Is it just me or do superchargers have slight lag?

baege · 05-11-2016, 07:30 AM

I appreciate this forum as a place where a crazy car guy can post random questions like this

So in pursuit of a low end torque rich car to replace my 2016 cayman I have recently test driven a 2016 audi S5 and a 2017 Jaguar F type S Coupe, both manual.

Both cars are supercharged and both supposedly make gobs of torque from relatively low rpms. However, I walked away from both test drives disappointed in the low rpm throttle response.

Basically what I am looking for is when I jab the throttle I feel that instant push in the back at low rpms that my old fox body 5.0 mustangs used to provide. I enjoy that feeling and the instant passing ability in traffic. I think it's good fun

My cayman doesn't offer that. I expected the s5 and the f type to offer that, but neither did. I swear with both I could feel a slight lag in the throttle response at lower rpms, almost like a turbo but much less evident.

In a way, even though my cayman makes significantly less torque, it had much more immediate throttle response than both cars and so in a way offered that immediate push in the back more so than either car. The throttle felt more direct and connected to the car than both the s5 and the f type. There is no lag with my cayman. Yet I felt some with both supercharged cars.

A quick google search reveals that some take the view that in fact superchargers do offer slight lag.

http://www.redline360.com/garage/wha...er-has-lag-too

I am very sensitive to lag, I don't like the lack of connection and directedness that it takes away, which is why I steer clear of turbo cars. I didn't expect to feel this with supercharged cars, but I still felt it.

Anyone else feel this way or I am just way too lag sensitive?

MightyMouseTech · 05-11-2016, 08:41 AM

You will get more low end boost with a turbo. Superchargers require RPM to build boost (the higher the RPM, the faster a supercharger spins) so tend to build boost gradually.

shadow191 · 05-11-2016, 08:58 AM

Audi uses a positive displacement supercharger so it builds boost at much lower RPMs than a centrifugal supercharger which is much more rpm dependent (max boost at redline). Roots blowers are much more efficient at lower RPMs than at higher ones.

But there is still going to be a momentary lag from when you tip into the throttle to when boost builds. Even though the supercharger will spin faster as soon as you get on the throttle, it will take a moment for it to move enough air.

burnrbr · 05-11-2016, 09:16 AM

The "lag" that you are feeling is from the supercharger bypass valve closing and the boost building. It is not from any rpm dependent variables. It's just the transition of the air pressure. The bypass valve allows air to bypass the rotors which prevents boost. If those cars you drove use a maf versus speed density, it will effect throttle response because the air measuring device is farther way from the intake valve. I tuned my previous 2009 CTS-V with maf only and speed density only. The speed density throttle response was much more crisp. The ECU for the CTS-V had tables that controlled the rate at which the bypass would close. Adjusting those tables made the boost hit even harder. IMO roots superchargers, compared to other boost generating devices, are the best at getting really close to NA throttle response.

RM7 · 05-11-2016, 10:08 AM

Having a very torque-rich car as my last car, I can attest that a lot of other things come into play, like being in the right gear at the right RPM. Said car was happy to cruise at 1000rpm due to the massive torque, but at that rpm you aren't going to explode out of any corners, it's going to take a long time to build up RPM and accelerate up a hill, but it would do it. An auto-trans is probably not the best way to experience this from a roll. My turbo car before that one would go more like god kicked it in the rear when I got the RPM up to the max-torque area, combined with short gearing would really make it seem like a rocket.

A good amount of power and short gearing is probably what you want.

smrtypants44 · 05-11-2016, 10:29 AM

My guess is a lot of the lag has to do with the throttle calibration also. I notice a lot of new cars have a bit of dead space in the pedal.

GuidoK · 05-11-2016, 12:27 PM

Quote:

Originally Posted by shadow191

But there is still going to be a momentary lag from when you tip into the throttle to when boost builds. Even though the supercharger will spin faster as soon as you get on the throttle, it will take a moment for it to move enough air.

