Why run SDS (or any other stand alone engine management system for that matter)?
There are several reasons for using SDS. The SDS, or any other stand alone engine management system, provides very precise control of ignition timing and fuel delivery. There is currently no easy way to reprogram the LH2.2 EFI chips. The conundrum is thus: when the limits of the LH2.2 are reached for performance reasons, then one basically hits a wall. While some modified chips are available, they are not readily so. There are also good reasons NOT to use a mere modified chip. Thus, c900 owners are in a situation unlike those drivers of many Japanese marques, which have plug and play ECUs readily available (see the wonderful Apex'i Power-FC for example). For us, the best way around the limitations of the LH2.2 is to install a stand alone engine management system.
Running SDS is a more efficient and precise way of making power on the c900. Instead of attempting to trick out the stock EFI to provide more fuel by the hard to come by fuel chip, piggy-back computer or rising rate fuel pressure regulator, or to play with the timing curve with piggy-back ignition controllers like MSD or Crane Cams setups - all of which are known as 'band aids' - SDS will do it all properly and precisely. These band aid approaches reek of inefficiency. Getting big power out of the stock EFI is definitely on the limits of the system. Sure you can do it, Damien Shulock pulled decent dyno figures a few years ago; Steve Yamamoto has similar figures. But in my opinion, going with stand alone is much easier, more efficient way of making power. The engine is not stressed so hard. I find it difficult to explain fully, as I'm not a mechanical engineer - I just know these automotive related things from playing with cars and reading reading reading.
Stand alone makes the tuning much more simple, and there's no mucking about trying to sort out little issues. Well, that's a misnomer. Yes, you need to tune the idle and cruising fuel and ignition maps; but this, I've found, is much much easier than plugging in large injectors into the LH2.2 system and trying to get the stock ECU to compensate at idle and cruise. The SDS allows one the ease and flexibility in tuning. Want more fuel at this point in the rpm or load based range? No problem, click click, dial it in. Want more timing advance or to bring to retard in slowly under boost and to end it at a certain point? Piece of cake, just punch the numbers in. This type of control is impossible with the stock setups. Personally, I was quite fed up with trying to play with the AMM mixture screw to get the car to idle properly with 30# injectors, or the trial and error required to bend the distributor's vacuum advance arm to bring the retard in to 12 degrees BTDC. No more, SDS makes these tuning matters a click away.
Further, tuning with the SDS means the fuel and ignition maps are customized for my engine. You can't do this with a chip. Finally, using SDS, I could control several related systems with just the programmer - like the cooling fan on/off point and water injection on/off point. This makes for an elegant installation.
By the time the time and especially cost of all of the 'band aids' have been added together, one would have well been on his or her way to purchasing a stand alone system. This should be kept in mind by anyone who is interested in serious performance.
Here's an excellent explanation of EFI systems in general.
The list below is of the SDS' adjustable parameters taken directly from the SDS website:
This was initially very intimidating. I had never really liked doing electrical stuff, yet strangely, at the end of any wiring I'd ever done, felt a good sense of accomplishment. I suppose installing SDS was no exception.
I began by reading the SDS website and installation manual over and over again. Then I asked questions of those who'd done the SDS install before on their c900s, namely Eric Ziegler and Roger Bell. Both were very helpful in their insights. I basically used Eric's idea for the location of the SDS crank sensor and the ignition coils. Accordingly, he supplied me with the appropriate lengths for the custom Magnecore wires. Roger's comment to me in an email that if he'd do it again, he'd install all of the SDS' fuses and relays in a nice little box was the one spark that pushed me to have my install perfect.
The next step was removing all of the wiring associated with the LH2.2 and APC. While I was in there, I also removed anything to do with air conditioning and the radiator cooling fans. Reasoning? I had already removed the AC components, so no need for the wiring anymore. And I had always experienced a lot of reliability issues with the stock cooling fans and their wiring. Instead, I would use the SDS to control the fans (with which I can set on and off points). Further, I would use a Flex-A-Lite fan. Running junkyard cooling fans had proved to be a worrying aspect of the car to me. New fans cost a bundle too. Not that the Flex-A-Lite was cheap, but it is more readily available than the Bosch units.
