First of all i'm going to make a little comparision between orinigal and upgraded parts, this parts are from WiiTech made in aluminium/aluminum in CNC machines.
They are sold separetly:
First item is the Nozzle chasis made in aluminum and the o-ring as you can see is different, the orginal is like 1911 style and with use it can turn upside down producing low gas efficience and sometimes block the nozzle forward.
In the upgraded part this is replaced with another rubber with the lips bit smaller preventing the effect that causes the original. Also this is more tight (only fits WiiTech nozzle) this helps improving blowback speed and gas efficiency or leaking. There is another aftermarket upgrade made by Action, is just the guide piston head, its made like an AEG piston head, a rubber with holds that expands when air gets in chamber sealling the chamber.
Here the weight comparision:
Original part 19grams
WiiTech part 9grams, less than the half of the weight of the original, and made from better aluminum.
Second item is the Nozzle kit, they include a new magazine valve, that produces much more FPS, also is included new springs for bolt recoil and nozzle recoil, also the part 71; all this springs are harder producing an insane ROF (almost 29bb/second depending on the gas and enviroment temperature)
The original made from plastic is only 4grams, but as all you know with full auto firing this usually brokes.
The new one made from high quality aluminum, is 10 grams a bit more heavy but much more strong.
This is the top gas version, which includes that red small valve, producing around 415 fps, the original cames with a rocket valve a bit bigger producing arround 390-400 fps.
There is a big problem in this part, first it had a pin full spanning the entire piece holding the rocket valve, that was easy to remove and replace the valve, but in the new version that pin is blind, ie it does not cross the entire piece so it is very difficult to remove and also is attached with a strong adhesive, and to replace the original valve it has to be heated with a soldering iron pin.
What is the problem now? if you don't glue that pin again it will come out and may get stuck inside the bolt blocking the nozzle.
Now i just ordered a KWA original Low Power bolt so the WiiTech original will get the winter vavle and i'll gue the pin so i will have two bolts with different power for different kind of games and rules.
Another problem that I've noticed is that the pins that hold the valves are bent with use, only happens to me or you too?
Left WiiTech, right KWA original.
As i said this cames with one mag valve that is crazy:
There is no aluminum in that valve, just compare to the original one, i never tried to use it but for sure it will increase the fps.
Here are the bolt recoil springs:
As you can see the new is bit shorter but much more stronger, producing that insane ROF, with the softer spring the speed slows a bit
Here the nozzle recoil springs:
With just 2 month of using, about 500 rounds, the original springs are smashed and destroyed, but.... the gun still working properly that just happend in kwa In the other hand there are the reinforced WiiTech springs with 6 month of usage almost 5000 rounds, they are quite well without breaking.
Due to restrictions in my country (spain) every primary gun (sniper and DMR not included) only can shoot at 350 fps, and if you want a submachinegun as secondary it must shoot less than 330fps, so i had to replace that rocket valves with this one:
Also made from aluminum CNC here in spain, in the pack cames a winter and summer valve, the summer is a bit bigger due to faster expansion of the gas in warmer conditions.
Finally here is the weight comparision of both kits:
And the WiiTech:
Here are the link of the products:
WiiTech Loading Nozzle Chassis US$25
WiiTech TopGas Nozzle US$43
FijoCustom Rocket Valves US$23.50
Action MP9 Piston Head US$11.50
WiiTech have some other products for the mp9 like an outher barrel that holds better the inner, maybe when i have more money i will buy it
As soon as i can i will make some video to show you the FPS and ROF with different configurations.
Hope you all enjoy this review, if there is any problem or doubt with this post please ask me
Edited by PJ-P09, 12 July 2013 - 08:32 AM.