How a Centrifugal Supercharger works

[KpaBap]

http://www.superchargeronline.com/content.asp?id=21

[font=Verdana, Arial, Helvetica, sans-serif][font=Verdana, Arial, Helvetica, sans-serif]The biggest drawback of the centrifugal supercharger is it's inability to make high levels of boost at low engine rpms. Typically, a centrifugal supercharger will make it's maximum (quoted) boost at the engine's redline rpm and nearly nothing at 1500-2000 engine rpm. Boost builds exponentially with engine rpm, meaning that boost comes on very quickly in the upper half of the powerband.[/font][/font]

(jerkit)

 

[KpaBap]

(jerkit)

 

[peepsalot]

So...

 

[KpaBap]

So I'm calling bullshits on the "no lag" claim till there's a dyno sheet to prove me wrong.

 

[Natey]

1. Now I know what that chirping sound is between gears. I was afraid I was pinging.
2. I need a BOV
3. Lag is nowhere near what is is with a turbocharger. The other night in Sonny's MSM, I really fell in love with the blower. Even at the higher revs, I felt a little lag with his car. With the s/c, once you're around 4kr's, you have instant power.

 

[KpaBap]

Well, Natey, having an extra 20 or so over the MSM hp will do that

 

[mp5jeff]

wait, you don't feel the power til 4k rpm? that is definately turbo territory , most turbo's sized correctly should be full spool around 3500 rpms(depends on alot of things but in the most part)

 

[KpaBap]

Yes let's make sure we're talking about the same thing here

When referring to lag I am talking about how long it takes for your FI device to make noticable boost that will produce a sizeable power gain, and not how "fast the car goes to redline", or how fast the car feels once in boost.

A centrifugal is a belt driven turbo (well, essentially) and its boost builds with RPMs, with full boost coming at redline. So, 2-3psi (if that) at 3000 rpm, is not "no lag".

 

[Super Matty P]

Is this thread geared towards me? If so, I have nothing to prove. I'll let my car do the talking for the ability of a supercharger.

I think one thing you should take into consideration is in the video you see of my car with the blower it's ideling at 800rpms and throwing a LOT of air around. I don't think anyone with a WOMP kit is going to be dissappointed with driveability.

 

[Natey]

Well, Natey, having an extra 20 or so over the MSM hp will do that

I'm talkin' bout throttle response. S/C is the W1NN@R!

 

[KpaBap]

I'll let my car do the talking for the ability of a supercharger

And that's simply what I asked for. Will be happy to withdraw pessimistic remarks once a dyno sheet and/or customer reviews prove me wrong.

 

[Super Matty P]

would you like me to post info directly from powerdyne's website descriping in detail why their blowers achieve better low-rpm numbers than any other centrifugal blower? Here's a quick list:

1. Internal step-up of 3.05:1

2. specially designed impeller using curved vanes and not straight to scoop air at low rpms

3. Larger inlet and outlet for faster response (3.5"/3" vs 3"/2.5")

 

[KpaBap]

like I said, the dyno tells all.

 

[Super Matty P]

actually I would have to say (like I've said from day one) that I'm doing this to create a better overall driving experience...peak numbers don't do much for me. A dyno curve will be good at showing power delivery but not really how driveable the car is.

 

[Rism]

Im gonna have to put a new message on my rear view mirror thats says, "Warning: MSPs in mirror are further than they appear"

 

[Aricjm15]

so if his blower is rated at 14psi at 6000rpm, at 3000 rpm it should make 7psi, and at 1500rpm it would make 3.5psi, so at idle your sitting at about 2psi

if its rated at 8psi at 6000rpm, thats about 1.3psi at idle

what turbo can make ANY psi at 1000rpm?

 

[MPNick]

actually I would have to say (like I've said from day one) that I'm doing this to create a better overall driving experience...peak numbers don't do much for me. A dyno curve will be good at showing power delivery but not really how driveable the car is.

This is a funny statement from someone who liked to hammered the s*** out of a memebr who made a post on how his car drove better and much smoother after he did a mod on his car. He was only spending around $650.00 for his setup. How much is your system here, thousands of dollars a bet.

Here is your post on it.

If he notices a more pleasureable driving experience thats awesome! It doesn't mean anything though because it could all be in his head. I remember so many people claiming their intakes gave them 20whp and stuff because thats what they wanted to think after spending that kind of money.

I don't see why you're so opposed to dynoing your product....if he says it feels better then you should have no problems with people wanting to see his AFR's and power curve.

Personally I hope people go out and dyno my supercharger kits. I'd love to see people be able to back up their claims with proof sometimes!<!-- / message --><!-- sig -->

 

[MPNick]

So I'm calling bullshits on the "no lag" claim till there's a dyno sheet to prove me wrong.

You do not need a dyno sheet. You are right. Unless we are talking about a very large turbo on a Protege or any other car. This turbo would not even be for a street car anyway. The turbo will always boost faster and make more lowerend torque. Not just peak number here. I mean big gains in power. You will get as much as 30% more lowend power from a turbo then a SC at the same boost level. Now if you are talking about a roots type SC the lowend toruqe numbers would be about the same but the SC would need to run more boost in order to do make the same power. The SC of any type would suck up more power just to turn/spin boost.

I have seen all of the SC compamies talk about how turbos have lag and thay do not. Sale BS is all it is. PSI for PSI the turbo will always make more power. The right sized turbo will always make more lowend power, both in peak numbers and average power.

 

[accuser]

if the argument here is what can put power to the ground more efficiently i would go with a turbo...

yes you can have 1.3 psi at 1500 rpm with a supercharger... but you will only get your max psi at 6000rpm...

with my turbo setup... i'm putting 10psi (full spool) between 3000 and 3500... lets see a charger with a 10lb pulley do that...

in terms of stability... SC all the way... a constant build in power... a steady torque curve... make the engine feel like it was built that way... with the added whistle of coarse

more boost throughout rpm range = turbo = constant power to the ground
(it can really kick you in the ass if your not expecting it... try sitting in 3rd... then mashing the gas at about 4 grand... 10 psi puts you in your seat)

stability and a steady torque curve = super charger = max boost at max rpm range
(not a constant psi throughout most of the rpm range.)

just my thoughts...
and matty... you shouldn't be afraid of the dyno... (unless you think the SC will not prove itself to the turbo protege's) although so far it looks like it will plus... a dyno and some good numbers will sell your kit... just saying its drivable isn't going to sell anything...

most of the people on this forum build their cars to toy around with... and make them faster... not more drivable (although both would be nice) lol

i know that if i'm gonna spend 3 grand on something... i want to make sure it does what i want...
COME ON MAN... MAKE AN AC RELOCATION BRAKET!!! that would make the car even more drivable... summers get humid man...

-pedro

 

[MPNick]

yes you can have 1.3 psi at 1500 rpm with a supercharger... but you will only get your max psi at 6000rpm...


Maybe in 4th or 5th gear. No way on the 2.0 stock engine. I have seen them a lot of 4.6 stangs. No boost under 2,000 at all. No power gains until 3,000.