chriswtx

iTrader: (5)

What do you guys think of this???Centrifugal Supercharger with a Wastegate for controlling boost, then you can pulley for 18-20psi of boost and have a boost controller so on the street and putting around you could run say 14psi max but still have the faster ramp boost curve of the smaller pulley and 20psi is just a push of a button away......

I know this has been discussed before and most said it wont work...Well here's one on a working car...

http://www.musclemustangfastfords.co...all/index.html


gotta love different boost settings at a push of a button...

Jake@EPP

In theory its a great idea, the problem comes with the belt traction.

If you have belt slip around 18psi then you will see as much or more belt slip at 10psi if your using the waste gate. The blower is still spinning the rpms but its being vented out, and still putting a large amount of strain on the blower. While it does work, the belt situation would become more apparent in a vehicle with a weaker bracket and or pulley setup.

chriswtx

iTrader: (5)

Ok..say no belt slip then...I don't have any at 18psi, just don't want the full 18psi all the time...

Jake@EPP

It will still be loading the setup more then it would with out it. That same say 650hp at 14psi , without the wg you will make more. With the wg you are consuming more crank power to spin the impeller rpms up there to make the same boost.

Not to mention the increase in IAT if you blower does not have a ideal map.

In ideal its great, but there is not much of a increase in midrange tq as there would be with a turbo.

I think its a great idea, but only to a certain extent, regulating a f1r with a 25psi pulley down to 10psi would probably be disaster, but to knock a few psi off it would likely survive well.

bboyferal

iTrader: (9)

Working as intended, it would offer the advantages of PD superchargers and turbochargers. I remember the idea being bashed once.

98turbls1

iTrader: (17)

I remember the issue being brought up about a year or so ago... Like Jake's saying, it can be done but what's the point with all of the other hassles involved... I'm pretty open minded so I'm not gonna bash it but I just like the simplicity of my setup and don't really want to goof with it too much... BUT I will say this, without thinking outside the box there is no way for improvement so I know that someone will eventually get it right...

gametech

iTrader: (1)

If you were so inclined, it might be more efficient to have a moveable butterfly (sort of like a throttle) mounted pre-blower. This would merely be an adjustable version of the restrictor plate idea some people are using to bump midrange without overboosting at high rpm with centrifugals. I don't think this would cause the excess charge temps you would see by just bleeding excess boost post-blower.

tt427ls1

Funny that this was brought up.I just made a setup for a 01 mustang that this customer ordered. I put a BOV on the intercooler setup that I made for him and he is running a s/c. I havent heard anything back from him though. So I wonder if it worked. I read that article in the mag. It really dosent say much about it other then its on the car and they have a graph. They didnt talk about any proplems it may has caused, but who knows.

Jake@EPP

It sure would cause excess inlet temps and also belt slip as well. Reason being is the air going into the blower would not be enough to feed what the impeller wants to do so it cavitates at the inlet on the SC and creates a super heated air as well as more strain on the impeller, all because it cannot be fed like it should. The inlet restricters work, but to downsize the inlet a large amount would be going against you.

gametech

iTrader: (1)

I fully understand your concerns about belt slip (hell, I'm mostly against the restrictor plate idea), but since a pre-blower restriction would merely lower lower the pressure going into the blower, what would cause cavitation? Also, how would it put more strain on the impeller? If you have ever put your hand over a vacuum cleaner hose you will note that the fan speed INCREASES when you block airflow, indicating LESS strain. I'm not saying you are wrong, I'm just curious as to the physics behind your statements. Maybe I am missing something.

stevieturbo

Way before I opted to use an LS1, I was trawling forums for info on different engines. My 2 choices were an LS1, or a 32v Cobra...it ended up being far too big physically..
There was a guy over on one of the Ford forums, with a Cobra motor, who built a boost control system using BOV's and an EBC. it did work, but eventually he crashed the car, and said he wouldnt bother doing it again.

A lot of hassle for nothing really.
But he did very good write-ups on it...Duncan somebody...


As for a variable restriction in front of the blower...I think it would be difficult to make a throttle valve work, unless it could be held quite tight. Surely the draw of air pulling, would try and suck it shut ?

But if working right, I guess its no different to a blower setup that uses the throttle in front of the blower, as opposed to after it like most LSx Centi blowers would.
After all, ALL PD blowers have their TB in front of the blower.

Perhaps build your throttle in front of the blower, and just limit the throttle opening via the pedal or stops, to limit boost.

kp

iTrader: (34)

Without a doubt thats the best way to do it,. But a big servo, or even cable activated butterfly in front of the blower would be the best way to go. If you were smart with programming that servo motor and it was fast you could eliminate the bypass valve as well. It would be way cheaper to just have some easily changed restrictor plates then farting around with BOVs and wategates.

No one ever said using a BOV or wastegate wouldnt work. You are just creating a lot of extra heat/parasitic loss and naturally it would make more power at 10psi with the proper sized blower/pulleys than a blower maxed out and bled off to 10psi most likely.

kp

iTrader: (34)

Odd thing is if you put your hand over the OUTLET of that same blower the speed increases as well That being said engines that move air through more freely may work the blower harder and increase belt slip as well even though its making less 'boooost'

A while back one of the procharger guys was here explaining why inlet restrictors were a bad idea on centii superchargers. Something about disrupting the flow and causing cavitation which makes it less efficient. His point wasnt it doesnt work, just wasnt sure of the 'more torque' theory of using a restrctor over it pretty much hurting flow across the whole range.

TS6

iTrader: (41)

I swear this comes up every month or two and I get a migrain every time I read it.

If you can't handle the power at full boost, zip tie a 2X4 to your gas pedal. There ya go, lower boost, less power, all for damn near free.

kp

iTrader: (34)

Wont work, I tried making a throttle stop on a stock PCM car for bracket racing and the whole 100% TPS thing screws you up.

It gives me a headache too, takes me 15 minutes to swap a pulley or blower

Websy21

iTrader: (34)

I was jsut going to say if you don't want full boost all of the time don't lay into it, easy as that. Why try to get a benifit from a turbo with a s/c by sacrificing efficieny and reliabilty. Just do it right once and get a turbo

DeltaT

iTrader: (5)

And no matter what size centri blower you put on there, however you yoke it down, you are not going to develop the low-range boost of a PD blower nor the fast & steep midrange blast of properly sized turbo(s). They are dependent on engine rpm. You'll get a bit steeper slope on your boost line, but not the radical shift I think you are envisioning.

Jim

bboyferal

iTrader: (9)

Well, you CAN lay into it WOT, just gotta shift at a lower RPM.

bboyferal

iTrader: (9)

Good point.