Running a WAI through the wringer

[FrugalFloyd]

The test route is a loop, 5 miles each way. I'll run it twice to accomplish each 20 mile test. Then I'll change parameters for the next test. I hope to do all the testing in one afternoon or one morning, to minimize variability.

More pix. Following shows the coupling between air horn and WAI.


Next photo shows the control A test air intake location. I put it there just to minimize my tube bending, but I'm thinking of running the tube up to the hole in the fenderwell (the dark area above the end of the current tube end), to get a real CAI effect for the control tests. What do you think?

[Project84]

I think the control test should be completely OEM. It's inconvenient, I know, because you already have the 3" tubing in there and ready to rock but...

CAI have been shown to increase horsepower and MPG.

Perhaps leave the tubing in the same type of location as your stock "air horn" as you're calling it was. If your OEM air intake tube was behind the radiator, place this tube behind there as well, even if on the opposite side as OEM.

[FrugalFloyd]

It's a PITA to remove the WAI. because I'd have to remove the battery and cruise control again. The control position puts the WAI's air intake in the same position on the right side of the engine bay, as the OEM air horn was on the left side of the engine bay. Both are up high, behind the radiator, taking in relatively warm air. That should be good enough to be a good control.

The fact that I can reposition the WAI to become a CAI by running it into the fenderwell, gives me a CAI test option. All I'd need is time at the drag strip to test its effectiveness.

[Project84]

Not neccessarily true... I have the x-gauge for instantaneous horsepower programmed into my SG! On level ground at a given cruise control speed, you could possibly test and see results.

Personally I think the added benefits of CAI or K&N filters in general, is they allow air to pass through easier, more air = more power just so long as you don't lean it out too much. So although you could set this up for a CAI test, its still running through your stock airbox and standard paper filter I presume... I doubt you'd see much, if any gain, even at a drag strip.

Hrmmm, makes me wonder what a real HAI w/ a K&N would do.

[drifttec101]

This sounds like a really good test setup. After you do the ABA testing on the same day a few times, I think it would be worth while to do a week long test with each setup and record MPG with pen and paper. That way you'll get a real world feel of any gains over some period of time.

[R.I.D.E.]

Originally Posted by SentraSE-R

It's a PITA to remove the WAI. because I'd have to remove the battery and cruise control again. The control position puts the WAI's air intake in the same position on the right side of the engine bay, as the OEM air horn was on the left side of the engine bay. Both are up high, behind the radiator, taking in relatively warm air. That should be good enough to be a good control.

The fact that I can reposition the WAI to become a CAI by running it into the fenderwell, gives me a CAI test option. All I'd need is time at the drag strip to test its effectiveness.

I like it Sentra. Looking forward to your results. It would be nice if there was a a fairly low ambient temperature when you did you test, so the difference would be more significant, assuming there is a difference .

regards
Gary

[Project84]

Originally Posted by R.I.D.E.

I like it Sentra. Looking forward to your results. It would be nice if there was a a fairly low ambient temperature when you did you test, so the difference would be more significant, assuming there is a difference .

regards
Gary

I see more benefits from summer driving w/ the HAI... I think it's because you can only gain 60-70*F at best unless in rush hour stop-and-go traffic. So in summer heat of 80-90*F ambient, your intake temps are like 150-160 which as I've observed, returns the best MPG.

In winter, lets say today for instance, ambient was 26*F, I think I remember my intake temp being 67*F while going 40 mph on the way home.

[FrugalFloyd]

Well, I'm bummed out. In a nutshell, virtually no difference.

I drove to the test area doing my usual P&G, with the WAI in its control position. IAT started at 55?F before I turned the engine on. It's 9.6 miles to the start of the route. I got there averaging 58.4 mpg, and the IAT had warmed up to 71?F. I'd pumped my tires to 45 psi cold. They were at 54 psi hot when I started the testing.

