not sure what type of turbo I have, any help

[87GN 98GTP]

I have what i was told was a pt67 with .63 exhaust housing and says .70 on compressor side, however im at 25lbs and only at 575whp, sure I can add more timing to get 600ish but starting to doubt its a 67 trim with that type of power with the setup in my signature. I looked at what i can see on the turbo with it on the car and nothing else says anything besides what i wrote to begin with..any clues

 

[hungerbuhler1]

Sounds like a Match.com date. You don't know what it is until you see pictures. Even then its sometimes unknown. Really need measurements to see her size

 

[bison]

Only 575whp@25psi? I don't see anything in your sig that would make your engine swallow more than 65lbs/min @25psi. You're about right where you should be @ 25psi. You could run a larger turbo and will still be within a few whp at the same boost.


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[87GN 98GTP]

but i thought a 67 would make 650-700whp? and my cam is a hydro 224/224

 

[bison]

but i thought a 67 would make 650-700whp? and my cam is a hydro 224/224

It will if the engine has the supporting parts. Turbos support mass flow. They don' just make power. With boost in the 29-30psi range id expect 675-690whp or about 80 lbs/min. It takes a lot to take advantage of even a non aggressive 224@.050 cam. It's possible you may be hitting some backpressure if you have a standard p trim ex wheel. Also lobe separation plays a role in backpressure and peak hp numbers


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[87GN 98GTP]

Ok. Well it's a very aggressive 224 from the cam company. You really think with a .63 exhaust side I'd make 100whp more?? And back pressure on wheel no clue. My tuner seems to think more on the turbo side plus the .63 exhaust side... Your. Thoughts bison


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[87GN 98GTP]

And I should have every supporting mod practically that is


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[bison]

You can't run a .63 ex. Too get the most flow out of a 76 p trim 65mm turbine it needs to be clipped and run with the largest a/r possible. In your case a .82-.85 a/r if running a 3 bolt. Look at the map for a T04Z compressor. It will show you what to expect out of that compressor. When you say very aggressive on the cam there's only two hyd lobes that comes to mind and are 8 sec lobes. If it is that lobe you need a lot more turbo to take advantage of its potential. Backpressure needs to be kept around 1.5:1 or lower or it will choke power at high rpm. You need backpressure data to know for sure what backpressure is. We can guess its fairly high if un-clipped ex wheel and lobe separation is 110-112 but we can't say for sure. With clipped p wheel I've seen 77-80lbs/min(700whp) myself so I know its possible. The engine was a 9:1 stock stroke with a 218/218 xfi cam and the lobe separation i used wasn't ideal because the turbine needed to be larger than 65mm. The engine was built for a 68mm turbine. It had quite a bit of backpressure.


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[87GN 98GTP]

Well my turbo is exhaust side .63. So should/can swap out just that part of the turbo maybe??


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[bison]

Well my turbo is exhaust side .63. So should/can swap out just that part of the turbo maybe??


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I'd consider swapping it out but I wouldn't bother unless the ex wheel is clipped, post pic of ex wheel.


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[87GN 98GTP]

Ok I don't have a pic unless u want 1 on the car. What do u mean clipped?


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[bison]

Post a pic of the ex wheel


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[87GN 98GTP]

Wouldn't I need to remove the turbo? Not sure if I'm comfortable doing that


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