A standard Saab turbo 16 engine with its 160 horsepower (175 in cars without catalytic converter) is surely not a rocket engine. On the other hand, like many other turbocharged powerplants it has a very good potential for simple and cheap performance increases. Unlike most other turbocharged engines from 80's and early 90's the Saab B202 engine has quite an advanced electronic control system, the turbo boost control module of it is called APC - that's a magic word in the Saab circles. Because of this (as you'll see) performance tuning a Saab doesn't neccessarily mean getting your hands dirty... I had to separate this page into four sections, the links are below.
I had definite plans to install a 5th fuel injector into my engine. This project had been going on for about a year now but I never seemed to have the time for it (the entertainment projects seemed to have a higher priority, lol!). But then I heard other guys' experiences that the 5th injector wasn't really helping any and that the problem was more with not enough cold air entering the engine. The rechipped Lucas fuel system should be able to keep up with its job even without the 5th injector.
So I decided it was time to experiment with something new. And went for the water injection. As I am writing this I have just collected all the parts and have done some testing with them but they're not yet installed in the car. So I will just report what parts I got and from where. There are many sources for water injection parts - it is just that some of the parts suppliers are serious in business - some are not. You will not be able to make a working water injection by using windscreen washer type pumps or such. It takes some special equipment to get a fine, high-pressure mist.
The first thing to consider is pressure. Since the water injection will be used during heavy loads only, you will have to spray the water into the inlet manifold which is already under pressure, up to 1,5 bars or whatever you fancy. This means that the water pressure supplied by the pump must be higher than that - and by a high marginal to ensure a fine mist. I went for the SHURflo pump which pumps at 100PSI / 7 bars. There is a fine specially-made pump available from ERL too, but it is the single most expensive item on their aquamist systems. The SHURflo pump is made for agricultural spraying and has a built-in pressure switch and check valve. It is ideal for the job.
The water jets are specially made items which should ensure a fine mist and a steady flow of water. Since these are a specialty item I decided to get them from the professionals, from ERL. The jets cost 16 €/USD each. I bought two sizes, 0.5mm and 0.7mm to be able to experiment with them. With 100PSI pressure the 0.5mm seems to run about 400 milliliters per minute which is enough, if not slightly too much, for the engine. A good rule of thumb is misting water at 20% of the volume of the gasoline being injected. And of course only under high-boost conditions.
Other items necessary for the setup include a pressure stabilizer (I used a fuel filter from a Cosworth 4x4), a solenoid water valve and a pressure switch to trigger the water injection. I also bought a water-level sensor for the tank.
Oh, the tank! I found out that in my overly crowded engine room there is a perfect spot for a secondary Saab windscreen washed tank on the right hand side, where the intercooler used to be. This tank will have the water level sensor mounted into it and of course a feed hose going to the pump. It is recommended that the tank is filled with 50% methanol and 50% water in the wintertime to avoid freezing. Another benefit from the methanol is an octane boost effect: the methanol has an octane of 105 which will help to prevent predetonation. But a drawback to consider is that methanol is known to react with aluminium and oxidize it. This means that the inlet ports at the aluminium Saab 16-valve head are at risk. The risk is mainly theoretical but to prevent extended exposure I will be running with plain water in the summer months.
Since the pressure switch turns on the water injection only under heavy boost conditions (I will probably set it at 0.8 bars / 13 PSI) the water tank will not need to be topped even at every gasoline fill up. I will wire up the water level sensor so that it will cut to pump and light up a warning light on the dash if the tank runs out.
So what's the motivation for water injection? Lower combustion temperatures, increased density of air, less chances of predetonation, possibly a bit more boost and ultimately more horsepower and reliability. All of this without affecting the fuel consumption and emissions at all. So generally speaking the water injection is a technique that would be much more widely used with turbocharged vehicles if only it would not be too much to ask for an average driver to fill up the water tank every once and while. Well, it gets more complicated in the wintertime with the poisonous methanol and all, but... Saab has actually experimented with water injection in one of their latest prototypes and they used a shared water tank for the windscreen washed and for the water injection. I will not spray methanol on my windscreen and therefore the two tanks are separate.
This tank is used for accumulating pressure on the high-pressure side of the pump. It enables an immediate fine spray as the solenoid valve opens and helps the pump to do the job. In fact the pump only cycles for two seconds at about 3 second intervals.
oh yes, a pressure switch for 100 euros is surely an overkill. But this happens to be a neat electronic device from Festo's professional range. It has an adjustable pressure setting with the possibility of pressure difference activation and so on... It works precisely as it is supposed to, no variation whatsoever.
Connecting the pieces into each other is like making a puzzle: you need all those little adapters and o-rings to get them all joined together. But at least the result is a good with no leaks or anything... lol!
