Saab 900 Intercooler Questions

in article DBAqg.92959$ snipped-for-privacy@bgtnsc04-news.ops.worldnet.att.net, Jeremy at snipped-for-privacy@att.net wrote on 04/07/2006 21:56:

Well, not all stock intercoolers are the same. The later cars had a plastic capped 9 row cooler which is more efficient than either the metal capped 9 row or the 15 row. It does still heat soak, but I have an idea which involves moving the oil cooler ... See below.

Abbott Racing make a "chargecooler" which will fit into the stock location. Theirs is further cooled by water.

It would be better to provide increased airflow (or a fan) to the stock intercooler. A mate of mine cooked up an intercooler fogging system, but he already has a FMIC from a Volvo.

My thought is to move (or replace) the oil cooler to a more central location in front of the radiator and install a scoop and pipe up to the stock intercooler. My other thought it to cut into the bonnet and install a scoop to force air down over the intercooler where that little plastic air dam usually sits.

Unless you have the Airflow/Carlsson bumper skins, you'll almost certainly have to remove/cut the lower airdam or grind off the towing lugs if you go for a FMIC. Volvo 760 or SAAB 9000 intercoolers seem popular, but they are not very efficient. Going for a FMIC will certainly involve custom pipe work and perhaps "clocking" the turbocharger.

One of the cleanest installations I've seen is by Aussie Alex Reid:

There was a plastic capped 9 row and a plastic capped 15 row, as well as a metal capped 9 row. I rate the plastic capped 9 row the most, but have no empirical evidence :)

Custom job ... Yes, there are advantages if you have a high flow charger. There will be increased lag as well. It depends what you want ... Long sustained top boost or fast spooling for short bursts?

Great! Fit it behind the intercooler to pull air through it. Have it actuated by boost, or if you're a little daring, drill and tap in a thermostat (like on the radiator).

Send me the other one will ya :)

It's there for a reason, so I suppose SAAB must have found it makes a difference. I've never had one on my current turbo and it's not on my immediate list for procuring, but if I did get one, I'd put it on. Why not? If you can get one easily, fit it.

Paul

in article C0D09BF8.3E46% snipped-for-privacy@blueyonder.co.uk, Paul Halliday at snipped-for-privacy@blueyonder.co.uk wrote on 04/07/2006 22:28:

Take a look at F900!

Matt (who now tunes Nobles and other exotica) sold the car to Si about a year ago. Si managed to crash the car again, but it's re-built and coming back up to scratch. The cooler is from a Lotus. It seems to fit with minimal upset, leaving the area where the stock intercooler is free for moving, say, the battery making room for a shallow exhaust elbow.

Paul

I have one of the metal capped 15-row and one plastic capped 9-row, the cars has the metal capped 9-row. Should I go with the Plastic 9-row?

Do you know the approximate cost, or the part #?

I was thinking along the scoop idea with two channels, one short one for the intercooler an the other for the air intake.

That was just an idea investigating the feasibility of putting a FMIC. Just throwing it out there for others to opine on.

Does anyone have an idea of the performance of the various 900 intercoolers? Is there any difference or is it a case of who Saab could get to supply intercoolers that month?

I am inclined to go for the long sustained boost. The push you back into the seat as you press the pedal is fun, but I like to cruise the Interstate at 90 mph. Radar/Laser detector on of course.

How would you tie it to the boost? Vacuum powered solenoid? This one needs further investigation/explanation.

You want the black powder-coated one or the painted one? Cause you ain't getting the powder coated one. ;)

Great Tips, Thanx JB

in article bdGqg.316874$ snipped-for-privacy@bgtnsc05-news.ops.worldnet.att.net, Jeremy at snipped-for-privacy@att.net wrote on 05/07/2006 04:19:

Well, I like mine :) See what others think on the matter.

The problem with the C900 is any ducting would have to come from the RHS of the car, due to the oil cooler filling up that area on the LHS. Move the oil cooler to a more central location and you've got a great hole to pop a scoop into.

By all means, feed the air intake with another duct ... Or turn the airbox around and feed it directly from the front of the car? I have seen people drop the airbox altogether, cut through the inner wing and place an open air filter onto the end of a pipe, supplying air through the wing by way of a scoop or slashes in the LHS wing. That gives a lot more space to mount a larger, more capable fan behind the standard intercooler.

Traditional wisdom has been to fit the larger cooler from the SAAB 9000 or a Volvo 760. People have done this for years without really investigating the effect. More modern intercoolers are very efficient for their size, so something much smaller, but strategically placed (or cooled with water) is a more "modern" approach.

The Lotus chargecooler on F900 I pointed you to shows a minimal use of pipework, less bends and leads to significant cooling, compared with the original. That car was built with 300 BHP in mind and over 160 MPH top speed.

A 60 trim T3 is on your shopping list, then?

You do need to balance up the flow rate with the pipe diameter. For example, the 8V pipework is 40mm in diameter to match the 40mm diameter turbo outlet. On the 16V car (and late model T8s sold in Europe and Scandinavia), a 45mm trim was used with the same pipework. On later T16s, 60mm pipework was used, which matched up nicely with the inlet and outlet on the intercooler, being

Once you go up to 3" (75mm) pipework, you're going to introduce some lag unless you beef up the turbo unit a bit.

Use a second/spare pressure transducer, like behind the kneeboard. My mate used precisely that to trigger his intercooler fogging setup. Simply, but effective.

See the inner wing picture half way down this page:

Paul