Go Back   DIY Go Kart Forum > Building Plans And Advice > Engines & Clutches

Notices

Closed Thread
 
Thread Tools Display Modes
  #61  
Old 06-29-2009, 10:09 AM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

or an emissions pump off a small car!
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
  #62  
Old 06-29-2009, 10:11 AM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

Quote:
Originally Posted by l0ll00l View Post
Dear god.. Please tell me no one has bought one...
as stupid as it sounds and looks for a real car that might work on a small engine
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
  #63  
Old 06-29-2009, 10:22 AM
ed1380's Avatar
ed1380 ed1380 is offline
Banned
 
Join Date: Mar 2007
Location: ATL, GA
Posts: 1,191
Thanks: 9
Thanked 26 Times in 26 Posts
Default

vw/audi have SAIP(secondary air injection pumps) its about a 1" outlet and blows pretty good. sucks up alot of amps though
  #64  
Old 06-29-2009, 10:23 AM
lerick lerick is offline
Junior Member
 
Join Date: Jun 2009
Posts: 15
Thanks: 1
Thanked 1 Time in 1 Post
Default

you should get a 4inch steel pipe for more safety it might be harder to make the holes but it will bhe more safe
  #65  
Old 06-29-2009, 10:39 AM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

Quote:
Originally Posted by ed1380 View Post
vw/audi have SAIP(secondary air injection pumps) its about a 1" outlet and blows pretty good. sucks up alot of amps though
thats why i mentioned the emissions pump it sucks in a good amount of air and is belt driven so as your engine revs higher more air is being sucked in and is simpler then a electirc fan with a fixed air flow speed
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
  #66  
Old 06-29-2009, 06:12 PM
blank blank is offline
Junior Member
 
Join Date: Mar 2009
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Default

This is more like, more ideas. If people really want a supercharger or such we need ideas to help. And to the ones who have more technical information when you put in your input try to help us (the less educated in this specific part of engines in general) understand how we can make this work...
So anyone got a few bucks to spend =P
  #67  
Old 06-29-2009, 06:19 PM
freakboy's Avatar
freakboy freakboy is offline
the names 'mater
 
Join Date: May 2009
Location: hick town
Posts: 4,012
Thanks: 134
Thanked 92 Times in 81 Posts
Default

some one should make a supercharger like the ones on older carby cars. where the carb sits on the super charger and it sucks more air and fuel in it. mabey have it belt driven and im gettin a idea here. my engine the intake is like right over the jack shaft extend the jack shaft have it belt driven and then it goes with what the tav speed is.
__________________
Pardon me, sir gangster! but it apears your pants are declining in elevation!
  #68  
Old 06-29-2009, 06:35 PM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

here u guys go: http://karting.4cycle.com/showthread...ight=smog+pump

heres what i ment about the emissions pump and theres a link to it
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
  #69  
Old 06-29-2009, 09:03 PM
frederic frederic is offline
The Junk Man
 
Join Date: Jun 2009
Location: New Jersey
Posts: 389
Thanks: 7
Thanked 42 Times in 37 Posts
Default



There are two defects with this configuration. First, the back of the belt is not exactly a traction surface like the ribbed side, therefore it will be prone to slip. Second, only about 15% of the pulley is covered by the belt, meaning it will be prone to slip.

Emissions injector pumps are of the vane style which is okay for higher flow, low pressure applications and this is exactly what they are for on a vehicle. They do not produce pressure, and if you were to remove the tube from your vehicle's injector pump, cork it, and thread in a pressure gauge you'd be lucky to find 1psi: http://www.pumpschool.com/principles/vane.htm

The emissions pump's sole purpose is to pump fresh air into the exhaust manifold(s) so the catalytic converter can use the pumped in oxygen (found in fresh air) to burn unspent fuel vapor and flammable gasses that left the engine instead of burning in the engine.

Ford units (which I am familiar with) take a hair under one HP to turn if the exhaust side is plugged and you'll get less than 1 psi. Lets round both to "1" to make the example easier to grasp:

A 5 HP briggs will give you 5 HP naturally aspirated, peak.

