Getting a pressure in syn on a two stroke is the HEART of why two strokes can perform so well.
The tuned two stroke is really done, starting with the exhaust tune.
I have played a fair bit with the 80 single and 40/60 singles , trying to find the smoothest tuning setup.
Not the peak power setup.
I have a ZDZ prototype intake bell-you can see a picture of one on the RE 40 on the Amelung site.
These are not yet released for sale.
Mine also has a coarse wire screen over the mouth.
As soon as my RE 40 arrives , I will see how much this bell helps.
Basically , I see it as a flow straightener-which is a good idea.
The only problem is that on the smaller bore carbs, the choke plate and bar is a big blob -in the way - so - I may remove the choke assy, clean up the carb and put a flapper valve on the bell for choking. this works well and is common use on some OS four strokes.
So far I have found that a tuned pipe-such as the K&S 80 can- with a 11-12" header is the easiest setup for most to use.
I have tried the full length tuned pipes also - any gain there is not worth talking about .
A big version of the VTech tuned can works great -but noisy and not as smooth.
o -once I get a tuned setup on my 40 in my new Hee Haww model ( the Clipped wing Taylorcraft), I will see if the intake bell setup helps that one.
It shouldn't hurt--
We have two 80's running with a tuned can setup from Europe which is discontinued (Damn!) similiar to the K&S and again using the 11-12" header.
We also have a Walbro carb on both and the performance is simply heartwarming.
These two engines are both turning 27x10 MenzS props at 6200. this and no midrange step- in fact you can NOT detect any transfer throughout the entire powerband.
We are setting up another one to see if this is a fluke,luck or whatever.
I looked at my ZDZ "venturi" and noted it seems to be spun from soft aluminum and then peaned neatly into a step in the flange.
It could be whipped out of a billet using a cnc machine -but the equipment used now to spin -such as the D Brown spinners would also do a great job. I would ask Dave -but it may not be a very high volume item--
I will let you know if the venturi I have is worth further research.
Please let me know how yous works -
You will probably find that tuning the exhaust THEN adding the flow straightener/ venturi/ tuned intake runner whatever it turns out to be -- is the best procedure.