A volumetric displacement supercarger (roots, twinscrew, TVS, G-lader) has instant boost. There is no other way to define it.
They are always rotating and virtually need no high rpm for making boost. (sub 2k rpm there is full boost)
However it needs to fill the plenum vacuum void, but that also has to be done with a NA engine. What I mean is that the space after the TB is vacuum. When the TB opens, air has to rush in (into the manifold etc), which takes time. How much time? for NA and a volumetric SC its the same I guess for the same amount of air? Except an SC engine usually has more power (for the same size/size manifold), so more air in takes more time, even force fed and during that time power increses.
But the volumetric SC moves enough air all the time. It never stops unless there is a clutch on the pulley. So when the TB opens, and as soon as the supercharger gets air, it makes boost. On my install the bypass valve is vacuum operated, so as soon as the tb opens, vacuum is gone and the bypass valve is closed. That goes instantly. (way faster than the TB can move anyway)
The same goes for the engine; as soon as air, fuel and a spark gets into the cylinders there is power (and exhaust gas)

I experienced no extra lag when I went from NA to volumtric SC (twinscrew) on the same engine.

The redline360.com link is nonsense, as it only covers centrifugal SC's, so they cut a story short by only telling half the truth...
Probably because they have a commercial agenda (they sell only turbo's, so a BS story that a supercharger also 'has lag' (of some sort) fits their commercial goals).

Quote:

Originally Posted by smrtypants44

My guess is a lot of the lag has to do with the throttle calibration also. I notice a lot of new cars have a bit of dead space in the pedal.

That is probably more true. an electronic TB in itself takes time to move, it isn't infinite fast. There is an electric motor and reduction gearing. The movement of the TB and the filling of the manifold with air is the lag.

baege · 05-11-2016, 03:35 PM

Quote:

Originally Posted by GuidoK

A volumetric displacement supercarger (roots, twinscrew, TVS, G-lader) has instant boost. There is no other way to define it.
They are always rotating and virtually need no high rpm for making boost. (sub 2k rpm there is full boost)
However it needs to fill the plenum vacuum void, but that also has to be done with a NA engine. What I mean is that the space after the TB is vacuum. When the TB opens, air has to rush in (into the manifold etc), which takes time. How much time? for NA and a volumetric SC its the same I guess for the same amount of air? Except an SC engine usually has more power (for the same size/size manifold), so more air in takes more time, even force fed and during that time power increses.
But the volumetric SC moves enough air all the time. It never stops unless there is a clutch on the pulley. So when the TB opens, and as soon as the supercharger gets air, it makes boost. On my install the bypass valve is vacuum operated, so as soon as the tb opens, vacuum is gone and the bypass valve is closed. That goes instantly. (way faster than the TB can move anyway)
The same goes for the engine; as soon as air, fuel and a spark gets into the cylinders there is power (and exhaust gas)

I experienced no extra lag when I went from NA to volumtric SC (twinscrew) on the same engine.

The redline360.com link is nonsense, as it only covers centrifugal SC's, so they cut a story short by only telling half the truth...
Probably because they have a commercial agenda (they sell only turbo's, so a BS story that a supercharger also 'has lag' (of some sort) fits their commercial goals).

That is probably more true. an electronic TB in itself takes time to move, it isn't infinite fast. There is an electric motor and reduction gearing. The movement of the TB and the filling of the manifold with air is the lag.

I think you and the poster who referred to electronic throttle calibration nailed it.

My cayman's throttle calibration is very good, it is very linear and responsive in normal mode. I actually don't like it in sport mode where it becomes twitchy and less precise.

