calculating forced induction?

[rohan93]

hey all i have a turbo diesel D21 navara, the turbo is bigger then stock, by a lot i believe, its a garret, and the a/r is .80, its running a pod filter to allow max air flow, but as we all know pods are the worst filters around, i put a normal airbox on and lost al power, and the turbo would not even spool up, is there any other option other than a pod filter??? any way to calculate, how much air intake i need for it to spool properly and run
cheers

 

[jjohn]

Seems very strange to loose so much, you didn't change anything else?
K&N make a pod as well if your worried about quality. Pods are no good for water crossings tho.

 

[rohan93]

i dont do anything extreme, so water crossings are no worry, all i do is snad work and a bit of mud, and yeah lost ALOT aha, dunno why, when you see TD28's in patrol with a really tiny snorkel.... how do i tell exactly what turbo i have???

 

[jjohn]

I would be looking around in case you bumped something else, don't know your model for specific advice sorry.

 

[rohan93]

nah after putting pod back on had full boost again, its weird
just not getting enough airflow

 

[Old.Tony]

You might consider a larger airbox out of a different vehicle? How large is the intake of the airbox you're using? Is the filter new?

You might look at a V8's airbox or a Land Cruiser's - anything with 4.5L of engine capacity or over should have an airbox large enough to service yours comfortably.

 

[Brock200]

From what i was told pod filters were designed for WRC cars as they allowed the turbo max airflow and they were still able to "shake" off the mud that would get on the filter. I have modified the stock airbox on my D22 to suit just a regular k&n Pod. I didnt purchase it for more power as they give you bugger all extra power (1kW at the fly if your lucky). I purchased it to save money on buying new airfilters, as you only have to wash them.

maybe you can consider modifying the airbox like i have on my d22 to fit a 3inch stainless tube that is long enough for the intake pipe to connect to one end and then pass through the box (which you can seal with sikaflex around both edges) and enough sticking out inside the box to fit a pod filter with a 3inch neck on it. I will try and get pictures of my setup on the weekend and post it up in the DIY section. Its a pretty easy modification and might serve your purpose. I would also consider getting a boost reading from the turbo to see what you are running considering you have an aftermarket turbo.

 

[Dion]

Larger airbox is the way to go, if you're talking about the Terrano airbox when you say standard one, it's pretty small. What happens to your boost if you run the standard airbox, without a filter in it? The best thing about bigger airboxes is that they flow better, but without reducing the filter effectiveness like a cheap pod filter, simply because they have more surface area.

Calculating the required airflow is possible but you need head efficiency data, etc, none of which is available for the TD27.

 

[rohan93]

i was starting thinking about custom fabbing an airbox so sit around the pod, i dont mind the pod filter itself, its the sucking noise and the dirt getting past the filter that i worry about

 

[Dion]

The dust will still get past with a box though?

 

[rohan93]

The dust will still get past with a box though?

ill just make it airtight therefore making it not run at all, ahahahaha but anyways was thinking making an aly box, witha panel filter and cold air induction, but it might all be re routed soon as im looking at intercooling it