Hi everyone,

I'm in the process of selecting a turbo for my 20b setup. My goal is to have a power potential of 850rwhp with a likely street use of 600hp.

As of now the setup is looking like the following:
-D series block
-street port or potentially half-bridge (depending on if I decide to be a bonehead)
-upgraded tensile strength OEM sized studs
-steel T2 flywheel
-microtech ltx12 and ls6 coils
-2000cc secondary injectors, twin walbro 400's, and 1000cc water/meth injection

My goal is to make as much power as possible on the lowest reasonable boost level. I do not care about spool as long as I can get full boost by ~5k. I'm not sure how the 20b responds, hence the reason I'm posting here.


So, it seems that an s480 will deliver enough CFM to meet my horsepower goals. I think in the past I saw a member make over 800rwhp with a similar setup at around 25psi. He was running the 1.32AR T6 exhaust housing and full size compressor cover (3.5 inch outlet)

Obviously the above turbo works, but how about an s480 CHRA inside a 1.1-1.2ar T4 rear and a compact cover from an s410. This turbo would still have a 5in inlet and 5in exhaust outlet, but it would have a much easier to work with 2.5 compressor outlet for the intercooler piping along with a quicker spooling t4 flange. I do not plan to rev over 8k so a 1.32ar may not be necessary.

Do you guys think this idea would be too restrictive to reach the power goals?

 

T4 is fine for 800whp.

You will have to look at turbine maps to determine the correct A/R (or guess)

that said, all things the same, a T6 housing will make a little more power at the same boost as a T4.

 

I'm going to take a look at the compressor maps. However, tentatively, I'm thinking a 1.25 T4 housing and a 2.5 outlet smaller frame compressor housing will be fine for now

Thanks!

 

Talk with Reed He willMI say 100mm. Semi p port on Alky and call it a day!

 

You are both insane.

 

Went with the S480 t4 1.15 78/87 turbine, 80mm compressor billet wheel inside a smaller frame 5in inlet compressor housing with 2.5in outlet. We'll see how it performs.

Thanks for the help.

 

How do you put a smaller compressor housing on? Do you get it machined to fit?

 

Yes, it was machined for the 80mm wheel.

 

i have this borgwarner t6 for sale,
used but excellent condition
the only problem is the rear exhaust housing needs to be replaced or repaired where the wastegate pipe is welded there's a hairline-crack.
new exh housings ar about $100 on ebay.
asking $500 +shipping!

 

pic of turbo
Located in Reno, Nevada.

 

and a link to the exact car this was in, exact same turbo and everything, was bridgeported and made 498 RWHP at only 12 psi!

 

What are the specs of the turbo?