noizmaker2

Running 1995 F150 w/351 4x4.
I've seen it mentioned in the timing bump threads to just drop in a K&N filter as part of the mod upgrade. Is there a noticable benefit to spending the extra $$ and going the Hi flow intake system verses the drop in K&N filter? Truck will be used mostly highway and towing 6000 lb boat couple times a month May-Oct.
Thoughts?
Thanks in advance..

ymeski56

If the engine is MAP, stick w/ the drop in. MAF engines can handle more intake air as the actual air flow & temperature is taken into consideration w/ fuel trim rather than just manifold pressure and incoming air temperature. Anything more than that, on a Map engine, will tend to lean your air/fuel ratio out under load, which is already at 14.68:1 (Courtesy of emmision controls) before you add extra air.

Joepbj

I have a Drop-In and I seem to get better mileage, although I replaced it when I changed the plugs, wires, cap & rotor so hard to really tell. I've examined the K&N and similar type CAI kits and IMO it's a waste of money. The stock intake is actually pretty well designed in my book. It's a lot of money for questionable results. I was hesitant about dropping the $50 on my "drop-in" but I suppose longevity should make up for the extra $.

But here is a question......if you did put a CAI on there and it "leaned out" the mixture......couldn't you remedy that by putting a 180/160 degree thermostat on there that should help richen things up? I'm sure it's not that simple and there's no way to really calibrate it, but it's an idea! How about being the guinea pig and trying it out, then letting us know? J/K

If I had more money to spare, I might just attempt this myself and get a wideband air/fuel meter installed so I could monitor the differences.....

ymeski56

As long as your engine reaches the temperature required for the ECU to enter closed loop function, it doesn't matter which thermostat. Before that temp is reached, you are in over rich warmup cycle mode. I run 16 BTDC, so I use a 180F to offset the slight increase in operating temp from the timing bump. You'll know if you don't reach closed loop temp if your only getting 10-11 mpg. Closed loop needs about 185F.

dewman

Before I bought my K&N drop in air filter, I went to their site and checked out the options. I have a 96 F150 4x4, 5.8L. The $45 drop in air filter was supposed to boost hp by about 6hp. The $300 cai kit was only supposed to increase hp by 8-9hp. Not worth the extra $$ imho, for the cai over the drop in.