GuidoK · 05-11-2016, 05:06 PM

Of course how laggy an engine feels also depends on the engine itself. I mean comparing a supercharged audi engine with maybe even an automatic (heavy torque converter) to say a merc engine maybe with manual is comparing apples with oranges. The 'lag' of an engine is of course also a sum of the engine itself. How much inertia (weight in the moving parts) etc etc.
If you look at an old fashioned f1 engine (non turbo) pretty everything else is laggy, NA or FI, the way those engines rev.
So maybe a factory SC engine is less revvy because moving parts is more heavily build.
As I said I didnt experience an extra lag when I converted my NA engine to twinscrew. And that makes boost pretty instant.
You can see how the boost on a twinscrew behaves in this old ESS video:

There is virtually no lag because the needle rises about as fast as it falls. That means that that's either the speed of the TB or the speed of the meter (but it's an analog pressure meter, so not with a sensor/electronics etc (so no electronic lag), just a pressure hose)

When the TB is closed, vacuum is pretty instant (the manifold is pressurized with about 50% more air, but the cylinders suck that extra 50% empty in 1 rev, so I dont think there is something as afterlag, at least not significantly. It would be the same as having a manifold that is 50% larger in volume).

The Wind Breezes · 05-11-2016, 10:09 PM

Sounds like the problem is not the supercharger but the powerband of the motors you drove. They don't make their torque low enough.

mremg · 05-12-2016, 12:44 AM

Just curious - Why the pursuit for low end torque car instead of Cayman? Not that a Cayman is weak down low..

m5james · 05-12-2016, 01:17 AM

Quote:

Originally Posted by burnrbr

The "lag" that you are feeling is from the supercharger bypass valve closing and the boost building. It is not from any rpm dependent variables. It's just the transition of the air pressure. The bypass valve allows air to bypass the rotors which prevents boost.

This is EXACTLY why right here. Factory restrictive intakes, exhaust and in this case a spring are there not to scare the old lady who moght buy that car as well. I've got a Harley F150 and went fully built motor, replaced the 1.6l Eaton with a 2.3l Kenne Bell and everyone told me to remove the spring from the bypass valve. I miss the linear boost response, but then again going from zero to hero is fun as well.

burnrbr · 05-12-2016, 06:34 AM

Quote:

Originally Posted by m5james

This is EXACTLY why right here. Factory restrictive intakes, exhaust and in this case a spring are there not to scare the old lady who moght buy that car as well. I've got a Harley F150 and went fully built motor, replaced the 1.6l Eaton with a 2.3l Kenne Bell and everyone told me to remove the spring from the bypass valve. I miss the linear boost response, but then again going from zero to hero is fun as well.

To add more clarity to my original post and to back up yours, the CTS-V had a computer controlled solenoid that managed the amount of vacume going to the diaphram on the bypass value. Tuning the tables that control it allows instant changes in vacume to directly effect the diaphram resulting in the bypass valve moving directly inline with the throttle body. It even had tables specific to changing gears in order to soften the torque hit to the drivenline during gear changes. I had the manual and after tuning those tables the torque hit was noticeably harder on fast full throttle shifts. When you removed the spring, you allowed the bypass value to move inline with the throttle body.

Most aftermarket supercharger kits have a direct vacume source to the bypass valve's diaphram. This is most likely why GuidoK experienced no "lag" after install.

GuidoK · 05-12-2016, 06:42 AM

yes, this is the response time of my bypass valve, vacuum activated.
I shot this video because the rubber bypass hose was collapsing under vacuum. Turned out there was a steel reinforcement ring inside that had moved. Now its clamped in place with a jubilee clip.
You can see the metal valvelever moving (actuated by the vacuum diaphram).
When driving, as soon as that valve closes, there is instant boost and you get that nice shock in the back. Especially around 3-4krpm when the engine gives max. torque
That bypass valve probably moves faster than the TB I expect.