I reset the Scangauge tripmeter and ran my first A test, cruise control at 31 mph, for 20 miles. CC averaged 51.3 mpg, 19.3 miles using 0.38 gal. IAT was 69?F, and water temperature was 198?F at the end. Conditions were dry, mixed clouds and sunshine, and <5 mph wind. Tire pressure stayed at 54 psi.

Now for the WAI test. I routed my WAI intake above the exhaust manifold, shut the hood, reset the Scangauge, and took off down the road. IAT jumped up quickly to 78?F - and then it dropped. Less than 2 miles down the road, my IAT was back below 70?F, and there it stayed for the rest of the test. Did my duct tape come unsealed? I was tempted to stop and check, but I had a test to conduct. At the end of the run, I'd achieved 53.4 mpg, 19.3 miles on 0.36 gal. IAT was 69?F, and water temperature was 198?F. First thing I checked was my duct tape job. Nope. It was still sealing the air horn/WAI connection. Tire pressures still at 54 psi.

Back to another control run. By now the ambient temperature had risen from about 55?F to the low-mid 60s, so I expected better results. Yep. The run ended with 53.1 mpg results, 19.3 miles on 0.36 gal, nearly identical to the WAI results. Oh, and the initial heat soak of the air charge repeated itself. When I started out, my IAT readings rose into the mid 70s briefly, then stabilized at 69?F again. I ended the run with IAT 71?F, and water temperature 198?F.

I P&Ged home with the WAI in working position, and got 62.5 mph for the 9.7 mile drive home.

The WAI results were so disappointing, I didn't see any reason to continue with them. I had some errands to run.

The main problem seems to be the WAI simply doesn't bring in warm air, but I don't know why.

Next step?

[Project84]

Originally Posted by Project84

I suggest a heat shield.

....

If your IAT's aren't more than 60*F above ambient, I suggest you mod it until it is 60-70*F above ambient at city speeds.

You may also end up having to do two tests now. If heat shielding doesn't help enough, you may need to ABA test a grill block to keep the fresh air out of your engine bay, record your results, then re-do this ABA on the HAI w/ the heat shield and the grill block in place to keep that fresh air out of the HAI.

EDIT: I was kinda waiting for the "HAI isn't getting hot" post from you. W/o a heat shield (and you may need a very tight one since your trying to suck air so close to the firewall), ambient air entering your engine bay is going to be sucked into that intake tube.

If you think about it, your firewall is going to deflect the air that passes through your radiator and into your engine bay. Its going to create low pressure, maybe even a type of vacuum area. Cars w/ the exhaust manifolds on the front of the engine have an easier task of heat shielding since the cool air hits the heat shield and is deflected. Your shiled will have to be very tight (no gaps) to work properly.

Maybe just crumple the intake tube and cram it between the manifold runners? If you squeeze the inlet a bit, even mash it, your engine will suck air through it still, don't worry about that.

[GasSavers_BEEF]

you could use some window flashing as a heat shield. also, I saw a guy in another thread use a throw away turkey pan (the aluminum foil kind) as one. that might be a good way for your experiment as it is cheap and when you are done, you can throw it away without feeling like you were really throwing much away.

many of us (maybe I should just speak for myself) struggled at first to get the temps up.

you may do better to pull you air from beside the engine and put the heat shield across the manifold. that way, the air has to travel past the manifold and hopefully pick up more heat that way.

on a side note: most of us that have done the WAI have also done a grill block. that may have also been a big factor in the amount of heat we are getting. I personally didn't think you would need a heat shield since the intake is on the front and the header is on the back.


***edit****
just to throw this out there, you kind of suprised me. I was really expecting this to end very negatively. we have had people before to do spurr of the moment testing.

I have to give you credit on a few things:
-you did the experiment the way you described
-you admited shortcomings (the temperature)
-you kept an open mind during the entire thing

not that it means much but I applaud you on your efforts and hope you continue on with the test as time permits (that was always my hangup)