ghettofabteg

i have a t3 turbo from a saab on my 92 integra 1.8L. turbine is .48, compressor is .43.

i'm experiencing some upper rpm choke and i was wondering if i can grind the turbine housing, making the clearance between the wheel and housing larger instead of clipping the wheel.

in theory it would slow the spool rate and add some lag, but would allow me to boost through higher rpms. also would be better because your not making the wheel smaller, but still making the clearance bigger allowing more air past the wheel.

i'm also gonna be putting a 57 trim compressor and housing onto the turbo, would this slow spool any?

BoostGear

First off, it's probably a bad idea to hand grind anything like this unless your steady... Please note if you grind or machine like Micheal J. Fox playing Jenga, step away and put the die grinder down!

Secondly, you can slightly port and heavily polish the turbine housing entry volute to help with spool and cast iron will shine like a mirror with enough time and love.

Lastly, On some turbo's you can machine a bell mouth exit away from the turbine wheel which helps to reduce back pressure around the turbine wheel. I have never done this using to much "free hand". You can see on this Mitsubishi Evo III 16G that some one has "ported" the turbine outlet after the exhaust wheel and did an OK job at polishing it. Another 20 minutes of polishing and this would have looked a lot better but it is not my work so I can't comment on who did it. That might help you.



My opinion has always been to think about efficiency across the system, and the faster you can get the exhaust gas in and out of the turbo, the better. If you are going this far, please also note that a small O2 Housing or a 2" press bent muffler shop downpipe are not helping your cause. This also goes into the theory of running a cat (dumb unless you have too) and a muffler that is restrictive.

Here is another google image find where if they spent another 20 minutes polishing the porting job they did they would see great benefits. NOTE: Take the turbine housing OFF the damn center section if you are going to port it... I am hoping this guy did

ghettofabteg

thanks, this definately answers my question. i've been trying to search in forums for it and didn't come up with anything. exhaust is 2.5" mandrel bent from the turbo back with a ebay high flow cat and high flow magnaflow resonator and muffler.

i definately am gonna take the turbo apart cause i'm swapping a ar .50 57 trim compressor housing on the oil/watercooled t3 center. the .48 turbine im hoping will be ok once i'm finished, now i'm fully boosted at 12psi by 2700rpms and i shift at about 7000 (redline is 7600). the turbo seems to "choke" or "fall off" at about 5500 so i need another 1500rpm or so am i'm willing to accept a little more lag, maybe it'll help with traction.

also, i have a BIG stage 5 t3/t4 t04 p trim turbo that is a ar .57 50 trim compressor and a ar .84 76trim turbine good for 600hp. i had that on there for a few months but it hit 5psi at about 5k so it's a little slow, that one i ported myself cause it was a divided flange turbine inlet and my manifold is not divided. yes i know to take the housing off and did, i actually have a friend who machines all his dirtbikes and quads and he "mirror finishes" all his ports and gets amazing results, i usually make him do all my porting work!!

i recently made a block off plate to block 1 of the 2 ports making all the exhaust enter the giant turbine housing through one smaller hole. its made from a space that goes between the turbo and manifold so i can spin it to choose if i want the exhaust to flow from the verry back of the wheel all the way past it or if i want it to just hit the edge of the wheel. not sure which would work better but it's experimental!!

BoostGear

So your second turbo is just a standard divided turbine housing or is it a variable vein turbine housing from a diesel style setup that is controlled by oil pressure or an electronic actuator? Just wondering.

I don't believe blocking off one side of the turbine housing will benefit you much because you have to think about the turbine wheel like the pin wheels little kids blow on. If you blow in the wrong spot, it doesn't spin or might lazily spin, however if you blow in the sweet spot, it takes off and sustains high speed... This is why making sure the volute of the turbine housing is hitting the sweet spot of the turbine wheel and flowing as smoothly as possible is crucial to efficiency.

njxfallsxin

hey i got the same year integra can you post up some pics of your set up?