how much did you make with your 3.8" pulley?
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Don't know. Probably 400-420whp.

 

how much did you make with your 3.8" pulley?
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Don't know. Probably 400-420whp.
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Wow.. if i pull off my 380whp goal on my 4" pulley, ill definitely upgrade to 3.8/3.6 next

 

how much did you make with your 3.8" pulley?
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Don't know. Probably 400-420whp.
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Wow.. if i pull off my 380whp goal on my 4" pulley, ill definitely upgrade to 3.8/3.6 next
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On our 1200 blower it isn't a problem. It flows significantly more CFM per the same size pulley over the 1220. But of course it depends on your tune as well on what you yield.

 

Where you ever able to figure out your issues?

 

I had the same problem man with my P-Tuning GT3076R Kit. We just couldnt get it to make good power. Given I still made 424whp on pump and 507 on race it should have made closer to 450-460 on pump and 550 on race. But in my case low compression and a small exhaust housing we deemed was the cause.

 

I have been reading a lot of psi and cfm issues from different gurus and smart as$es.
Been doing both board searches and google searches for a while now.
Some people say psi doesnt matter at all and only cfm does.
Some people say the higher cfm your blower has, the easier for your psi to go up. (which makes most sense to me)
Yet some people say that an output of X psi from a blower, makes a different output compared to a blower with higher cfm producing the same psi.
Got lost on this.

Ill post my results as soon as I have my car retuned. I wont be able to do that until next tuesday



I hope I dont get to that conclusion
How can you tell that you have low comp? mine had 220,200,200,190

 

Pounds of boost is only a measure of restriction to flow. Though many of us use it as a reference to horsepower output it really isn't. The reason it correlates is because within each car platform and turbo, many of us are familiar with what X amount of boost from Y turbo compressor or SC correlates horsepower wise. It is more accurate to refer to pounds of air/min or cfm when correlating power ACROSS engines and compressors. If you were looking at a compressor map your boost pressure would be used to calculate your compression ratio and from there your pounds of air/min or cfm. Spend some time on garrett's site learning how to read compressor maps and calculating flow. Hope this makes sense.

 

Makes a lot of sense! However, still too complicated for my noob mind to process

I'll put it in a more specific way: Does an engine with a 1200blower/9psi setup outperform the same engine with a 1220blower/9psi setup?

Searched the boards and found someone saying that the same psi for a 1200blower, can actually add more boost than that of a 1220 blower with the same psi. I really dont know if I can agree.

Sorry for the noobness.

 

PSI amount doesn't directly correlate to power as mentioned, its used as more of a reference point since we are discussing the same motor/platform. 7psi means something very different on a V8 motor then a F22 as a reference point. What matters is the cfm given from the blower or turbo at a particular rpm and if your motor can consume it, if it cant, it will be measured as psi at the manifold, a restriction. A highly efficient large displacement motor may see 200hp yet only measure 7psi at the manifold, even though the cfm is through the roof and the motor is able to suck it up. That same set up on a small displacement motor would see much higher psi at the manifold with potentially similar power, or less depending on a few other factors.

In the case comparison between A 1200 blower and a 1220, the 1200 impeller design is more aggressive so it pushes more air aka cfm at the same blower rpm as the 1220 at a particular point in the compressor map, which when coupled to the same motor as a F20/22 in our case, sees a higher psi at the manifold. So if both blowers have a 3.8" pulley, the 1200 may be producing 100cfm more then the 1220, and on the same motor this correlates to seeing a higher restriction/psi measured at the manifold.

Now to add, its important to size the compressor to the displacement of the motor. Too big of a blower on too small of a motor will drag the motor down with higher parisitic loss before the blower can be spun fast enough for the motor to offset this and make more power over a smaller blower. If your only planning on making 300-325whp on this motor, a 1200 likely wont offer you any benefit over a 1220 and in fact the 1220 may offer a slight bump in overall efficiency at that hp level due to less parasitic losses when the blower is being operated at this lower level. For our motor the 1200 seems to hit the overall sweet spot in the compressor map, with minimal parasitic loss yet highly efficient in the 10-16psi range where we like to run them, producing anything from 350whp to over 500whp. Some have decided to try the Novi 1500 and have had some limited success, one of the characteristics you will find with that blower on our motor is that not only is it a outdated design like the novi1000 and so not very efficient in its sweet spot, but you have to be willing to spin it to its maximum rated limit or beyond before it offsets any power the 1200 can yield on our motor, and I mean minimal, seeing 25-26psi at the manifold but only netting 30-40whp over a 1200 at similar presser. Novi also makes 2000-2500-3000 etc, none of which would operate on anything but a high displacement v8.

This is a little involved, but hopefully I articulated it well and accurate enough for it to make some sense. In simple terms, you can think of the 1220 1200 1500 blowers like small to large turbos in a way, but with the addition of parisitic losses.

 

Damn Junky you a engineer