...old dodgy phone video

baege · 05-12-2016, 07:47 AM

Quote:

Originally Posted by The Wind Breezes

Sounds like the problem is not the supercharger but the powerband of the motors you drove. They don't make their torque low enough.

the f type makes 332 ft lbs at 3500 rpm
the s5 makes 325 ft lbs at 2500 rpm

so they supposedly make pretty good torque down low

similar to what my old fox body mustang made (300 ft lbs at 3200 rpm)

but they certainly don't feel as torquey as my old 5.0's did

baege · 05-12-2016, 07:48 AM

Quote:

Originally Posted by mremg

Just curious - Why the pursuit for low end torque car instead of Cayman? Not that a Cayman is weak down low..

cayman S is actually relatively weak down low

ever since I first got a taste of low end torque in a 1989 mustang 5.0 I've liked low end torque and I can not lie

RM7 · 05-12-2016, 10:10 AM

I found my turbo 2.0 subaru engine would rev extremely fast, much faster than my big torque-rich V8. Had nothing to do with torque really, but one might think that the fast-revving was a result of it. I disagree with the guy about the superchargers, even volumetric ones aren't putting out the same amount of PSI at lower RPMs than turbos, but the issue with turbos is they drop off around 5K or so usually, while superchargers keep building HP and torque at higher RPMs. Now, this might also lead to an engine that is happy to rev, so there could be additional factors that add to your enjoyment. Also, short gears make a difference IMO.

shadow191 · 05-12-2016, 10:34 AM

Only centrifugal superchargers build boost all the way to redline. A positive displacement blower usually makes full boost somewhere relatively low and then stays at that boost level.

FWIW, I had a car that I put a Vortech on and then swapped for a turbo setup. At the same boost levels, the turbo setup is faster and easier to drive. A properly sized turbo won't drop off in higher RPMs and your powerband is much better than a centrifugal setup that doesn't even make full boost until redline.

Having driven a positive displacement setup vs. a centrifugal setup on the same model car, I think for daily driving or stoplight racing, the positive displacement is better. It makes the car feel like it has a bigger motor whereas the centrifugal makes a lot of power and is great if you're making highway runs, but it's not as practical for daily driving.

Quote:

Originally Posted by JamesNoBrakes

I found my turbo 2.0 subaru engine would rev extremely fast, much faster than my big torque-rich V8. Had nothing to do with torque really, but one might think that the fast-revving was a result of it. I disagree with the guy about the superchargers, even volumetric ones aren't putting out the same amount of PSI at lower RPMs than turbos, but the issue with turbos is they drop off around 5K or so usually, while superchargers keep building HP and torque at higher RPMs. Now, this might also lead to an engine that is happy to rev, so there could be additional factors that add to your enjoyment. Also, short gears make a difference IMO.

GuidoK · 05-12-2016, 12:27 PM

they usually say that a centrifugal SC makes '10% more power for 15% of the revrange'.
The rest of the situations a twinscrew is supposed to be faster (as you can see in the first video I posted, it pretty much makes full boost at 1700rpm or so).

One thing the cetrifugal SC has as a plus is that it produces less heat (especially also since it's not active for a large part of the revrange), so it's easier to make a low boost setup (5psi or so) where you can get away without having extra cooling (intercooler or charge cooler).
That means you can make really affordable low boost kits that are really easy to install. That appeals to the diy mechanic that can install a kit on his own driveway in an afternoon for $3k or so. Simple obd tune to go along and bob's your uncle.

FType22 · 05-12-2016, 12:56 PM

Came here to read the question, stayed here to learn everything and more I needed to know about blowers.

burnrbr · 05-12-2016, 08:31 PM

Quote:

Originally Posted by JamesNoBrakes

I found my turbo 2.0 subaru engine would rev extremely fast, much faster than my big torque-rich V8. Had nothing to do with torque really, but one might think that the fast-revving was a result of it. I disagree with the guy about the superchargers, even volumetric ones aren't putting out the same amount of PSI at lower RPMs than turbos, but the issue with turbos is they drop off around 5K or so usually, while superchargers keep building HP and torque at higher RPMs. Now, this might also lead to an engine that is happy to rev, so there could be additional factors that add to your enjoyment. Also, short gears make a difference IMO.