A 5 HP briggs with 1 psi of boost will give you 5.38 HP peak, but you're losing 1HP to drive the injector pump - so you're down to 4.38 peak HP.

You either need to find, buy or make a pint-sized supercharger or turbocharger based at least loosely on say, the Garrett design. Anything short of that will be an amusing adventure to learn something, but with fruitless results.

Thinking about it some more, a "wipple" design is probably easier to machine, but again the clearances must be real tight or you won't get any real pressure. Forced induction requires pressure, AND flow, not one or the other.

You cannot make power out of nothing.
  #70  
Old 06-29-2009, 09:17 PM
Raywelder's Avatar
Raywelder Raywelder is offline
Not an Admínistrator
 
Join Date: Mar 2009
Posts: 767
Thanks: 5
Thanked 35 Times in 34 Posts
Default

Well if someone works something out, Let me know! I have tons of room on my bike to turbo or SC my opposed twin.
  #71  
Old 06-29-2009, 09:47 PM
Raywelder's Avatar
Raywelder Raywelder is offline
Not an Admínistrator
 
Join Date: Mar 2009
Posts: 767
Thanks: 5
Thanked 35 Times in 34 Posts
Default

What about a tiny turbo for a motorcycle or atv,
  #72  
Old 06-29-2009, 09:58 PM
Raywelder's Avatar
Raywelder Raywelder is offline
Not an Admínistrator
 
Join Date: Mar 2009
Posts: 767
Thanks: 5
Thanked 35 Times in 34 Posts
Default

http://cgi.ebay.com/ebaymotors/SUPER...lenotsupported
  #73  
Old 06-30-2009, 04:33 AM
BradenM BradenM is offline
Etre Et Durer.
 
Join Date: Dec 2008
Location: In a big jar of Nutella, nom nom nom
Posts: 616
Thanks: 17
Thanked 30 Times in 29 Posts
Default

A tiny tubo would work on your opposed twin. Whats the displacement?
__________________
Quote:
Originally Posted by gokartcrazy View Post
omg i almost poopied my man thong i didnt know my brother wore thongs too
  #74  
Old 06-30-2009, 05:34 AM
sideways's Avatar
sideways sideways is offline
Unfinished projects king.
 
Join Date: Feb 2009
Location: Perth, Western Australia
Posts: 1,509
Thanks: 42
Thanked 151 Times in 114 Posts
Default

Quote:
Quote:
Originally Posted by ed1380
http://cgi.ebay.com/ebaymotors/Elect... 5fAccessories

Dear god.. Please tell me no one has bought one...
i might acctually get one, thier worth an experiment i think. you've got to remember that we are dealing with engines less than a tenth of the size here, you could even butcher one so that it ran off a pulley instead of electricity BUT we have to make some kind of governer system to keep the supercharger spining at the same revs contantly other wise as revs go up so does pressure produced wich could cuase all kind of problems, even on a briggs thats still limited to 3600rpm the pressue is going to double for idel to flat out, a centrifugal type governer mounted on the pulley could be made fiarly easily but adds compexity

Raywelder see the tubos i posted before, they will get you your boost, reliably
  #75  
Old 06-30-2009, 06:44 AM
frederic frederic is offline
The Junk Man
 
Join Date: Jun 2009
Location: New Jersey
Posts: 389
Thanks: 7
Thanked 42 Times in 37 Posts
Default

Quote:
Originally Posted by Raywelder View Post
That looks to be sized appropriately!

Quote:
Originally Posted by sideways View Post
i might acctually get one, thier worth an experiment i think. you've got to remember that we are dealing with engines less than a tenth of the size here, you could even butcher one so that it ran off a pulley instead of electricity BUT we have to make some kind of governer system to keep the supercharger spining at the same revs contantly other wise as revs go up so does pressure produced wich could cuase all kind of problems, even on a briggs thats still limited to 3600rpm the pressue is going to double for idel to flat out, a centrifugal type governer mounted on the pulley could be made fiarly easily but adds compexity
Let's say the 1-2psi rating is not bogus (I've seen these fans before and know several who got nothing out of them).

