Turbine size?

[XLR8ING]

Hey guys,
A buddy of mine has a T04B with a 0.48 turbine and 0.60 compressor, and similar 3.1 MPFI engine to mine
Is the 0.48 turbine too small for a modded 3.1?
I'm afraid he's gonna choke the engine, or worse, get boost spikes.
I'm not super knowledgable on turbos, so anyone got any ideas? What turbine a/r are you guys running?
Thanks!

[rickykline]

that is really small.... im running a 63 ar and im getting full boost around 2800-2900 rpm.... with a 3400 granted..

[TurboZ24]

T04B with a 0.48 turbine

Is this a T04 turbine section? Or just a .48 T3 turbine section?

[XLR8ING]

It's a T3 turbine, with a T04B cold side.
We were thinking of switching to a 0.63 hot side, and excuse my ignorance, but can it be used with the same turbine wheel? The wheel it's got seems to be a 77 trim if my calculations are right. The turbine wheel measures 1.91" exducer x 2.18" inducer.
Has the 0.63 hot side got a bigger exhaust hole that will make it too big for the wheel it's got now? Or is that a good thing? Help not choke the engine?

And Ricky, how's the 38mm wastegate work? Again, in a worry about him choking the engine, we kinda figured on over 40mm to be safe.
Thanks guys!

[TurboZ24]

I actually run a .48 A/R stage 2 turbine on my 3.1's with a compresor that's roughly the same as the T04B S1/S2. That turbo will be fine for a slightly modded 3.1, stock compression, mild turbo cam, a little head work. It did 230 wheel HP at 6 psi, not to bad for basically a stock 3.1.

The A/R of the housing is the actual housing, it doens't affect the turbine wheel. You can swap A/R's, so long as the housing was intended for the same wheel (turbonetics uses stage 1-5 on the T3. A current "base" garrett T3 is a stage 3.)

[XLR8ING]

Really? I knew you had a different set up years ago, but didn't realize it was that small.
This one is very similar, just a T04B V1/V2 style compressor.
I understand the A/R is the housing, so if we wanted to swap turbine housings, we'd just have to make sure the inside wheel area matched, correct?
Thanks Curtis!

[TurboZ24]

The turbo on the built 3.1 was a T4 .7 A/R P trim turbine with a 60-1 compressor. IT would do 500-600 Crank HP.

This is the turbo I currently run on the pretty much stock 3.1 that is in the Cav now. Built motor is getting 2 turbo's like your buddy has.

[Guest]

my buddy has a .63 a/r t3 housing on his 3.1 and has full boost of 7 psi by 2500 rpm. Its a T4 cold side too. But an E not a B so even bigger.

[XLR8ING]

By 2500 rpm huh? What rpm does the turbo run out of steam?

Curtis, how fast did the 0.48 turbine spool? I'm assuming it was quick, but did it run out of steam too soon? Was it too much bottom end torque to be streetable? Do you know which turbine wheel you were using on it? Other than the measurements I listed earlier, we've got no info on the turbine wheel.

I was talking to Herman at Cherryturbos.com today. He's local to me, and he says even if he uses a 0.63 turbine housing, the same amount of air is going through the same wheel, and the wheel he's got will still be too restrictrive for a 3.1 engine. It'll spool a slight bit later, but that's all.
His solution is to clip the turbine wheel to relieve some of the restriction, stay with the 0.48 housing, and use an internal wastegate.
But of course then it's gotta be rebuilt and balanced all again. Cherry Turbos has already balanced this turbo with the previous owner.
Money is the issue with that since the cost would be double that of a bigger wastegate to help deal with the restrictive turbine.

I know now why I've stayed away from turbos for so long. My brain hurts!!
I've posted a couple of pics we took when we took it apart.

Thanks again for the helps guys!

[Guest]

Stay away from cherry turbos. I don't know if the guy knows what he is talking about or not. He recommended a T3 based turbo for a N star. PBJ put it on his n star fiero. No idea on how much power he made, but he blew the motor up on 4 psi of boost. It was a hot air machine is all it was. I think teh famous quote was "torque inducing multiplier" Or something like that. Yea I knwo makes no snese.

The turbo my buddy has even with the T3 exhaust housing can support upwards of 600 hp. Proven on Hondas. So it wont' be running out of steam anytime soon. He dynoed it. It pulls all the way to 6k rpm. Like I said, its a E based turbo, not a B. Big difference, even with the exh wheels.

Here is te difference. B style turbo on left, and his E style on the right.

[rickykline]

i dont see a .48 ar flowing enough to produce high hp numbers... i just dont see it flowing the enough volume to keep from being a restriction...

[TurboZ24]

"Curtis, how fast did the 0.48 turbine spool? I'm assuming it was quick, but did it run out of steam too soon? Was it too much bottom end torque to be streetable? Do you know which turbine wheel you were using on it? Other than the measurements I listed earlier, we've got no info on the turbine wheel."

The .48 spools pretty fast, probably 2000-2200 rpm it will hit a decent level of boost. As for does it "crap out", peak HP on this mostly stock 3.1 was delivered at 5600 rpm, so I don't think that's bad at all.

It has a stage 2 turbine wheel. It's very fun to drive and very streetable, not uncontrollable like mine was.

So, 229 wheel HP and 262 wheel ft lbs @ 6 psi, stock 3.1, hyper pistons, mild head work, mild turbo cam, that's it. I fully expect 270-280 wheel HP at 10-12 psi, which is as much as I ever intended to run on it.

"high HP" and FWD really don't go together well.

[XLR8ING]

Thanks for all the help guys.
We've been talking, and since budget is an issue, I'll likely bolt this one on his car for now with a 50mm wastegate, and see how it goes.
I believe this turbine wheel would be considered stage 1. But again, no real info on it.

He's not planning on running a ton of boost, 6-8 psi roughly. So he'll need to make sure he can "bleed" off enough exhaust with a bigger wastegate.

Ricky, doesn't the housing really just control boost/rpm onset?
As I see it, the size and shape of the wheel, and size of the exhaust hole in the housing determines how restrictrive a turbine would be. For example, the picture Shaun posted of the T3 turbine looks much more free flowing than mine, simply because of blade shape and spacing. It may also have a different size exhaust hole, but I'm not sure.

Thanks again guys!!

[nocutt]

Thanks for all the help guys.
We've been talking, and since budget is an issue, I'll likely bolt this one on his car for now with a 50mm wastegate, and see how it goes.
I believe this turbine wheel would be considered stage 1. But again, no real info on it.

He's not planning on running a ton of boost, 6-8 psi roughly. So he'll need to make sure he can "bleed" off enough exhaust with a bigger wastegate.

Ricky, doesn't the housing really just control boost/rpm onset?
As I see it, the size and shape of the wheel, and size of the exhaust hole in the housing determines how restrictrive a turbine would be. For example, the picture Shaun posted of the T3 turbine looks much more free flowing than mine, simply because of blade shape and spacing. It may also have a different size exhaust hole, but I'm not sure.

Thanks again guys!!

You are absolutely correct...the characteristics of the wheel is also critical, not just the housing, size etc. If you are on a budget, then go ahead and clip the wheel as long as this outfit a.) knows what there are doing, b.) you do not push lots of boost...in the end you will still do better with a bigger housing and a less 'restrictive wheel'...
also one cannot trully compare boost onset in relation to said housing...quite tricky...

[XLR8ING]

That's exactly what I was thinking.

I just find it funny how there's so much info out there on sizing compressors for a particular engine, but next to nothing for turbine sizing.
I realize the compressor size is maybe more important, but come on!