SR Nikki update
10-10-11, 07:00 PM
#1
Team SR
Thread Starter
SR Nikki update
Just wanted to let everyone know things are coming along. Unfortunately my father-in-law passed away a couple of weeks ago which delayed things a bit. But I wanted to show you guys a teaser of the secondary venturi I finally finished developing compared to stock. Enjoy...
10-10-11, 08:15 PM
#2
Nice. What is the new inner diameter? Also looks like you have re-cut the outlet angle as well. I'd be very interested to learn your measurements and to hear how it performs (if you are willing to share haha)
I cut mine a lot more conservatively, only sharpening the inlet angle. Still far from optimum especially on the primaries but the gains are very noticeable.
You may be interested in this bit of gold from Sterling's site
I cut mine a lot more conservatively, only sharpening the inlet angle. Still far from optimum especially on the primaries but the gains are very noticeable.
You may be interested in this bit of gold from Sterling's site
...flow bench testing done by my associate Carl Perez has shown the stock Nikki venturi shape to be so inefficient and far from optimal that flow gains comparable to boring the venturis several mm can be achieved solely by optimizing shape. The ultimate difference is that an optimized venturi shape allows air flow to produce a stronger signal to the main fuel circuit, whereas simply boring out the venturis to attain the equivalent air flow will weaken the signal at low to mid throttle so much that the carburetor will have little power below 3500 RPM.
10-11-11, 07:18 AM
#4
Team SR
Thread Starter
My new inner diameter is the same as sterling's. Primaries are cut from 20 to 22mm and the secondaries are 28 to 29mm. And I actually didn't cut the outlets. For my SR nikki's I smooth out and do a basic polish the entire airway to cleanup and remove any transition lips from the different angles inside.
And to answer your question clubber, I'm currently taking orders through my website http://www.srraceengineering.com
aragami78 was the first to send us his carb., the cut venturi you see in the picture is going into it.
One of my goals later today is to try and accurately compare the stock vs. SR Nikki venturies to eachnother using volume by water, so I can give everyone an exact percentage difference of the whole venturi, not just the inner diameter.
And to answer your question clubber, I'm currently taking orders through my website http://www.srraceengineering.com
aragami78 was the first to send us his carb., the cut venturi you see in the picture is going into it.
One of my goals later today is to try and accurately compare the stock vs. SR Nikki venturies to eachnother using volume by water, so I can give everyone an exact percentage difference of the whole venturi, not just the inner diameter.
10-11-11, 09:16 AM
#5
Hmmm I see. One thing I would like to find out is how the best cut you can get on a 20mm primary venturi (limited by the material of course) compares to a far more optimised 22mm venturi in terms of velocity. We know the 22mm venturi will win on flow, but what about low RPM responsiveness.
10-11-11, 12:18 PM
#6
Team SR
Thread Starter
So I conducted a total volume by water test on the modified vs. stock and got 10.4% more on the secondaries and 15.4% more total volume by water on the primaries. This was to test how much mass reduction I was able to achieve across the entire airway.
I was still able to achieve the same inner diameter numbers as sterling with a similar profile.
Not bad...
I was still able to achieve the same inner diameter numbers as sterling with a similar profile.
Not bad...
10-11-11, 09:21 PM
#7
Just wanted to let everyone know things are coming along. Unfortunately my father-in-law passed away a couple of weeks ago which delayed things a bit. But I wanted to show you guys a teaser of the secondary venturi I finally finished developing compared to stock. Enjoy...
Worked on my fuel line and orderd a Mallory fuel pump/regulator today in preperation for the SR Nikki. My noisy Holly Blue is driving me insane lol.
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11-11-11, 07:22 PM
#9
Team SR
Thread Starter
Pictures of the work, our first official customer SR Nikki should be done in a week or so.
Mech. Secondary modification. Same as Sterling...
Booster Venturi's
Mech. Secondary modification. Same as Sterling...
Booster Venturi's
Just did a bunch of engine bay clean up and fixing some chipping clearcoat. Cant wait to see how the carb looks when its all done and on the engine 
