Here is another test done by Larry at Sound Performance!! This is the Precision 6266BB vs the BW EFR8374.

As per Larry @ Sound:
""I tested these turbos on the same car. 3.4L 10-1 compression supra 2JZ. The BW spooled 70 RPMs faster than the PTE but was down almost 40 RWHP. Precision Turbo 6266DBB is a much better option and when you consider that the list price on the BW is $1100 more than the PTE, it is a no brainer!

Great job guys! I always knew I was selling the best and finally had my chance to prove to the world that I was.





...The BW turbo was a divided turbo on a divided twin scroll header. The PTE was an undivided turbo!...

...Air temps were 65 at the beginning of the pulls and 130 at the end of the 6266 pull. On the BW the air temps hit 136. Not a huge difference. The EBP hit 64 on the 6266 and 69 on the BW. The 6266 had a .81 but I am not sure about the BW...

...both tests were with the same external WG although I pretty much had it clamped closed! I tried a .96 on the PTE and did not pick up any hp, only lag! We are clearly out of compressor wheel, not an EBP issue....

...BW Compressor 62.6/83mm, turbine is 74mm with 1.05 a/r divided housing. PTE is also 62mm compressor wheel, not sure on the other dimension. 66mm turbine wheel with .81 a/r undivided turbine housing...

 

thanks for posting. did the manifold have 1 ewg or 2?

 

does it matter when you're not really opening it (...or them)?

 

for spoolup on a twinscroll turbo, yes. ultimate power, no.

 

Wait so were they both tested on the same twin scroll header?(even though the pt was a single scroll housing)...

 

I think if you re-read this it does answer the question

 

me and friends had 3 BB precision turbos fail on us... smoking ets... and the service and support suck... the EFR we have runs great and one that failed was looked at and BW did give feedback.

Precision does make the power!