Modifying the Stock Air Intake System

[justin700]

Thanks; Ill look into those parts.

Do we have any hard numbers on what this mods gives us in terms of power and fuel?

[goldstar]

No, I don't. No quantitative data.

Happy Motoring!

[smokstac]

Now that I've moved I hope to try this out soon.

Had a friend in VA that covered his CAI with a mini Heineken keg to keep the water out of the filter without affecting air flow.

[justin700]

I just completed the 1st mod and it's great. Can feel the car rev up faster now. I have to admit, it was much harder to cut then I first presumed. While trying to keep some structure in the piece, then all the supports broke Not sure how important they are but I have none left. I also used a file instead of sandpaper, much faster. Ill post pictures up when I get a chance.

[goldstar]

I'm glad the mod worked well for you. Your results are similar to the ones I obtained - faster throttle response and a freer revving engine. If you carry out the rest of the mods expect to obtain a further small, but noticeable, increase in performance.

I also used a file to clean up the edges of the cuts. I used sandpaper to smooth the interior of the curved inlet tube where it joins the air box (post #3).

Sorry about the broken supports but I don't know if you'll experience any negative effects from the damage. My guess would be that you will not, however.

If you continue with the mods, keep us posted.

Happy Motoring!

[justin700]

goldstar,
Do you have any suggestions for a more permanent method of blocking the drain holes in the snorkel?

[goldstar]

Not really, since I've only used duct tape. I have found it very long-lasting, easy to apply, and it does the job. Furthermore it can be easily returned to stock configuration should that become necessary.

If I were to try something else, I might get hold of some 1/16" aluminum flat stock wide enough to cover the holes, cut it to an appropriate length with a hacksaw, deburr it with a flat bastard, and fasten it to the snorkel with black silicone adhesive. Alternatively, find an air box or intake parts of similar material at a junkyard, cut out the pieces you need, and adhere them to the snorkel. Whatever material you use, make sure it can withstand high heat as it sits over the radiator. This would eliminate such materials as polystyrene, for example.

Happy Motoring!

[justin700]

Awwwk, I think ill stick to the tape method just for the ease of removal, if it ever came to that. This probably isn't the best place to ask, but do you have any other mods for improving power and response?

[goldstar]

Awwwk, I think ill stick to the tape method just for the ease of removal, if it ever came to that. This probably isn't the best place to ask, but do you have any other mods for improving power and response?

It's okay since your question is part of your response to material in this thread.

http://www.wihandyman.com/forum/showthread.php?t=51915

Happy Motoring!

[justin700]

Thanks, Looks good

[justin700]

goldstar,
Have you ever thought of attaching and aftermarket pod filter? Would their be much to gain? And what would be needed to do this?

[goldstar]

justin, I have thought of installing an aftermarket pod filter but rejected the idea on a number of grounds.

SRI
My main objection to this type of system is that it results in the ingestion of hot underhood air. Since there is a negative correlation between intake air temperature and power output, it's likely that any improvement due to reduction in flow restriction would be more than offset by the rise in intake air temperature over that of the ambient. It gets mighty hot underhood, particularly in the summer. Also, to whatever degree it's useful, there is no possibility of any ram effect due to the forward motion of the vehicle with this completely enclosed system.

When Racing Beat was involved with the development of the MP3, they experimented with replacing the OEM air intake system with an SRI. They found that the replacement system had a negative impact on emission requirements (although they didn't specify the details), and so concluded that the factory setup was a better option for the production model MP3.

CAI
While this type of system enables the ingestion of cooler intake air since its pod filter is located outside the engine compartment, it nevertheless has problems of its own. The pod filter is located in the wheelwell and a number of studies have shown that in many cases the air pressure is less than atmospheric in this location leading to an overall decrement in power output. It goes without saying that the air intake should be located in an area with at least normal atmospheric pressure, if not slightly above, for maximum power output.

The low down placement of the pod filter makes it highly susceptible to water ingestion when the vehicle travels through standing water leading to the heartbreak of hydrostatic lock.

Again, no possibility of ram effect due to the forward motion of the vehicle.

Then, there are factors that we can only speculate about. In regard to ram tuning (the technique that ensures maximum cylinder-filling in a given range of rpms), it's likely that the length and volume of the intake tract of the stock engine has been optimized between the air box and the IM to ensure max cylinder filling in the rpm range most suitable for a road car. This is certainly the opinion of Julian Edgar and his associates who maintain the value of keeping the factory intake system as stock as possible while at the same time reducing restrictions to flow as appropriate, especially between the inlet and the air box. That, after all, is the point of this thread. Nobody knows how the varying duct lengths of the aftermarket intake systems may affect the ram-tuning capabilities of the engine, for better or worse. There is a considerable difference between the duct lengths of SRI and CAI systems. They can't both be right, can they?

For more information, all of the above statements have been referenced either in this thread or in other threads scattered about this Forum which can be accesed via a simple search.

Happy Motoring!

[dbmazda]

Why not just pull out your air box & put a K&N ( With pre-charger.) on the air flow meter?
Adding something to keep it steady?
Like what I did to my Subaru I had once.

[irishkev90]

Did you not read his reasons for not going that route? They make perfect sense. Yes, I know I have an aftermarket intake setup, but if I had seen this thread beforehand, I would have done my best to optimize the stock system just as goldstar has.

Sent from my HTC Incredible using Tapatalk.

[tradosaurus]

I believe this mod is not good for higher fuel efficiency. The colder the air the more power the car will generate but the lower fuel economy. I would rather bring warm air in from the engine.