You will need to provide 10 amps to drive the fan for a 2psi gain. That 2psi gain will make a 5HP peak engine give 5.66 HP, for a .66 HP gain.

Watts = HP * 746

492.36 watts

It's a 12V fan motor that draws 20 Amps so 12V * 20 A = 240W of power necessary.

You would gain 492.36 - 240 peak watts (252.36)

Or, 0.338 peak horsepower gain.

That's assuming the non-sealing fan actually can deliver 2psi, which it cannot.

This is assuming the engine is operating at peak HP RPM all the time and the engine's ability to turn an alternator to provide the necessary electricity is 100% efficient and has no friction.

A free spinning new alternator without any electrical load whatsoever requires 0.21 HP to spin at the necessary speed where it could produce useful electricity.

To your kart you've added a 25 lb alternator plus the additional weight of the fan, belt and pulleys and new intake tract which lowers the usefulness of the additional 0.338 peak horsepower.

Alternators are barely 75-80% efficient, reducing the usefulness of that gain even further.

By all means, buy one and play with it. It's an excelent learning experience that can help you understand how turbochargers and superchargers work.

Regarding hacking a "real" turbo to make a supercharger, that's very doable, but again the power gained has to exceed the power drawn otherwise it's not a useful system. For a turbo intake housing (scroll) to be efficient, you need to spin the thing above what the boundary layer of air in the housing will shear at, as that's how it seals. Typically this is in the 50,000 RPM and up range. So you will need to devise a device or mechanism that takes the 3600 RPM off the crankshaft and "steps it up" to at least 50,000 RPM. That adds weight, cost, packaging issues, and so on as well.

Anyway, here is a "monkey way" to size a turbo from donor vehicles, and while not precise mathematics it at least puts you in the ballpark.


Destination displacement x destination engine RPM
--------------------------------------------------------- = destination turbo quantity
Donor displacement x donor engine RPM x donor turbo qty

Lets say you have pull a Chrysler turbo out of the junkyard, off a Dodge Daytona. The donor part of the equasion would work like this:

Donor (2.5L * 6500 * 1) = 16250

And lets say you're going to put that turbo onto a 351W Ford engine (5.8L), the math works out like so:

5.8L * 5500
------------ = destination turbos (1.96307)
16250

This means to turbocharge a Ford 351W small block V8, you would need approximately 1.96 Dodge Daytona factory turbos, meaning two.

Regarding a motorcycle turbocharger... what is the displacement of a 5 HP lawnmower? 125 cc? What is the displacement of a turbocharged motorcycle? 750 cc? Do you think there could possibly be enough hot, expanding exhaust to drive that turbo? Probably not. It will spin, sure, but it won't have enough power to generate any boost and it adds weight which reduces your overal kart's performance. Adding 50 lbs of "stuff" to a small go-kart that probably weighs 250 lbs total is a massive performance hit as compared to adding that same 50 lbs to say, my 6997-lb F350 crewcab.

While the math is the same for philosophical discussions, things that are "tiny" (like a kart) are more heavily influenced by minor adjustments in the parameters.
  #76  
Old 06-30-2009, 07:31 AM
frederic frederic is offline
The Junk Man
 
Join Date: Jun 2009
Location: New Jersey
Posts: 389
Thanks: 7
Thanked 42 Times in 37 Posts
Default

Quote:
Originally Posted by fluxcored View Post
Sir, you do know that this is the stuff legends and billionares are made of? An odd ball with a crazy idea which everybody sez and dismisses as not doable or not worthwhile.
I am not trying to discourage anyone from experimenting, if that's their thing. By all means. Certainly, experimenting and brainstorming is a great way to learn. I've done many things along these lines myself.

Unfortunately, the automotive aftermarket crowd has tried all of these ideas and the rear-world success rate (despite the claims) is zero, and I'm sharing this as well as some of the simpler math because I'm trying to save people the effort involved in building such things only to be disappointed...

To fabricate your own supercharger or turbocharger you need to be able to provide much more CFM than the naturally aspirated engine would normally take in, at a given pressure.

