does anyone know the size of the turbo's that they ran on these kit 550hp kit

 

S257 and S366 I do believe. The 366 has a t-4 flange and a bigger housing, but is essentially a silver bullet.

 

i am just wanting to find something i can find a turbo off a big small truck to work for my big turbo on my twins just need to figure out what i can pull it off of

 

which truck is getting the twins??

 

Look for turbos off of a 13-15L engine, that should be a ball park size. If you can get a K31, you'll be laughing. Quick spool, waste gated and will easily go to 550+ hp.

 

I do have a spare K-31 available. Its not a small turbo. I would put it into the 600rwhp plus area. The biggest S200 series turbo compressor impeller is 56mm (turbine 68mm, A/R 1.22) that I have on my Borg Warner sheet. A S300 with a 58mm inducer would be a good choice as well. The S200 is rated at 58lbs/min and the S300 is rated at 65 lbs/min. The S200 is slightly bigger than stock and the S300 would be slightly bigger than the S200. The K-31 is almost the same size as the BTH-3B. IMO a S475 is a better choice than either one, first for price and spool-up. The K-31 has a pretty big turbine housing and that darn wastegate costs extra $$$. Sitting on the bench, the S475 spins easier.

Tater's 4202R turbo will be about as fast as you could get for a nice sized twin primary.

 

BD doesn't really use the common terms to describe their turbo's. (eg, 62/12). They prefer to describe the turbo's using CFM and A/R ratio.

Here is a reply from Piers Harry who now works at BD Diesel in Abbottsford, B.C.

Piers:

"There are a couple of options, but I'll give you the skinny on various models

Super B = 57.1mm inducer wheel, flows 870cfm
Super B Special = 64.5mm inducer, flows 1160 cfm
R700 primary = 71.1mm inducer, flows 1370cfm
R850 Primary = 74.6 mm inducer, flows 1552cfm"


You can see how small the Super B really is. The Super B is the secondary (top) turbo on the BD Towing Twins & the BD R700 Twins.

There are numerous used turbos & twins kit for sale but the frigging low Canadian dollars makes it tough.

...Joe

 

turbo guys...........

New holset HX55 nonwastegated non VGT. off a new detroit DD15, can you check out my post in the 2nd gen performance section. any input is welcome.


now when we talk inducer wheel/ compressor wheel size if I stick my digital calipers to the open fins in the inlet is that the measurement people talk about as in 62mm 64 or 66? how about turbine same thing I imagine?

 

Joe, any word on the exhaust A/R's and the size of the primary on the small set of twins?

Luke, the inducer is the compressor inlet, as you figured.

 

Ok, I am no expert by any means on turbo's but I have been gathering info on the BD Twins kits.

BD Towing twins:

57/65/14 0.80AR S300 (60lbs/min) over a
66/71/14 1.10AR S300 (80lbs/min).


The BD R700 twin's:

Same secondary (top) turbo as the towing twins.
A larger primary (bottom) turbo: S400 71mm.

 

Thats common borg warner stuff. They match-up with the list of turbos that I can get. I didn't know that a super B was that small. Usually the first number is the inducer size and the second is the turbine size. The third number is turbine housing size. The A/R is a better term for both the size of the compressor housing and turbine housing. Its a ratio of the housing area divided by based off the radius of the impeller or turbine. The R700 and R800 area just the S471 or the S475, both common and cheap primarys.

I have a garrett VNT 4088. It has a large compressor housing and large turbine housing. The compressor inducer is around the 62mm size. You can't rotate the housing at all and are fixed. It will make a nice garage trophy, but that about it. It using oil pressure and a soleniod to move the variable guide vanes. Tate and I had it torn down last month. Its new as well. Its off a IH477 engine. I was gonna use as a big single, but not with a 62 inducer. To small of compressor to really wake the truck up to live with the laggy spool-up.