Outer Limits 4x4 Board

KiwiBacon wrote:

nzdarin wrote:I don't believe the 2.5 x HP to cfm as that would mean that every K&N people are using is way to small, and in most cases the correct size K&N provides very little (if any) restriction. With my motor if we worked on 2.5 x HP it would mean I'd have to fit a filter with 1500cfm which is just rediculous! But I'd be happy to be proven wrong. The filter I've fitted is rated at about 1000cfm as I figured that would allow a bit of clogging without restriction. My truck hasn't been on to the dyno yet (within the month it will be) so I can't support this with results yet.

So your truck has 600hp?

1500cfm/2.5 = 600.

That's is what the turbo, fuel system etc has been speced to do. The motor is still running factory compression so alot will depend on how much boost and timing we can run. All things according to plan it will be running about 10psi which should equate to somewhere between 550 and 600.
Dyno time will tell all. The plan is not for outright power but to have good power across a very large rev range. Peak torque should be about 3000 to 3500 rpm, with peak hp about 6000 and redline is 7300.

most if not all high performance filters you talk about will have a cleaning solvent and an oil you have to put on it,the reson i dont like the paper filters is that in a sealed (no drain holes) airbox and a little bit of water, it actually damages the paper element to the point if you get a light on the inside of the filter you can see where the water has damaged the filter (distorted and holes). i have a unifilter (foam) in a gu 3ltr airbox ,it keeps al the dirt out of the intake, you cant see any dirt on the pipe as i did with the paper element, easy to clean with the solvent and oil and away you go takes me about 15-20 mins. i have had no major problems other that the fact that it clogs easily (i might was it about 2 times a weekend) BUT then again you clean a paper element out just as much, but next time you blow a paper filter out get a lead light on the inside of the filter and have a look through it.youl see a lot of little pin prick holes.
Holes = Low restriction! BAD filtration
My 2Cents
Cheers Duane

And that's why blowing filters out with HP air is bad practice.

Your experience with unitfilters is the same as mine - they are so labour intensive to keep running.

toyota factory paper filters are washable IN WATER. (Yes, really)

Steve.

yes but its what you use the car for, eg. ive done winch challanges befor, and the dust that it generated the car was starting to missfire and blow smoke. the unifilter was good because in 20 mins we were all good to go again, we washed the filter out ,sat it on the rocker cover it dried in 5mins,oiled and we ready to go,washing a k&n or bmc it takes 1 hour+ ,as washing paper elements out,you have to let it drie.
i spose if i were to use the vehicle in really dusty situations i was always go unifilter. but if it was for daily driving i would go the biggest surface diameter filter i could find as this wouldnt be so lobour intensive.

nzdarin wrote:

KiwiBacon wrote: So your truck has 600hp?

1500cfm/2.5 = 600.

That's is what the turbo, fuel system etc has been speced to do. The motor is still running factory compression so alot will depend on how much boost and timing we can run. All things according to plan it will be running about 10psi which should equate to somewhere between 550 and 600.
Dyno time will tell all. The plan is not for outright power but to have good power across a very large rev range. Peak torque should be about 3000 to 3500 rpm, with peak hp about 6000 and redline is 7300.

A few quick calcs indicate your power figures are a little ambitious.

Using the 10lb/air per minute per horsepower rule of thumb, you'd need 20psi and perfect intercooling to get enough air into a 4.5 petrol to get 600hp at 6000rpm.
That's with VE assumed at 85%.

Since perfect intercooling isn't possible, you're talking about 25-30psi. Not many petrol engines can handle that.

Gwagensteve wrote: toyota factory paper filters are washable IN WATER. (Yes, really)

Steve.

I run one of these 100 series toyota filters in my truck, made a custom vortex airbox to fit it.

I think they're cotton rather than paper.