Installing a mandrel bent intake and high-flow air filter can be one of the cheapest and most rewarding upgrades you can do to your Supra. In many cases the 20 year old stock intake parts can be dry and cracked which can cause un-metered air to enter the intake which leads to poor running.

This upgrade will also allow more air to enter the engine which leads to more power and better throttle response.

The parts you will need to complete the project are as follows. You will need a 3" mandrel bent U pipe. A good place to find these are at JC Whitney.

You will need 2 silicone 3" couplings and a 3" to 2 3/4" reducer connector. I bought these at a local speed shop for $5.99 each. They should not be hard to find as these are commonly used on Honda intakes. If you cannot find any locally I suggest www.hightempsilicone.com

You should pick up6 3"-4" hose clamps. You will also need a cone type air filter with a 3" opening. I recommend the 5" S&B racing filter available at Cyberspace Automotive.

A can of high temp engine enamel in whatever color you would like. You will also need access to a welder or find someone to do some welding for you. Short pieces of 1/4" steel pipe and 1/2" steel pipe will also be necessary. The total cost for all these parts before shipping is around $90.

First you will need to make some cuts on the pipe to create the 3 pieces you will need to complete the project. The fist piece is indicated by the letter A in the picture above. This piece goes over the top of the engine and into the throttle body.

The second piece is just above the letter B in the diagram above. This piece goes from the airflow meter and meets up with pipe A. When making the cut for pipe B you should temporarily install pipe A to figure out the distance and angle of the cuts, especially if you have a strut tower bar as I do. You will want about a 1/2" clearance all around the pipe. Getting the fit right is a little tricky and care should be taken to make sure you get it right before you make the cut.

The third piece is just a short 3 or 4" piece of straight pipe that can be cut from section E from the diagram. This is the piece you will use to mount the new air filter.

Next you will need to attach the 2 hose barbs to reconnect the stock hoses on the intake. To get an idea of where to drill the holes, hold the new pipe with the bent end towards the throttle body and make the marks where they need to be. The holes should be approximately 5/8" and 1/4".

Next you need to have the hose barbs welded on. The above picture shows brass barbs attached with epoxy but this setup proved to be too fragile and failed after a few weeks. I later had steel barbs welded on and they are there for good.

Now make sure to clean the pipes with soap and water to remove any metal shavings and debris that may have gotten on them. This will also make the paint stick well.

To paint the pipes I used 500 degree engine enamel. Engine enamel takes longer to dry then normal enamel but it provides a more durable surface and won't melt from under-hood temps.

Once the pieces have dried its time to install everything. Using the silicone connectors and either the original clamps or new stainless steel ones put the pieces together and twist and turn things to get them well situated then tighten down the clamps.

You may need to unbolt the Airflow Meter to change its position slightly to allow things to fit better. Connect the lines that attach to the barbs on the intake and tighten those as well.

Lastly use the 3" section of 3" pipe as a coupling to join the cone filter and the sort curved piece of rubber hose that was part of the stock air-filter assembly.

Then just attach it to the Airflow Meter using a clamp. Rotate the cone until it points directly ahead to give maximum open space around the filter.

All in all this was a very easy and rewarding project that gave power gains all across the power band and enhanced the wonderful sound the engine makes when at wide open throttle.
 

This Article was written by By Wesley Hetrick 6/6/2002