Your statement about boost pressure and rpm is only correct for very small turbos compared to large postive displacement superchargers. The new Z06 has a smaller supercharger at 1.7 L compared to the previous 2.3 L on the ZR1. It's spun faster for more boost lower the rpm while making roughly the same overall boost as the 2.3. The 2.3 L has a higher HP potential given it's higher flow capabilities. Small turbos aren't fun and large PD superchargers are; the inverse is also true :-)

burnrbr · 05-12-2016, 09:47 PM

Off topic comment... the Harrop supercharger for the S65 uses the same rotor pack as the the new Z06 which is the TVS1740. It isn't the highest power option available given ESS V3 or the Gintani turbos, but IMHO it has the best boosted throttle response across the entire rpm band for the S65. I love the throttle response of my S65 but want more power. The Harrop may be in my future.

05-11-2016, 07:30 AM	#1
baege Lieutenant Colonel 1459 Rep 1,667 Posts Drives: 2023 R8 RWD Coupe Join Date: Jun 2009 Location: Ontario, Canada iTrader: (0)	Is it just me or do superchargers have slight lag? I appreciate this forum as a place where a crazy car guy can post random questions like this So in pursuit of a low end torque rich car to replace my 2016 cayman I have recently test driven a 2016 audi S5 and a 2017 Jaguar F type S Coupe, both manual. Both cars are supercharged and both supposedly make gobs of torque from relatively low rpms. However, I walked away from both test drives disappointed in the low rpm throttle response. Basically what I am looking for is when I jab the throttle I feel that instant push in the back at low rpms that my old fox body 5.0 mustangs used to provide. I enjoy that feeling and the instant passing ability in traffic. I think it's good fun My cayman doesn't offer that. I expected the s5 and the f type to offer that, but neither did. I swear with both I could feel a slight lag in the throttle response at lower rpms, almost like a turbo but much less evident. In a way, even though my cayman makes significantly less torque, it had much more immediate throttle response than both cars and so in a way offered that immediate push in the back more so than either car. The throttle felt more direct and connected to the car than both the s5 and the f type. There is no lag with my cayman. Yet I felt some with both supercharged cars. A quick google search reveals that some take the view that in fact superchargers do offer slight lag. http://www.redline360.com/garage/wha...er-has-lag-too I am very sensitive to lag, I don't like the lack of connection and directedness that it takes away, which is why I steer clear of turbo cars. I didn't expect to feel this with supercharged cars, but I still felt it. Anyone else feel this way or I am just way too lag sensitive?
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05-11-2016, 08:41 AM	#2
MightyMouseTech Major General 4352 Rep 6,196 Posts Drives: 13 135i 6MT LeMans Blue MSport Join Date: Feb 2013 Location: Ottawa, Canada iTrader: (0)	You will get more low end boost with a turbo. Superchargers require RPM to build boost (the higher the RPM, the faster a supercharger spins) so tend to build boost gradually.
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05-11-2016, 08:58 AM	#3
shadow191 Lieutenant Colonel 182 Rep 1,681 Posts Drives: 2017 Volvo XC90 R-Design Join Date: Dec 2012 Location: GA iTrader: (3)	Audi uses a positive displacement supercharger so it builds boost at much lower RPMs than a centrifugal supercharger which is much more rpm dependent (max boost at redline). Roots blowers are much more efficient at lower RPMs than at higher ones. But there is still going to be a momentary lag from when you tip into the throttle to when boost builds. Even though the supercharger will spin faster as soon as you get on the throttle, it will take a moment for it to move enough air.
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05-11-2016, 09:16 AM	#4
