Intercooler Fans and Open Air Filters [Archive] - SaabCentral Forums

: Intercooler Fans and Open Air Filters

16th April 2002, 07:01 PM
I know a lot of you have replaced the stock snorkel/air box set up with an open filter, to allow a fan to be mounted to the back of the intercooler, and as i have a bit of free time at the mo i looking at doing this with my convertible. Can you guys help me with a few questions:

1) Air currently passes throught my Lucas AMM vertically, if i switch to an open filter, will the AMM be alright mounted horizontally or will this cause problems?

2) What size filter will fit? K&N or JR part numbers that people have used would be a great help.

3) I'm okay with mounting the fan itself but have no idea about how to wire the thing up. Where should i take power from? And how would i go about connecting up a new switch in one of the blanks on the dash, beneath the heater controls? Where do i pass the wiring through the firewall, that kind of thing?


1990 900 T16 conv, 110k
1987 900 T8 3d, 145k (

<font size=-1>[ This Message was edited by: akamal on Apr 17, 2002 12:03am ]</font>

Johann F
17th April 2002, 04:12 AM
I have the same Lucas set up as you and have done the mod - here is the method;
I used a JR filter with an 85/90mm opening ( I will have to double check the exact serial number). I removed the original bendy AMM to turbo intake pipe completely and used a cut down CV boot to attach the AMM directly to the pipe going to the turbo. The large end fitted with a large jubilee clip on the AMM and the tappered end was cut back until it fitted over the smaller pipe and secured by a nother jubilee clip. At first I just hung the body of the AMM from the IC pipe with a few large zip ties but I later made a small bracket which I bolted through the nose of the cone to the inner wing. make sure you rotate the AMM so there is not too much strain in the connector plug and the same wires do not foul the throttle lever. You can also try removing the mesh on the AMM for even more airflow! You should now have a slightly better throttle response and possibly (hopefully) feel more power at higher revs. You will also get more air through your IC which will help as well. Now as we know the IC is not very big on the C900 and at low and medium speeds there is not enough airflow to take the heat out of the charge. Put a fan on the back and you can get more airflow at lower speeds - nice.
I used a fan from a Metro abandoned in my street - it fits well and can be simply attached to the black plastic the IC with 3 self tapping screws. I drew the power off the large fuse link on the opposite wing and ran a thick wire round the bulkhead. Make sure you put a fuse in (I used an in-line sealed one). This goes to a relay which I put on the inner wing and is connected up to the fan wiring. I got hold of a spare push switch to go in the blanks next to the lighter socket and ran some thinner control wires through the bulkhead ( there are a few grommets under the L hand speaker pod)to operate the relay. That's it - when I'm in standing traffic on a hot day I just leave it on and it gets fresh air into the area of the cone filter so I don't get that flatspot where the engine sucks in a lot of hot air - you can really feel a power surge sometimes on a quick pullaway!. On the move I can't really feel a difference - but maybe I will when the weather gets hotter!. ON the M-way I leave it off as there is enough airflow from the speed of the car to do the job.
The only fiddly bit was getting the control wires through the bulkhead - remove the L hand speaker pod and get someone to help feed it through. ( maybe I can will post you some digital pics of the setup)
<font size=-1>[ This Message was edited by: Johann F on Apr 17, 2002 9:16am ]</font>

<font size=-1>[ This Message was edited by: Johann F on Apr 17, 2002 9:24am ]</font>

20th April 2002, 06:04 PM
Thanks Johann, My filter should be arriving early next week, so we'll see how i get along putting it all together...