What about this sized compressor shell?

[Hit_N_Run-player]

Well in my great search for the perfect sized turbo i have come across this and was wondering if the sizing was too small...

The smallest part of the Inducer bore is 45mm, and the the compresser exducer (whatever you want to call it i suck on technical terms) the part where the air goes to your intake manifold is about 2inchs wide. Is this too small? i can get my hands on some other larger sizes but i want the turbo to spool fast and not be some huge beast, just for every day driving....

[Hit_N_Run-player]

oh yeah this is for the ka24de on a 92'

[nissanfanatic]

What'ya know? A 92 KA-T in the works?

AR on the housing? 2 inches is pretty common. I believe the SR's T25 use 1 7/8" outlet. My T04B has a 2" outlet. AR ratio ultimately determines how much power the turbocharger will support. The laggieness really depends on the wheel trim(s) and the turbine housing. You could run a huge compressor housing and a really small turbine housing and make big power along with pretty good spool times. That one doesn't look too bad. But focus on turbine ARs for spool times.

[Hit_N_Run-player]

What size should i be looking for on the a/r trim on the turbine housing? Tomorrow night when i go over to work with my dad ill look the through the turbo room at his companys shop and pick the one im looking for out... ahahaha i love having connections with free stuff..lol

[Hit_N_Run-player]

i did all the math to figure out the AR trim on this compresser housing and re-did all my measurements to make sure and came up with a .62 AR ratio. What turbine should i look for?

[nissanfanatic]

Well its kind of a ratio. For a general explanation, the bigger the compressor, the smaller turbine housing your going to want. You should read my turbo sizing write-up in the FAQ suggestion box and look at some compressor maps. If these turbochargers and parts exist at your dads company, then they should have spec sheets. IF you size the compressor correctly, then the turbine ARs are a cake-walk. Below .6ar is low end. .6ar-.7ar midrange. .7ar and above is high end. This is only if the compressor is sized correctly. If not, these are not accurate.

[Hit_N_Run-player]

spec sheets, why didnt i think of that. Ill look up the codes on the compresser housing and find out the exact trim..Thanks nissanfanatic, you've helped me alot lately!!

[nissanfanatic]

What kind of math did you do to come up with exact compressor housing ARs? The only formulas I ever found were flow formulas. They would just tell me how much air the engine would flow at a certian amount of boost. Then I just read the compressor maps. Please let me in on some info.

[Hit_N_Run-player]

I thought this was the right formulas so i did that...Its not the most accurate thing but it helps give me a good estimate i guess..lol I think i might ditch this housing though and find another one tomorrow..


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The turbine housing A/R (area/radius) ratio is the area (A) of any turbine inlet scroll cross-section divided by the distance from the center of that cross-section to the center of the turbine shaft (R). For any given turbine housing, A and R vary in the same proportions, so all As divided by their corresponding Rs yield the same dividend--which is the A/R ratio.

The R in A/R is the distance from the center of the cone's cross-section to the center of the turbine shaft. A smaller R imparts a higher rotating speed to the turbine; a larger R gives the turbine shaft greater torque to drive the compressor wheel (because the lever arm R is longer).

[Hit_N_Run-player]

oh and i got that info and formula from the FORCED INDUCTION forum in the TURBO tech 101 section...

[nissanfanatic]

Gotcha. I already knew that formula. I though you had some magic formula that would give you the exact size compressor housing for a certian engine or something.lol

[Hit_N_Run-player]

lol..i wish!!! save a lot of confusion throughout learning this stuff..

[nissanfanatic]

Its not too bad once you learn it. I have it practically memorized. I just used some of those forumulas in my article to size a carburetor for my dads 388CID SBC camaro. I like it this way. If it was easy, everyone would do it.