DIY Ram Cold Air Intake on 3rd Gen CTD

[Diesel_Dave]

Originally Posted by ron

I dont know if this translates to Diesel but Ill add it. I installed a ram air intake on my 2003 toyota techoma the first drive I gained 4mpg from 21 to 25 at 65mph the next time the confuser had detected the lean condition and adjusted the fuel ratio.NOTE now when I drive at 35 mph the ram air will hold the speed at 35 with no throttle, nice for in town.

This study by Oak Ridge National Labs found that fuel economy for fuel-injected gasoline cars was basically unaffected by intake restriction:
http://ecomodder.com/forum/showthrea...omy-22633.html

They were more focused on plugged air filters, but I think the pressure effects of ram air is basically the same thing in reverse.

The results make sense to me: less intake restriction and your throttle will just be further closed. Therefore the TOTAL restriction (from outside the vehicle to intake manifold) remains the same. Diesels are a different story however.

[ron]

my intake is 3in by 16in rectangle scoop reduced down to 3in flexible alum dryer vent into the side of the filter box, from bumper up to the box, no water problems or bugs.does the computer adjust the fuel ratio? I think any increase in fuel/air ratio will help the diesel

[oil pan 4]

Originally Posted by ron

I think any increase in fuel/air ratio will help the diesel

With diesels you want to cram as much air into the cylinders as possible, there is no throttling, just a turbo to further stuff even more air into the cylinders. You just dump in more fuel to go faster or pull harder.
We do not have to worry about air fuel ratios.

[ron]

BLACK SMOKE = to much fuel. my post should have read air/fuel ratio. I have a 99CTD do the newer TD use any computer control for fuel.

[Diesel_Dave]

My truck (2007.5) was the first one with a VG turbo and has closed-loop AFR control. That being said, there's still an benefit, because if the air can get to the compressor better, then the VG won't have to close down as far to deliver the same air. Therefore, exhaust manifold pressure goes down and, therefore, pumping loses go down--you pushing against less pressure during the exhaust stroke. It all sounds complicated, but I've seen it proven with an engine in a test cell.

If the diesel doesn't have a VG turbo, then you correct--the benefit comes from higher AFR.

[Diesel_Dave]

For what it's worth, I set another new record on my morning commute this morning. 57.8 mpg on the overhead. My previous best was 57.2 mpg. I think it's too soon to say it's attributable to the intake, but it's a good sign. This dispite the fact that it was quite cool this morning and I got slammed by one red light, that probably cost me ~2 mpg.

[oil pan 4]

Before I put ram air on my non turbo diesel I measured 11 inches of water worth of restriction in side the air cleaner at full speed.
After ramair I had no measurable restiction.
Replacing the very restrictive intake on my non-turbo with the ram air delivered an instant 2mpg highway fuel economy boost.

Now I have a turbo just like yours and I am in the process of building a very over sized ram air fed air cleaner with a paper element. There is too much fine dust around here to run something like a K&N air filter so I went with the largest off the shelf air cleaner I could find.

Removing the ram air pipe for A-B-A testing would waste fuel.
How much fuel, I don't know if I care to find out.

[Diesel_Dave]

What did you use to measure that restriction?

[oil pan 4]

I found a filterminder and installed it.
The sad thing was those readings were with a brand new air filter.

[MGB=MPG]

i just ran some measurements today on my ram induction

i wonder if you have a turbo charger .. that would make a difference

anyway.. i have a NA 110CID old school gasser with a ram air down on the deck
2 in pipe feeding to an air box in front of a Skinners Union Carb

my ambient temps were about 100F on the intake

my test points were out side the pipe at the funnel and inside the pipe
with and with out a pre filter..

on the test point outside the pipe i saw
1 inch water at 40MPH
2 inH20 at 50
2.5 inh20 at 55
3 inh20 at 60
3.5 inh20 at 65

then i moved the sampling point inside the pipe

i saw i inch H20@40
1.5 in H20 @ 55
2 inh2o at 60..

then i put the prefilter on
saw
1 INH2O @40
1.5 INH2o@50
2 INH20@60

as i was going along with the sample tube in the pipe i became aware that it made a BIG difference if i was in neutral throttle or trailing throttle

i mean what throttle setting i had . i became aware that as my manifold pressure went down ..so did the over pressure in the pipe

at WOT 0 INHG manifold i was pulling vacuum in the pipe [ level not noted maybe 2-3 inh2o]

at my cruise setting of 15 INHG manifold i was showing

1.5 inH20 Over pressure in the pipe

i noticed at 55-60 mPH cruise AND 15 INhg MANIFOLD I WAS SHOWING 1.5 INh20 oVER PRESSURE
ON A HILL CLIMB 5% grade 40 mph top gear 10 inhg showing 1/2 in H2O over pressure

finding that throttle setting and the resultant manifold pressure transfers directly in to the induction pipe near the inlet makes my test series much more complex..
i need a data logger .. in my vintage vehicle a data logger is a rider with a stubby pencil
..
of some interest ..when the sampling pipe was Outside the pipe , i noticed i could detect overpressure increase Bow waves off of oncoming traffic and over pressure reduction when i entered the draft following a vehicle
[slipstream]

this test sequence is much more complex than i had counted on

.... next i intend to move sampling point to the air box ahead of the filter
try to record ..
speed . manifold pressure and measured pressures
then after the filter in the air box

INTUITIVELY .. i perceive this manometer very useful ..
as long as i can read an induction pressure Positive , i think i am in the increase FE zone

what do you think
who can plan a proper test sequence for me ?

my final config will be with a sensor pipe after the filter in the air box and a nice little u-tube manometer on the panel [yet to be fabricated]

i expect to see the same kind of values before the filter . hard to know what i will sample after the filter..

comments ..remarks .. suggestions?