Wastegate on a Centrifugal blower - interesting

[Ekliptix]

http://www.musclemustangfastfords.com/tech/mmfp_0708_vortech_centrifugal_supercharger_wastegate_install/index.html

This is pretty interesting.
You can pulley a blower for 20psi (for example) so the boost ramps up quicker to make more torque, but you can control the max boost at 10psi (for example) with boost controller connected to the wastegate on the charged side of the blower pipe.
Ideally, you could achieve your desired boost at a low rpm and hold it there.

There's probably a lot to consider like:
- blower efficiency range
- putting the wastegate before or after the intercooler
- if putting the wastegate after the intercooler, would there be any value in rerouting the intercooled and vented air from the wastegate back into the inlet of the intercooler.

Anyway, I thought it was pretty interesting.

[Toma]

Originally posted by Ekliptix
http://www.musclemustangfastfords.com/tech/mmfp_0708_vortech_centrifugal_supercharger_wastegate_install/index.html

This is pretty interesting.
You can pulley a blower for 20psi (for example) so the boost ramps up quicker to make more torque, but you can control the max boost at 10psi (for example) with boost controller connected to the wastegate on the charged side of the blower pipe.
Ideally, you could achieve your desired boost at a low rpm and hold it there.

There's probably a lot to consider like:
- blower efficiency range
- putting the wastegate before or after the intercooler
- if putting the wastegate after the intercooler, would there be any value in rerouting the intercooled and vented air from the wastegate back into the inlet of the intercooler.

Anyway, I thought it was pretty interesting.
Yep, a few "serious" guys are doing it.... seems to work well.

Efficiency - same as a turbo, they have compressor maps... just plot the curve, and stay in an "acceptable" region when dialing in the boost. Not normally much of an issue as these things really ramp the boost in with rpm anyway, blowing them straight into atmosphere doesn't hurt em (ie flow bench applications)

Before the intercooler ALWAYS. Why waste intercooler capacity on air you are just gonna vent?

[Moe Man]

neat so like 10 psi at 2000rpm?

hahaha nuts

[JRSC00LUDE]

Originally posted by Moe Man
neat so like 10 psi at 2000rpm?

hahaha nuts

That's not so fun when you have no traction....... :(

[Moe Man]

i was thinking the same thing right after i posted that

:rofl:

[Dritto]

Positive displacement blowers! Twin screw for the torque, screw this centrifugal nonsense. Why reinvent the wheel??

Centrifugals are good in certain applications, but IMO they aren't the best choice for a street ride. Twin screw or roots are the better choice! Especially on a Mustang geezz....


And again, why purchase an expensive YSi-Trim Vortech when you can consider a base Kenne Bell kit (for instance) is just $3100 and it'll make you 10psi @ 2000rpm out of the box????? ($3100 on a 5.0)

[dimi]

Very popular with the S2000 crowd, since most are used to very little torque to start with, and its great on the track.

Wouldn't bother with it on a mustang, roots/twin screw as was previously mentioned, unless you plan to track your car?

[zieg]

Originally posted by Ekliptix
- if putting the wastegate after the intercooler, would there be any value in rerouting the intercooled and vented air from the wastegate back into the inlet of the intercooler.




no. it will still be hotter after the intercooler than it is when it goes into the blower. 1st law of thermodynamics.

[alloroc]

Originally posted by dimi
Very popular with the S2000 crowd, since most are used to very little torque to start with, and its great on the track.

Wouldn't bother with it on a mustang, roots/twin screw as was previously mentioned, unless you plan to track your car?

Unless I am misreading your post i think you are slightly mistaken...
a mustang is the perfect place for a centrifical blower to be installed as mustangs actually have enough bottom end torque without the blower to get off the line and once the fan curve starts to rise they benefit from the blower from about 2.5k revs on.

