo Help...

MikeH686

Mine is only two inches though.
10 Year Member
Oct 11, 2011
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Waldorf, MD
So I have a good opportunity to buy two borg Warner s300 turbos for pretty dirt cheap and was wondering if you guys could help me out with the exhaust housing part. The specs on the turbo are as follows:


Exhaust wheel inducer 73 exducer 64

Compressor wheel 63 inducer. 92 exducer.

Exhaust housing AR is .48

I found online a .91 AR housing for this turbo that fits the exhaust wheel. My question is will this housing be too big for a twin setup?

347 8.5 looking to make 600 to the wheels on around 10 lb of boost.

Let me know what you guys think both turbos are brand new
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You sound like you could do some reading on theturboforums.com - they have a lot of resources that could help you learn about turbos.... except compressor maps. May as well be hieroglyphs.
 
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You don't like ever loving compressor maps? They remind me of psychometric charts lol I'm just wondering how this will act with such as higher AR on a twin setup Im afraid it will not be enough as a single setup but too much as a twin setup and that the turbos won't be at full potential as twins
 
.91 does seem a bit large for twins. I use a .96 on a single p trim... and it doesn't spool as fast as I anticipated. I'm afraid .91 twins would make running twins pointless. I haven't been doing this long, however so don't take my word as gospel. I second @hoopty5.0 . Hit the turbo forums and ask. There is more knowledge over there than you'll be able to take in weeks of reading..
 
my 2cents. Unless you have a complete kit I think twins are just more hassle than worth on a street car, more plumbing, more heat and less space. There are lots of guys making silly amount of power on cheap ebay turbos these days.
 
I don't see the more plumbing part I plan on using a set of pony down headers with these turbos and for the downpipe im doing a fender exit exhaust so the piping isn't going to be much I know the heat factor but I'll get the exhaust side all ceramic coated now for the cold side I'm still debating on whether or not to keep them seperate or Ying them together
 
I vote single . Once is enough to keep up with trust me my buddy had one we worked on. And i would run the exhaust under the car with an electric cut out. side exit is cool as :poo: but i bet it will get annoying on a street car.
 
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I vote single . Once is enough to keep up with trust me my buddy had one we worked on. And i would run the exhaust under the car with an electric cut out. side exit is cool as **** but i bet it will get annoying on a street car.
I was thinking the same thing. Especially with a 600 hp goal/street car.
 
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I vote single . Once is enough to keep up with trust me my buddy had one we worked on. And i would run the exhaust under the car with an electric cut out. side exit is cool as **** but i bet it will get annoying on a street car.

Yes they are annoying. A coworker of mine has his done that way, albeit he's now at around 1800 rwhp.. it is loud as heck with it in front of you going down the road. He didn't change to this configuration until he sized up to a 108mm single. He previously had an 88 mm single which he ran out the back and it did just fine. He prides himself on having a streetable car with that much hp, but admits he hates the exhaust noise.
 
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Now if I go single though I feel this turbo will be too small am I right? I will have to call borg Warner today to see what housings they offer because obviously the .48 is too small I will need something in the .65 to .70 range at least
 
Now if I go single though I feel this turbo will be too small am I right? I will have to call borg Warner today to see what housings they offer because obviously the .48 is too small I will need something in the .65 to .70 range at least

I believe you are right, but .70 may even be a bit small. I'd look and see what the "kit" companies spec out for a 5.0 liter single and go with that, provided you are at 5 liters still. if you are running a 347 or larger the .96 should do fine. Like I said, I have a .96 that spools a little slow(on a 302), but I plan on a 347 later..

edit: I have a .96 turbine, .80 compressor.

Hope this helps.
 
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I decided to decline on the offers of the twins and now gonna focus on going the single route I spent all weekend both researching turbos looking at maps which is monotonous let me tell you. I've talked to a few companies on what they recommend. Precision tells me to go with a pt7175. A dealer of borg Warner has given me the option of going with a s300sx3-66. I'm leaning towards the Borg Warner mainly because I can get it in a 90* compressor housing. The only reason I would want that is because I have smooth aprons and would want this to be as clean as possible. Get a set of headers where the turbo is on the drivers side. Hopefully I will only have to make one hole going into the bay for the piping after the intercooler. Here is a picture of the borg Warner now i don't know if precision offers this for theirs or not haven't dug that far yet.
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