Question for those of you running the BEP .55 housing on HX-40's

[turboglenn]

Just wondering how restrictive you guys ar finding the .55 housing to be and also what kind of HP numbers have been seen using it. And lastly how much of a difference in spool it's making in comparison to some of the factory holset housings?

it just seems to me that a .55 housing would be majorly restrictive to a turbo this large but then agian the DSM community has seemed to embrace the concept of choking the hell out of a large compressor wheel with a tiny turbine to utilise the large compressor wheel early on in the RPM range as well as cancel out the poor flowing exhaust energy (or lack there of) that our heads are known for (some days i really do wish i had build a honda engine, their head design is so superior to ours it shames me at times when i am doing work on a customer car that can spool the same turbo as a DSM but only 1500 RPM or more earlier

Also, with my question about the .55 housing, i just canm't stop thinking about how bad that has to be choking that compressor. On my old 57 that i ran for 10 years and experienced in a fe different configurations, i had both .48AR and .63 AR turbine housings and when i finally had perfected my setup and was working to extract more top end the change from the .48 to the .63 was VERY VERY notable and made 42 hp difference in the end. On the .48 i bested a 396hp, and when i went to the .63 (with a few other VERY minor changes including some cam timing adjustment) I moved up to 438hp and 396 became my torque number , spool was only offset by about 500RPM or so, but the overall feel of the car was much better, power pulled to a higher RPM and as stated improved nicely.

So, your thoughts, dyno numbers and experiences would be apreciated

 

[kp116]

It is very restrictive but I loved my bolt-on hx40 set up. The only dyno number I have is when it made 470whp on 32psi and on a mustang dyno. That same day it trapped 129mph in a 3150lb car. It trapped a best of 134.6mph having some ignition break up issues in 4th. When it was first on the my car I had a stock intake and BC 272's and with that set up it seemed to work very well. I did later put on a jmf smim and kelfords 272 and it ran worse. Makes sense, sense with the stock intake and bc's it had awesome midrange and worked well with the small housing. With the smim and bigger kelfords those wanted to the set up to breath better up top but the small .55 a/r housing was choking up top. I never got to the dyno with higher boost levels but I am sure it would have mad somewhere around mid 500's I would think on a dynojet.