Dinan Intake Observation

[JEllis]

I posted this in my build thread but figured it was worth posting here as well.

I bought this intake for pure aesthetic and sound purposes but I made some observations while installing the intake. Here is the Dinan intake side by side with the OE intake.

IMG_0855 by JEllis, on Flickr

A lot of people have questioned any advantage a Dinan intake has over a drop in filter. Here you can see the size difference in the collars that attach to the filter. Dinan claims theirs is 30% larger. It certainly looks less restrictive. I am not sure if there is anything to be gained from the larger intake collar but I figured it was worth noting since it is a significant difference from the OE intake collar.

IMG_0857 by JEllis, on Flickr

Food for thought. I don't really care if this thing is making any real power as the sound coming from the motor is awesome with it.

[8600RPM]

It is often deceiving when people advertise decrease in restriction or increases in volume or flow. While you can have a legit increase in flow from a less restrictive piece such as this, it often can lower or decrease the air movement's velocity as you lose velocity of flow with a larger diameter. Now that can be good or bad just depending on the application. In exhaust for example, you can put a large diameter piped exhaust on a naturally aspirated car like ours and it will truly be larger diameter, higher overall flow capacity but in the end the exhaust gases will flow at a slower velocity and actually lose performance due to loss of scavenging.

On the intake side, the speed at which the air is flowing into the engine is often a piece of the puzzle and as long as an engine is getting enough air, then the higher velocity of the air can be a good thing. Opening up the diameter may allow for more airflow potential but the engine does not need more air necessarily and the pumping losses associated with moving in, inherently slower moving air due to a larger diameter can decrease power. That is why so many intakes rob horsepower, not to mention head soak.

I would venture this is such a small difference it doesn't do good or bad in general. However it is a good example of how its a good marketing tool to say its 30 percent less restrictive for example but that doesn't necessarily translate into more power or performance for a given application if there is no need for more overall air and the air is now simply moving more slowly.

Turbo cars can be different animals and you can get away with less velocity on intake or exhaust side in favor of more diameter but I am talking about naturally aspirated applications.

[JEllis]

Originally Posted by 8600RPM

It is often deceiving when people advertise decrease in restriction or increases in volume or flow. While you can have a legit increase in flow from a less restrictive piece such as this, it often can lower or decrease the air movement's velocity as you lose velocity of flow with a larger diameter. Now that can be good or bad just depending on the application. In exhaust for example, you can put a large diameter piped exhaust on a naturally aspirated car like ours and it will truly be larger diameter, higher overall flow capacity but in the end the exhaust gases will flow at a slower velocity and actually lose performance due to loss of scavenging.

On the intake side, the speed at which the air is flowing into the engine is often a piece of the puzzle and as long as an engine is getting enough air, then the higher velocity of the air can be a good thing. Opening up the diameter may allow for more airflow potential but the engine does not need more air necessarily and the pumping losses associated with moving in, inherently slower moving air due to a larger diameter can decrease power. That is why so many intakes rob horsepower, not to mention head soak.

I would venture this is such a small difference it doesn't do good or bad in general. However it is a good example of how its a good marketing tool to say its 30 percent less restrictive for example but that doesn't necessarily translate into more power or performance for a given application if there is no need for more overall air and the air is now simply moving more slowly.

Turbo cars can be different animals and you can get away with less velocity on intake or exhaust side in favor of more diameter but I am talking about naturally aspirated applications.

Good points. Really just an observation since I believe many here were under the impression (including myself) that the Dinan intake was really just a OE tube reproduced in CF and a larger filter. In Dinans defense, if anyone has the facilities to test the gains/losses of a modification like this, they do. But, like you said, the gain or loss in power is most likely negligible.

[8600RPM]

looks badass and I am sure sounds great! Worth it for sound alone

[Hujan]

Funny, J; I am about to install a Dinan intake myself. Take a look that the elbow itself. The Dinan one is far more open than the OEM one (for better or worse).

I actually like the Dinan intake for several reasons: A clamping filter instead of one held in place by compression, metal fittings at the PCV hose, a re-usable filter, and sound. Most of all, I wanted mine to blend into the plenum and air box instead of the gloss black OEM elbow, so I hit it with a wrinkle-black look.

[Ezio]

i would buy one for sound also.

[JEllis]

Originally Posted by Hujan

Funny, J; I am about to install a Dinan intake myself. Take a look that the elbow itself. The Dinan one is far more open than the OEM one (for better or worse).

I actually like the Dinan intake for several reasons: A clamping filter instead of one held in place by compression, metal fittings at the PCV hose, a re-usable filter, and sound. Most of all, I wanted mine to blend into the plenum and air box instead of the gloss black OEM elbow, so I hit it with a wrinkle-black look.

Nice. Text me if you run into any snags. I have some thoughts on the fitment.

[BibleOnTheDash]

What are the differences between this and a drop-in filter though? Can you tell the difference in sound?

[JEllis]

Originally Posted by BibleOnTheDash

What are the differences between this and a drop-in filter though? Can you tell the difference in sound?

In terms of sound, probably no difference.

[BibleOnTheDash]

Originally Posted by JEllis

In terms of sound, probably no difference.

Ahh I see, would you be able to recommend a certain drop-in? K&n, AA?

[JEllis]

I haven't used a drop in but if I did I would probably go with BMC... OE for Porsche, Ferrari, Merc Motorsports

[Hujan]

Originally Posted by JEllis

Nice. Text me if you run into any snags. I have some thoughts on the fitment.

