Econmancer

The idea behind the project is to reduce some of the heat soak on the SAAB 9-5. I think every 9-5 owner in a warm climate has exited the highway in the heat of summer and found the car lacked power once they tried to enter street traffic. It’s especially scary when making a left turn and finding the car will barely move. This is a simple and cheap project that only takes an evening to install and can hopefully reduce or eliminate the heat soak symptoms for many of the 9-5 owners out there.

To be clear, the better solution is to replace the stock intercooler (located behind the radiator) with either a drop-in performance model or a custom FMIC (front mount intercooler). I understand that both options are expensive and could be mechanically difficult  for some people, so I looked into this easy and low-cost water spray system.

The cost of this intercooler water spray system is about $50.

You will need:
Trico Products 11-102 Windshield Washer Pump
ScanTech Windshield Washer Check Valve
Toro Blue Stripe Drip Fogger, 3.0 GPH Model # 53651
Toro Blue Stripe Drip Starter Kit Model # 53724
Cable Ties

You’ll have a lot of options on this project. Feel free to experiment with other parts and see if you can improve on this basic design. Leave a comment on this post if you discover something that might help others.

You can purchase all of the Toro “Blue Stripe” parts separate, but I found it costs less to just get the “starter kit” and the fogger heads. If you don’t get the starter kit you will need some blue stripe tubing (maybe 10 feet worth), four “Blue Stripe” fogger heads, and five of the “Blue Stripe” T-connectors. The heads that come with the starter kit will not work in this project because they are designed to drip and not spray.

The washer kit listed gets you all the parts you need on that end of the system. You could pick up used parts and save some money. You’ll need the water reservoir, a pump (able to create 10-30psi), a switch, related wiring, and some extra tubing if you decide to buy the parts separate.

These instructions are for a four spray-head system. It could be adapted to a two head system that only shoots water on the lower part of the radiator and intercooler. This could be a good option if you have trouble getting to the area behind the front grill of the car. I don’t have first hand experience with the 2003 and newer 9-5s, but they look like a pain when it comes to grill removal. On the ’99-02, you can just pop the entire grill off with a little pressure.

Instead of the momentary switch that comes with the washer kit, you could use a mercury switch attached to the accelerator pedal or a Hobbs-type pressure switch that will automatically activate the spray at a specific turbo pressure. One issue I can see with more automated switching systems is the amount of water in the reservoir. I get about 1 minute worth of spray per 2-quart tank. You’d quickly run out of water if you weren’t careful.

The Instructions:

Lift and prop the hood

Detach the battery during installation. We’re working with electricity and water here.

Remove the front grill or whatever it takes to get get access to the area in front of the radiator.

Roughly measure the length of tubing needed to go across the front of the radiator, down both sides to the lower part of the system and across again. For me, I cut two 1’6″ lengths of tube and two 1′ lengths of tube. This left me with plenty to trim for an exact fit later.

Cut four tiny 1.5″ lengths of tubes. These will connect the fogger heads to the T-connectors.

Gather the four fogger heads, five T-connectors, the check valve, and some zip-ties

The check valve works as show below. Be careful that you have the flow going the correct way or the water won’t move when you press the button.

What you’re going for is something similar to the above. The tubing is in tan, the foggers are “O”, the T-connectors are “T” and the check valve is the “L” shape.

Start at one fogger, attach the tubing and zip-tie it to the car, then work around to the next fogger. I tried to do all the plumbing and then install, but I had to trim just about every piece of tube once I got it behind the grill. So I recommend building it in place and only trimming the tubes once.

I placed the top two sprayers beside the horns, using the horn brackets to hold the sprayers in place.

The bottom two sprayers I attached to the lower grill area.

Once all four foggers are in place and connected to each other, you can roughly aim the heads where you want the water mist to hit. You then fine tune the aim once everything is up and running.

Follow the instructions that come with the washer kit on how to plumb the reservoir to the motor and connect the wiring.