[alloroc]

Originally posted by Ekliptix
http://www.musclemustangfastfords.com/tech/mmfp_0708_vortech_centrifugal_supercharger_wastegate_install/index.html

This is pretty interesting.
You can pulley a blower for 20psi (for example) so the boost ramps up quicker to make more torque, but you can control the max boost at 10psi (for example) with boost controller connected to the wastegate on the charged side of the blower pipe.
Ideally, you could achieve your desired boost at a low rpm and hold it there.
Anyway, I thought it was pretty interesting.

I tried this a long time ago on a 4ag redtop with a sc12 installed and it worked pretty good, my piping was garbage though and I ended up dismantalling it along with some other experimental mods I had on the car. I think I had it holding around 6-8 psi and could go as high as 10. It must must have worked because I blew a piston - ring landing - not long after I made it more 'conventional'


It could also have been a tank full of bad gas too as i had the redtop ECU ( no knock sensor.) Who knows, but 4 years later and I'm still not done the rebuild.


funny thing is I think Rage laughed at me when I suggested it was even possible.

[alloroc]

Originally posted by Ekliptix
http://www.musclemustangfastfords.com/tech/mmfp_0708_vortech_centrifugal_supercharger_wastegate_install/index.html

- if putting the wastegate after the intercooler, would there be any value in rerouting the intercooled and vented air from the wastegate back into the inlet of the intercooler.

Anyway, I thought it was pretty interesting.

Nah, its still hot unless they are spraying the intercooler or something over the top. I did notice they had the blowoff valve vent about 8 inches from the air filter. I think I would have tried to pipe it somewhere else. In calgary I would make it (and the wastegate air) blow on the battery or something else I would want to warm in winter. Not that those guys give a shit about winter ... just sayin'.

[Toma]

Originally posted by Dritto


And again, why purchase an expensive YSi-Trim Vortech when you can consider a base Kenne Bell kit (for instance) is just $3100 and it'll make you 10psi @ 2000rpm out of the box????? ($3100 on a 5.0)
Cause a "base" ken Bell will get WALKED all over bu a Novi 1000 even

[Dritto]

Ok, not trying to argue here, but explain the logic behind the baby Novi being able to walk a KB when pullied to the same PSI?

[Annoyingrob]

likely efficiency of the compressor itself.

10psi is not 10psi. There's a heat aspect too.

[Dritto]

Originally posted by Annoyingrob
likely efficiency of the compressor itself.

10psi is not 10psi. There's a heat aspect too.


You're right, and I totally get that, but my real question here is why the difference might be so pronounced. I mean (coming from a layman of course) that the centrifugal might do 4-5 PSI at 3k-4k rpm where as the twin screw is producing 10psi at very low RPM.

You won't likely see 10psi in the manifold from either blower after the air is done traveling through the inlet restrictions etc, I get that, but I still don't understand how the baby Novi would produce a faster car.

And I respect everyone's opinion here, so I'm not trying to prove anyone right or wrong, just curiosity of course!

[alloroc]

Originally posted by Dritto



You're right, and I totally get that, but my real question here is why the difference might be so pronounced. I mean (coming from a layman of course) that the centrifugal might do 4-5 PSI at 3k-4k rpm where as the twin screw is producing 10psi at very low RPM.

You won't likely see 10psi in the manifold from either blower after the air is done traveling through the inlet restrictions etc, I get that, but I still don't understand how the baby Novi would produce a faster car.

And I respect everyone's opinion here, so I'm not trying to prove anyone right or wrong, just curiosity of course!

You would need to compare the fan curves to be sure. Toma is out of his gord when it comes to political issues, but when it comes to cars, I would believe him. Truth, is a centrigual fan is much more efficient than a twin screw, and if you set it up as they have in the link posted by the OP you can see that, yes the centrifugal fan, does lose in the bottom end but makes more power up top.

