Vespa Dry Lake Racer lives...

See cars and bikes being built for the salt

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BONES
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Re: Vespa Dry Lake Racer lives...

Post by BONES »

The guys with the Budfab streamliner did it with their 50cc engine
They first tried nitros but couldn't control a small enough shot.
I'm sure there is some pictures on their site
Bones
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RGV
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Re: Vespa Dry Lake Racer lives...

Post by RGV »

Image

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF
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Re: Vespa Dry Lake Racer lives...

Post by internetscooter »

Very nice - their config would look even more complicated finished because they'd have to run an oil pump and cooling etc.

On the comments about pressure - I am starting off with very mild boost, not only do I have to worry about seals etc but leaks in the carb itself (I have been told it is better to enclose it and pressurise the enclosure) - version 2 will be a lot more advanced :)
Paul
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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
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RGV
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Re: Vespa Dry Lake Racer lives...

Post by RGV »

Dont forget to pressurize your fuel supply or fit a fuel pump that will supply more pressure than you have boost. ;)

Electric water and oil pumps would be the go?

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF
internetscooter
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Re: Vespa Dry Lake Racer lives...

Post by internetscooter »

RGV wrote:Dont forget to pressurize your fuel supply or fit a fuel pump that will supply more pressure than you have boost. ;)

Electric water and oil pumps would be the go?

Dave
Thanks Dave - I was hoping I would get away without the fuel pump but I was not thinking at all about fuel back pressure. A quick google shows I have to get a pressure referenced pump so it adapts the fuel pressure to what is happening boost wise.
Paul
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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
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RGV
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Re: Vespa Dry Lake Racer lives...

Post by RGV »

Hey Paul. Some have just pressurized the fuel tank from the plenum/air box, a big line works best so the pressure stays equal between the 2. Honda did this on a bike that had a cool air induction that pressurized the air box at speed. Might create a bit of lag having to pressurize the air box as well as the tank but might not be a problem out on the salt.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF
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JonB
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Re: Vespa Dry Lake Racer lives...

Post by JonB »

Any reason not to go draw through rather than blow through on the carby Paul?
Will make your install much simpler.

jon
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Underhouse Engineering
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Greg Watters
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Re: Vespa Dry Lake Racer lives...

Post by Greg Watters »

if you go blow thru make sure the carb can be removed easily, you will be doing it often till you get the jetting right

i tried blow through on my first turbo gsxr back in 03, gave it up as a bad joke after pulling the carbs off for the 15th time and brought a basic microtech , throttlebodies off a later bike and aftermarket pump reg etc
had it running same day i finished fitting and tuned next day,

since helped a mate do a turbo blow through and this time with more experiance we got it right pretty quickly , mostly because of a pitot tube that gave better use of dynamic air pressure raising bowl pressure a little more than plenum pressure, giving enough fuel at pressure without flooding the cyls in transition , your supercharger probably will give less trouble than a turbo
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Re: Vespa Dry Lake Racer lives...

Post by internetscooter »

Thanks for the tips - I have no room for draw through unfortunately. I do have a o2 sensor which will make life a bit easier and it should not be that hard to remove (2 host clamps).

I am now thinking V2 will be fuel injected :)
Paul
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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
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RGV
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Re: Vespa Dry Lake Racer lives...

Post by RGV »

Lots have tried F/I 2 smokers, many have failed. Microtech etc have trouble working out what to do when a engine comes on the pipe. BUT it has been done. This is a F/I CR500 MX bike. probably one of the easiest to do, either full throttle or none and has loads of power to start with.

http://www.youtube.com/watch?v=tNAtmKzqo9A

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF
internetscooter
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Joined: Mon Nov 20, 2006 12:18 pm
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Re: Vespa Dry Lake Racer lives...

Post by internetscooter »

I did "consider" trying this as one stage but the fuel throughput wasn't enough:

http://www.chinese-parts-canada.com/tur ... ction.html

I'll probably be able to look into direct injection by the time I get around to this improvement ;)
Paul
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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
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gennyshovel
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Re: Vespa Dry Lake Racer lives...

Post by gennyshovel »

:?: :?: :?: MMMMMM :?: :?: :?:
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
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JonB
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Re: Vespa Dry Lake Racer lives...

Post by JonB »

If you do go EFI MAF rather than MAP will be your friend.

jon
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Underhouse Engineering
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dplecko
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Re: Vespa Dry Lake Racer lives...

Post by dplecko »

Got a couple of these you can have if you want them?

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dplecko
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Re: Vespa Dry Lake Racer lives...

Post by dplecko »

For your blow though carb make sure your fuel pressure regulator is actually 1:1 boost referenced. Today just checked my well known high end brand regulator and the ratio is more like 0.8:1. Might not seem like much error, but if your boost pressure is significantly higher than your base fuel pressure then relative fuel pressure can be critically low e.g. 5 PSI base 15 PSI boost = 0.8 x 15 = just 2 PSI effective fuel pressure (FP only increasing by 12 PSI not 15 PSI). Took me quite some time to get my small head around that one.
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