Forced Induction for the daily driver.

[beefcake]

Don't say that.
You will get murdered on here.

Torque does matter to a point.
However if it was all about TQ, then we would all be racing Diesels.

I am going to shoot a video of the dash of our Mustang, on a 1/4 run.
And then time how long the tach is below 3,000 RPM vs. sitting right in the "sweet spot" for a centrifugal.
Actually on second thought I don't have to. Somewhere I have the datalog from our 2011 Stock GT going 10's with the i1. I just need to find it.

that's my whole point

in a race, on your shift points, your coming in 5500-6000 on the shifts, you less than 1 second of the race at that point

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[sqidd]

People want to argue the "low end torque" all day. Torque doesn't win drag races, HP does.

Fixed

There is about a zillion other forms of racing where torque does win.

Arguing centri vs PD really is stupid unless the argument is about one specific task. No one blower does everything better. It's like arguing what is hotter, blondes or brunettes. Whatever turns you on is best.

 

[pinero61]

I like centri's and turbos simply for the fact that the power comes on gradually, and they do better on the top end than roots style compressors. It easier on the drive line, and you don't blow the tires off with a throttle blip.

 

[pinero61]

Fixed

There is about a zillion other forms of racing where torque does win.

Arguing centri vs PD really is stupid unless the argument is about one specific task. No one blower does everything better. It's like arguing what is hotter, blondes or brunettes. Whatever turns you on is best.

I agree, each shines within its own element.

 

[sqidd]

ok, maybe saying positive boost is not accurate. However, if a twin screw is spinning, is it not compressing air, increasing airflow over what a non SC engine would be making at the same throttle input and rpm? Making a similar response to just giving an NA car more throttle. I hope I'm explaining this idea right. Anyhow, i'm also not trying to make the impression I know much about SC, which I don't. Just trying to get a better understanding. As I see much back and forth on whether a pd supercharger is doing "work" 100% of the time or not. I understand there are some "bypasses", do all superchargers include this? I'm under the impression they don't.

When the bypass is open there is zero boost. There is vacuum.

All the PD blowers I know about have bypass valves.

Normally if I call someone wrong, I give them an explanation...so do tell.

Blowers are more expensive than turbo's for the OEM's to use.

 

[pinero61]

When the bypass is open there is zero boost. There is vacuum.

All the PD blowers I know about have bypass valves.



Blowers are more expensive than turbo's for the OEM's to use.

But, as said, turbos do not give the seat of the pants fast like blowers do. Which, is what matters to most people.

 

[sqidd]

I am going to shoot a video of the dash of our Mustang, on a 1/4 run.
And then time how long the tach is below 3,000 RPM vs. sitting right in the "sweet spot" for a centrifugal.

How about another video of the car on the street showing how much time it is below 3,000?

1/4 racing is not a good predictor of what will make a street or track car good. If it were we would all be driving "nitromethanes" (poking at your diesel comment;)).

There is an old saying in circuit/roadracing. "You pass 3,000rpm twice when revving to 6,000rpm".

 

[foghat]

But, as said, turbos do not give the seat of the pants fast like blowers do. Which, is what matters to most people.

Depends on the setup. My twin turbo 135i brought on full torque hard and fast.

 

[ProChargerTECH]

ok, maybe saying positive boost is not accurate. However, if a twin screw is spinning, is it not compressing air, increasing airflow over what a non SC engine would be making at the same throttle input and rpm? Making a similar response to just giving an NA car more throttle. I hope I'm explaining this idea right. Anyhow, i'm also not trying to make the impression I know much about SC, which I don't. Just trying to get a better understanding. As I see much back and forth on whether a pd supercharger is doing "work" 100% of the time or not. I understand there are some "bypasses", do all superchargers include this? I'm under the impression they don't.




Normally if I call someone wrong, I give them an explanation...so do tell.

Air not being used needs to be bypassed or blown off.

The downside to most roots/screws is that the extra air is bypassed.
Meaning its looping from the bottom of the blower, to the inlet of blower.
Which can cause heat to build up over time, even if not being used at WOT.

Yes centrifugals move excessive air as well, however it is "BLOWN OFF" and not bypassed.
Meaning we dump that extra air thats not being used, before it even reaches the intercooler.
And its not looped back to the front of the blower.
This keeps the IAT's down as the car is driving normal, and no heat soak.

Also nature of a centrifugal compressor is a lower temperature per psi.

On daily drivers, also remember that most everyone picks up MPG's while driving their cars/trucks normally after installing a ProCharger.
Obviously people don't buy a supercharger for a tiny uptick of MPG's, however its sure nice that its there.

 

[sqidd]

But, as said, turbos do not give the seat of the pants fast like blowers do. Which, is what matters to most people.

It's what matters to me in a street car. I want my stuff to punch HARD down low.

If I were building a car that went to the strip a lot and actually cared about a few 10ths I would build a centri or turbo car. For a track car I would rather be NA, but if I had to have forced induction it would be a centri or turbo car. For driving around on the street, blasting some twisty back roads and making the occasional trip to the 1/4 I'll take a PD blower.

There is a tool for every job.

 

[pinero61]

Depends on the setup. My twin turbo 135i brought on full torque hard and fast.

Well, so is my modded 3.5l Eco in my Fx4, but it doesn't feel as fast as my buddy's modded Hemi. Which, is almost a second slower in the 1/4.

 

[sqidd]

Also nature of a centrifugal compressor is a lower temperature per psi.

Data?

 

[pinero61]

It's what matters to me in a street car. I want my stuff to punch HARD down low.

If I were building a car that went to the strip a lot and actually cared about a few 10ths I would build a centri or turbo car. For a track car I would rather be NA, but if I had to have forced induction it would be a centri or turbo car. For driving around on the street, blasting some twisty back roads and making the occasional trip to the 1/4 I'll take a PD blower.

There is a tool for every job.

I agree with you on which is best for what application, but for parts longevity in a street car, I would say turbos/certi's are better. Just for the fact that they gradually build torque, and don't slam it into the drive train like the roots style.

Plus I love winding the gears out

 

[DivineStrike]

So, since heat is ultimately the killer of an engine. Would it be safe to say a centri supercharger would be the "best" fi to use if you wanted to have fi and hit up a road course. I understand with most superchargers you get heat soak and turbos build up a lot of heat as well

At least if what is being said in this thread about centris is true

 

[sqidd]

I agree with you on which is best for what application, but for parts longevity in a street car, I would say turbos/certi's are better. Just for the fact that they gradually build torque, and don't slam it into the drive train like the roots style.

Plus I love winding the gears out

I'm just debating for the fun of it here.

A centri/turbo car will see higher RPM more often. And RPM is the #1 killer of motors.

If the tires are spinning there is no driveline shock.

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