help with twins

Cummin2000

Cummin2000

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Jun 6, 2010
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Im new to this site but ive been on cumminsforum.com for over 2 years. I thought id try to get an answer on here since almost everybody here has twins.

Im currently running a s300 (62/65/12) with farmboysdiesel 150hp injectors and i want to go with twins asap. So help me pick a s400 to use as a bottom turbo. I bought the s300 from jacob kidd a couple months ago and its not enough air for the injectors.

Id also like to know who makes a cheap/decent 2/3 twins kit since i already have a top turbo.
 
i want it to be a good daily driver/sleeper. I dont tow much at all. I want to be able to use my truck everyday but if i see a race i wanna win.

i was told on the cumminsforum to look into a s473 or s475. I wanna know which one would work best with my current s300 and not be smokey or laggy.

and that would be awesome if i could get pointed in the direction of a twins kit for a decent price.
 
S475 is common to use.

My gf's CR has a 62/71/14 over a S471 with a 1.10 ar and spools wicked fast

Granted CR's are a different beast but but that little primary seems to due quite well.

Define "see a race" Like stop lights, freeway, drag?
 
yeah id say go the route of a s471 or s472 if you want a quick spooling setup. an s475 would be good as well, little more laggy but a real good setup
 
Turbine size is very important too. Most people forget about them and just size the compressor, a poor practice IMO.

I vote for a s471/83/1.1 or s475/83/1.1 depending on your use. I think the smaller turbine wheel and housing would serve your purpose better. $.02
 
would you guys happen to know the best place to buy a twins kit with a s400 turbo?
 
Cummin2000 said:
Im new to this site but ive been on cumminsforum.com for over 2 years. I thought id try to get an answer on here since almost everybody here has twins.

Im currently running a s300 (62/65/12) with farmboysdiesel 150hp injectors and i want to go with twins asap. So help me pick a s400 to use as a bottom turbo. I bought the s300 from jacob kidd a couple months ago and its not enough air for the injectors.

Id also like to know who makes a cheap/decent 2/3 twins kit since i already have a top turbo.
Click to expand...

I don't know much about the farm boy injectors, but a 62 should spool a set of 150's perfectly. Maybe the farm boys are just dirty.
 
ive read all over the farmboys injectors are just as good as ddp. There 7 hole edm'd injectors. The 62 is a smaller ex. housing though he recommended a 62/71/14 but i already had the 62/65/12 before the injectors so i want to keep it if i can
 
could i get more opinions on what to use for a bottom turbo?

Im thinking of going for the s475/83/1.1 right now. I dont mind lag as long as theres not a huge cloud of smoke. what i really want is a low smoke decently fast truck thats an awesome daily driver.
 
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hows this one sound?

Turbocharger Name - S400SX3
Compressor Wheel Inducer - 75mm
Turbine Wheel Inducer/exducer - 83/74
Turbine Outlet -4inch V-Band
Turbine Inlet - T-4
Turbine A/R - 1.10
Horsepower Rating - 450-1000
 
Thats a great choice for something with great spool up, but w/ the t4 foot and 83/74 exh. wheel, drive pressures will be an issue depending on how much your fueling, you might need a ext wastegate. Also having a t4 foot its harder to find pipe builders who use a t4 foot for their hot pipe, BD though is one.

People saying a 71mm over a 74mm inducer wheel, I doubt youd notice much different warrant going smaller, one these big 10 blade inducer s400 series turbo's the exhaust size plays a much bigger componet of spool up than the inducer wheel, IMO.

Cummin2000- Look at the s400 sx4 not the sx3, youll get the 74mm turbo with the big exhaust wheel (helps with drive pressure, but the 1.1 a/r housing which will give you much beter spool up.
 
bh10 said:
Thats a great choice for something with great spool up, but w/ the t4 foot and 83/74 exh. wheel, drive pressures will be an issue depending on how much your fueling, you might need a ext wastegate. Also having a t4 foot its harder to find pipe builders who use a t4 foot for their hot pipe, BD though is one.

People saying a 71mm over a 74mm inducer wheel, I doubt youd notice much different warrant going smaller, one these big 10 blade inducer s400 series turbo's the exhaust size plays a much bigger componet of spool up than the inducer wheel, IMO.

Cummin2000- Look at the s400 sx4 not the sx3, youll get the 74mm turbo with the big exhaust wheel (helps with drive pressure, but the 1.1 a/r housing which will give you much beter spool up.
Click to expand...


What are considering big? 96mm?


Also how do you know which S400's have 6,8, or 10 blades?
 
I guess really not that big compared to some 71-78mm.
 
80mm and up run an 8 blade IIRC, which is a laggy wheel.

I cant edit my first post, but I wasnt thinking about the number of blades, I was thinking exhaust blades not the inducer wheel, but is s474 is a 7 blade, somebody correct me if Im wrong, I ran a couple a while ago, and honestly forgot, I know my s480 is a 8 blade.
 
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bh10 said:
80mm and up run an 8 blade IIRC, which is a laggy wheel.

I cant edit my first post, but I wasnt thinking about the number of blades, I was thinking exhaust blades not the inducer wheel, but is s474 is a 7 blade, somebody correct me if Im wrong, I ran a couple a while ago, and honestly forgot, I know my s480 is a 8 blade.
Click to expand...



Thanks.

I was just wondering how chris had S478 with 6 blade.
 
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