Saab 900 windscreen washer tank
Osa-Tattis, Helsinki Finland
Paid a visit to the great local boneyard. Tried to fit tanks from a Mercedes, Volvo and others. Fortunately it was the genuine Saab tank that was the best fit! It will go into the place where the stock intercooler used to be.
Saab 9000 Intercooler
Last Update 28th July 2002
I did the best I could to improve the standard intercooler but it did not get me far enough. Especially on hot summer days the performance suffered enormously from increased inlet air temperatures and there was no way the standard IC could be able to cool the air efficiently.
I went the route many others have gone before me and purchased a used intercooler core from a Saab 9000 Turbo from 1993. The IC units on post-1991 cars are different from the older ones in that their air ducts are pointed straight down instead of straight back. This makes it much more easier to install one on a Saab 900.
The installation of the cooler involves disassembling the front end and cutting away some excess materials in there... So this is really not a job for the average appearance tuner but isn't too complicated either. You need to get rid of the tow hooks and halves of the secondary bumper supports. A grinder will do a good job in getting rid of them. And the extra hook holding the bonnet in the "middle but not locked" position has to be removed as well. And few pieces of the air dam needs to be cut away... But really nothing radical.
Special care needs to be taken when mounting the ic in between the bumper and the AC condensor: there's enough room but the bumper bolts need to be cut a little and you have to make sure that the remainders do not rub holes throught the IC end tanks. Yep, it is possible to install this IC into a Saab with air conditioning and the AC system does not have to be touched at all.
The way to route the IC hoses is pretty obvious. A 180-degree from the IC tanks with as short diameter as possible will help in getting the hoses into the engine bay. The existing aluminium pipes between the turbo and the standard IC can be used in installation. The rest of the pieces you need to improvize: I used plastic 90- and 45-degree turns with 60mm outer and 50mm inner diameter. These are made from PVC plastics and are intended for pool piping. The 60mm radiator hose will clamp nicely on them and on the standard aluminium pipes as well as on the IC outlets. So all you need are some turns and about one meter of 60mm radiator hose.
Since the radiator hose is subject to quite a high pressure and has a length of max 40 cm I have plans of replacing it with custom-made aluminium pipe. Will have to look into this in the near future. Not much can be done about the hose going from the turbo to the ic: it comes very close to the upper radiator hose and the distributor but should not harm them in any way. Another tricky place is getting the same hose under the bumper and into the IC since the AC aluminium piping is seriously in the way. I plan on replacing some of the aluminium IC pipe with custom-made flexible AC piping when servicing the system the next time.
Since the 9000 IC is BIG the hoses do stick out a little from under the bumper. Well, some say this looks pretty nice and aggressive, some say it looks stupid. Anyway, there's not much to do about it. It is the only way the core will fit in there. There's always the possibility of faking the hoses as auxiliary lights... :) See the first photo on the left to get the idea.
Here's a list of parts of what I used:
Est. cost (€/$)
Standard from a 1993 SAAB 9000
A local dismantler
Do NOT buy an IC from a pre-1992 9000 for this purpose. And make sure that the core is in a good shape.
About one meter is needed. I used this hose to duct quite a long stretches from the turbo to the IC core and then on to the manifold. I think I will end up replacing most of the hose with solid piping to prevent the possible leaks and bursts of the hose.
turns made of PVC plastics
A local plumbing shop
I used 4 pcs 90 degree turns and 2 pcs 45 degree turns. These are made of grey ABS plastics and are a perfect fit for the 60mm radiator hose. They have 50mm inner diameter.
These are expensive bastards but I did not want to compromise by installing cheap clams that will rust out. A 55 to 75 mm clamp will be fine.
Last Update 28th July 2002
If you want to get more power out from an engine you'll obviously need to feed more gasoline into it. And since burning the extra gas requires the presence of additional oxygen, it is in my opinion quite smart to pay some attention to the air inlet. And since it is probably the cheapest modification, I'll start by explaining what I've done to it. Keep in mind that these air inlet modifications do not increase your horsepower by themselves, even though that's what the K&N salesmen are telling. But it is still an important part of the whole.