To achieve this you need flow, and pressure, and you can't do that without a seal of some kind, and that's why I keep harping on this.

Here is a "ballpark truth". If you have a 5 HP engine, and you want it to produce 10 HP at the same RPM, you need to double the airflow (cfm and pressure) and fuel.

You can easily figure this out as well.

CFM = bore x stroke x RPM/1728

Double that figure for the minimum CFM requirements of your forced induction device, then find a forced induction device that can maintain that CFM well above atmospheric pressure?

That will give you 10 HP out of a 5 hp engine.

Can your little fan provide 150 cfm at 10 psi?
  #77  
Old 06-30-2009, 08:28 AM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

i'll give that supercharger plan a try but frederic you just really killed my inspiration dude.... lol
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
  #78  
Old 06-30-2009, 08:35 AM
Kaptain Krunch's Avatar
Kaptain Krunch Kaptain Krunch is offline
Pro Junk Collector
 
Join Date: Jan 2009
Location: vermont
Posts: 4,520
Thanks: 66
Thanked 279 Times in 260 Posts
Default

why dont we all get sled and mc engines, that way we dont need to supercharge. Besides, a supercharged lawnmower engine wouldnt last very long.
__________________
"If you want, I can teach you how to make a bomb out of a toilet paper roll and a stick of dynamite"
  #79  
Old 06-30-2009, 09:14 AM
frederic frederic is offline
The Junk Man
 
Join Date: Jun 2009
Location: New Jersey
Posts: 389
Thanks: 7
Thanked 42 Times in 37 Posts
Default

Quote:
Originally Posted by Kaptain Krunch View Post
why dont we all get sled and mc engines, that way we dont need to supercharge. Besides, a supercharged lawnmower engine wouldnt last very long.
Right! Or, if you guys are using a 5HP engine and want 10HP, get a used 10HP lawnmower engine. It's likely to be a lot easier to install than a homemade supercharger system on a 5 HP

The cheapest way to make "more" power with gasoline is to increase physical displacement, generally speaking.

This is why "car guys" often swap out small blocks for big blocks. Then once they get "used" to big blocks and are again unhappy with performance, they get into forced induction and/or nitrous.

"There is no replacement for displacement". Ask any hot-rodder ;-)

Quote:
Originally Posted by Rotore View Post
i'll give that supercharger plan a try but frederic you just really killed my inspiration dude.... lol
Not trying to discourage, just wanting to share what little knowledge I have hoping those interested in this don't waste time and money. I've been down this road myself and after a while it got expensive for no measurable gains.
  #80  
Old 06-30-2009, 09:31 AM
Rotore Rotore is offline
Teh SPIK
 
Join Date: May 2009
Location: Caguas, Puerto Rico
Posts: 1,666
Thanks: 23
Thanked 25 Times in 24 Posts
Default

Quote:
Originally Posted by Kaptain Krunch View Post
why dont we all get sled and mc engines, that way we dont need to supercharge. Besides, a supercharged lawnmower engine wouldnt last very long.
i dont need my engine to last long dude thats why i'm willing to try it

Quote:
Originally Posted by frederic View Post
Right! Or, if you guys are using a 5HP engine and want 10HP, get a used 10HP lawnmower engine. It's likely to be a lot easier to install than a homemade supercharger system on a 5 HP

The cheapest way to make "more" power with gasoline is to increase physical displacement, generally speaking.

This is why "car guys" often swap out small blocks for big blocks. Then once they get "used" to big blocks and are again unhappy with performance, they get into forced induction and/or nitrous.

"There is no replacement for displacement". Ask any hot-rodder ;-)



Not trying to discourage, just wanting to share what little knowledge I have hoping those interested in this don't waste time and money. I've been down this road myself and after a while it got expensive for no measurable gains.
i have to disagree with the no replacement for displacement comment lol ask anyone who owns/tunes/or races a wankel and relax dude i was just messing with you like i've said before its hard to offend/discourage me.
__________________
"No one is going to open doors for you your whole life, sometimes you have to open the dor yourself." Eddy
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:44 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.