bigger or smaller? turbo

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Jan 5, 2014 | 09:27 AM

#51

d-bo

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It would be more so that you're running more boost and progressively making less power per psi because either the wheel can't move that much air and keep up, or youre creating back pressure in the exhaust housing because the motor is putting out too much air that the turbo can't move quick enough. Which I think would just lead to boost creep

Jan 5, 2014 | 10:00 AM

#52

ScorpionT

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Quote:

Originally Posted by lude92_si

So from that I only see a wheel difference. But I'm not sure on the a/r sizes. Like I said I'm new to turbos and just going by what bullseye told me.

The S256 specs listed on the site are slightly incorrect. The compressor exducer is 76mm.

Quote:

Originally Posted by lude92_si

And both look to come in the t3 .70a/r so how would this hurt the efficiency scorpion? Just trying to understand all this.

The smaller housing is a choke point.

Quote:

Originally Posted by d-bo

fp Blacks and FP reds and FP zeros shouldn't work either in theory. You're pairing a huge wheel with a tiny exhaust wheel and housing but ppl still trap 150mph with them. Picking up 40mph in the back half Lol.

Is there more efficient ways to do it ? Sure. But I don't really think it will hurt you as much as it would seem on paper.

Also.... They only make t3 in .70 sizes for BEP/bw. His manifold is t3. And his downpipe is standard vband so he's limited to BEP or garrett
The only thing garrett offers would be a gt35r which then you're stepping up to a 62mm wheel

Its true, but you lose a huge amount of efficiency. The other thing is you are talking about a turbo being used on an Evo. They work fine with the unusual pairing, but an F series works better with a larger turbine wheel.

The S200 housings are divided T4 but with a small bit of machine work they can fit on a T3 manifold. The downpipe would need to be modified.

Quote:

Originally Posted by baZurk

I thought the s256 and s259 both use the compressor housing from the s300sx fmw which houses a 61.5mm wheel.

The S256 uses a 3" inlet, 2" outlet. A properly built S259 uses the same cover as the S300, which is 4" inlet and 3" outlet.

Will stuffing a 59mm compressor into your turbo work? It could. Will it be anywhere near ideal? Definitely not.

What happens is you end up with too much compressor for the turbine wheel. Pre-turbine pressures become high and the turbo works harder to make the power. You push the turbo out of the efficiency range. What can happen is slow spool for the power you are making, high turbine pressure, high EGTs, etc...

Jan 5, 2014 | 01:31 PM

#53

lude92_si

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Joined: Jun 2003

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From: Michigan

I'm open to advice for a Turbo that will fit my pfab elm T3 and I have a 3" vband down pipe. Really would like a faster spooling Turbo with good mid and can make 600whp.

I know I want alot. Time for some more research.