Write-Up: Installing FWI Filter, Heat Shield, Air Scoop

Coolant temps are usually around 185-190ºF when sitting that long. I see where you're going, with the metal tube it certainly heats up. The IAT sensor is metal, too. I might try modifying the stock sensor so that it's insulated from the pipe somehow.

Here's the finished scoop with mesh ($3.00 from Ace Hardware):

cool man! now you gotta get a ram air emblem from a grand am!!!!!

Heck yes... I'll write it across the windshield in white vinyl!

Looks nice Aaron! Maybe I'll try that out next weekend.

you know what might be nice with that scoop? If you used a wall cap (the outlet piece of a range vent or bathroom fan) instead of just blocking off the hole that leads into the engine compartment.

I don't know if it has a specific name, but the duct has a little unidirectionnal clapper that would allow air to escape at speed, but close off at idle.

Interesting idea, but I have no problem with IAT at speed.

I made an air scoop back in the day, It worked great around winter time and with cooler temps, but i think it was worse at hotter temps. It doesnt help when you Riv is Black.

The results weren't spectacular, but for the price, I don't expect a huge difference. My goal is to get the coolest air possible into the intake. There may be more I can do, but haven't figured it all out yet.

To look at it from a cooling/cost ratio, I estimate my $25 invested in the shield and scoop gave me a 3º average drop in IAT. That's -.120º F per dollar.

A ZZP intercooler kit is $1000 and gives you 135º average IAT drop. That's -.135º F per dollar. Shows just how effective (and expensive) an IC is!

Yesterday I did some further testing at 89ºF ambient temp. I was able to get down to 82º IAT for a few seconds while cruising, and a sustained 80º IAT at 86ºF ambient. I'm still trying to determine if my IAT sensor is off, or if there is some kind of "wind chill" happening here. Regardless, these are the best temp drops I've recorded so far.

Additionally, I was able to shift my "speed of ambient temp" from 60 mph down to 40 mph. This is the speed above which IAT starts decreasing, and below which it begins to increase. This is probably the biggest benefit I've seen from the mod.

the idea was more to evacuate the hot air faster once you start moving.

I see. It might help, especially if the compartment were sealed, but I still don't know which way air wants to move between the fenderwell and engine bay. Could be the pressure inside the bay is greater, if that's the case i'd want to keep it shut at speed.

I discovered today that the wind chill effect is in fact real. Went out to the car after work. It had been sitting for 10 hours. Before turning on the engine, I did a scan showing IAT of 81 F. Ambient temp according to A/C control was 90 F, but as you know the car had been sitting into the sun all day, and that reading usually stabilizes after a few minutes of driving. So started driving and watched ambient temp drop a couple degrees per minute until it reached exactly 81 F. At the same time, IAT was decreasing to as low as 75 F at 80 mph. I wanted to be sure the ambient temp wasn't changing, so turned around about 5 miles out, returned to work, and ambient was still 81 F. In fact, it remained the same as I headed home, increased to 82 F after 10 miles, then went back to 81 as I reached home 20 minutes later.

I'm surprised at the accuracy of both the IAT sensor and our car's onboard thermometer. Both seem to be spot on, and i noticed while driving that if one changed, it was only a matter of seconds before the other followed. Watching this behavior has convinced me that the 5-7 degrees below ambient readings are correct, which is great because I cannot ever remember going sub-ambient before these recent mods.

AA wrote:

I'm surprised at the accuracy of both the IAT sensor and our car's onboard thermometer. Both seem to be spot on, and i noticed while driving that if one changed, it was only a matter of seconds before the other followed. .

in the limited driving I have done with my new scangauge, I have noticed the same. temp gauge on a/c panel is very close to IAT, at least until idling after the motor is warmed up.

keep in mind it takes my motor alot longer to warmup (EGR removed) and runs very cool unless idling in hot weather.

A long overdue finishing touch, I found a piece of drain cover at the local home improvement mart. Here's my intake before:



And after:



This wasn't hard to do with a utility knife and scissors. It adds a nice finishing touch, but also somewhat shields the fenderwell from heat.

