Vespa Dry Lake Racer lives...
Moderator: DLRA
Re: Vespa Dry Lake Racer lives...
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
They first tried nitros but couldn't control a small enough shot.
I'm sure there is some pictures on their site
Bones
Re: Vespa Dry Lake Racer lives...
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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- Location: Melbourne
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Re: Vespa Dry Lake Racer lives...
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
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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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
Re: Vespa Dry Lake Racer lives...
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
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
-
- Posts: 475
- Joined: Mon Nov 20, 2006 12:18 pm
- Location: Melbourne
- Contact:
Re: Vespa Dry Lake Racer lives...
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.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
Paul
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DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
---
DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
Re: Vespa Dry Lake Racer lives...
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
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
Re: Vespa Dry Lake Racer lives...
Any reason not to go draw through rather than blow through on the carby Paul?
Will make your install much simpler.
jon
Will make your install much simpler.
jon
DLRA#1115
Underhouse Engineering
Underhouse Engineering
- Greg Watters
- Posts: 760
- Joined: Mon Sep 27, 2004 8:57 pm
Re: Vespa Dry Lake Racer lives...
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
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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- Joined: Mon Nov 20, 2006 12:18 pm
- Location: Melbourne
- Contact:
Re: Vespa Dry Lake Racer lives...
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
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
---
DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
Re: Vespa Dry Lake Racer lives...
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
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
-
- Posts: 475
- Joined: Mon Nov 20, 2006 12:18 pm
- Location: Melbourne
- Contact:
Re: Vespa Dry Lake Racer lives...
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
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
---
DLRA #647
89.664 mph (aiming for 100mph+)
www.vespalabs.org
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Vespa Dry Lake Racer lives...
MMMMMM
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
Re: Vespa Dry Lake Racer lives...
If you do go EFI MAF rather than MAP will be your friend.
jon
jon
DLRA#1115
Underhouse Engineering
Underhouse Engineering
Re: Vespa Dry Lake Racer lives...
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.