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Mile High VX
09/05/2015, 08:07 PM
So nobody really makes a CAI for our beloved VXs so I'm going to make my own.

My thought is to remove the stock intake box.
Use a K&N RX 4120 that actually will fit inside the cold air duct in the front fender. It has the filter in the nose as well for maximum air flow. I believe this will be better than a filter that has a solid end. The collector at the fender is 4 3/4" wide and has a depth of about 3".
Have my local muffler shop bend me a tube that will connect the MAF to the new filter placement using 3" stainless pipe.
Use the OEM black tube from the throttle body to the current MAF location.

My biggest question is where does the MAF really need to be in this process? I would like to leave it where it is and connect it to the new pipe, but I could relocate it to the filter end, near the front fender if that's better for some reason.

The other two options for a filter are both K&N; one is the RX 3990-1 (which is really a big filter) and the RX 4140 that's smaller, but also requires a 3 1/2" pipe. The MAF connector is a 3".

Just looking for some feedback.

Thanks.

ipd
09/05/2015, 09:58 PM
My understanding is the only difference in MAF location has to do with turbocharged cars. On N/A cars, it shouldn't make any difference, afaik. But I'll let someone else chime in.

ron
09/05/2015, 11:46 PM
I have a hot shot intake and cone filter that I bought used and refurbished a while back. The maf sensor is positioned in-line after the filter. I believe the maf needs to be after the filter to get a cleaner reading as it would be prone to contamination if positioned before the filter. Sensor is highly sensitive to dirt which will affect your engines performance and/or throw codes.

ipd
09/06/2015, 12:17 AM
That's a given that it comes AFTER the filter. I think OP's question is about whether it makes a difference if the MAF sits immediately behind the filter, or immediately before the intake manifold. In my opinion, it shouldn't really make any difference.

Mile High VX
09/06/2015, 06:23 AM
That's a given that it comes AFTER the filter. I think OP's question is about whether it makes a difference if the MAF sits immediately behind the filter, or immediately before the intake manifold. In my opinion, it shouldn't really make any difference.

Yes, this is the question...does it matter where in the stream the MAF is located...Thanks.

ipd
09/06/2015, 08:57 AM
And just a hunch, but most of the time, a CAI has very little effect on engine power. Sometimes the CAI can actually increase intake temperature because the open-air filter is getting more hot air from the bay, because there's nothing to shield it from the engine. That's why I'd be more interested in making a VX-proto-style hood vent, since it will help cool the engine bay. I'm not saying it won't work at all, but the only way to factually determine efficacy of a CAI is to have a digital temp readout on the filter.

Even still though, bear in mind that if you have a hot bay, the air flow has to make it up to the manifold, and will get heated along the way. That's the biggest reason for having a vent. You can put scoops on, but they won't help to bleed the hot air, and scoops really only help with ram-air in a sealed system.

WormGod
09/08/2015, 06:59 AM
Short ram or CAI, completely performance worthless in the VX. You will also find yourself cleaning it a LOT more often since we sit high and that allows a lot of dirt, dust, etc to crawl up from below. I tried a few designs and though they all looked cool, completely not worth it. Though, I am also supercharged, and I just found I was getting cooler air via stock airbox.

Mile High VX
09/13/2015, 06:13 PM
Thanks Gary and all...

I decided to just cut the fender side out of the stock air box and the bottom between the mounting bolts and up to the base of the filter.. I had an extra one so I can go back to stock if I don't like it. So far it's been fun having the intake noise, but we'll see if anything else like better mileage comes along for the ride.

I'm using an old style GREEN filter that's supposed to have better airflow so we'll see.

Thanks again.