Has that helped at all Aaron?

The cover is mainly for aesthetics. I haven't noticed any measurable improvement. I think the shield and scoop have made the most difference. It's still a very small difference, though.

Alrighty, here's my thoughts on the ram air setup -



Aaron's scoop location is probably a little less than ideal because the air dam is blocking it. It'd be better (and a helluva lot more work) to put the scoop in the air dam, where there's a high pressure area to help cram the air in.

How to fab it though, I do not know. In a couple weeks I may pull those plastic pieces and see what the area is like. Maybe it would be possible to carve a new one out of the foam they use in the R/C airplane hobby, make a mold off of that, and cast a custom rubber air dam? I've never done anything like that before, but it sounds like fun.

If it's possible, why not pull some air from the passenger side, or make a deeper, more aggressive air dam -





Here's a couple of airbox ideas -





And a cheapie scoop thought -

quote: "Aaron's scoop location is probably a little less than ideal because the air dam is blocking it. It'd be better (and a helluva lot more work) to put the scoop in the air dam, where there's a high pressure area to help cram the air in."

If I were trying to cram air into the fenderwell, the location I chose might not be ideal, but as I posted in the other thread, I don't believe in the benefit of ram air with FI application, and I don't understand the purpose anyway. Any high pressure created in the intake is going to be moot compared to the suction of the blower. Even if it did make a difference, the gain would be in the form of extra boost. If I want that, I'm going to swap to a smaller SC pulley.

As Troy was saying in the first thread, the true benefit of such an intake is lower IAT. The purpose of my "air scoop" is mainly to vent the fenderwell to the cooler outside air, rather than source it from the hot engine bay. Consistently lower IAT shows it has worked to at least lower intake temps by a few degrees. The scoop is shaped like it is so that it protects the fenderwell in case of splashed water from the tires.

The IAT was really low on the cruise home today. At 70 mph I saw a sustained 73ºF intake temp with 81ºF ambient temp according to my climate control reading.

You've got a point against ram air if you want a precise amount of boost and no more. If ram air works with an SC. My guess is that it's only good for a fraction of what the SC can do, and at speed, but it probably adds a little.

But I think this location is also more of an IAT thing. With your arrangement ( which is the best I've seen so far) you're still picking up engine air. In the set up I diagrammed, you wouldn't pick up any engine air while moving, and while sitting it would have to diffuse out into cooler air before it could get to the intake.

What I drew may or may not be worth the effort it would take to build. I like to build though, more than I like to drive (thanks to deer, kids, cops, and other road hazards). I might give it a shot.

True, I think a dedicated "inverted snorkel" like the one you are suggesting would be the absolute best for IAT. More important than location is the fact the tube would be completely sealed from the engine.

My design is not 100% sealed, so it pulls a mix of outside air + engine bay air, but the current arrangement is showing to be superior to simply putting a cone in the fender, which is what most FWI installs are.

When the car is moving, I don't see how heated engine bay air can enter my air vent location. It's not behind the air damn, it's beneath it. I think any hot air that gets through is being pulled around the heat shield. At idle, I think even a sealed tube in your ideal location is going to inhale heated air that surrounds the car when stopped.

(Didn't mean to create a poop storm. I was in a rush and didn't edit for reader sensitivity)

hows this working in the winter months AA?

I like that design Jack, you should give it a try man

Quote :

hows this working in the winter months AA?

Just fine. IAT is same as outside or slightly lower. At idle, it goes up a little, but not very much.

AA wrote:

Quote :

hows this working in the winter months AA?

Just fine. IAT is same as outside or slightly lower. At idle, it goes up a little, but not very much.

COOL.................... no but literally COOOOOOOOOOOOOL

I made a very basic FWI today out of some materials I had lying around and as I was extracting the existing air box I saw this small sensor in the corner, what is the purpose of this sensor? Is this how you are measuring the IAT? What would happen if you ran the car without the sensor? Thanks!

The purpose of that sensor is to measure IAT! Without it, your PCM would have a difficult time calculating correct air/fuel mixtures, and for some reason, the A/C does not work when the sensor is disconnected.