Build me a motor for an f1a
10-29-2014, 09:25 AM
#21
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This post is getting out of control . I just want an 8sec car on pump gas lol. I have had both d1 an f1a on my same 376. D1 seemed to run out up to for me. I'm just lookin for right motor.
10-29-2014, 09:28 AM
#22
Hell up until a while ago... A lot of the blowers where sourcing impeller wheels from turbo companies and just machining the wheel to fit on the blower shafts...lol
10-29-2014, 09:29 AM
#23
There are no larger blower maps published from I have have seen. If there is post it
A blower is actually much simpler than a turbo. You dont have a turbine playing with VE. And shaft speed is known 100%
If anyone has a map for a larger blower post it and we can plot it for different engines
But you can look at any map and gain general characteristics
I am on my phone. I will try to put together a an example here
A blower is actually much simpler than a turbo. You dont have a turbine playing with VE. And shaft speed is known 100%
If anyone has a map for a larger blower post it and we can plot it for different engines
But you can look at any map and gain general characteristics
I am on my phone. I will try to put together a an example here
10-29-2014, 09:30 AM
#24
its not a claim... its a centrifugal compressor... it has a compressor map just like any other centrifugal compressor... What TURNS it has NO bearing on where the wheel moves the most air efficiently. Take a look at any compressor map... and look at the shape of the right side of it.... If you are looking for the maximum mass flow from the wheel... there is a certain pressure ratio you have to get to in order to obtain that. IF the pressure ratio drops below that... actual mass flow drops off and it makes less power.
Hell up until a while ago... A lot of the blowers where sourcing impeller wheels from turbo companies and just machining the wheel to fit on the blower shafts...lol
Hell up until a while ago... A lot of the blowers where sourcing impeller wheels from turbo companies and just machining the wheel to fit on the blower shafts...lol
10-29-2014, 09:50 AM
#26
It is what you were asking. You asked for someone to build you a motor for an F1A, and we're discussing the benefits from different strokes and different displacements, and flow characteristics to best take advantage of the F1-A.
What rotary and LJMS was stating is that the blower has a specific efficency based on both rpm, and backpressure. So if it's too low, you'll make less power, too high, again, the same.
I guess that's why Procharger specs the engine HP range for them.
10-29-2014, 11:26 AM
#27
It is what you were asking. You asked for someone to build you a motor for an F1A, and we're discussing the benefits from different strokes and different displacements, and flow characteristics to best take advantage of the F1-A.
What rotary and LJMS was stating is that the blower has a specific efficency based on both rpm, and backpressure. So if it's too low, you'll make less power, too high, again, the same.
I guess that's why Procharger specs the engine HP range for them.
What rotary and LJMS was stating is that the blower has a specific efficency based on both rpm, and backpressure. So if it's too low, you'll make less power, too high, again, the same.
I guess that's why Procharger specs the engine HP range for them.
We can control the shape of the curve with how we build the motor... but the efficiency of the unit comes down to how much air mass the engine consumes.... versus how much air mass the blower puts out. Thats what controls the pressure ratio that the wheel sees.
10-29-2014, 12:39 PM
#29
I've seen compressor maps for Vortech superchargers before, but not for Procharger. I don't think many of us have put much thought into why a specific sized engine works better with one unit compared to another. This thread is actually quite helpful in understanding "why" better.
10-29-2014, 02:12 PM
#31
STMZ28's car will go 8.90's the next time it goes to the track on pump gas...
Build a copy of his combination and yours should go a couple tenths quicker given the fact you are 300 pounds lighter than he is.
10-29-2014, 05:11 PM
#34
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That's cool Cecil is 45 mins from me. I was sayin with your old set up is crazy time an mph for what you have. I have a 376 with basic parts stick car though to but it shows no where near the power of your car an mine is lighter.
10-30-2014, 05:55 AM
#37
It's not as simple at 370 vs 408. It's how much air can a given engine consume. It may just be that all else being equal a 370 and 408 both sit within the acceptable areas of the super secret compressor map. One will possibly allow the compressor to sit at a higher efficiency meaning low IAT's and more CFM.
As a theoretical example: All else being equal minus stroke
A 370 allows an F-1a to run at 73% efficiency
A 408 allows an F-1a to run at 68% efficiency
Chances are the extra cubes will outweigh the 5% lost at the compressor.
As a theoretical example: Different motors completely except bore
A 370 allows an F-1a to run at 73% efficiency
A 408 allows an F-1a to run at 60% efficiency(maybe due to different heads or cam)
It is possible that the 370 would produce more power. Low end tq probably not.
It is literally the exact same thing as matching a compressor wheel to target power goals. Centri companies just take some of the complexity out and say “use this charger for a given N/A hp range” rather than providing a compressor map. While also hiding the actual compressor efficiency ratings of their compressors of course.
http://www.vortechsuperchargers.com/page.php?id=656
If you look at a vortech compressor map, it is much wider than a turbo which allows a much wider range of engine combos than a single turbo would.
To the OP: I would personally run the 370. Keep the piston higher in the sleeve and reduce piston velocity.
As a theoretical example: All else being equal minus stroke
A 370 allows an F-1a to run at 73% efficiency
A 408 allows an F-1a to run at 68% efficiency
Chances are the extra cubes will outweigh the 5% lost at the compressor.
As a theoretical example: Different motors completely except bore
A 370 allows an F-1a to run at 73% efficiency
A 408 allows an F-1a to run at 60% efficiency(maybe due to different heads or cam)
It is possible that the 370 would produce more power. Low end tq probably not.
