I have a Garrett 50 trim T3/TO4E at the moment and Im going to upgrade to a 57. Are the external dimensions practically the same? Basically, I have a hood exit downpipe and velocity stack intake want to know if I'm goin to have to re-fab them.

 

yes they are the same externally.

 

Yes they are both utilizing the .60 a/r compressor housing so exterior dimensions will be the same. 50-57 trim really isn't much of an upgrade. If your turbo is in good shape then I would personally leave it alone unless doing an actual upgrade to a larger turbo. The 50 trim and 57 trim are both going to get you to around 400-425 whp. Look below at comp maps both flow about 45-48lbs/min. Also the 50 trim is more efficient in the higher pressure ratios.

 

400 is the max I wish to achieve. Its a d16 vitara setup with bisimoto 2.4 cam. Its a fairly aggressive cam, so i wanted to take advantage of the bigger cam with more turbo. Right now the 50 trim i have is a .48 ar, so I think it'll run out of puff trying to rev this cam out to 400. The 57 would be a .63.

 

Just but a .63 housing for the 50 trim its cheaper. I mean you can do what you wish but both turbos are going to make the same power overall. The 50 trim should have a better powerband. And installing a .63 housing will help you out up top

 

You mean get just a compressor/exhaust housing? Sorry, I've never delved into swapping different parts around.

 

You will need to see what size exhaust wheel is on your current 50 trim... Some of the 50 trims had stage 2 turbine wheels, some had stage 3. This will determine what housing you need also. For 400hp you will want a stage 3 turbine wheel. If you do have a stage 3 wheel on your current turbo, just purchase a new .63 A/R housing, or a reputable shop can swap it out if you don't want to take it apart yourself. It's only a few bolts, not any harder than removal/install of the turbo itself.

On a D series, I would stay with the 50 trim, as it is WAY more efficient at the upper boost levels that it will take to make 400 on a SOHC.

 

Physically they all share the same dimensions, different turbine housings will change things like downpipe/charge pipe fitment but it's a negligible change.

 

It's DEFINITELY going to be in the "upper boost levels". I made 273hp/252tq on a stock head/intake/throttle body with boost cut set to 21 psi. (I kept it just under that, lol.) With the Bisi cam, and upgraded intake mani/throttle body, it'll be more efficient, but it's still a D-series head with about 7.6:1 compression with Vitaras if I remember correctly. So yeah, I'll be pushing the boost levels to get anywhere near 400.

I appreciate the info guys! Looking at the maps you can see a very noticeable difference. I guess I kinda had the mentality of: 57=higher number than 50=more turbo=more power.

 

You can't push the 50 trim much above the mid 20s are far as pressure goes. You'll be at the shaft spees limits of the turbo

Having a compression ratio that low is doing you no good and is actually making everything worse. You shouldve waited for custom length rods or gone with forged pistons. 10:1 is a much more efficient CR and you'll have more torque, power, efficiency and better turbo response. All at a lower boost level than what you're running now

Plus you'll get better fuel mileage and the car won't suck so bad to drive out of boost like it is now

 

Duly noted, thanks. Hopefully it'll make nice power without a lot of pressure thanks to the new cam/intake.
More power/tq is always nice, but if it makes what I want, it makes what I want. It isn't unpleasant out of boost at all the way it sits! I think this may be, in part, due to the fact that my car is lighter than most. (2155 with me in it.) I also have a pretty short tranny (91 SI) so that helps.

 

I figured you would have had a lot higher numbers than 275 at 20psi from a 50 trim...??I saw 375 at 24psi with stock head/cam d16z6 with vitaras and normal length rods. This was on a 60 trim, which was not as efficient as a 50
Trim at that boost level. I put down 250whp on a tiny greddy kit at 17psi....

 

I put down over 250 at 7psi lol ******* single cams

 

It's because he's running a compression ratio of 7.6:1, that's why it makes such poot numbers

It won't make what you want. Your out of turbo due to compression ratio

 

https://honda-tech.com/forums/forced-induction-16/d16-vitara-build-pump-gas-420whp-319tq-2740947/

This guy did it...

I guess I won't know til I get this cam back in and see what happens.

 

He barely did it, and he was over the efficiency point of that 57 trim.. No way that was 93 octane doing that on such a high reading dyno. He may be using E85 and calling it "pump gas" in an effort to impress others and his own ego and being technical about it.

Not hating on it, but I find that rather unrealistic

 

He said 92 octane on the original post. I'm not saying I'll get there with my setup. Like I said, it's all here-say until I actually get the car back together.

So theoretically if his car is 100% legit, the 50 trim would have been a better choice for him due to higher efficiency at that 25-26 psi range?

 

 

Don't know why anyone would use a 50 trim for over 20 psi the 57 will kick its ***

 

https://honda-tech.com/forums/forced-induction-16/s2000-60whp-log-mase-manifold-501whp-e85-2977167/

I made 501whp on my old 50 trim with e85@17psi. I now run a gtx3576r and am much happier.
Keep in mine this is on a stock s2000 engine with 11:1 compression.

When I had the 50 trim on my stock evo8 engine it also made 500whp on e85@30 psi of boost.

 

Regardless.. I call shenanigans. But in essence, overall the 50 trim would be a better choice from the 20-25psi range. Your specific amount of boost pressure may vary, but would still be within that range.

 

Actually, not really... The 50 trim's efficiency actually increases with boost pressure. Remember, the difference between the two is only about 2.6mmin the inducer for overall size, (They use the same exducer and turbine wheel), but the 50 trim has a better conversion rate at higher ratios.. (You might need to look at those maps carefully again )

 

Well, thanks for everyone's help. I've decided to get a .63 housing and see what it does. I'll post back whenever Bisi sends me my cam back.

 

When I re read a couple posts I realized. Both good units with lag haha