This is before making more clearance... Had to cut about an inch for the dam compressor and turbine. More for the compressor I think.


Post BFH

 

Looks like i'm going to be breaking out the bfg and dremmel again. Seeing your turbo, i'm thinking about whether i should go with a gt3271.

 

This turbo is cheaper. It's a journal bearing T3, twin scroll, .78 hotside, 72 trim compressor I think. (I thought it was a 52 trim, looking up specs...)

EDIT: 71mm compressor wheel. Hence GT3271

 

So its a GT but not ball bearing?

 

Si.

TurboByGarrett.com - Catalog

 

I drive my buddies' 600 hp Lightning on occasion - 4 speed auto tranny and that thing absolutely rips. Best part of the auto in that thing is you can be sipping your energy drink with one hand while laying waste to a 600cc super sport bike, no problem. For the miata, don't know if I'd ever want an auto - this car is all about the driving experience.. but if I ever owned a 'dyno queen' built for the highways I would be all about a built auto.

-Ryan

 

Do yourself a favor and buy one of these:

Angle Grinder

Get a cutting wheel and a grinding wheel. Don't mess with a friggin dremel to do the engine bay mods. Every swap guy needs to cut the ears out of the engine bay and widen the engine bay. This is what we use. I have a B&D from walmart, but they're all good enough.

Pat,
You do realize you're losing power with the filter right off the compressor housing, right? I watched a before and after dyno session on a 600+whp DSM where the owner was testing intakes and intake positions and he baselined with the filter right off the compressor. After he moved it forward a foot and built a small shield to stop it from sucking in turbine heat he picked up mid 20s whp.

Frank

 

What about going with an air:water intercooler and a big "ice bucket" vs. an air:air if you're doing drag racing? That seems like an easy way to keep the air temp down and make some more power.

I think the majority on the forum are missing out on some free power because of this... including me. Isolated intake air box ftw.

 

He's built a cold air box since those pics were taken.

 

I see. So i guess that gt32 is actually smaller than the turbo that i am considering?

 

This is gonna be good

 

Post rebuild pics after the...um...temporary 400hp


Good luck mayyynnn!!!

 

Haha, I will be building a motor at the same time so i will document that process as well

 

I see there are several variations on the GT30. Some are bigger, some are smaller, and that varies with the A/R of the turbine selected. With my GT3271, the compressor and turbine are very well matched. I follow that dotted line that goes right up the middle of the island almost exactly with my setup.

 

I think it can be done with out the front mount wess. 50/50!! please experiment with the real **** and find a medium of cooling and octane dont pigeon hole your self to one mix.

 

Haha, i already have a front-mount and all the piping. I will just have to get a bigger one. It would take quite a large amount of water to make that power without an intercooler. However, it would be pretty awesome if i could manage to make the power without it. People around here would take water injection a bit more seriously imho.

 

Ok, I've been thinking about my turbo choice dilemma. At this point, I am leaning more towards a gt2876. It will flow about 48lb/min. That should put me where I need to be. Also, it will probably spool faster than the 3076.

However, I was wondering which exhaust A/R to go with. I guess I don't fully understand how to decide. I would like to go with the .64 if it will flow what I need to. Also, this will let me keep the t25 flange and internal gate therefore keeping my manifold and downpipe.

 

You need to do more research before you go picking a turbo. 100% decide on an ultimate power goal and go from there.

That turbo map might peak to the right at 48 lb/min running exactly 2.5 bar, but.... Odds are, you'll never get in that region of the map. You have to do the math and calculate what your PR is at a given flow, and see where you end up.

I'm gonna find a badass site and post the link in a sec.

ALSO: The turbine is the main thing that dictates how much power you make. See the efficiency plot on the compressor? Know what that really means? The compressor takes a certain amount of power to compress a given mass flow of air to a certain pressure ratio for a given mass flow rate. I could actually do the math if you want as we're doing this kinda stuff in thermo II right now.

But basically the more air you try to compress, the more you try to compress it, and the less efficient your comp is at a given point, the more power it takes. Again, the more power it takes... Keep thinking about that.

That power comes from the turbine. It's the boss. It makes the rules. If you need 30 HP to drive the compressor and the turbine is sized to do 22HP, you ain't gonna get 30.

Anyways, I'll find that link and post it in a sec.

 

Squirrel Performance - Turbo Calculator Version 4

 

480 flywheel hp = ~400whp
BSFC = .44
100*F AIT's
7500 RPM redline
2 PSI delta across IC
Full boost by 4K.
Boost onset at 2K.


GT3271





Everything the same, but 420 flywheel HP = ~350whp




440 fwhp/365whp