2g Head stock intake vs. 1g Head cyclone intake

[untouchablecc]

I have been seeing a few guys with 6bolt engines switching to a 2g head. The reason i am told is because there is power to be gained because of how the 2g head flows and having smaller intake ports allows for more over all torque.

My question is does anyone know what the better torque and over all power adder would be between a 2g head with a stock IM vs a 1g head with a functioning cyclone.

Now my reason for comparing the two. Both setups are closely related being that both set ups make a narrow channel for air to increase airspeed and up the velocity making more torque. The difference is a cyclone opens up depending on the rpm activation point. Allowing for peak HP to be achieved.

I dont want anyones opinion of the cyclone being trash or a waste of time because i have a functioning one on my car and the spool up is night and day.

 

[toofast82]

I absolutely loved my cyclone intake when i had my dsm. I used a modified wga to actuate and was very satisfied.
You could still use the cyclone on the 2g head if you epoxy the runners to match.
Search a user named 94awdcoupe, he has pics in threads of the epoxied runners on 2g head and I believe him to be the one who came up with the wga mod on the cyclone

 

[untouchablecc]

Well i actuate my cyclone with dsmlink but same concept. Its one of my favorite mods yet. I wanted to know the torque and power output of a stock 2g head with intake vs the cyclone because they are both centered around making more torque. I didnt think i would get real good results posting this because its something that would have to be dynoed to see the results. A 2g head with cyclone would be interesting although i dunno what the gains would be. The intake ports are a lot smaller so i im just wondering what effect it would have. I understand on the 1g head having equal ports to match the intake allows for the top end to stay the same but blocking off half the runners makes the torque increase. On a 2g head where the intake ports are already smaller im not sure what to think but im sure there would be a gain on bottom end.

 

[talonDSMerr]

You're right that a dyno is the only concrete way to determine which of these two setups is better. But, in theory, the Cyclone/1g head should produce more torque at lower rpms.

I did a little searching and found some dimensions on 1g/2g intake ports and the runner diameter for the cyclone. Per RRE, the 1g head intake port has a cross sectional area of 2220mm^2. The 2g, on the other hand, is 1568mm^2. The runners of the cyclone manifold have 38mm diameter and thus have 1134mm^2 cross sectional area per runner.

These numbers are important because Airflow rate = (area)*(air velocity). For engines with identical turbo, boost, tuning, etc., airflow rate will be constant. Because of this, decreasing area results in an increase of air velocity. Since the cyclone, with one runner open and the other shut, has a smaller cross-sectional area than the 2g runners (assuming the 2g manifold runners have cross-sectional area equal to the 2g intake port), the charge air velocity will be approximately 38.3% higher for the cyclone. However, because the cyclone's area opens back up before the 1g head intake port, some of this velocity is lost, but the inertia of the moving air will help keep velocity up into the cylinder, and higher intake velocity equates to an increase in torque in low rpms.

Keep in mind this is all theory, and includes assuming the runner lengths are equal for both intake manifolds.

 

[untouchablecc]

That is really good information. Knowing the the dimensions of the ports really gives you a birds eye view of whats going on. I was thinking the 2g head would provide more torque from just looking at the ports but in reality the cyclone really does restrict that much more airflow providing a really fun effect. I have never really gotten to use a 2g head and i have one laying around so the question popped into my head but know this its prob better to stick with my set up. I want to see what a hx40 does matched to a cyclone + antilag.

 

[talonDSMerr]

Yep, from a numbers perspective, the cyclone is the way to go. The idea behind it is the same as variable geometry turbochargers, and yet people don't seem to get as excited about it as they do about VGT's. I'm assuming more people focus on the high top-end horsepower numbers that come with short-runnered SMIM provide. The evo3 manifold may flow more top-end than the cyclone, but for a fun torque machine with lots of grunt down low, the variable runners on the cyclone manifold fits the bill perfectly.

In the end, I'm sure whether you go with 1g head/cyclone manifold or 2g head/evo3 manifold, both will give good results.

I've got a cyclone sitting in my garage and I'm waiting to pair it with a 2.3L stroker and divided HX-35 in an attempt to make a killer street setup with low-end power and quick spool. That'll be fun