Might be too late to text you, but would be curious to hear your thoughts. I fiddled with it last weekend, but stopped when I realized I didn't have the little extender to keep the filter snug against the spring-loaded nub in the airbox. (I subsequently found it in the box.)

But it seemed to me that it was somewhat difficult to install. In particular, it is difficult to ensure that the rubber seals are fully seated. Before giving up, I'd decided that it was probably easiest to install the elbow on the plenum without the filter and that little plastic transition piece. Then, once the elbow is snug, slip in the filter-and-transition thing as one piece.

But I could be way off on this and would be curious to hear your thoughts.

[JEllis]

Originally Posted by Hujan

Might be too late to text you, but would be curious to hear your thoughts. I fiddled with it last weekend, but stopped when I realized I didn't have the little extender to keep the filter snug against the spring-loaded nub in the airbox. (I subsequently found it in the box.)

But it seemed to me that it was somewhat difficult to install. In particular, it is difficult to ensure that the rubber seals are fully seated. Before giving up, I'd decided that it was probably easiest to install the elbow on the plenum without the filter and that little plastic transition piece. Then, once the elbow is snug, slip in the filter-and-transition thing as one piece.

But I could be way off on this and would be curious to hear your thoughts.

I installed the intake as one piece. It was a little difficult to get the rubber all thew way around on the manifold but not impossible.

[FogCityM3]

Just as an FYI to those who may attempt this in the future, I install all the pieces rubber gasket, elbow, and transition piece as one piece and then slip on the filter last. It's the same way for subsequent filter changes (I change my filter instead of cleaning), just loosen the clamp, pry the knob to unseat the filter and pull the filter off from the transition piece. Re-insert the new filter, push it around the transition piece, push it down together with the knob so that it's snug, then tighten the clamp.

The MS intake elbow I would say is harder to install, given the rubber couplings are much harder and I believe the elbow sticks out even more.

Love the Dinan intake piece, except I got a CF plenum to match the elbow

Originally Posted by Hujan

Might be too late to text you, but would be curious to hear your thoughts. I fiddled with it last weekend, but stopped when I realized I didn't have the little extender to keep the filter snug against the spring-loaded nub in the airbox. (I subsequently found it in the box.)

But it seemed to me that it was somewhat difficult to install. In particular, it is difficult to ensure that the rubber seals are fully seated. Before giving up, I'd decided that it was probably easiest to install the elbow on the plenum without the filter and that little plastic transition piece. Then, once the elbow is snug, slip in the filter-and-transition thing as one piece.

But I could be way off on this and would be curious to hear your thoughts.

[Elwolfe]

Quick question on the air velocity issue.... As some have mentioned in this and other threads, when you put on a larger diameter charge pipe the air in that portion of the system should move slower. But, since the air is then moving into the engine through the exact same opening regardless of what intake you have installed, wouldn't that then re-increase the velocity regardless of what's upstream in the system?

I'm not an induction expert by any means, so there may be other factors I'm not considering... Thanks for any clarity you guys can provide.

[Leonardo629]

I just messed around with an online air flow calculator, air speed actually remains the same when go to a bigger duct, but CFM increases with the bigger duct. More air means more power as long as the ECU can adjust for it.

Originally Posted by Elwolfe

Quick question on the air velocity issue.... As some have mentioned in this and other threads, when you put on a larger diameter charge pipe the air in that portion of the system should move slower. But, since the air is then moving into the engine through the exact same opening regardless of what intake you have installed, wouldn't that then re-increase the velocity regardless of what's upstream in the system?

I'm not an induction expert by any means, so there may be other factors I'm not considering... Thanks for any clarity you guys can provide.

[Elwolfe]

Cool, thanks for the info Leonardo.

[CSBM5]

Velocity definitely is a function of the cross sectional area for the same mass flowrate. Assuming you hold the mass flowrate constant, and you increase the cross sectional area (diameter, what have you), velocity of the fluid falls.

[New2Roundel]

Originally Posted by JEllis

Food for thought. I don't really care if this thing is making any real power as the sound coming from the motor is awesome with it.

Originally Posted by Hujan

I actually like the Dinan intake for several reasons: A clamping filter instead of one held in place by compression, metal fittings at the PCV hose, a re-usable filter, and sound.

Hi guys, can either of you comment on the change in sound after the intake install? I'm considering an aftermarket setup, not for power (though I don't want to lose any either!), but for sound.

[sterile stork]

Originally Posted by Hujan

Funny, J; I am about to install a Dinan intake myself. Take a look that the elbow itself. The Dinan one is far more open than the OEM one (for better or worse).

I actually like the Dinan intake for several reasons: A clamping filter instead of one held in place by compression, metal fittings at the PCV hose, a re-usable filter, and sound. Most of all, I wanted mine to blend into the plenum and air box instead of the gloss black OEM elbow, so I hit it with a wrinkle-black look.

Oh wow, that looks great! Was the crinkle coat a DIY?

[Hujan]

Originally Posted by sterile stork

Oh wow, that looks great! Was the crinkle coat a DIY?

Thanks! It was actually just Plasti-Dip since I just wanted to try it out to see if I liked it. It is a perfect match for the OEM plenum and airbox. It's surprisingly durable.

[Hujan]

Originally Posted by New2Roundel

Hi guys, can either of you comment on the change in sound after the intake install? I'm considering an aftermarket setup, not for power (though I don't want to lose any either!), but for sound.

Sound change is not as dramatic as you might think. It's hard to describe, but it just seems to sharpen the buzz-saw induction sound the S65 makes. It's a bit less muffled and muted than with the OEM setup. It's a nice compliment to a good exhaust.