Procharger VS Turbo Dyno Graphs
11-11-2008, 10:14 PM
#1
Procharger VS Turbo Dyno Graphs It seems like a small frame turbo and a D1sc make similar peak numbers but I wanted to know if anyone has the dyno graphs comparing similar engine setups only difference one being a procharger and the other being a turbo.
I'de like to see the difference in the area under the curve between a centrifugal SC and a turbo. If you have a twin screw blower dyno graph for comparison sake, that would be interesting too
I'de like to see the difference in the area under the curve between a centrifugal SC and a turbo. If you have a twin screw blower dyno graph for comparison sake, that would be interesting too
11-12-2008, 05:05 AM
#4
Here is a dyno graph from an LS2 with a 4.00 stroke crank, EPP blower cam, stock AFR 225 heads, stock LS2 intake and throttle body, methanol injection, 1-7/8 Kooks headers and ProCharger F-1A at 14.4 psi of boost on our Mustang Chassis Dyno. This CTS-V was just dyno'd on another dyno and made 815 rwhp, so the numbers are consistent.
Maybe someone can post up a similar turbo build. Bob
11-12-2008, 12:11 PM
#5
Wow comparing the graph above to this pretty basic turbo setup. Even though the procharged engine makes about 200 more peak whp if you look at the hp and tq curves and compare them.. the turbo setup is creating more area under the curve untill about 4500-5000 rpm.
https://ls1tech.com/forums/forced-in...s1-camaro.html
And the turbo setup has less expensive parts in it. Ls1 vs ls2 and AFR heads vs factory castings.. Plus its an F1A not a D1sc and the turbo setup is running less boost on a more restrictive setup.
I already knew this but I always find comparing the graphs to be really an eye opener
I think in reality cars on the street, doing highway pulls and what not are under even more load than on a load bearing dyno and the turbo will only spool faster and the difference will be even greater.
https://ls1tech.com/forums/forced-in...s1-camaro.html
And the turbo setup has less expensive parts in it. Ls1 vs ls2 and AFR heads vs factory castings.. Plus its an F1A not a D1sc and the turbo setup is running less boost on a more restrictive setup.
I already knew this but I always find comparing the graphs to be really an eye opener
I think in reality cars on the street, doing highway pulls and what not are under even more load than on a load bearing dyno and the turbo will only spool faster and the difference will be even greater.
Last edited by sciff5; 11-12-2008 at 12:17 PM.
11-12-2008, 12:36 PM
#6
Both have their pros and cons and ridden in and drove sts lt1 and ls1 cars, ati lt1 and ls1 cars. own twin turbo ls1 car. Had many single turbo dsm cars.Also rode in and drove paxton lt1 car.
Observations..the centrificals are nice and controllable. They build boost as function or rpm so that can be a good thing lower boost at lower rpm helps in the traction department. At the track leaving at higher rpms the differences between turbos and centrificals narrows. On the street you can still gear down if you are in a higher gear on the super or turbos to get you more boost or faster spool up depending on which power adder you are talking about. The centrificals do not really have lag or delay waiting for spool up. But they ramp up their boost output which of course means they won't see the area under the curve of the turbos.
Course too big a turbo can give a pretty lousy area under the curve and narrow powerband as well. Turbo guys don't mention this much!
You can also get boost off the line with things like two steps and antilag devices and stall converters help in an auto car as well.
Course you can rev up your centrifical and make more boost off the line as well.
So in real life not as much differences. Going up slowly thru the gears the centrifical will be puttting out less boost than the turbo.So the turbo has the advantage there if sized right.
Now take a twin screw and you have an even broader powercurve than the turbo. They can come in super strong down low and carry it to the end of the rpm band. Not as efficient still as turbo and all that bottom end can actually be very very hard to hook up.
At least with turbos you can buy electronic boost controllers that let you ramp up the boost according to gear or rpm .I happen to have one of those on order.
There is a good book out with tons of dynos on the ls1 engines. It has all the different power adders. They freely admit you cannot beat the turbos for area under the curve and efficiency and power output per pound of boost . But as said there are still some pros and cons to each power adder.
Observations..the centrificals are nice and controllable. They build boost as function or rpm so that can be a good thing lower boost at lower rpm helps in the traction department. At the track leaving at higher rpms the differences between turbos and centrificals narrows. On the street you can still gear down if you are in a higher gear on the super or turbos to get you more boost or faster spool up depending on which power adder you are talking about. The centrificals do not really have lag or delay waiting for spool up. But they ramp up their boost output which of course means they won't see the area under the curve of the turbos.
Course too big a turbo can give a pretty lousy area under the curve and narrow powerband as well. Turbo guys don't mention this much!
You can also get boost off the line with things like two steps and antilag devices and stall converters help in an auto car as well.
Course you can rev up your centrifical and make more boost off the line as well.