burnrbr Second Lieutenant 73 Rep 285 Posts Drives: 2017 M3 Comp DCT Join Date: Jul 2015 Location: Jacksonville, FL iTrader: (2)	The "lag" that you are feeling is from the supercharger bypass valve closing and the boost building. It is not from any rpm dependent variables. It's just the transition of the air pressure. The bypass valve allows air to bypass the rotors which prevents boost. If those cars you drove use a maf versus speed density, it will effect throttle response because the air measuring device is farther way from the intake valve. I tuned my previous 2009 CTS-V with maf only and speed density only. The speed density throttle response was much more crisp. The ECU for the CTS-V had tables that controlled the rate at which the bypass would close. Adjusting those tables made the boost hit even harder. IMO roots superchargers, compared to other boost generating devices, are the best at getting really close to NA throttle response.
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05-11-2016, 10:08 AM	#5
RM7 Brigadier General 3052 Rep 3,658 Posts Drives: Camaro SS 1LE Join Date: May 2015 Location: Alaska iTrader: (0)	Having a very torque-rich car as my last car, I can attest that a lot of other things come into play, like being in the right gear at the right RPM. Said car was happy to cruise at 1000rpm due to the massive torque, but at that rpm you aren't going to explode out of any corners, it's going to take a long time to build up RPM and accelerate up a hill, but it would do it. An auto-trans is probably not the best way to experience this from a roll. My turbo car before that one would go more like god kicked it in the rear when I got the RPM up to the max-torque area, combined with short gearing would really make it seem like a rocket. A good amount of power and short gearing is probably what you want.
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05-11-2016, 10:29 AM	#6
smrtypants44 Captain 544 Rep 914 Posts Drives: 2022 X3M Join Date: Jul 2015 Location: Tulsa, OK iTrader: (2)	My guess is a lot of the lag has to do with the throttle calibration also. I notice a lot of new cars have a bit of dead space in the pedal. __________________
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05-11-2016, 05:06 PM	#9
GuidoK #buildnotbought 14303 Rep 5,567 Posts Drives: Z4 3.0i ESS TS2+ Join Date: Jul 2012 Location: Tinkering in the garage iTrader: (0)	Of course how laggy an engine feels also depends on the engine itself. I mean comparing a supercharged audi engine with maybe even an automatic (heavy torque converter) to say a merc engine maybe with manual is comparing apples with oranges. The 'lag' of an engine is of course also a sum of the engine itself. How much inertia (weight in the moving parts) etc etc. If you look at an old fashioned f1 engine (non turbo) pretty everything else is laggy, NA or FI, the way those engines rev. So maybe a factory SC engine is less revvy because moving parts is more heavily build. As I said I didnt experience an extra lag when I converted my NA engine to twinscrew. And that makes boost pretty instant. You can see how the boost on a twinscrew behaves in this old ESS video: There is virtually no lag because the needle rises about as fast as it falls. That means that that's either the speed of the TB or the speed of the meter (but it's an analog pressure meter, so not with a sensor/electronics etc (so no electronic lag), just a pressure hose) When the TB is closed, vacuum is pretty instant (the manifold is pressurized with about 50% more air, but the cylinders suck that extra 50% empty in 1 rev, so I dont think there is something as afterlag, at least not significantly. It would be the same as having a manifold that is 50% larger in volume). __________________ Z4 3.0i \| ESS TS2+ supercharger \| Quaife ATB LSD \| Brembo/BMW performance BBK front/rear \| Schrick FI cams \| Schmiedmann headers+cats \| Powerflex/strongflex PU bushings \| Vibra-technics engine mounts \| H&R anti rollbars \| KW V3 coilovers/KW camber plates \| Sachs race engineering clutch \| tons of custom sh#t
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05-11-2016, 10:09 PM	#10
The Wind Breezes Lieutenant Colonel 924 Rep 1,848 Posts Drives: 135i N55 DCT Join Date: Apr 2015 Location: USA iTrader: (0)	Sounds like the problem is not the supercharger but the powerband of the motors you drove. They don't make their torque low enough.
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05-12-2016, 12:44 AM	#11
mremg Private First Class 55 Rep 129 Posts Drives: TT RS, NC MX5 Join Date: Dec 2015 Location: SoCal iTrader: (0)	Just curious - Why the pursuit for low end torque car instead of Cayman? Not that a Cayman is weak down low..
