Centrifugals and Low End Torque

[80FoxCoupe]

Maybe, but a centri has a lot of positive aspects I like. It’s just curious since it seems a relatively simple tuning change to mitigate its biggest weakness.

The theory is there. Try it and tell us how you like it.

Sponsored

 

[theruleslawyer]

This was interesting.
https://www.motortrend.com/how-to/sucp-1211-supercharger-wastegate/

 

[andrewtac]

This was interesting.
https://www.motortrend.com/how-to/sucp-1211-supercharger-wastegate/

I didn't realize a centri blower made none linear boost. It looks like a straight line to me when I plot my boost vs rpm. The theory is great, and I almost went down this road. I decided to get the pulley and not the wastegate. I am faster now than had I got the wastegate. I could probably get a smaller pulley and wastegate it, but I am just going wait until the motor is built and then fully turn it up. It had been shown to work, but mine and solarflare and others have also shown the stock motor holds together, so why not enjoy all the boost; knock on wood, I'll probably break something now.

And the thing you are trying to eliminate, the negative, is what I see as a positive. Easier on parts, traction, drivability, the street, and so on with a softer hit.

 

[80FoxCoupe]

This was interesting.
https://www.motortrend.com/how-to/sucp-1211-supercharger-wastegate/

Bam there you, for it up and let us know what you think!

 

[Toy Cobra]

The stock gen 3 engine with CS/Oil pump gears are solid. The block is the big limiting factor. We broke 2 at around 1140 wheel.

QUOTE="andrewtac, post: 3476831, member: 57609"]
I didn't realize a centri blower made none linear boost. It looks like a straight line to me when I plot my boost vs rpm. The theory is great, and I almost went down this road. I decided to get the pulley and not the wastegate. I am faster now than had I got the wastegate. I could probably get a smaller pulley and wastegate it, but I am just going wait until the motor is built and then fully turn it up. It had been shown to work, but mine and solarflare and others have also shown the stock motor holds together, so why not enjoy all the boost; knock on wood, I'll probably break something now.

And the thing you are trying to eliminate, the negative, is what I see as a positive. Easier on parts, traction, drivability, the street, and so on with a softer hit.
[/QUOTE]

 

[barkingspud]

I didn't realize a centri blower made none linear boost. It looks like a straight line to me when I plot my boost vs rpm. The theory is great, and I almost went down this road. I decided to get the pulley and not the wastegate. I am faster now than had I got the wastegate. I could probably get a smaller pulley and wastegate it, but I am just going wait until the motor is built and then fully turn it up. It had been shown to work, but mine and solarflare and others have also shown the stock motor holds together, so why not enjoy all the boost; knock on wood, I'll probably break something now.

And the thing you are trying to eliminate, the negative, is what I see as a positive. Easier on parts, traction, drivability, the street, and so on with a softer hit.

Non-Linear? LOL. So, using a Wastegate has some benefits if you have the right use case. For example, if you want to "adjust" boost levels for different driving profiles. Think Street and Strip. I want 7lbs of boost for the street and need to use 93 octane. For the strip, I want 14lbs of boost and run E85. There are several iterations of this but in essence, they are the same. Sure, you overspin the blower and create more heat (this can be mitigated with a larger intercooler) but in the end it can be beneficial for the right purpose as outlined above.

 

[80FoxCoupe]

Non-Linear? LOL. So, using a Wastegate has some benefits if you have the right use case. For example, if you want to "adjust" boost levels for different driving profiles. Think Street and Strip. I want 7lbs of boost for the street and need to use 93 octane. For the strip, I want 14lbs of boost and run E85. There are several iterations of this but in essence, they are the same. Sure, you overspin the blower and create more heat (this can be mitigated with a larger intercooler) but in the end it can be beneficial for the right purpose as outlined above.

Again, the theory sounds fine. Try it out.

 

[barkingspud]

Again, the theory sounds fine. Try it out.