So in real life not as much differences. Going up slowly thru the gears the centrifical will be puttting out less boost than the turbo.So the turbo has the advantage there if sized right.
Now take a twin screw and you have an even broader powercurve than the turbo. They can come in super strong down low and carry it to the end of the rpm band. Not as efficient still as turbo and all that bottom end can actually be very very hard to hook up.
At least with turbos you can buy electronic boost controllers that let you ramp up the boost according to gear or rpm .I happen to have one of those on order.
There is a good book out with tons of dynos on the ls1 engines. It has all the different power adders. They freely admit you cannot beat the turbos for area under the curve and efficiency and power output per pound of boost . But as said there are still some pros and cons to each power adder.
11-12-2008, 01:45 PM
#7
347ci with out of the box AFR 225s, a mild turbo grind from flowtech, stock LS6 intake, and a T76 turbo. Also these numbers are uncorrected because the weather station was wigging out on the dyno giving false high numbers but SAE correction factors from that day/time were 1.02.
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11-12-2008, 03:21 PM
#8
Both have their pros and cons and ridden in and drove sts lt1 and ls1 cars, ati lt1 and ls1 cars. own twin turbo ls1 car. Had many single turbo dsm cars.Also rode in and drove paxton lt1 car.
Observations..the centrificals are nice and controllable. They build boost as function or rpm so that can be a good thing lower boost at lower rpm helps in the traction department. At the track leaving at higher rpms the differences between turbos and centrificals narrows. On the street you can still gear down if you are in a higher gear on the super or turbos to get you more boost or faster spool up depending on which power adder you are talking about. The centrificals do not really have lag or delay waiting for spool up. But they ramp up their boost output which of course means they won't see the area under the curve of the turbos.
Course too big a turbo can give a pretty lousy area under the curve and narrow powerband as well. Turbo guys don't mention this much!
You can also get boost off the line with things like two steps and antilag devices and stall converters help in an auto car as well.
Course you can rev up your centrifical and make more boost off the line as well.
So in real life not as much differences. Going up slowly thru the gears the centrifical will be puttting out less boost than the turbo.So the turbo has the advantage there if sized right.
Now take a twin screw and you have an even broader powercurve than the turbo. They can come in super strong down low and carry it to the end of the rpm band. Not as efficient still as turbo and all that bottom end can actually be very very hard to hook up.
At least with turbos you can buy electronic boost controllers that let you ramp up the boost according to gear or rpm .I happen to have one of those on order.
There is a good book out with tons of dynos on the ls1 engines. It has all the different power adders. They freely admit you cannot beat the turbos for area under the curve and efficiency and power output per pound of boost . But as said there are still some pros and cons to each power adder.
Observations..the centrificals are nice and controllable. They build boost as function or rpm so that can be a good thing lower boost at lower rpm helps in the traction department. At the track leaving at higher rpms the differences between turbos and centrificals narrows. On the street you can still gear down if you are in a higher gear on the super or turbos to get you more boost or faster spool up depending on which power adder you are talking about. The centrificals do not really have lag or delay waiting for spool up. But they ramp up their boost output which of course means they won't see the area under the curve of the turbos.
Course too big a turbo can give a pretty lousy area under the curve and narrow powerband as well. Turbo guys don't mention this much!
You can also get boost off the line with things like two steps and antilag devices and stall converters help in an auto car as well.
Course you can rev up your centrifical and make more boost off the line as well.
So in real life not as much differences. Going up slowly thru the gears the centrifical will be puttting out less boost than the turbo.So the turbo has the advantage there if sized right.
Now take a twin screw and you have an even broader powercurve than the turbo. They can come in super strong down low and carry it to the end of the rpm band. Not as efficient still as turbo and all that bottom end can actually be very very hard to hook up.
At least with turbos you can buy electronic boost controllers that let you ramp up the boost according to gear or rpm .I happen to have one of those on order.
There is a good book out with tons of dynos on the ls1 engines. It has all the different power adders. They freely admit you cannot beat the turbos for area under the curve and efficiency and power output per pound of boost . But as said there are still some pros and cons to each power adder.
11-17-2008, 09:06 AM
#9
I actually calculated using this site
http://www.f-body.org/gears/
How much my rpm will drop shifting into the next gear while racing if I'm hitting my shifts.
Say my redline is 7k and I have 4.10 gears and a 25" tire.
1st gear if I shift at 7k rpm I start 2nd gear at 4700rpm
Shifting at redline in 2nd gear drops me to 5100rpm in 3rd gear
Shifting again at redline in 3rd starts me at 5400 rpm in 4th
Shifting at redline in 4th puts me at 5200rpm in 5th
Shifting at redline in 5th puts me at 4700rpm in 6th
I am sure the 5th and 6th gear will be off because of the tire expanding at those speeds but needless to say when racing.. power at 3000 rpm doesnt matter on the street unless your taking off from a dig.. and most high power street cars have such insane traction issues a little less instantaneous power might be a good thing in "some" instances.