Most everyone that I know of does not have drag radials and does not use them on the street and as I stated above both V8's have more than enough power to light up the tires on the bottom end so the extra power provided by the screw (a whipple in this case) is moot.


http://images.musclemustangfastfords.com/images/mmfp_0708_16_z+vortech_centrifugal_supercharger_wastegate_install+dyno_results.jpg

[Dritto]

Originally posted by alloroc


You would need to compare the fan curves to be sure. Toma is out of his gord when it comes to political issues, but when it comes to cars, I would believe him. Truth, is a centrigual fan is much more efficient than a twin screw, and if you set it up as they have in the link posted by the OP you can see that, yes the centrifugal fan, does lose in the bottom end but makes more power up top.

Most everyone that I know of does not have drag radials and does not use them on the street and as I stated above both V8's have more than enough power to light up the tires on the bottom end so the extra power provided by the screw (a whipple in this case) is moot.


http://images.musclemustangfastfords.com/images/mmfp_0708_16_z+vortech_centrifugal_supercharger_wastegate_install+dyno_results.jpg

Sorta true... I mean, I can dump the clutch in a Civic and smoke the tires too. 400ft/lbs is a reasonable amount of power to hook on even semi-decent street tires. Maybe not from a hard launch, but as long as a street car can hook when you mash the pedal rolling at 5mph, you're doing OK.

The dyno is definitely interesting, but it's hard to judge since we don't know anything about the blowers being used, whether or not they are both intercooled. Anyway, it's definitely interesting to see the centri matching the power output of the twin screw at 7psi LESS.

[Ekliptix]

Originally posted by Dritto


Sorta true... I mean, I can dump the clutch in a Civic and smoke the tires too. 400ft/lbs is a reasonable amount of power to hook on even semi-decent street tires. Maybe not from a hard launch, but as long as a street car can hook when you mash the pedal rolling at 5mph, you're doing OK.

The dyno is definitely interesting, but it's hard to judge since we don't know anything about the blowers being used, whether or not they are both intercooled. Anyway, it's definitely interesting to see the centri matching the power output of the twin screw at 7psi LESS.
I have not tried a KB blower, but the centri on my 5L making a whopping 6.5psi max boost makes enough torque to blow the street tires off from a 45km/h roll. That's with 340ft/lbs

One reason I prefer the centri is that it is way quieter, especially mine since it's internally belt driven rather then by gears. People don't know the car is blown. That's just a preference though. I know on many cars (corvette for example) an aftermarket hood is required for a roots blower, where a centri does not require one.

Here's the dyno chart with boost being logged. I'm making 90% of my peak torque at only 1.2psi of boost: http://i18.photobucket.com/albums/b109/Ekliptix/Mustang/Dyno4.jpg

[alloroc]

Originally posted by Dritto


Sorta true... I mean, I can dump the clutch in a Civic and smoke the tires too. 400ft/lbs is a reasonable amount of power to hook on even semi-decent street tires. Maybe not from a hard launch, but as long as a street car can hook when you mash the pedal rolling at 5mph, you're doing OK.

The dyno is definitely interesting, but it's hard to judge since we don't know anything about the blowers being used, whether or not they are both intercooled. Anyway, it's definitely interesting to see the centri matching the power output of the twin screw at 7psi LESS.

One observation was made was that the intake manifold temp actually got lower as the RPM's went up. They attributed this to the efficiency of the intercooler, but the efficiency of the fan is just as important, and with a wastegate you can marry your fan selection and discharge pressure to maintain peak efficiency. Unfortunatly with the screw setup with a wastegate like I had on my rolla the only benefit is you can pull back the peak boost to match the fuel you are using, (not necessarily a bad thing though)


The quality of the air is just as important as the quantity. I think this is something Ross Farnham of sdsefi fame has been preaching for the last 15 or 20 years.

[Dritto]

Thanks for the dyno Ekliptix, definitely good to have the first hand experience/opinion.

My 5.0 is getting a blower this summer. I'm still thinking the KB personally, but it always pays to check out all your options before buying.

I hope you don't mind but I think I'll send you a quick PM and ask of your 5.0 experiences with the blower.