It's not a theory, I've been doing it for a few years. Wastegate with manual boost controller. Works like a charm

 

[andrewtac]

Non-Linear? LOL. So, using a Wastegate has some benefits if you have the right use case. For example, if you want to "adjust" boost levels for different driving profiles. Think Street and Strip. I want 7lbs of boost for the street and need to use 93 octane. For the strip, I want 14lbs of boost and run E85. There are several iterations of this but in essence, they are the same. Sure, you overspin the blower and create more heat (this can be mitigated with a larger intercooler) but in the end it can be beneficial for the right purpose as outlined above.

The boost comes in linear not exponentially, or so it seems when I plot it. Yes there is slope, unlike constant boost but still linear.

I don't disagree there are cases for it, and it sure is talked about quite a bit; but if doesn't seem to get used much. I know folks used then more a few years back, but most of it here is talk about it. I was really close to doing it, had the items in my cart, but just deleted everything but the pulley. If I were changing between 93 and 85 on a regular interval maybe. But not race gas versus 93, I'd just change pullies at that point, with the griptech it is minutes. On the street I can blow the tires away from a dig, more torque sooner would make that worse. And roll racing I paddle down to a gear where I am in the power band, if I wastegated I'd have less available power. Maybe if I didn't have a converter it would make more sense to get more torque sooner as well, wastegate would be cheaper.

Correction previous post uses it.

 

[barkingspud]

The boost comes in linear not exponentially, or so it seems when I plot it. Yes there is slope, unlike constant boost but still linear.

I don't disagree there are cases for it, and it sure is talked about quite a bit; but if doesn't seem to get used much. I know folks used then more a few years back, but most of it here is talk about it. I was really close to doing it, had the items in my cart, but just deleted everything but the pulley. If I were changing between 93 and 85 on a regular interval maybe. But not race gas versus 93, I'd just change pullies at that point, with the griptech it is minutes. On the street I can blow the tires away from a dig, more torque sooner would make that worse. And roll racing I paddle down to a gear where I am in the power band, if I wastegated I'd have less available power. Maybe if I didn't have a converter it would make more sense to get more torque sooner as well, wastegate would be cheaper.

Correction previous post uses it.

I don't roll race or street race. I even have a different tire/wheel setup for the street vs strip. Griptech pulley, check. Converter, check. Agreed that you have less available power using a wastegate, by their very nature, that's what you get. If my car didn't see any street driving, I'd ditch the wastegate entirely but alas, I drive it on the street a bit. 7lbs on 93 is enough to melt the tires but it's still safe enough that my Girlfriend or Daughter can drive it. Car is plenty quick at the strip. best of 9.38@149 so far. Shooting for that 8 second pass this coming season.

 

[andrewtac]

I don't roll race or street race. I even have a different tire/wheel setup for the street vs strip. Griptech pulley, check. Converter, check. Agreed that you have less available power using a wastegate, by their very nature, that's what you get. If my car didn't see any street driving, I'd ditch the wastegate entirely but alas, I drive it on the street a bit. 7lbs on 93 is enough to melt the tires but it's still safe enough that my Girlfriend or Daughter can drive it. Car is plenty quick at the strip. best of 9.38@149 so far. Shooting for that 8 second pass this coming season.

I never valet, and never let others drive the car (unless they have experience with fast cars). But agree if others drove the car I would do this. Also, I never put 93 in it; I planned on it initially have not and never plan on it now.

 

[Jackson1320]

Non-Linear? LOL. So, using a Wastegate has some benefits if you have the right use case. For example, if you want to "adjust" boost levels for different driving profiles. Think Street and Strip. I want 7lbs of boost for the street and need to use 93 octane. For the strip, I want 14lbs of boost and run E85. There are several iterations of this but in essence, they are the same. Sure, you overspin the blower and create more heat (this can be mitigated with a larger intercooler) but in the end it can be beneficial for the right purpose as outlined above.

There are a few setups where a torque booster setup is a good idea. But it always comes down to controlling boost. A torque booster setup at say 15psi doesn’t make any more heat than a standard setup with a 15psi pulley. You are spinning the supercharger faster so there’s a little more parasitic loss but you are making the same total boost pressure so the same heat.

 

[80FoxCoupe]

It's not a theory, I've been doing it for a few years. Wastegate with manual boost controller. Works like a charm

Sounds good!

Sponsored