SC and TT Characteristics Compared & Discussed
- Thread starter nota4re
- Start date
It's being done with centrifugal chargers in the diesel hotrod world currently.
How coincidental, Kendall and I just discussed this the other day. Are you reading this Kendall
Fast Freddy
GPS'D 225 MPH
skyrex
FORD GT OWNER
Ask Richard Hille. He ran a couple laps in a TT GTX1 at Willow at the GT school I went to a year and a half ago. I think he has taken a few of the SC configurations around the track as well.
- Aug 25, 2006
- 4,436
I suspect that with a long straight that the turbo would be wicked fast !!
As for the activity through the corners; I do not know
Rick has had both of his gals there; one a turbo and the other a Whipple so maybe he will comment.
Shadowman
Mullet
FORD GT OWNER
Yes and yes
I absolutely love it. Maybe a few less hp's on top but plenty down low when driving it around like most ofus do 95% of the time. Oh, and it does pretty well at the Mile too.
Mullet
FORD GT OWNER
soroush
Ford Gt Owner
- Aug 8, 2007
- 5,256
Mullet
FORD GT OWNER
"if" I were building a track GT I would go with a SC setup for more linear power instead of the hit turbos give. Granted it would have to be a 1000hp SC setup because anything less is unacceptable.
soroush
Ford Gt Owner
- Aug 8, 2007
- 5,256
making a 1000 to the wheels with a sc has been relatively difficult up until now. thats the surprising part.
Mullet
FORD GT OWNER
BlackICE
GT Owner
I like to know more. Must be running extreme race fuel with an updated fuel system, pumps and injectors. Possbily other mods, air box, intercooler, water injection.
tmcphail
GT Owner/Vendor
Doesn't need one since it is not a positive displacement charger and it's upstream of the turbo. I'd love to talk forced induction and have some experience with singles and compounds but it's apples and oranges comparing diesel setups and gas setups. I do get a kick out of people talking about lag in a parallel twin setup for gas. This is lag http://www.youtube.com/watch?v=bt8w3qlzZhs Somewhere north of 1200hp and over 2000ft lbs tq. Sorry for the getting this thread off in the weeds. Please continue what is an interesting discussion.
http://www.youtube.com/watch?v=bt8w3qlzZhs Somewhere north of 1200hp and over 2000ft lbs tq. Sorry for the getting this thread off in the weeds. Please continue what is an interesting discussion.
Last edited:
"if" I were building a track GT I would go with a SC setup for more linear power instead of the hit turbos give. Granted it would have to be a 1000hp SC setup because anything less is unacceptable.
How do yo propose to transfer that power level into acceleration - current tire adhesion characteristics are not compatible with such power levels on a road course requiring variable shifting patterns, braking and speeds between each corner. Racing on road courses does not allow for the degree of throttle control necessary for the "mile" or dragstrip , but must be flexible and responsive within the adhesion range of the tires.
The SC Advantage #1: Dominance in the lower RPMs
As a generalization about power delivery, I hope that we can all agree that the SC holds a very DISTINCT advantage over a TT car in the first half of the RPM range. In the charts in this thread (for equal amounts of boost), the TT system doesn't match the SC's power output until 4200 RPM - as this is "finally" where the turbos can get to the boost PSI that the SC's deliver from 2000 RPM upward. Without splitting hairs, does everyone agree with this? The lower RPM range is "owned" by the SC set-ups. (For simplicity, let's try to keep the discussion GT-related as we could easily digress into other types of SC's where the power delivery is significantly different than the screw type of blowers available for the GT.)
Further, with the "right now", "stump pulling" power delivery of the SC's in the lower RPM's (and I'm not excluding a strong punch in the higher RPMs as well), the sensation CANNOT help but bring a smile to your face. This experience and this feeling - certainly has its home. If you're tooling around the neighborhood and feeling a little spunky, it's nice to know that with just a quick jab of the right foot, almost regardless of RPM, the car lurches toward WARP drive! In essence, the car feels as if it has an 800 cu in motor in it! Case in point: Take a TT car and an SC car and set the rev limiter to 4500 RPM and turn a test group of car junkies loose with the cars for a few days and ask them which one they'd rather have. Every one of them is gonna take the SC car. Case closed. EASY decision.
As a generalization about power delivery, I hope that we can all agree that the SC holds a very DISTINCT advantage over a TT car in the first half of the RPM range. In the charts in this thread (for equal amounts of boost), the TT system doesn't match the SC's power output until 4200 RPM - as this is "finally" where the turbos can get to the boost PSI that the SC's deliver from 2000 RPM upward. Without splitting hairs, does everyone agree with this? The lower RPM range is "owned" by the SC set-ups. (For simplicity, let's try to keep the discussion GT-related as we could easily digress into other types of SC's where the power delivery is significantly different than the screw type of blowers available for the GT.)
