WSID Wicked Wednesday 31st Oct

Make larger air boxes to go on top of your carbs if room permits. Then run them together to a joint plenum. From there route a some piping to a nice big Air filter where space permits. This will reduce noise and would prolly work better than your current set up without hampering economy/performance as much.

Good thoughs with the airbox/ air cleaner.

There must be a science to it since all modern cars seem to have such long air intake paths yet I doubt they'd do it if it strangled the horsepower like I suspect it does on my car. Mind you I'm sure induction noise is like red paint; both make your car faster without the need for mechanical modification.

I've always liked the cold-air-box idea. If the small manifolds are not a step backwards they'll stay and give me room (1.5 inches or so) to look at a cold air box. with a decent volume.

Like exhaust theory it can get quite complicated to figure out the ideal airbox volume I hear. I've heard of people dyno testing with an inflated balloon in a large airbox. They simply alter the volume the balloon and see how it affects performance. Then they deduct the baloon volume from the airbox volume to come up with the best airbox size.

It would be nice to feed the boxes cold air from either side of the inner pressing below the vents under the back window. But like usual I'll have to move a couple of things to make room for that.

The cold air boxes will have to miss the hex bar linkage anchor points and be angled to clear the engine lid. They'd have to mount the same way as the dellorto air cleaners so I can access the jets easily. I think some quick release pins on the deck lid will also be necessary.

I think I'm turning into a Gunna!

CT

fullnoise wrote:I might try the PVC. At the moment I've just got some fan housing ducts, some IDA velocity stacks and foam sock filters all held together by a couple of hose clamps. I want to keep things easy to remove so I can swap back to the normall dellorto style air filters in minutes.

The only problem is that my engine is rich at 2500 rpm due to fuel stand-off. It's just a little more obvious with the turbo tops on. But I can live with it.

Have you been down the strip lately?

CT

I run my bike at willowbank on a semi regular basis but I haven't taken my bug to the strip yet, but I'm gunna.

Are you running velocity stacks under your turbo tops?

A good example of airboxes not hurting power is my motorbike. I'll explain.
I ride a ZRX1200R, these bikes have a cult like following in the USA, and as such there is a huge amount of tuning done to them over there.
The airbox design on these is not the best and has been described as terrible, however testing with the same bike on the same dyno on the same day, with airbox and without and with jetting optimized for both setups there was virtually no difference between the two.

The point is so long as your not restricting the breathing and you can optimize the fuel curve you won't lose any power.

An interesting thing I read about airboxes is that some are designed to slow the air down and gain more air density. This type of airbox uses quite a small inlet, from memory as small as 40mm on a 2L inline 4.