I basically spent all of January and February of 2002, IIRC, removing all of the unneeded wiring and tidying up what I was going to keep. Then it was time to plan out what I was going to install.
From Roger's initial comment, I was motivated to have the tidiest install around. Thus all of my SDS related fuses and relays sit in a fuse/relay box salvaged from an 8v 900. This box is found where the APC sits on 86+ 16vT cars, and that's where I installed it on SAABOTR. At this point in time, I began planning all of the wiring that would have to run through this box, for I wanted to integrate everything very very nicely and seamlessly. So, while I removed several stock systems, I also implemented several new systems and redid a few existing wiring systems that I had added over the years, like the auxiliary gauges. I also took the opportunity to integrate my upgraded, heavy duty piggy back headlight wiring harness and driving light wiring.
All of this removal and integration was done with just two references: the Bentley 16v manual and Townsend Imports site. This is excepting, of course, the help I received from several members of the Turbo! list.
The trick (and tricky) part of the install was finding the right parts to a) handle the +15 (switched) and +30 (battery) power loads with the 'cleanest' possible power and b) making it look nice and seamless, and not hacked.
I initially purchased some aftermarket power distribution blocks, but I ditched these when I stumbled upon a tip on the Karl's 99 Tips Page. Karl mentioned using some 'wire bridges' from 240 Volvos. These are perfect. They have six smaller, regular sized spade terminals, and then two larger spade terminals. Perfect perfect perfect! So, one day after my April exams in 2002, a friend and I raided the local Pick Your Part. I scoured every Slovo in the lot, and snagged as many of these bridges as I could. Using two of these in the SDS install, I was able to separate my +15 and +30 power very tidily. Most excellent. Further, every single connector was soldered and wrapped with heat shrink tubing. This was a hugely time consuming process, but once I started aiming for perfection, I went all the way.
Here you can see my final wiring diagram. Obviously used whilst I was working on the car, as evidenced by the fingerprints!
And the end result is a very tidy engine bay. Wherever there is blue tubing, I took out stock wiring and integrated my own stuff. Note the Swedish theme going on with the yellow electrical tape! :)
SDS is compatible with many of the stock sensors, which makes the install quite seamless looking and very tidy. The following are useable, with some notes:
The SDS requires several of its own sensors to function properly. However, from the compatibility section just above, you can see that most of the OE sensors will work with SDS. Thus installation of the TPS, knock sensor and water temp sensor was nothing special. However, fabrication was required for the crank sensor and MAP sensors, as well as the coils and injector resistor pack. Also, the SDS ECU and programmer were installed.
CPS
The SDS crank sensor is a very simple
affair compared to those used by other stand alone systems like Wolf, Haltec,
Motec, etc - even simple compared to Saab's own DI/APC and Trionic setups.
These systems use a disc with notches or rings on the circumference of
the disc. The sensor reads the crank position by way of these notches
or rings with the hall effect principle. SDS also uses the hall effect,
but uses magnets imbedded into the crank pulley (or in my case, flywheel).
Why the flywheel? Easier to get at. On most SDS installs, the crank sensor is installed to read off the pulley; but on most cars, the pulley is up front. At any rate, using the much larger flywheel should theoretically give much better resolution for the crank sensor. Unfortunately, I neglected to take a photo from the front when I was mounting the sensor, but the back of the sensor is visible in the photos below. Because the sensor has to have a 2mm-4mm gap between it and the magnets, I had to push it towards the back of the flywheel slightly. I used a chunk of 6061 aluminum stock as a spacer. My buddy Marty helped with getting the spacing right, his use of my angle grinder helped in making the mating surfaces just right, as some of the aluminum stock had to be ground away. The aluminum spacer was drilled and tapped to mate the sensor to it, then drilled again for holes to accomodate another two bolts which mate the sensor and spacer combination to the flywheel side endplate of the engine. The endplate was again drilled and tapped. Everything is quite secure, no problems once the setup was completed.