[YamahaV8]

I am confused as to why they are calling it a waste gate when it is clearly a BOV. The theory on how it works is right but it is a BOV not a waste gate. A waste gate controls turbo boost by adjusting how much exhaust gases goes through the turbine of the turbo. On a supercharged system there is obviously no exhaust components that have to do with the boost. This BOV is just unique in the ability to adjust its leak rate to keep a specified PSI setting.

[962 kid]

Originally posted by YamahaV8
I am confused as to why they are calling it a waste gate when it is clearly a BOV. The theory on how it works is right but it is a BOV not a waste gate. A waste gate controls turbo boost by adjusting how much exhaust gases goes through the turbine of the turbo. On a supercharged system there is obviously no exhaust components that have to do with the boost. This BOV is just unique in the ability to adjust its leak rate to keep a specified PSI setting.

It's called a wastegate because that's what it is. A BOV's function is to prevent compressor surge by venting pressurized air when the TB closes. A wastegate's function is to regulate boost by dumping "waste." It doesn't matter if it's dumping air before or after it goes through the engine, it still works the same and has the exact same function.

[YamahaV8]

Originally posted by 962 kid


It's called a wastegate because that's what it is. A BOV's function is to prevent compressor surge by venting pressurized air when the TB closes. A wastegate's function is to regulate boost by dumping "waste." It doesn't matter if it's dumping air before or after it goes through the engine, it still works the same and has the exact same function.

I see what you are saying. I just assumed that a wastegate only dealt with exhaust gases. Is the wastegate for this supercharged setup constructed like a BOV cause it looks like one in the pictures?

[zieg]

no, the wastegate is constructed like a wastegate. it opens when you reach your desired boost, not when there is vacuum in the manifold like with a BOV.

[alloroc]

Originally posted by YamahaV8


I see what you are saying. I just assumed that a wastegate only dealt with exhaust gases. Is the wastegate for this supercharged setup constructed like a BOV cause it looks like one in the pictures?

Maybe you are looking at the BOV because they have one of those too?
Remember a wastegate located at a S/C outlet will just be venting to the amosphere but they are a bit more complex than a BOV

A bov cannot be used to control boost because it operates over a small proportional range and is either controlled directly by the pressure of the pipe it is connected to, or a diaphram and plunger that operate off the the intake manifold. A BOV is designed to be pressure safety valve and that it does - admirably.

The wastegate valve is driven by an actuator and as such it not only operates over a larger proportional range but can be controlled via an extrernal signal (ie. pressure line from a boost controller on pnumatic valves, hydraulic fluid pressure on fluid actuators, or even an electronic signal if the actuator happened to be electric.

[YamahaV8]

Originally posted by alloroc


Maybe you are looking at the BOV because they have one of those too?
Remember a wastegate located at a S/C outlet will just be venting to the amosphere but they are a bit more complex than a BOV

A bov cannot be used to control boost because it operates over a small proportional range and is either controlled directly by the pressure of the pipe it is connected to, or a diaphram and plunger that operate off the the intake manifold. A BOV is designed to be pressure safety valve and that it does - admirably.

The wastegate valve is driven by an actuator and as such it not only operates over a larger proportional range but can be controlled via an extrernal signal (ie. pressure line from a boost controller on pnumatic valves, hydraulic fluid pressure on fluid actuators, or even an electronic signal if the actuator happened to be electric.

OK I see. I guess I have never dealt with a supercharged system close up. Thanks for the explanation. :clap:

[alloroc]

Originally posted by YamahaV8


OK I see. I guess I have never dealt with a supercharged system close up. Thanks for the explanation. :clap:

What those guys are doing is not your typical setup. Depending on the location of the throttle plate some S/C systems don't even have a BOV and almost none have wastegates.

[962 kid]

Originally posted by ZiG-87
no, the wastegate is constructed like a wastegate. it opens when you reach your desired boost, not when there is vacuum in the manifold like with a BOV.

move the hose from one port of the wastegate to the other ---presto-- chango it works like a BOV ... it's almost like magic