The Saab engine originally has a snorkel-like air inlet tubing and an airbox which make the inlet air's path very restrictive. Some people say there are 12 almost 90 degree turns in the inlet path, but I never even bothered to calculate... :)
In july 1999, after performing some of the tweaks mentioned below, I decided to install an open-cone filter, but installing it into the engine compartment would actually have been a worse setup than the original: The air inlet should be sucking as cold air as possible. I got an idea to install the filter into the left fender, right between the front wheel and the front light assembly. I realized that in order to provide the filter with a sufficient air flow I could make a slight appearance modification: In the original setup, all the air is sucked in through the gap between the bonnet and the front light assembly. I decided to install an additional grille in the place just above the bumper, behind the front light assembly and in front of the wheel arch. I spent a lots of time looking for a suitable grille: The tuning-parts dealers were offering too aggressive looking pieces of plastic for ridiculous prices: $80 a piece! Finally I found just the perfect grille from a local boat-accessory shop, and paid $10! Of course, I was going to install the grille only to the driver's side: I wasn't looking for an appearance enhancement, just the opposite. Painted it red to keep it as invisible as possible. By the way, the hole was cut by a local body shop - it might not be a good idea to drill/saw it yourself: you'll bend the body sheet VERY easily.
After making the necessary holes (one additional hole was needed for the air duct into the inner wall, of course) I scrapped the old air box and ducts. The AMM was installed horizontally instead of the original vertical + 90deg. pipe turn setup. People with BOSCH injection have a completely different setup with the AMM originally in horizontal position. The Lucas AMM is not a hot-wire type like Bosch, but instead it measures the air flow via an additional side-channel. This means that the passage through the meter has no obstacles at all - good for the air flow! The hose connections to the AMM are quite large: diameter is 80mm. It was quite difficult to find proper hoses to extend the air channels with, but after a long search I got an one meter piece of heavy-duty cooler hose from ARES Oy for $30. The same hose in silicone would have been $200! The open-cone filter connected to the end of that hose is from JR, got it from BSR.
In order to fit the 80mm hose into the standard 60mm plastic hose going to the turbo I had to find a "funnel". After a long search I concluded that there wasn't anything available at the local plumbing shops. Then I came up with a perfect idea: The standard Saab CV rubber gaiter is perfect for the purpose!
After installing the inlet system I made another move: In order to enhance the air flow through the poorly-placed intercooler I decided to add an electronic fan. The increase in external air flow would result in better intercooler efficiency leading to decrease in inlet air temperature and it leading to higher air mass and added knock protection. Now that the air box was gone, there was plenty of room for a really large fan (instead of the small power supply fans some are using). I bought a Fiat 127 engine fan from a junkyard for $20. With a few pieces cut and bent from aluminium, it fitted perfectly over the standard intercooler and stayed in place. I soldered a small control box consisting of a transistor, capasitor, a few resistors and a relay to control the fan operation (any time delay circuitry will do). Engaged by a micro switch installed at the throttle axle, the fan will start at 1/4 throttle and stay on for 30 seconds or as long as the throttle is applied. This enables the fan to stay on while switching gears or standing in traffic-lights. The fan doesn't make a lot of noise, but with more than 70 watts of power it provides a good air flow. This setup has worked very well, but I haven't had the time to measure the temperature drops yet.
Update 28th July 2002: replaced the standard intercooler with a front-mount unit from a Saab 9000. The fan trick worked well with the standard intercooler but there is really no comparison to a properly placed and properly sized cooler. If going for the 9000 intercooler is at all possible, I highly recommend it.
Made of ABS plastics, painted red. I mounted it with simple l-shaped pieces screwed into the grille from the inside. The seams are fixed into the sheet metal with double sided tape. I've also added a stainless steel grille inside of the plastic grille.
The hose was needed to extend the inlet tubing. 80mm will fit to the Lucas AMM, Bosch will use smaller hose. This size was very hard to find, as it is only used on heavy trucks. Light plastic hoses available from Etola, for example, do not tolerate the heat under the bonnet.
This is used between 80mm hose and original piping. It was very cheap at Biltema, but personally would not even consider using one for its intended purpose: Biltema's parts are famous for their very poor quality.
JR is a French filter brand. It is regarded as being equivalient quality with K&N but without that extra brand price. I was looking for a K&N locally, but it seems that K&N doesn't manufacture a model that would have fit to the place. JR has a 80mm diameter, the length is about 12 cm. Had to order mine from BSR in Sweden, they had the model in stock.
Radiator fan from a Fiat 127
Osa-Tattis, Tattarisuo Helsinki
The fiat fan is very small considering it is a radiator fan (well, the Fiat itself is quite compact!), but powerful enough to circulate enough air. I had to bend a few pieces from aluminium to attach it into the back of the intercooler. No screws are needed, it holds there with a band. The aluminium pieces can't be seen, unfortunately, in this picture.
Micro switch, delay circuitry
local electronics shop
I built a very simple time delay circuitry into a small plastic box. My circuit is made with a single transistor and is adjustable from 15 to 60 seconds, approx. You might wan't to make a more advanced circuit around a 555 timer chip, for example. The net is full of interesting diagrams... The micro switch is attached to the two free holes in the throttle body (near the throttle plate axle) with a piece of aluminium. The switch is triggered by the throttle cable actuator.