Maxi

FYI, I went to a local shop that had a Skunk2 IM in stock so that I could compare it to my ported Y8 manifold. Here are some of the pictures I took (please ignore the port sizes on my Y8 manifold, since they have all been modified).


here's the Skunk2 IM...nice simple ITR-like design


here's the Skunk2 IM and Y8 IM side by side...pretty signifcant differences in design! Notice how the main intake chamber is short and fat on the Y8 manifold and longer and slimmer on the Skunk2 manifold. Also notice how the runners on the Skunk2 manifold are relatively straight while the Y8 manifolds have more bends in them. These design differences would lead me to believe that the Skunk2 manifold would foster higher velocity and thus better high rpm horsepower figures, while the Y8 manifold should produce better torque and midrange IMO...but hey, I'm totally hypothesizing here so take it for what it's worth


here you can see just how much bend the Y8 manifold runners have on them to reach "up" to the intake chamber compared to the flat Skunk2 manifold that has nice straight runners that should, in principle, help the air get to the combustion chamber more quickly (again, its a velocity design aimed at high rpm power gain IMO).


nice view of the back side of the Skunk2 IM


here again you get a sense of how the Y8 runners have larger bends in them, particularly near the ports that mate to the cylinder head. Certainly nothing drastic and the bends are gradual so I doubt they're restrictive in any significant way. You also get a sense in this picture of the potentially larger runner diameter on the Skunk2 manifold compared to the Y8, but I did not measure to verify this. Visually, the inner and outer diameter of the Skunk2 runners looked bigger to me. The runner lengths, however, appeared to be about the same if you were to straighten them out.


here again you get a sense of how "flat" the Skunk2 IM is compared to the Y8 manifold. On the Y8 manifold the runners have to bend almost at a 45 degree angle to meet up with the "raised" intake chamber. I don't necessarily think this is going to restrict air flow on the Y8, but it will slow velocity IMO.

One last tidbit of secondhand info to add to the confusion According to Skunk2 their manifold made 5-6 horsepower on a stock D16Z6 engine, but they had to increase the fuel pressure by 3-4psi to get these results. If you don't increase the fuel pressure, they say you may gain little to no power.

Hope this sheds a bit of light on the differences between the Y8 manifold and the Skunk2 manifold. I personally like the design of the Skunk2 manifold and if I didn't have a Y8 manifold that was all port-matched and ready to rumble I'd consider buying one, but with builthatch's experience with the Y8 manifold I really don't see this particular part as a bottleneck or weakness in the overall system so I've invested my D-series dollars in a 'Bisimoto header instead

KevronsEG

you said 5-6 HP well i have seen y8's on z6 get 8WHP so not sure what to think

Civic_95_Si

I just got my Skunk2 manifold today. Little FYI the throttle bodyinlet is 62mm. Up from the stock D16Z6 56mm. about 1/4" increase.

A D NOH

5whp on a d16z6 with just a d16y8 manifold? I wonder if the ratio of gained whp between the Skunk2 IM and the Y8 manifold would be the same when adding mods such as a cam, compression, etc.

Understand what i mean?
like y8 gains 5whp on stock d16z6
skunk2 gains 5whp on stock d16z6
y8 gains 8whp on stock d16z6 with xxxx cam
skunk2 gains 8whp on stock d16z6 with xxxx cam.. Or do you think the skunk2 would be better further down the road?

I just made the crap above up, so dont go quoting me on HP gains, haha

Maxi

you have a good point, Civ616. On the other hand, a friend of mine lost power when he swapped a Y8 manifold on his Z6 that had I/H/E, a Zex 53900 cam and ecu chip. *in best Johnny Carson voice* that's some weird wacky stuff

senpai

Daniel

Thx for the comparison. Now all someone needs to do is get a write-up comparison to see the power differences between a Y8, Skunk2, Edelbrock, etc. intake manifolds for D-series engines. That'd be interesting to see.

blackeg

power comparison and dyno charts would be very interesting

SOHC_MShue

i think i'll just stick with my y8. Buying the skunk2 mani would probably be a waste of money if you already have a y8 mani.

kommon_sense

Considering that you can find a y8 IM for $50-$75, I don't know that the skunk2 is worth getting for most people.

KevronsEG

well i ahve y8 manifodl on my jdm d15b and i love it on the 9th i'm hitting teh dyno so i will post my numbers. its a jdm d15b with y8 manifold 10lb flywheel,act clutch and j's knook off intake with 2.25 exhaust es oval muffler. so i will see what she does. not really hoping for good numbers myself......

piscorpio

Good pics, thanks for the visual comparison.

DXturbo

looks good! now im wondering what i should get for my turbo charge app. what do you guys think? y8 or skunk2 for my turbo d16z6?