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05-12-2016, 06:42 AM	#14
GuidoK #buildnotbought 14303 Rep 5,567 Posts Drives: Z4 3.0i ESS TS2+ Join Date: Jul 2012 Location: Tinkering in the garage iTrader: (0)	yes, this is the response time of my bypass valve, vacuum activated. I shot this video because the rubber bypass hose was collapsing under vacuum. Turned out there was a steel reinforcement ring inside that had moved. Now its clamped in place with a jubilee clip. You can see the metal valvelever moving (actuated by the vacuum diaphram). When driving, as soon as that valve closes, there is instant boost and you get that nice shock in the back. Especially around 3-4krpm when the engine gives max. torque That bypass valve probably moves faster than the TB I expect. ...old dodgy phone video __________________ Z4 3.0i \| ESS TS2+ supercharger \| Quaife ATB LSD \| Brembo/BMW performance BBK front/rear \| Schrick FI cams \| Schmiedmann headers+cats \| Powerflex/strongflex PU bushings \| Vibra-technics engine mounts \| H&R anti rollbars \| KW V3 coilovers/KW camber plates \| Sachs race engineering clutch \| tons of custom sh#t
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05-12-2016, 10:10 AM	#17
RM7 Brigadier General 3052 Rep 3,658 Posts Drives: Camaro SS 1LE Join Date: May 2015 Location: Alaska iTrader: (0)	I found my turbo 2.0 subaru engine would rev extremely fast, much faster than my big torque-rich V8. Had nothing to do with torque really, but one might think that the fast-revving was a result of it. I disagree with the guy about the superchargers, even volumetric ones aren't putting out the same amount of PSI at lower RPMs than turbos, but the issue with turbos is they drop off around 5K or so usually, while superchargers keep building HP and torque at higher RPMs. Now, this might also lead to an engine that is happy to rev, so there could be additional factors that add to your enjoyment. Also, short gears make a difference IMO.
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05-12-2016, 12:27 PM	#19
GuidoK #buildnotbought 14303 Rep 5,567 Posts Drives: Z4 3.0i ESS TS2+ Join Date: Jul 2012 Location: Tinkering in the garage iTrader: (0)	they usually say that a centrifugal SC makes '10% more power for 15% of the revrange'. The rest of the situations a twinscrew is supposed to be faster (as you can see in the first video I posted, it pretty much makes full boost at 1700rpm or so). One thing the cetrifugal SC has as a plus is that it produces less heat (especially also since it's not active for a large part of the revrange), so it's easier to make a low boost setup (5psi or so) where you can get away without having extra cooling (intercooler or charge cooler). That means you can make really affordable low boost kits that are really easy to install. That appeals to the diy mechanic that can install a kit on his own driveway in an afternoon for $3k or so. Simple obd tune to go along and bob's your uncle. __________________ Z4 3.0i \| ESS TS2+ supercharger \| Quaife ATB LSD \| Brembo/BMW performance BBK front/rear \| Schrick FI cams \| Schmiedmann headers+cats \| Powerflex/strongflex PU bushings \| Vibra-technics engine mounts \| H&R anti rollbars \| KW V3 coilovers/KW camber plates \| Sachs race engineering clutch \| tons of custom sh#t
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05-12-2016, 12:56 PM	#20
FType22 First Lieutenant 145 Rep 300 Posts Drives: 2011 e92 M3 Join Date: Nov 2015 Location: NY iTrader: (1)	Came here to read the question, stayed here to learn everything and more I needed to know about blowers.
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05-12-2016, 09:47 PM	#22
burnrbr Second Lieutenant 73 Rep 285 Posts Drives: 2017 M3 Comp DCT Join Date: Jul 2015 Location: Jacksonville, FL iTrader: (2)	Off topic comment... the Harrop supercharger for the S65 uses the same rotor pack as the the new Z06 which is the TVS1740. It isn't the highest power option available given ESS V3 or the Gintani turbos, but IMHO it has the best boosted throttle response across the entire rpm band for the S65. I love the throttle response of my S65 but want more power. The Harrop may be in my future.
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