Modified an '07 Intake

What a difference! Took my '07 Candy Red Viffer and went a little drastic with a Mockup Manifold. I've been researching for a week on the Intake Tract and any related mods to no avail. So I decided to do this ..










Here's the rundown

Removed the Flapper Completely, Snorkel tossed, reshaped the left and right intake passageways completely - to mirror eachother. In the process, I only added 8 ounces of extra weight with the use of Alluminum plating, epoxy, gasket silicone (to mend areas not epoxied), and 5 alluminum rivets. Took about 2-1/2 hours. The work I did was rough, but honestly it doesn't really matter because this is a mockup and still in under revision.

I was aiming at making two intake tracts to keep low and mid range torque in check, but keep enough airflow to smoothen out the twitchiness iin the damn throttle.



What I did

If you look at the pictures below, you can see that the side that had the Snorkel had the roof lowered, and the rouding curve to the backside top angled in more.

Meanwhile, the opposite side, where the Old Flapper Door used to be was
narrowed and a floor was added to lengthen passageway of the intake tract to match the other side.

















The Ramp coming up both sides is actually at the same angle, and the ceiling down below is also at an equal level.















The Outcome

I was aiming for better flow on the bottom (to correct for the gutted cat turbelence), better mid-range strength and hoping it wouldn't effect the top-end pull. As it turns out, it seems to have bolstered the bottom and midrange enormously, and the VTEC transition is more linear (keeps pulling into and through VTEC at the same rate) and the pull is linear as well with a little fizzle at the top - around 12,000 rpm. The VTEC take-off I felt before is gone - but that happened right after I modifed the Cat by Gutting the interals (this gave it more top end, yet wekened the bottom end - was a poor tradeoff). But the feeling now is more like a stouter stock feeling with a larger CC engine.

If I was to label this manifold - I would call it a Touring Manifold. One for lugging weight, and shooting around town. I wouldn't put this on a Track Bike or one that you are trying to chase a 1000RR down with - that needs a straighter shot manifold and your low-end is just not going to be there. I honestly do not think a "Both Worlds" Manifold can be achieved without some kind of Flapper Door arrangement on both sides with a straighter shot and a lot of patience to work with. Just my two bits on the matter.

However, being that I run her 2-up with Bags and I need the midrange - this is perfect for my needs, but I am going to continue working on it because it feels like I could shift to some more top-end - however, again, a complete redesign of the top cover would probably be needed for a straighter shot.



How it Feels

- I can leave from a Dead-Stop in Second without much use of the clutch - 1500 rpm easily, basically slow-to-a-near-stop and go. Cranking it is no problem as it goes eagerly!

- It's strong as hell with 170 lbs + 110 lbs + 30 lbs including bags from a dead stop to 110. Low and Midrange is much stronger then stock.


Up to this point I had the following mods, and the VFR just never felt strong on the bottom end (except just before the gutted cat when all I had was the K&N, PCIII and O2 Sensor Bypass).

Gutted Cat - completely (two internal cat cylinders removed with guts) - I do not recommend, if anything remove the honeycomb material only
Micron SS Exhaust with Titanium Midpipe
K&N Filter
Evap and PAIR Deleted
PCIII running Exhaust Maps for Staintunes
was running with Intake Flapper Valve Disabled till this mod

(Motad Header is to arrive around the 22nd of September)


Hope this inspires others Viffer Owners out there to start working on similar ideas :thumbsup:

 

I also removed the Foam and Rubber Shrouding that keeps the debris out of the Intake Track which is usually attached to the front-side of the Intake Cover. I was finding that not only was this introducing small rocks and dirt into the Intake when you remove the cover, but that it was not creating a very good seal with the foam on the right side - as evident with the junk ending up in the pleats of the K&N.

This was what I added in it's place









It's a Filter Pad that can be bought at any Aquatic Pet Store that is cut and zip-tied at the intersections, and to the wiring looms .. and then I made a custom bracket to hold back the upper edge against the frame.

Since I don't drive the VFR in the rain, this will block any large debris from entering the intake track. However I feel Honda placed the Large Foam pad there to block water - something you may want to consider. Especially those I've read that remove this piece entirely and leave it wide open. It's a straight shot from the tire to your intake. Plus this area is pressurized at speed.

Another side-note: one other small modification was to raise my tank 1/2 inch with the use of spacers to get more air underneath the front-side.

 

I removed the flap 'n foam piece entirely. I really looked like an afterthought to me. I wasn't too crazy about the fact it just jammed in there with nothing really securing it in place. I was guessing it was some last minute engineering Honda did to get the intake noise down to EPD levels or something. I don't run a flapper or a snorkel and I can say that small children, animals, and some road debris does wind up on top of my BMC airfilter - but that's what airfilters are for.

 

I am pretty sure that Honda placed the Foam Pad where they did to block off the area from having any debris entering the intake tract - but of all things, when I get stuck in the rain, and having later washed the bike - I look up at the top of the motor and sometimes notice a streak of light mud that tend to radius out from the tire - from the center bottom lip of the lower fairing, all the way to just in front of the horn - which is also where the area of the opening that we are discussing. In my opinion muddy water would pass the intake filter (no doubt in my mind actually - even if it was mist). And not only do I think it would pass, but it would eventually, given time, cake up the intake filter ever so slightly. And that's why I don't ride her in the rain with what I've done (if I can help it). And I've been thinking about blocking this area off once again with some kind of rubber sheathing because of this and the hot air when stuck in traffic.

Just to note: Blowing into the The Factory Foam Spacer reveals that it doesn't flow any "free" air what-so-ever. Also with the factory foam spacer/pad in place - hot air from the headers, radiators, oil cooler, hoses ... isn't allowed to raise up and enter the air intake - a low-speed consideration.

 

The only thing I could to better would be to make an air scoop and place it in that highly pressurized area - with the mouth just below the lower steering pivot of the frame. This area doesn't get debris from the tires.

It would have to use a flapper door actuator and a custom flapper door in that scoop. The flapper door would flip open at speeds above 40 or so - this way the heat wouldn't be a factor from the oil cooler or that area in general. The duct itself would require the horn to be relocated, and the duct would run underneath and forward of the radiator bridging hose - heat insulation of some kind would be needed to keep heat from transfering to the duct being that it would be so close.

Given the opening in between the frame and the front cylinder head cover isn't a whole lot to work with, and the consideration that the Cylinder head slides forward to aft, there would be a clearance concern. So the duct might be better off terminating just before the cylinder head with rubber sheathing to block off the debris on the sides, and keep the air flowing forward and pressuring the area just below the airbox to get the air to flow upward.

Heak soak of the intake material is another consideration. Fiberglass would get hot in summer heat being right up against the cylinder head. So that is something to keep in mind.

The appearance of a single intake opening as seen from the front of the bike if going to be detractive and out of place on a VFR.

As I write this, with all things condered, it just doesn't work out. You're better getting the air from the topside of the tank in the narrow opening with spacers.

 

Regarding the intake mod, a friend who has a gixxer 1000 rode her last night and couldn't believe the amount of grunt and midrange it had now. He said it was great. But he did notice the VTEC transition was different, and that the effect above 7,000 wasn't as wild. He said it didn't quite feel like anything happened like it did before - but he never let it tach out. And we didn't get a chance to run them. Sometime this week we will and I'll get back to this post, and I'll know for certain what effect it had on the top end (against a '07 GSX-R 1000 and an '06 1000RR).