Now is a good time to install the switch. The location and whatnot are up to you, obviously.

There is a nice space for the water tank between the battery and the headlamp. Use your favorite method to secure the tank into place.

Run a length of tube from the check valve to the washer motor and then fill up the reservoir with water. The system should be complete. I found that I had to run the washer pump motor longer than I expected the first time to get water flowing into the system, but the check valve will keep the water in the tubes once it’s there so you won’t have to prime again.

You should see something like this:

The videos doesn’t do justice to the amount of water being sprayed. It’s a very fine mist, so you’re only seeing the largest drops in the video. I plan on putting butcher paper on the radiator and recording the spray again so you can see where all the water is going. It sprays at about 2-quarts per minute.

Fine tune the direction the water sprays and check for leaks. I had to zip-tie the tubing where it attaches to the pump because it shot off from the pressure the second day I tried it.

I haven’t used the probe thermometer to check for exact changes in temperature, but I can get the radiator water temperature gauge down to what should be about 195 degrees* with the spray system (9 o’clock on the gauge), this at highway speeds on a 100+ degree day. It’ll take a real thermometer to find out what is truly going on, but the basics are there.

*I had the dealer change the sensitivity on my stock water temp gauge with the use of a Tech II a few years ago so there should be little to no dead spot in the gauge reading. Still not ideal for real data, but gives a rough estimate about changes in temperature.

Special thanks to a certain SAABCentral member that helped me with this project, but wishes to remain anonymous.

I’ve just installed a turbo intercooler / radiator water spray system on my SAAB 9-5. I want to see if it reduces the heat soak that the 9-5s suffer from in hot weather and after a spirited drive (sometimes even when the weather isn’t that hot). I think every 9-5 owner has at least once tried to make a left turn and found that the car suddenly had a total lack of power. I hope to correct that issue cheaply with the water spray.

The setup cost me $45 and took one evening to install. I want to test it out before I post a detailed how-to, but I thought I would show a couple of videos as a teaser.

There are many people online that said they’ve cured the heat soak by upgrading the intercooler, either with a larger one in the OEM space behind the radiator or a smaller FMIC behind the lower grill of the bumper. This would be the ideal solution if you are having real trouble with heat soak, but it’s expensive and takes mechanical knowledge many people do not have. I hope after I test this system to have a simple and cheap way of combating the heat soak in the SAAB 9-5 specifically for people not looking to drastically modify their car.

I just purchased a Forge diverter valve, also known as a bypass valve, for my SAAB 9-5 as a birthday present to myself. My stock Bosh DV was obviously weakened, but the diaphragm had not deteriorated to the point of hooting. I ordered the FMCL007P Forge DV and spring set from Amazon.com for $135 plus $13 S&H.

I was surprised by how big it was compared to the stock Bosh DV. The extra bulk is mainly in the screw-off top. I installed the green spring and inserted none of the spacers.

Forge lists the springs as:

Green – 5-15 PSI
Yellow – 15-23 PSI
Blue – 23-30 PSI

Spacers are used to nudge the spring tension. The LPT 9-5 would use green or green with spacers. I would encourage people to try both the green, green with spacers and yellow springs and see what they discover for themselves. I have read of Aero owners using the yellow spring with spacers.I have no input to give about the blue spring because I don’t want to try it out in my SAAB. I know it is too strong for my LTP and I don’t want to damage anything.

Installation:

This wasn’t even a five minute job. Opening the hood took longer than this installation. I used a pair of pliers to release the two tension collars that hold the stock bypass valve in place. The valve comes out with some wiggling. Carefully remove the vacuum hose on top with your fingers or with a very light touch of the pliers if it is stuck.

Then install the new Forge bypass valve by reversing the steps. I guess you might leave the vacuum hose for last when you install. Some people post about the vacuum hose being too tight to go on the new diverter valve. The advice given to them is to heat the little hose in a glass of hot water to make it more pliable. I didn’t have any problems installing the vacuum hose on mine.