It is literally the exact same thing as matching a compressor wheel to target power goals. Centri companies just take some of the complexity out and say “use this charger for a given N/A hp range” rather than providing a compressor map. While also hiding the actual compressor efficiency ratings of their compressors of course.
http://www.vortechsuperchargers.com/page.php?id=656
If you look at a vortech compressor map, it is much wider than a turbo which allows a much wider range of engine combos than a single turbo would.
To the OP: I would personally run the 370. Keep the piston higher in the sleeve and reduce piston velocity.
Last edited by Exidous; 10-30-2014 at 06:03 AM.
10-30-2014, 06:47 AM
#38
So let me continue this discussion and ask this question. All else being equal, cam, heads, intake, exhaust, piston bore, and blower speed, but the only variable being the stroke, by going from the 3.625 to the 4.000 would allow the motor to ingest more air with each event, which would then lower your boost pressure on the blower at all rpms. Isn't less pressure on the blower also decreasing the force required to turn the blower? As the boost pressure goes up, you have a more dense air charge, which adds additional load onto the blower, which then increases it's parasitic loss.
That's the big argument turbos guys make against a blower is that it robs horsepower to turn the blower.
So back to the example above. We have 2 motors, identical in every way except for the crank stroke. So the 416 at 6800rpm might see 12psi of boost, while the 370 at the same 6800rpm could see 16psi of boost. Isn't that 4psi difference going to change the parasitic drag on the blower?
I'm also confused as to why you have the bigger cube motors having the blower run at a lower efficiency. I understand the compressor maps, but as the rpms change, so does the spot in the compressor map, so with a bigger motor, you simply get into the same pressure range later in the rpm window than with a smaller motor.
Again, without seeing the maps for their efficiency, it's a guess. I'm going to stop over at the Procharger booth next week at SEMA and talk to them about my plans, and see what they say with what crank stroke to go with based on my desires with the car. Hell, maybe I'll pull the trigger on a F1-A-94 while I'm there. I'm sure that will work well with a 416.
That's the big argument turbos guys make against a blower is that it robs horsepower to turn the blower.
So back to the example above. We have 2 motors, identical in every way except for the crank stroke. So the 416 at 6800rpm might see 12psi of boost, while the 370 at the same 6800rpm could see 16psi of boost. Isn't that 4psi difference going to change the parasitic drag on the blower?
I'm also confused as to why you have the bigger cube motors having the blower run at a lower efficiency. I understand the compressor maps, but as the rpms change, so does the spot in the compressor map, so with a bigger motor, you simply get into the same pressure range later in the rpm window than with a smaller motor.
Again, without seeing the maps for their efficiency, it's a guess. I'm going to stop over at the Procharger booth next week at SEMA and talk to them about my plans, and see what they say with what crank stroke to go with based on my desires with the car. Hell, maybe I'll pull the trigger on a F1-A-94 while I'm there. I'm sure that will work well with a 416.
10-30-2014, 08:01 AM
#39
I have nothing to back this up but I think the difference in load based on 12 ro16 PSI is negligible unless you are in a surge area of the compressor MAP. I am certain that you are right in that it does matter, I'm just not sure how much.
Using your/our example, stroke increase only, a decrease in PSI would happen but so would an increase in CFM. Lowering your pressure ratio and moving your flow to the right. Which if you are the left/surge side of peak efficiency it might move you into that peak efficiency. However if you are already far to the right/choke it may move you into the areas where efficiency plummet(IE a way oversized motor).
All of this is of course min/maxing and is only REALLY important for the folks that are class racing or trying to get every last ounce of power. Given how wide the maps are on these centri's, as long as you are close, it should be good enough. Certainly not as critical or picky as using the right turbo.
Using your/our example, stroke increase only, a decrease in PSI would happen but so would an increase in CFM. Lowering your pressure ratio and moving your flow to the right. Which if you are the left/surge side of peak efficiency it might move you into that peak efficiency. However if you are already far to the right/choke it may move you into the areas where efficiency plummet(IE a way oversized motor).
All of this is of course min/maxing and is only REALLY important for the folks that are class racing or trying to get every last ounce of power. Given how wide the maps are on these centri's, as long as you are close, it should be good enough. Certainly not as critical or picky as using the right turbo.
10-30-2014, 08:43 AM
#40
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I have nothing to back this up but I think the difference in load based on 12 ro16 PSI is negligible unless you are in a surge area of the compressor MAP. I am certain that you are right in that it does matter, I'm just not sure how much.
Using your/our example, stroke increase only, a decrease in PSI would happen but so would an increase in CFM. Lowering your pressure ratio and moving your flow to the right. Which if you are the left/surge side of peak efficiency it might move you into that peak efficiency. However if you are already far to the right/choke it may move you into the areas where efficiency plummet(IE a way oversized motor).
All of this is of course min/maxing and is only REALLY important for the folks that are class racing or trying to get every last ounce of power. Given how wide the maps are on these centri's, as long as you are close, it should be good enough. Certainly not as critical or picky as using the right turbo.
Using your/our example, stroke increase only, a decrease in PSI would happen but so would an increase in CFM. Lowering your pressure ratio and moving your flow to the right. Which if you are the left/surge side of peak efficiency it might move you into that peak efficiency. However if you are already far to the right/choke it may move you into the areas where efficiency plummet(IE a way oversized motor).
All of this is of course min/maxing and is only REALLY important for the folks that are class racing or trying to get every last ounce of power. Given how wide the maps are on these centri's, as long as you are close, it should be good enough. Certainly not as critical or picky as using the right turbo.