S200 turbo map explanation.

[dovlet]

Help please. Is this good for m54b30 15psi? Please describe why with explanation.

Many thanks in advance.
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[vollosso]

Depends on the end goals. Describe your goals and maybe we can help.


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[dovlet]

Depends on the end goals. Describe your goals and maybe we can help.


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Bro, it is project of one friend of mine. My opinion it is not sufficient turbo for 15psi 3l. Goal is about what ever 15psi can give. I think it is about 400-450 HP.

[Mklock]

I got 510whp out of an s200....so i'm not sure if that helps. Im almost certain it was tapped out because it tapered boost off at about 6500 rpm.

S52 on pump gas no meth.

[Nutzy]

It depends on your view of it. I have an S256 on my 2.8 running 18psi, it doesn't want to run any more boost than that. The post-IC temps are in the 50C range. Is it ideal? Nup. Does it haul ass? Yep. Does is being less than ideal bug me? Yep.

I will attach a pic of an SX-E compressor at 15psi on 3.0 liters. This compressor looked pretty nice on my 2.8 at 20-something psi. The reason this compressor looks good is because the map leans over more to the right, rather than more to the vertical, like most do. The difference is being oriented towards flow at lower PR, whereas there seems to be a heap of turbos that appear to lean towards small displacement and high boost. Or at least that is my take on having played with a heap of maps. Happy to be corrected though.

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[someguy2800]

It will work. An S362sx-e is probably a better choice.

[dovlet]

Gents, what is the efficiency on turbo map means? Is there relation with temperature? I meant, as low efficiency higher intake temperature.?

[Mklock]

That probably holds truth but at 15psi I think you'll be fine, you would be close to your goal I'm sure. Took 19 psi for my 510whp run.

Id go with the s300 frame like said before though. Theres no room on the 200 frame if you want any more power.

[vollosso]

Gents, what is the efficiency on turbo map means? Is there relation with temperature? I meant, as low efficiency higher intake temperature.?

The % of air compressed / moved vs heated


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[Butters Stoch]

It will work. An S362sx-e is probably a better choice.

This ^^
3.0-3.2L should probably have at least a 61+mm compressor wheel.
Unless there are 2 of them ; )
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[dovlet]

Thanks all, many useful info.

That probably holds truth but at 15psi I think you'll be fine, you would be close to your goal I'm sure. Took 19 psi for my 510whp run.

Id go with the s300 frame like said before though. Theres no room on the 200 frame if you want any more power.

I cannot understand how you got 19 psi with s200? Probably you may had a lot of issue with low efficiency and high intake temperature? Am I right? Because 19 psi is placing your Turbo behind chock line where efficiency is less than 58%.

[Mklock]

Never had problems with heat intake temps, and yes the turbo clearly ran out of efficiency because it tapered boost off at redline. I also ran the biggest hotside I could.

Put simply this is a great turbo for ONLY 450whp. Past that results may very. I would guatentee an s257 could achieve 450whp.

[dovlet]

never had problems with heat intake temps, and yes the turbo clearly ran out of efficiency because it tapered boost off at redline. I also ran the biggest hotside i could.

Put simply this is a great turbo for only 450whp. Past that results may very. I would guatentee an s257 could achieve 450whp.

tqvm

[Robocop]

hey guys dumb question.
So if it turbo is 'maxed' does that mean it will not make any more boost or just that it will not make any more power?
say from 23psi to 30psi it just blows hot air but WILL make keep making more boost.?

[Butters Stoch]

hey guys dumb question.
So if it turbo is 'maxed' does that mean it will not make any more boost or just that it will not make any more power?
say from 23psi to 30psi it just blows hot air but WILL make keep making more boost.?

Both kinda.
Sometimes it just won't make anymore boost.
Remember boost is only what the engine can not consume.
So, if a small turbo is used, with a real big engine, then the engine may consume all the air even the hot air when the turbo is out of its efficiency range and just not make anymore of either.

Like say you were to install a 5858 on a 6.X liter Corvette. The turbo will max out at XX boost and just not make any more. Also, as rpm rises, boost will fall as the engine needs more air at higher rpm. So say its maxed out at 7psi at 4000 rpm. Then at 5,000 rpm boost will fall to 6.5 or 6 psi.

But, it will also stop making power before any of that.

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[Nutzy]

hey guys dumb question.
So if it turbo is 'maxed' does that mean it will not make any more boost or just that it will not make any more power?
say from 23psi to 30psi it just blows hot air but WILL make keep making more boost.?

It depends which side of the turbo is maxed out. Given that boost is a 'measure' of restriction across the whole motor (intake, ports, valves, exhaust manifold, turbine section, exhaust system), if the turbine had reached choke flow, you may still be able to keep increasing boost, but realise very little in the way of power gain. On the other hand, a compressor that has reached choke flow will exhibit falling boost, super hot discharge temps, and possible over-speed.

[dovlet]

So, above means, after chock line still can find live, but very weak & primitive. Not useful and can destroy turbo due to over speed. Also, if I am not mistaken choke line means your exhaust gases speed is higher than turbine hot side impeller speed. Correct me if I am wrong.

[Def]

So, above means, after chock line still can find live, but very weak & primitive. Not useful and can destroy turbo due to over speed. Also, if I am not mistaken choke line means your exhaust gases speed is higher than turbine hot side impeller speed. Correct me if I am wrong.

Choked flow means the flow is going sonic through the smallest gas passage. More flow can be obtained by continuing to raise the inlet pressure, which raises the density of the flow, but NOT the speed.

Has nothing direct to do with wheel speed.

[dovlet]

Choked flow means the flow is going sonic through the smallest gas passage. More flow can be obtained by continuing to raise the inlet pressure, which raises the density of the flow, but NOT the speed.

Has nothing direct to do with wheel speed.

Yes, agree but, If you have no restriction you will never obtain back pressure. If turbo has capacity of 50lb/min and engine consumption is 70 lb/min you will get chock with no pressure and overspeed your impeller. To avoid this you should have turbo which provides more air than engine consume.

[Def]

Yes, agree but, If you have no restriction you will never obtain back pressure. If turbo has capacity of 50lb/min and engine consumption is 70 lb/min you will get chock with no pressure and overspeed your impeller. To avoid this you should have turbo which provides more air than engine consume.

I have no idea what all that nonsense means...

[hotdish]

I have no idea what all that nonsense means...

A turbo too small will still make vacuum instead of boost and spin too quickly

[someguy2800]

So are we talking about putting a gt25 on an 8 liter big block chevy? This entire conversation has turned into pointless stupidity.

[dovlet]

So are we talking about putting a gt25 on an 8 liter big block chevy? This entire conversation has turned into pointless stupidity.

We just want to understand how chock line is acting.