Welke bak op 1.4 16v (afh) blok?

[golflx]

Ben nu bezig mijn golf 1 (1.1) om te bouwen naar 1.4 16v afh op cbr 600 carburateurs. Zit nog in de fase dat alle onderdelen verzameld worden. Er komt een 4 2 1 rvs spruitstuk en zal zo rond de 120 a 130 pk moeten leveren.

Wat is de beste 5 bak voor deze set up? Ik vraag mij af of een ahd of ahz te kort zijn? Zal je met deze bak veel meer winst pakken in je sprints t.o.v. bijvoorbeeld een ceg bak?

Ideeën?

[Sjon]

1.4 16v met crb600 carb's, dat zullen 34 of 36mm zijn, zal best lopen, maar doe maar grotere:
38 of 40mm komen ook veel beter uit qua poorten.

Bak mot je lekker zelf beslissen.
Toevallig heeft me classic een 1.4 16v met AHD bak icm kleine wieltjes sprint dat heel leuk,
maar ik rij weinig op de snelweg met dat ding => (te)veel toeren.....

[golflx]

sjon bedankt voor jouw antwoord. Over die carburateurs...ik ben verre van een specialist maar heb wel veel gelezen. Mijn venturis zijn 36mm en op de engelse fora zeggen ze.

Heres the way to calculate the correct carb sizes for the job,

Venture size = √ (0.6 x Inlet valve Diameter^2 x Number of inlet valves / 0.85)

just to let you know 0.6 is an estimated flow coefficient, i would expect it to be that being ported and polished,,, may be 0.5 if not,, and if you
think you have an F1 head which you wont 0.7

the 0.85 is effective area dont worry about the its just a percent!

For top end power round up to the nearest mm
For bottom end round down 2 mm

for example 6n 16v

√ 0.6 x 29.5^2 x 2 / 0.85 = 35.05mm

Hier gaan jullie veel sneller voor grotere venturi's...wat zijn de voor en nadelen?

[bobrosco]

voor zover ik weet geeft een grotere venturi lagere luchtsnelheid en dat zorgt er voor dat je heel hoog in de toeren vaak iets betere vulling kan krijgen. Maar het nadeel is dat je dan onderin wat gaat inleveren op koppel.

[Mark]

*kuch*

We praten hier toch over CV (constant velocity) carbs ?
...jeweetwel met van die schuiven die op en neer gaan = variabele venturi

CV (Constant Velocity) CARBS

     Both Hitachis and Mikunis are CV carbs.

     In respect to these carbs, I'll be talking about the intake side, and the exit side. Air comes into the intake side and exits out of the engine side as fuel mixture.

     The CV Carb has a more complex air control system than the two carbs described above:

---The butterfly valve sits toward the engine side of the carb. It is opened and closed by means of the throttle and throttle cable and controls the amount of air that can flow through the carb.

---But the slide is retained. It sits in the middle of the carb on the intake side, before the butterfly. But instead of being pulled up and down by the throttle cable as in the slide carb, it now has no direct connection to the throttle cable at all. It is now attached to a rubber diaphragm and is raised and lowered by vacuum (depression) introduced on the top side of this diaphragm through holes drilled up through the slide.

Now we'll try to figure out how CV carbs work.

     When the butterfly valve is closed, very little air is moving in the carb bore. (The engine is getting some air and fuel through the pilot circuit, which we'll describe later.) With little to no air flowing, the air in the carb bore and the air in the closed chamber above the diaphragm are at close to the atmospheric pressure of the outside air.

Open the butterfly, and several things happen.

1. Air now speeds through and venturi effect (depression) at the point of the slide (variable venturi) is created.

2. The depression at the venturi is transmitted up through the holes in the slide to the closed chamber above the diaphragm. This lowers the density of the air in that chamber.

3. The open air below the diaphragm now wants to rush into that chamber to equalize the pressure, but it can't because there is no passage.

4. So it does the next best thing and tries to push its way in through the underside of the diaphragm.

5. The diaphragm can't let the air in, but it is flexible so gives way it is pushed up by the outside air pressure.

6. As it goes up, it pulls the slide with it, and the slide pulls the tapered fuel needle up in the fuel hole.

7. More air flows, more fuel is pushed into the air stream, and the engine accelerates or runs at higher revs.


     When the throttle is cranked on the slide carb, the slide is pulled up immediately by the throttle cable, expanding the variable venturi suddenly, and causing the lean stumble described above.

     When the CV butterfly is opened, the slide does not immediately jump up to a much more open position. It raises gradually as the increasing engine revs provide the needed depression (at the venturi), which is then transmitted to the chamber above the diaphragm. As the slide rises, the increasing depression also encourages more fuel to enter the carb bore and combine with the greater air supply now available. And the higher the slide goes, the more fuel the tapered needle permits to flow. In other words the genius of the CV carb is that the fuel from fuel hole can now "keep up" with the increasing air available--maintaining the mixture at proper ratios during the acceleration process.

     In summary, the CV carb provides quick enough acceleration (no lean stumbles to slow things down) which is also smooth. And overall we get a "kinder, gentler" carb which gives us less twitchy responses as we make small throttle adjustments.
http://www.viragoownersclub.org/Dr%20Piston/CV_carbs.htm

[Sander Beer]

ik rijd ook met een ahd bak lekker kort voor te sprinten of op track days ideaal maar als je veel snelweg doet niet zo ideaal
ongeveer 4500tr/min bij 120km/h met 175-50-13 in zijn 5e