My initial plan was to run two crank sensors,
one each on the pulley and flywheel, with one acting as a backup.
However, the machinist with whom my engine builder contracted to do the
work mucked up the holes for the magnets on the pulley, so that plan went
out the window. Anyway, the flywheel mount is working just fine.
Actually, there's more to the story than that. I originally mounted
the crank sensor higher up, near the starter and a part of the block that
jutted out, forming a nice little 'V' shape - all per Eric Ziegler's install.
However, it wouldn't read, for some reason, so I moved the sensor down
to a more perpendicular location. This was a big pain in the ass
because the magnets had already been mounted in the flywheel. Necessarily,
everything had to be redone on the flywheel. Fortunately, this was
the point that I went to England for a two week vacation in August 2002,
so I had a break!
Coils
As I chose the SDS EM-3F system, which
does away with anything to do with the distributor, I got a real distributorless,
multi-coil ignition setup. No more worries about the distributor's
cap, rotor or the worst, dodgy wires on that stupid little hall effect
sensor connector. Bleah! Using the F system has no performance advantages
over the E system (which can utilize stock distributors), but I really
wanted to get rid of the distributor. It makes for a neater, more
modern engine bay too. I know Roger Bell used the E system;
Jeff Proposki's Haltech install looks like he used the distributor, and
so did Matthew (dunno his last name) on the Motec install on his NG900.
Anyway, I mounted the coils in the same location Eric Ziegler did - on
a plate where the AC condensor sat. I managed to find, in a junkyard,
a steel plate off a car without AC, and this made mounting the coils much
easier. The use of these coils required custom plug wires - Magnecore did
them no problem. For looks, I removed all of the guts off a dead
DI cassette, then cut a hole in it. Through the hole, I ran the plug
wires. The DI cassette does nothing otherwise.
Injector resistor pack
Right next to the coils, you can see where
I mounted the resistor pack, with velcro, to the cabin air intake.
These resistors are required when running low impedance injectors, and
were supplied by SDS.
TPS
As mentioned above, I used a stock TPS
from an 2.1L, LH2.4.2 equipped '91 900S. Actually, I used the entire
throttle body, as I was under the impression that they LH2.4.2 TPS mounts
differently than the LH2.2 TPS, but I could be wrong. Whatever, they
bolt right up, and you can see it in the CPS picture too. It doesn't look
much different than the LH2.2 TPS.
MAP sensor
The SDS takes into account manifold pressure
when computing the fuel injector pulsewidth, as all modern EFI systems
do. It utilizes a MAP sensor; c900s never came with a MAP sensor,
so this was something that I had to add. Using my favourite 6061
aluminum stock, I again drilled and tapped the thing, secured the map sensor
to it, then mounted it to the inside (engine bay side) of the driver's
side inner fender with some angle stock. Piece of cake, works, well
out of the way. The finished bracket is picture here on the rear
spoiler of the trusty family '88 9000T.
Air temp sensor
Not visible in the pictures, but mounted
to the IC pipe between the IC and TB. Since no one makes a M12 x
1.5 weldable bung, I had my engine builder just weld a chunk of aluminum
to the IC pipe. Then I drilled and tapped this appropriately.
Water temp sensor
Per stock, through the intake manifold,
into the head.
Fast idle solenoid
SDS does not support any form of automatic
idle control. I ditched the LH's AIC and now adjust idle purely by
the throttle screw. However, SDS does have the fast idle solenoid
to help the engine get up to temperature. I had to cut a bit off
one of the mounting tabs of the solenoid for it to bolt up to where the
AIC used to bolt up - on the thermostat housing.