So again this brings me to the question of why are turbo cars (especially ones equipped with stupidly long final drive ratios) such strong highway runners especially as speed goes up?
http://www.f-body.org/gears/
How much my rpm will drop shifting into the next gear while racing if I'm hitting my shifts.
Say my redline is 7k and I have 4.10 gears and a 25" tire.
1st gear if I shift at 7k rpm I start 2nd gear at 4700rpm
Shifting at redline in 2nd gear drops me to 5100rpm in 3rd gear
Shifting again at redline in 3rd starts me at 5400 rpm in 4th
Shifting at redline in 4th puts me at 5200rpm in 5th
Shifting at redline in 5th puts me at 4700rpm in 6th
I am sure the 5th and 6th gear will be off because of the tire expanding at those speeds but needless to say when racing.. power at 3000 rpm doesnt matter on the street unless your taking off from a dig.. and most high power street cars have such insane traction issues a little less instantaneous power might be a good thing in "some" instances.
So again this brings me to the question of why are turbo cars (especially ones equipped with stupidly long final drive ratios) such strong highway runners especially as speed goes up?
11-17-2008, 10:45 AM
#13
Supras and vipers come to mind. both around 3.0. Supra being a little longer, viper being a little shorter
And both have double overdrive.. Come on.. thats stupid long
I can see why zombie would need 2.75 rear gear with no overdrive
And both have double overdrive.. Come on.. thats stupid long
I can see why zombie would need 2.75 rear gear with no overdrive
11-17-2008, 10:58 AM
#14
I am not even liking my 3.42 all that much around town when off boost. Sure you can give it gas and the turbo boosts and spin them off but still I guess like more snap and responsiveness around town off boost. So think 3.54 is my all around choice for in town and highway and 3.73 might be choice with m6.
My car can build boost very quickly with the 408 and the smaller aps turbos so really see no big need to go way down on gear but hey whatever floats your boat.
And still after closely pouring over the old boosted lists see zero evidence that really low gears make the car faster in the 1/4 mile . Of course if you are forced to shift to overdrive then you could get a bit faster by going to a gear that gives you the higher mph thru the traps without the shift.
You guys can have your doggy gears. And as for top speed think my top speed in fifth with 3.54 is still way way up there. Course going to have a 4l80e in spring anyway but still more than enough top speed with 3.54s. Unless you like going to bonneville or something.
My car can build boost very quickly with the 408 and the smaller aps turbos so really see no big need to go way down on gear but hey whatever floats your boat.
And still after closely pouring over the old boosted lists see zero evidence that really low gears make the car faster in the 1/4 mile . Of course if you are forced to shift to overdrive then you could get a bit faster by going to a gear that gives you the higher mph thru the traps without the shift.
You guys can have your doggy gears. And as for top speed think my top speed in fifth with 3.54 is still way way up there. Course going to have a 4l80e in spring anyway but still more than enough top speed with 3.54s. Unless you like going to bonneville or something.
11-17-2008, 02:02 PM
#18
14.5 psi, no meth.... TT35R LS7 with good fuel. It spun after peak tq.
Roots will win from idle to 2500~, but will die after peak tq.
It all depends on what you want to do really... Im thinking of going YSi on the Z only because of price and weight.
11-17-2008, 02:41 PM
#19
No doubt about the roots being the wrong choice if you need power up top. I'de like to know about centrifugal superchargers vs turbo.. or maybe twin screw vs turbo, now that there seems to be a reasonably priced twin screw kit coming out for the GTO.
11-17-2008, 06:41 PM
#20
I've yet to see a turbo setup making alot more power than my D1SC at similar boost levels. 740 RWHP at 13 psi through an A4. So far the only real benefit to turbos I've found is the ability to adjust boost fast. Since I have a right foot I can actually modulate my throttle input to control spin. Its a novel idea.
I've owned several turbo cars, IMHO its not worth the headache for a possible few extra HP. Packaging, exhaust leaks, heat, etc. are all issues of turbo cars. Whats the worst that could happen on a blower car? Belt slip. If you know how to adjust it its not much of an issue.
On my graph (which I can't post) I make about 550 RWHP the second the throttle is mashed and climb from there. Since I have a properly sized torque convertor I stay at 12-13 psi throughout a run.
I've owned several turbo cars, IMHO its not worth the headache for a possible few extra HP. Packaging, exhaust leaks, heat, etc. are all issues of turbo cars. Whats the worst that could happen on a blower car? Belt slip. If you know how to adjust it its not much of an issue.
On my graph (which I can't post) I make about 550 RWHP the second the throttle is mashed and climb from there. Since I have a properly sized torque convertor I stay at 12-13 psi throughout a run.