piaggio zip carter tune

[WDJ]

hello everyone.I found a picture on the sip-scootershop.com,it is a piaggio zip carter--malossi mhr team tow.The first picture.what about the carter tune?is it good?
the second pictures,Another method for carter tune.which is better?
either,do you have the third method for the cater tune?

 

[Zmod]

it looks okey! Not bad i don't think there is any major change in hp between these tuning style might on top be +- 0,2 hp. But this is my oppinion =) Not facts. =)

 

[Wieger]

2nd picture, I see a hole. you've dug too deep, it's in the thread-hole of the cilinder mountings. but that's irrelevant in your question.

Both things will not give Huge power differents. Only is the cartervolume at the first picture a bit smaller. That are things that do care.

 

[Fabrizi Dude]

so basically carter tuning is a waste of time ?

 

[WDJ]

so basically carter tuning is a waste of time ?

This is what I wanted to ask.

 

[waxhead]

I cant say for the zip engine
But its worth while on the mina engines

 

[Wieger]

I just wanted to say that cartertuning is much overrated. It's worth doing! of course, but it's no world making business.

The main thing is to fit the transferports and get your right carterpressure.

 

[Sonic-speed]

You can without problem pull 21+ HP with a stock flow in the carter, but with tuned transfers. But a good flow tense to give around 5-10% in general. But it ends up like every other tuning, in the fact of "how" you adjust the engine, and inlet/carb. especial in addition to the carter tuning.

 

[WDJ]

Well, I would like to know which one is more fit my scooter?
i have MHR TEAM REP Cylinder\MALOSSI ROTOR IGNITION\PHBL 25\PHBG 19\VL13\MALOSSI RACING inlet\POLINI EVO Crankshaft\malossi racing exhaust.
and how much hp about that?

 

[Sonic-speed]

Well, I would like to know which one is more fit my scooter?
i have MHR TEAM REP Cylinder\MALOSSI ROTOR IGNITION\PHBL 25\PHBG 19\VL13\MALOSSI RACING inlet\POLINI EVO Crankshaft\malossi racing exhaust.
and how much hp about that?

You can't put it out that way. The HP reply on your ability to adjust the engine. The HP gained from the flow-tuning isn't either something you can put a number on. Around 5-10% - sometimes more, sometimes less. I would pick number 2, because it seems to me that nr. 1 has used chemical metal, and the angle of the gasflow-channel isn't very optimal imo. So nr. 2

 

[Fabrizi Dude]

from what i can see pic #2 is the best method but not to that extreme, just a little rounding and flowing as it doesnt make the biggest diffrence
thats what i would go with

 

[Sonic-speed]

from what i can see pic #2 is the best method but not to that extreme, just a little rounding and flowing as it doesnt make the biggest diffrence
thats what i would go with

For the today's Piaggio high performance engines, the flow 2# is not extreme at all. Remember, the stock carter is made for an engine that perform at 3-4 HP. To gain the max HPR you need to modify it, that's also very logical.

 

[Areomyst]

Here is a more aggressive examples done by members of scooter-attack. I don't know German so it is hard for me to browse the site. Looks like they just added an English section. I think most of us are already on scooterforum though.

[ir]http://www.scootertuning.de/gallery/files/6/6/2/5/7/bild0261-med.jpg[/ir]

It is not uncommon to cut through the block when doing the more 'extreme' carter flowing. I use Devcon aluminum putty to fill the hole, then sand it back down to the level of the block.

~Josh

 

[apriliafan]

e

The flow does not have only influence at the peak power....

5-10%?<---these are also just suggestions.As Sonic Speed mentioned right,SOMETIMES more/less.

Each layout has their dis/-advantage what perform diffrent at certain circumstances...
The fuel mix,(flow speed) changes by creating ur own ramp...but too MUCH aint too good as long as u respect the other factors like for example the precompressure.
By creating a too high Volume(taking too much off) could have an negative result.
So keep the compressure and precompr. in mind...
I ve seen for example many tuner who let the the upper corner to the boostport sharp and cornered...Also seen that many leave the crankside(the wall in the middle next to the crankshaft)untouched...
For instance there is many diffrent theories and u cant tell for sure which is defenetely the best.
I doubt some1 here has its own dyno at home,doing step by step and testing any change XD.

I recommend u the 3rd pic of ur last post,cuz i dont like to work with chemical metals to optimate the flow curve
Btw,as easy at it seems on the pics,the practical stuff could turn out as a real challenge

 

[waxhead]

Modern pipes will suck the mixture right out of the cases and cause the reeds to open (again) when the motor comes on the pipe. This is why v-force reeds are so good as they react quicker and take advantage of this
By allowing a clear path to reed block by porting the cases correctly you also take adavantge of this as well
Personally i would not put a scooter together for myself with out doing the cases

 

[WDJ]

so i think the pic1 keep the pressure and flow speed good.but it use the chemical metal is not good and have other drawbacks too.
pic2 has high Volume,maybe not,according to the actual situation.
i will in these cases to find fit my scooter.

 

[waxhead]

What is the drawback with chemical metal
I have never had a negative issue with it at all
as long as you are careful in preparing the alloy correctly

 

[apriliafan]

Modern pipes will suck the mixture right out of the cases and cause the reeds to open (again) when the motor comes on the pipe. This is why v-force reeds are so good as they react quicker and take advantage of this
By allowing a clear path to reed block by porting the cases correctly you also take adavantge of this as well
Personally i would not put a scooter together for myself with out doing the cases

I got a pic what might explain it better,and NO,the exhaust does not suck the mixture right out..at least not exactly...part of
This is caused by the PREcompressure(in the crankshaft self(piston moves down) and the reeds open.
In other words..
Two strokes are all about the exhaust. When combustion occurs in a two stroke, the piston is pushed down by the expanding gases uncovering the exhaust port. The exhaust gas rushes out into the header pipe and a pressure wave is created. This wave can be either positive or negative in pressure. If it is a positive wave and hits a change in diameter in the tubing of the exhaust pipe it changes to a negative wave. Hit another change in diameter and the wave changes back to positive.
:-D


http://upload.wikimedia.org/wikipedia/commons/5/52/Arbeitsweise_Zweitakt.gif

Try to have a look and do an research also on "scavenging".
Now doing/flowing the crankcase has influence on its speed and therefore the performance as already said.

 

[waxhead]

We will have to disagree on that one
A modern pipe can scavenge that hard it will pull a negative pressure in the crankcases and actually pull the reeds open

Thats a very basic gif i use at work when i am explaining to students two stroke fundmentals, its good for showing basic two stroke operation

 

[apriliafan]

We will have to disagree on that one
A modern pipe can scavenge that hard it will pull a negative pressure in the crankcases and actually pull the reeds open

Thats a very basic gif i use at work when i am explaining to students two stroke fundmentals, its good for showing basic two stroke operation

If the exhaust is well made and designed for the cylinder, the "wave"(like on the pic) with negative pressure reaches the exhaust port just as it is fully open. This sucks a part of the new intake charge into the exhaust pipe. Then, just before the piston closes the exhaust port again, this negative wave changes to a positive wave and pushes the fresh intake fuel charge BACK into the cylinder.

?!