You can see how much more it sticks out compared to the Bosh bypass valve. Plenty of clearance on the 9-5, so this isn’t an issue.

Observation:

My stock diaphragm style Bosh DV was weakening and didn’t consistently hold or release pressure. The Forge DV has increase the feeling of performance, but obviously just replacing the failing DV has made a difference. I leave it at this because don’t have a turbo pressure gauge or dyno to confirm my feelings with hard numbers. The T7 recognizes when the turbo pressure is too great and responds by lowering performance, and I have no idea if there is a gray area of increased turbo pressure; where there is more boost than stock, but not so much that the computer fights it. One SAABCentral poster described a 1-2psi increase after adding the Forge with a yellow spring. The pressure being read from his after market gauge. But like I said, I don’t have any instruments to read the pressure or performance and the SAAB 9-5 likes to foil bolt-on performance parts.

There is also a difference in sound. The Forge has what I would call a three syllable sound. My Bosh only had two syllables when it released. The Bosh was a K-Shhh sound and the Forge is more of a K-tik-Shh sound. It doesn’t sound is any louder, it is more that it now sounds like a “BOV” instead of a random air leak; same volume, more distinct sound.

More information about Forge and Bosh diverter valves.

“The great diverter valve face-off”

The SAAB 9-5 uses a diverter valve (DV) or bypass valve in place of a blow off valve (BOV). The casual term “hooter valve” is sometimes used because of the sound it makes. The DV functions like a BOV, but it recirculates the released air back into the air intake instead of releasing it into the atmosphere. I haven’t tried it, but I understand that letting the SAAB 9-5 release pressure into the air will be read by the T7 as a vacuum leak and the car will go into limp mode with a CEL.

UPDATE:

Getting a performance diverted valve, like the one made by Forge, and installing it in the reverse configuration will further enhance the sound of the turbo.

This trick comes from Chris 9-5, a moderator on the SaabCentral forums. It was in a thread from July of 2007. I found it while searching for Forge diverter valve information. The OP had posted about weak turbo pressure and Chris 9-5 suggested the following modification:

Remove the top vacuum tube from the boost control valve and then plug the loose tube.

Chris 9-5 explains that it bypasses a one way valve that can become faulty.

It worked wonders for the OP. Chris 9-5 recommended that only people with weak turbo symptoms should make this modification.

As far as I knew I didn’t have any problems, the car drove as spirited as the day I purchased it. I had all the power I needed, the car was quick… so I naturally decided it wouldn’t hurt anything to try this trick.

The results were dramatic! It is like driving a different car. My whole driving experience is totally enhanced. The most noticeable change is when the transmission kicks down at wide open throttle on the highway. I really feel the torque steer for the first time, just like the OP in the thread described.

Here is how I plugged the vacuum line; I found a bolt that was the right diameter and cut it down to about an inch long. I then painted the head to make it look nicer. It’s that easy.

Some people in the thread didn’t see a difference when they removed their line. Other people tried it and found the change remarkable. The people who have made this modification haven’t seen any problems and I will make a post if I see any negative results on my 9-5. I’d say people should give this a try and see if they get back some turbo pressure. Just revert it back if there wasn’t a positive change in performance.

Previous Turbo Post 

This was going to be the weekend where I rebuilt my turbo. I got halfway into removing the turbo and I ran into a banjo bolt that wouldn’t budge. Liquid wrench didn’t help and my 12 point socket was starting to damage the bolt so I’ve put everything back together and will pick up some six point sockets for my 1/2inch wrench so I can give it another try.

The good news is that I think I can get to my stopping point again in half the time it took me last night… now that I know what I’m doing. What surprised me was the exhaust nuts came off  with no problem.

I also need to get a set of low profile ramps to raise the car instead of my stands. That should give me some more operating room under the car.