Average Al

i would invest in a y8 just because of the price and if it didn't work out just throw it out

Maxi

the Skunk2 manifold really looks ideal for a built high rpm naturally aspirated engine, or even a stock engine that is staying na that wants to pick up some top end performance. I wouldn't bother with one if you're going turbo though. The Y8 manifold should be just fine for turbo IMO.

elevatethis

I dont see how an NA setup would really benefit from this, if anything it would just shift the powerband further into the higher rpms. This is not something anyone would want to have on their daily driven car, such as myself, where just driving to and from work I don't try to ever have vtec come on.

Wouldn't the skunk manifold work better than the y8 for a FI setup since the runners are short and wide?

Good post though, I rarely get to see a visual comparison between parts until I've already bought them

kommon_sense

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DXturbo &raquo;</TD></TR><TR><TD CLASS="quote">looks good! now im wondering what i should get for my turbo charge app. what do you guys think? y8 or skunk2 for my turbo d16z6?</TD></TR></TABLE>

I wouldn't bother with either unless you get them for free. The z6 is similar to the y8. You won't see a lot of improvement by switching.

kommon_sense

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elevatethis &raquo;</TD></TR><TR><TD CLASS="quote">I dont see how an NA setup would really benefit from this, if anything it would just shift the powerband further into the higher rpms. This is not something anyone would want to have on their daily driven car, such as myself, where just driving to and from work I don't try to ever have vtec come on.
</TD></TR></TABLE>

Its hard to use the terms "NA" and "daily driver" together when you are talking about a 1.6L engine. I agree with you. I really wouldn't want this on my daily driver. This appears to be best suited for high rpm applications.

Spade

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kommon_sense &raquo;</TD></TR><TR><TD CLASS="quote">

I wouldn't bother with either unless you get them for free. The z6 is similar to the y8. You won't see a lot of improvement by switching.</TD></TR></TABLE>

You won't see a lot of improvement, but you will see improvement. ESPECIALLY on Forced induction applications.

Marauder

What I don't get, is that you need to raise fuel pressure 3-4 psi to see an improvement?? What would happen on the stock Z6 if you turned up the fuel pressure the same?

Some has seen 8whp on a Y8 swap into a Z6.....that doesn't seem right. Then why does the Y8 engine only make 2 more horsepower at the flywheel than a Z6 between the model year changes?

For high RPM use.....duhhh...compared to most cars on the market, Honda's rev to much higher rpm's than most! When you want to go fast in a Honda, you shift at redline, hence that the reason you want to tune the powerband from the shift point to the revs the motor drops down to after the shift.

Nice pics and review on the Skunk IM!

ramz7887

Nice review of the new skunk2 im. I don't know why you would need to increase the fuel pressure with the new manifold. I would like to see the dyno sheets when someone gets one. Also how hard is it to change a im? can you do it in less then 3 hrs?

Marauder

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ramz7887 &raquo;</TD></TR><TR><TD CLASS="quote"> Also how hard is it to change a im? can you do it in less then 3 hrs?</TD></TR></TABLE>

Depends on how much you have wrenched on your car and how much you know about it. I have changed a few manifolds, and when I'm in a hurry, I can do the job in about 1 1/2 hours. The first time I did it, think it took about 4 hrs.

Maxi

well, it is really tough to say which manifold is better for forced induction without knowing the cc's of the plenum (main chamber) and the runners. Turbos, I would think (I have no real experience with forced induction), need volume and lots of it, rather than velocity. If the Skunk2 manifold provides more volume in the rev range where a turbo set-up makes its power, then yes I agree it would make a good turbo IM, but its design sure looks like a naturally aspirated one when you compare it to the ITR manifold for example. The runners, btw, appear to be very close to the same length on the Skunk2 manifold and the Y8 manifold, but again I didn't measure anything up so this is all just guess work. The only way to know for sure it to try both manifolds out on a dyno and at the track and see which works best in the real world.

Marauder

Looking at it in more detail....I wonder how the manifold was designed. It doesn't seem like CAD software was used, maybe a fabricated manifold was made and turned into a casting? Here's a pic with comments. Since I design parts myself using Pro/Engineer, these points just seem to stick out.

Civic_95_Si

Today I was quoted labor for install on a t/b and IM, it was for 3 hours.

" Group-A Autosports, inc. recommends the following performance products to maximize power gains:
a.Header, high-flow exhaust system
b.Cold-air intake system
c.Fuel pressure regulator
d.Camshafts/adjustable cam gears
e.ECU upgrade(For OBD|| equiped vehicles)"

I guess with all the extra air flow in alittle fuel correction with a FPR couldn't hurt. I'll try to hit a dyno w/ wideband after mine is installed. A before and after is too expencive.