Further, with the "right now", "stump pulling" power delivery of the SC's in the lower RPM's (and I'm not excluding a strong punch in the higher RPMs as well), the sensation CANNOT help but bring a smile to your face. This experience and this feeling - certainly has its home. If you're tooling around the neighborhood and feeling a little spunky, it's nice to know that with just a quick jab of the right foot, almost regardless of RPM, the car lurches toward WARP drive! In essence, the car feels as if it has an 800 cu in motor in it! Case in point: Take a TT car and an SC car and set the rev limiter to 4500 RPM and turn a test group of car junkies loose with the cars for a few days and ask them which one they'd rather have. Every one of them is gonna take the SC car. Case closed. EASY decision.
BlackICE
GT Owner
Agreed, but somehow during mile events that same euphoria below 4000 is lacking in my SC setup. The 1st 3 gears, no complaints, pulls very strong, the last 3 could have used some more power, which the TT have. Since I drive more on the street below 4000 I feel the SC setup is right for me. But then for those with the newly installed TT setup, I am sure they all will smile during the next Mojave mile and will be disappointed at well with the 205 MPH cap.
Mullet
FORD GT OWNER
with the gas pedal?
in all seriousness if I had to choose a car with linear power and one with a more abrupt delivery I would pick the linear for obvious reasons
The SC Advantage #2: Packaging (and maybe its relative: cost)
Another advantage of the SC - and a lot of Automotive companies will confirm, is packaging. The supercharger, while a complex and highly engineered piece of equipment can be packaged more reasonably than can a turbocharger system. With the SC, you have the highly engineered blower itself with a belt to be turned by the engine. You need to incorporate a bypass valve (for when the throttle plates snap shut under boost). Typically an SC will have its own (relatively maintenance free) oil supply. A screw type of SC (or "meat grinder" if you prefer) will typically sit atop the engine which is a natural place to "receive" the metered air and then finally push it down through an intercooler which is increasingly found to be incorporated in the valley between the cylinders. (Ford GT, ZR1, etc.)
In contrast, the Turbo system is more complex. First, you have to position the turbo(s) and for best efficiency they need to be in the exhaust stream and more upstream than downstream.... more or less right where the OEM's would like to place their CATs. With the turbo(s) positioned, now you need to give them an oil supply - both a feed line as well as a drain line. Modern turbochargers are also water cooled - so add a water-in and a water-out line to each turbo. Like the SC install, a turbo also needs a bypass valve (or two) to deal venting pressure when the throttle is closed. But, the turbos also need a means of regulating boost - so an install must comprise of a wastegates and any associated vacuum plumbing. Finally, the turbos have to be fed metered air, and they have to also route the compressed air back up to the intake. All in all, there is a lot of "plumbing" that needs to be designed and installed - adding a lot more components and complexity over a comparatively simple SC set-up.
In summary, the packaging of an SC system is simpler, typically lower cost because of this, and arguably fewer points of failure. This is another area where the SC - whether OEM or aftermarket is advantageous (and often lower cost) compared to a turbo system.
Another advantage of the SC - and a lot of Automotive companies will confirm, is packaging. The supercharger, while a complex and highly engineered piece of equipment can be packaged more reasonably than can a turbocharger system. With the SC, you have the highly engineered blower itself with a belt to be turned by the engine. You need to incorporate a bypass valve (for when the throttle plates snap shut under boost). Typically an SC will have its own (relatively maintenance free) oil supply. A screw type of SC (or "meat grinder" if you prefer) will typically sit atop the engine which is a natural place to "receive" the metered air and then finally push it down through an intercooler which is increasingly found to be incorporated in the valley between the cylinders. (Ford GT, ZR1, etc.)
In contrast, the Turbo system is more complex. First, you have to position the turbo(s) and for best efficiency they need to be in the exhaust stream and more upstream than downstream.... more or less right where the OEM's would like to place their CATs. With the turbo(s) positioned, now you need to give them an oil supply - both a feed line as well as a drain line. Modern turbochargers are also water cooled - so add a water-in and a water-out line to each turbo. Like the SC install, a turbo also needs a bypass valve (or two) to deal venting pressure when the throttle is closed. But, the turbos also need a means of regulating boost - so an install must comprise of a wastegates and any associated vacuum plumbing. Finally, the turbos have to be fed metered air, and they have to also route the compressed air back up to the intake. All in all, there is a lot of "plumbing" that needs to be designed and installed - adding a lot more components and complexity over a comparatively simple SC set-up.
In summary, the packaging of an SC system is simpler, typically lower cost because of this, and arguably fewer points of failure. This is another area where the SC - whether OEM or aftermarket is advantageous (and often lower cost) compared to a turbo system.
Last edited: