2001 Frontier cold air intake

christ77 · Oct 22nd, 2004, 07:12 AM

I am wanting to do a "bolt on" modification to my nissan. Sounds like a cold air intake may be a simple mod that a do it yourselfer can do. I have a KNC filter and am going to acquire 2 inch tubing for the intake. I couldn't see buying one of the kits that I have seen on the web. Basically they all are the same - a filter and tubing.

A couple of questions:

I was looking under the hood, what is the empty black box on the fender well for? Some sort of sound damper? I plan to just bypass this - I'll just remove it from the vehicle.

There are two rubber vacuum lines coming off of the current air duct, I am going to have a single line come off the tubing and T to take care of these.

Any other considerations, gotcha's?

Step two is to get exhaust headers and also go to dual exhaust with the $$ from my tax refund.

jadcock · Oct 22nd, 2004, 08:41 AM

I don't mean to discourage, but Nissan spent a lot of money on designing an intake system that would be quiet, that would provide cool and DRY air to the system, and that would work without rattling, etc. Spending 20 bucks and re-engineering it yourself will not provide the results you are looking for. If you are looking for more power, and understand there will be tradeoffs, I would encourage you do purchase one of the engineered intake systems, because those should at least have SOME engineering methods put into them (like maybe a mandrel-bent tube, etc). If you have an open cone, you still run the risk of pulling water into the engine, but if you don't do a lot of off-roading, that might not be a problem. It probably won't happen anyway, but the risk is always there. That's why Nissan put a large box on the end of the intake tube. It probably quiets the intake some, but the biggest benefit is providing the engine with cool air from outside the engine compartment (it gets hot in there!) and it also does a good job of separating water from air, if you happen to get in a situation where you ingest water into the system. That large box will probably allow the water to settle at the bottom and possibly drain out. If you suck water into the cone, it's curtains. Again, that PROBABLY won't happen, but you run the risk. And I'd trust something an aftermarket supplier fabbed up before I trusted something I did myself, because I don't have access to a dynomometer to verify different designs, etc.

The next step would be a good muffler on the exhaust. Something like an Edelbrock or Dynomax would probably give you the best flow. Flowmaster will be loud, if you like that. Duals will be added expense and good for looks, but performance-wise, it'll be similar to a good single outlet system. If I were you, I'd spend $150-200 on a good intake system, and have a shop weld-in a Dynomax muffler (or buy a cat-back from 4x4parts.com) and call it good. You'll probably add 10-15 hp to the engine (7-10 at the wheels probably) and you'll probably notice a difference in acceleration. Bump the timing 2-3 degrees and you'll really feel it.

Good luck,

Azgrower · Oct 22nd, 2004, 09:16 AM

Drill several 1.5" holes in your air box for a "colder" air intake.

As for the exhaust. If you are doing a true dual out, be careful that you dont get too large of a tubing size, like 1.25" max. Larger diameter tubing will cause the exhaust velocity to slow too much, and you can actually lose power. Borla makes a very nice exhaust that is not too overpowering in sound, but gives a nice "growl". If you looking into headers, dont bother with shorty type headers, get the full length or "long tube" headers. Look into Thorley Tri-Ys, ASM, or TOG headers for the highest quality.