i've never really thought about this before and have never owned or worked on one to need to think about it. tonite i was talking with few other people about cars and got to talking about blowers and turbos. how does an engine with either a blower or turbo make vacumne? wouldn't there be positive preasure in the intake? ok i said it was stupid and i hated to ask, but i did. try not to laugh at my ignorance too much. thanks

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ICON Motorsports
1st & 3rd

 

while i cant answer that question, i would like to know. Second there arent stupid questions only stupid people, and asking that doesnt make you one. Everyone here started off knowing nothing and had to ask questions at one point.

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-Stock Tbi 305 with a lot of damn miles
-Edelbrock Z28 TES Headers
-3 inch Catco High Flow Cat
-3 inch Edelbrock Catback
-SSM Subframe Connectors

Stereo
-Pioneer DEH-P4100 cd player
-Polk Dx9 6x9s

 

Of course there are stupid questions, and stupid people...but fortunitly most of them live in Homestead Florida.

To answer your question they don't have vacuum in the manifold for alot of thier operating range. They have positive pressure...thats why it's called forced induction. They do see vacum at idle and low rpms tho usually..depending on the system.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports


[This message has been edited by Jester (edited December 31, 2000).]

[This message has been edited by ede (edited January 01, 2001).]

 

ok jester i was thinking it must be along those lines, but how does the brakes and other vacumne operated controls work, like ac/heat/vent controls, cruise controls. they'd need constant level of vacumne, or a way to store it, which i know is a problem with power brakes and a cam with lot of overlap.

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ICON Motorsports
1st & 3rd

 

Well it regains vacuum for brakes when you let off the gas and the throttle blades close. as for what happens to other vac. powered accesories..I have no idea

 

If I remember correctly, a turbo uses vacuum (Or should I say manifold pressure) to control the wastegate which controls boost. I don't have much experience with either one, but I do understand the basics of each, and I believe both should produce vacuum at idle.

EFI vehicles that have the add on blower kits, get a separate computer MAP sensor and various other computer related items to control the timing, and often additional injectors (I'm speaking of the TBI chevy truck setup being that it's the only aftermarket sysem I've dealt with)

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Working on:
'84 Z28 LG4 305
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is in shop!

Awaiting results from all 8 ASE tests.

Starting to look like the Kicker poster child!

 

O.K. - I can see it now - "Moderator Wars" I think Vader has his next emmy-winning role!

I'm surprised Ed didn't mention the well-published talents of the Sunshine Stater's ability to count past two-digit numbers...

Round One - JESTER!

Incidently, cars with GMC or Roots-type blowers on the street generally use either hydraulically assisted brake boosters stolen from full-sized station wagons, vans, or light trucks and are pressurized by the steering pump - OR, they use a separate electric or mechanical vacuum pump and reservoir.

Round two - Vader!

Ed was describing his question as "stupid", but was smart enough to ask when he didn't have the information. How "stupid" is that?

Round three - EdE!

Sorry. I'd love to hang around and referee the rest of this match, but it's getting close to midnight, and I gotta go get ready to "drop my ball" if you know what I mean...


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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0

 

HEY we can do 3 digits!!!!! It just takes 10 of us, less if we can get some refugees to help that havn't gotten shoes yet.



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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

now i do feel stupid, i've changed the eletric vacumne pumps on caddys. that would make it all a lot easier wouldn't it to have a seperate motor for making vacumne.

actually vader i like jester. i just hate to pass up a chance to have fun at his expense. he's even on my christmas card list.

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ICON Motorsports
1st & 3rd

 

JESTER!

KNOCK IT OFF! I expect that kind of stuff when I read something from Box O Rocks, but not in your posts.

Now I have to try to get Diet Coke off my freakin' monitor. At least the coffee washes off pretty well. I'm still chuckling and choking on carbonated NutraSweet. YUCK!

O.K. - Round four - Jester and his Cuban immigrants...

(Ed - I know. I was just trying to get on the bandwagon. I'm sure I'm on a few "lists" as well...)

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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0