Two years ago when I converted my SBC to fuel injection, I just mounting the air filter off the throttle body under the engine vent because it was the easy fix at the time. This location is far from ideal, and infact my intake air temp ranged from 50 to 65 degrees C (about 125 to 150 degrees F) as measured from the sensor at the tip of the air filter after about 20 minutes of driving.

Before Pic:


The RamJet throttle body has a 3 1/2"round flange (similar to LSx engines). I used a 3 1/2" U bend (16 ga mild steel) from Summit (HOK-12385HKR $41.95) and it was all the tubing needed (I purchased the long pipe too, but did not need it).


I really hated to do this part, but the cold air is on the other side of the inner wheel well, so a hole was cut (4" hole saw) to make room for the tube to pass through.


Here is the intake tube welded up and prepped for coating:


I wanted to insulate the pipe to help reduce some heat transfer, so I coated the pipe with truck bead liner:


Once it dries, it will be painted blue. More to come later....

After the coating dried, the intake tube was painted blue to match the car. The 4" hole was sanded down and painted as well, then a 5/16" fuel line was sliced down the center and used as a gromet between the intake tube and the metal hole. With the hose around the edge, the intake is fairly snug it the hole and will not bounce around or even try to fall down any further.

Here are a couple of pics from the top:



Here is the new filter location:


On the 30+ minute test drive with city and highway cruising, the intake temp (sensor mounted in turn right before throttle body) was about 35 degrees (95 F) on the highway and raised to about 40 C (104F) in town. The ambient air temp was about 80-85F. Before this mod, the intake air temp for this trip on this tempature day would have been around 55-59 C (131- 138F).

Adding the original type spash guard between the cradle and frame will help close off some of the engine heat some more. There is also room for a much larger air filter, so that will probably be my next upgrade.

Some other temps (from inferred digital temp gun) when I turned the car off after the test drive, the passenger side engine vent was 162 F and the drivers side was 142 F. The decklid was 143 F and the stage 2 scoop on the passenger side was 100 F as was the passender door and front fender.

Wow! Looks real good!!!

I was thinking about making something similar, but my t.b. is a ported stock style tpi throttle body that is oval.

Hopefully sometime I will be able to find something similar to what you made for my oval t.b.

Thanks for the compliment!

For a TPI/LT1 throttle body you will need to start with an oval to round elbow like the ones below. After that the pipe just needs to go down. On mine the center of the hole in the chassis to the center of the throttle body is about 9" to the front of the car. With a 3 1/2" pipe this leaves adequate room for the flange on the air filter to clear the brace that is welded to the firewall side. The 3 1/2" pipe was bent to a 7" radius (measured from inside edge of pipe), so a perfect "L" shaped pipe would stop bending 5" from the center of the hole, or 4" from the center of the throttle body. Just guessing from the pictures, but it looks like a simple "L" pipe off the end of these elbows would work without any welding!

There could be variation in placement of engine front to back, so It might be wise to start with a "U" - and cut it so the pipe will angle to the back of the car to gain any additional clearance.


http://store.summitracing.c...N=700+0&autoview=sku


http://store.summitracing.c...N=700+0&autoview=sku

[This message has been edited by fieroguru (edited 07-01-2007).]

Wow, thanks alot for the info on the TPI version, and adapter. I will post pics when I make one... might be a while till I get around it though.

The new filter location allows for a much larger filter than I had before, so I had to get a larger filter.

Old Filter:


Size comparison old and new:


New filter installed:

What are you going to do, when it rains?

Kevin

Not enough water is going to come up to even consider a second thought. If hydrolock is a concern, simply don't drive into a lake and you'll be ok

quote Originally posted by Lambo nut: What are you going to do, when it rains? Kevin

Drive it. I had the filter right under the deck lid vent exposed to rain for 2 years and drove the car rain or shine and through the occasional unplanned downpour without issue. Unless the entire filter element is submerged in water, it will be easier to pull air (not water) through and minimal water will make its way into the engine.

If the filter element is completely submerged, yes then the engine vacuum would pull a great deal of water into the engine (all it can pull) and bad things would happen. But for this to happen the water level would have to be close to 18" deep and there would be all kinds of other issues with a fiero in 18" of water.

So you don't think the filter getting totally saturated from the water being flung off the tire, is going to cause any problems with air flow, what so ever? The filter woud be OK there, if it is covered with a shield, to protect it from water being thrown from the tire, and possible road debris.

And who said anything about hydrolock?

Kevin

I have the stock plastic wheel well liners installed - I took them off to get a picture of the filter. The liners keep the vast majority of the wheel debris from the filter.

I am not the least bit concerned with water mist coming in contact with the filter - like I said the engine filter has been getting rained on for 2 years with no harm.

Sure this location will require frequent cleaning (like the previous location).

quote Originally posted by fieroguru: I have the stock plastic wheel well liners installed - I took them off to get a picture of the filter.

Ok, they were not in the picture, so that is why I asked the first question. All should be good to go then.
Without them, I doubt you would get far in a good rain. Mist would not be a problem, like in the underhood area, but being totally saturated from the water coming off the tire, I'd almost bet you wouldn't make it home. Anyone who has ever got their open element air filter too wet, like atop a V8 Ford or Chevy etc., while washing their car at the car wash, will know what I am talking about.

Kevin

The MAF and air intake tube on my 3800SC is 3 1/2" in diameter. Since my engine will be running increased boost the design of my CAI is a K & N fiter in the the Fiero air filter canister that is modified with welded 3 1/2" inlet and outlet tubing going to a side scoop that will provide a ram air effect with the coldest available outside air. This system should provide air going into the engine at slightly above ambient temperatures.

------------------
87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

cool!

------------------
"A guy know's he's in love when he loses interest in his car for a few days." -Tim Allen

He who dies with the most toys... still dies.


Check out my restoration!

I really like that, it is a very graceful and effective design. You should be proud, it really looks and functions well, and was inexpensive; a rare combo!

------------------

More info at: https://www.fiero.nl/forum/Forum1/HTML/043357.html

Yeah don't worry about water, my Toyota truck filter eats water all the time. If its an issue, or your worried about hydrolock until you can make a mudskirt, just take some medium-density sponge, cut it to fit and jam it inside the intake behind the filter. It works as a good fix until you can fab something up, and stops almost all the water.
-Dave

------------------
---85 GT Notchback---
--1994 Toyota Tacoma, Lifted, 35 MT's, Locked, Exo'd, Complete Off-Roader---
---1974 Hyundai Pony, Worst daily driver, ever---

Very nice install.

Thanks for all the compliments.

Maybe this summer I can get the car to the strip and make a few runs with the hot air intake and the cold air intake to see what the performance difference in mph is.