Having Trouble Pickin Turbo

PittSpeed Automotive
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I am far from a tree hugger you homo! and I won’t argue with your dumbass as you aren’t worth my time and this is why! (if you go back and read I told you why precisions puts out slightly better numbers sometimes and that’s not even important…what’s 1hp or 5hp when you make 400? so STFU)

:finger: agreed :finger: so fuck off boosteditfag

yes you are correct! but there are several other factors that go into it…comp. efficiency, flow of motor, etc etc…just to give you guys a quick synopsis since I don’t have time to explain it all:

Most larger turbos use a ported shroud compressor housing which are designed to increase your turbo life by eliminating the damaging effect of compressor surge. Compressor surge and flutter usually occurs between ~1800–3000 rpm or so before you start building boost. For instance, when performance products are added to increase horsepower (MBC, EBC, etc etc), the compressor wheel accelerates faster and compressor surge and flutter becomes more apparent and damaging due to the fact that it’s not seeing enough air come in. Ported shroud compressor housings are designed with larger intakes and sometimes inducer bleeder rings. Utilizing a larger intakes results in increase in choke flow, allowing more air to flow into the compressor wheel. The inducer bleed acts to broaden the range of the compressor wheel, smooth out air flow, and eliminate turbo compressor surge.

here is an explanation I quickly found on the net:

Blow-off valve myth #2: The fluttering sound is usually believed to be the blow-off valve. In reality, it is caused by a blow-off valve, but does not come from the blow-off valve. If the spring pre-load is adjusted too tight, this will cause compressor surge, which as described above is the sound of air exiting the turbo.

Compressor surge: You can think or surge as the point at which the compressor blades begin to “slip” in the air, losing their pumping ability, much like an aircraft wing loses its lift when it stalls. In a turbo, this happens in a series of bursts, as the blades slip, then bite, slip then bite. This sets up a pulsing wave in the turbo piping and explains why the sound has that characteristic “flutter”.

The interesting thing about compressor surge is that it occurs much more readily at low turbo shaft speeds. At these low shaft speeds, on road cars this is generally between 2000 and 3000 RPM, compressor surge is not much of a problem, as the loads generated by the surge are miniscule compared to what the turbo encounters at high boost. However, if surge occurs at high RPM and boost, it is possible to reduce the turbo life and/or damage the compressor.

and here is another:

A condition when boost in a turbocharged or supercharged engine tries to flow back up into the turbo or supercharger. This reverse-flowing boost tries to stop the compressor from spinning, which not only causes turbo lag when shifting gears on a manual transmission vehicle, it also causes wear and tear on the turbocharger.

http://www.enjoythedrive.com/content/?id=22417

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/\ pretty much what I said, just bs’d out a wee bit too much.

I’m not talking about shifting or anything, just wide open throttle. So the fact of the throttle plates is irrelivant.

Yes, a BOV is used to prevent a surge when the throttle is closed. What I am talking about is different. I am refering to exceeding corrected mass flow, more or less. The surge line on compressor maps is where the compressor is giving up. You need to stay away from plotting on a map near there. Obviously, you have too much pressure with not enough volume…aka turbo is way to big for the engine to swallow…just like i said before.

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Irrelevant. A turbo will only flow so much air, and the extra displacement will up the torque, not the horsepower. In this case, anyways.

:1320:

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Irrelevant. A turbo will only flow so much air, and the extra displacement will not up the horsepower. In this case, anyways.

That is, unless you weren’t even talking about power, and were talking about spool, or something else. In that case, sorry to have singled you out.

Regardless,

:1320:

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just pick one so i can race your 10 seconds talon

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Haha love this stuff …

I do agree go 35R great turbo with fast spool. Could just start out with a .63 exhaust side and if its choked out go to the .82 to make it flow but starting small will help spool and midrange for that wanted powerband. Plus ATP sells housings cheap like 180 or 200 bucks I think.

I went with a T3/GT40 (or whatever its named now haha) from cheapturbo a lot of guys have had great spool and power numbers with it and its cheap. :bigthumb:

Could also go with a T3/ TO4R but that is a LAG GOD unless you tach high it will have a bad powerband.

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So what youre telling me is that a 1.0 liter with a GT30R will make the same amount of power as a 2.3 liter with the same turbine? :confused:

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basically, if you understand how turbos work, cfm = hp if you could get the 1.0 liter to flow the same as the 2.3 liter with a particular turbo tye would (in a perfect world) make the same hp. the reason this isn’t true is it’s easier to get the 2.3 to flow that kinda #'s than the 1L…which would have to revv to 139847932147234rpms to do it, but yes according to science he’s correct

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hence the reason you shouldn’t use what a peice of paper says when comparing to the real world.

kind of like the rotary engine…looks awesome on paper but we all know how they work in the real world

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rotarys would have worked if they would have solved the apex seal problem, GM had a 4 rotor vette that they dropped because it didn’t “sound” like a v8 and marketing didnt’ think it owuld sell

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lol that or the fact mazda has exclusive rights to the rotary motor design and shoulda woulda coulda don’t cut it

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wankel made the motor for gm it was a concept - look it up

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I don’t care who it was made for…mazda owns the rights…look it up

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Aside from what Kurt said, yea, sort of. While a lot of factors have to be the same, it is the truth. I was more referring to his going from 2.0 to 2.3, not something as drastic at 1.0 to 2.3, etc.

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I am sorry at 2.3L will make more HP and torque than a 2.0.

more cylinder volume means the ability to burn more fuel

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So if stroking a motor out from 2.0 to 2.3 is irrelevent. Why would anyone do it?

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GM also made a turbine powered concept. Woulda been pretty cool except the engine got to like 1000 degrees.

Its true, seen it on TV

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this entire thread made me stupid, and dumbfounded at the same time…

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Wrong, sorry. The turbo will only flow so much air, limiting HP potential.

Let’s nail down some facts here.

  1. Every turbo has a maximum airflow it can flow, and therefore (since power is directly related to airflow) every turbo also has a maximum amount of power it can support.

  2. At a set airflow (for example, if you are maxing out a turbo) you are making an amount of power directly related to that airflow. As such, the displacement is not relevant. If you’re getting, say, 45 lb/min of airflow out of a turbo, it doesn’t matter if you have 1.5 liter or 2.5 liters, assuming similar engine design (compression ratio, tuning, etc) the power production is going to be the same.

  3. Due to this fact, the maximum amount of power a turbo can support is not related to the size of engine it is installed on.

On something like a 5 liter engine, weird stuff starts to happen in order to achieve, say, 400 whp worth of airflow, you need to operate at a much lower PR than on a 2.X liter, and therefore you get into a different range of the compressor map, etc.

Not to mention a 5 liter motor might be able to make that kind of power, sans turbo.

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