Fuel pump relay
This is recommended, as it replicates
the LH's fuel pump relay. Basically, if the SDS does not detect ignition
after a certain time, it will cut fuel off. I understand it is required
in some drag racing rules, but it's a good thing to have safety-wise.
Install - just plugged the wires into the stock location, pretty much.
ECU and programmer
The ECU was mounted in the same location
as stock, but I used velcro. Velcro was nice and easy, no need to
fabricate another bracket. The SDS ECU is not as wide, but longer
than the stock ECU, but nonetheless, fits into the passenger footwell easily.
If you touch the carpet, you can feel the ECU behind it. Pity I didn't
put it in a more visible location - it is gold anodized...hmmm...there's
a thought, maybe I'll move it somewhere else so I can show it off!
SDS will run without the programmer, but it is obviously needed for tuning. It is also quite nice to have visible all the time to monitor the engine's operating parameters, so I wanted to put it in a nice location inside the cockpit. Like an R34 Skyline, now I can monitor such esoteric functions like injector duty cycle, intake air temperature, throttle position, etc etc...
Specs on some of the items used by SDS.
SDS' own tech info on installation of the crank sensor.
Saab's Automatic Performance Control (APC) system is an old yet cool system. For the majority of those seeking extra performance from their c900, either tweaking the APC or installing a modified APC unit will give enough of a gain to be satisfied. However, its results are a bit inconsistent.
I think of the APC as Saab's boost controller, before they went and integrated things with Trionic. I removed the APC , this could be a bit contraversial in the eyes of most Saab enthusiasts. The APC is an excellent system. However, I have personally found its use to be a bit inconsistent. Furthermore, by the time a modified APC, rising rate fuel pressure regulator, bigger injectors, MSD or Crane ignition systems are all grafted onto the car, one would have spent enough to acquire a stand alone system. Anyway, back to the point: by being able to precisely control fuel and spark, one can tune the engine to avoid detonation altogether, and thus the APC wouldn't be active anyway. The SDS does provide capability to retard ignition timing should detonation be encountered, so there is some protection there. But by using the GReddy boost controller, a consistent boost level is maintained. Rock solid boost is the result.
There are a multitude of boost controllers available on the market. The most simple are the purely mechanical types. I don't have much experience with these, never used one - but basically it uses mechanical means to regulate the operation of the wastegate actuator. The electronic ones do the same thing, but with the ease and precision of electronics and in-car tuning.
I chose the GReddy Profec-B because it is one of the, if not the, most simple of the electronic boost controllers. Others are quite cool with their features - Apex'i, Blitz, HKS, GReddy and other (predominantly Japanese) manufacturers have units that are packed with features like in-gear boost limitation, digital displays, graphs, peak hold or datalogging, etc. Myself, I wasn't sure that I could integrate all of these features into SAABOTR (for instance, how would the boost controller know which gear the car is in? The Saab gearbox is purely mechanical, there are no electronics associated with it) and I also wanted to keep the boost controller simple - there would be enough to worry about with tuning the SDS. Oh yeah - and I chose an electronic boost controller because SDS told me I should! :)
Fortunately, through a friend, I obtained the Profec-B second hand, for relatively cheap, especially as it included the optional remote control. The control consists of a single button mounted on the steering wheel that allows the driver to select between the Profec-B's low or high boost settings. Haven't played much with it yet, but maybe later. I could see myself running a higher boost profile along with water injection; then turning this down to normal when the water injection is not operational.
The fuel system is not much different than stock. Indeed, the stock fuel pump will flow enough for 300hp. All of my fuel lines are original, with the exception of the short return line from the fuel pressure regulator (FPR), and a new line from the FPR to the fuel rail.
That said, I have upgraded all of the major components of the fuel system.
Fuel pump
My pump was an unknown quantity - it was
the one that came with the car, dunno how old it was. For ease of
installation, I purchased a Swedish
Dynamics fuel pump. This eliminates the pump as a potential trouble
spot. The SD pump is remanufactured to put out more than a stock
pump. Gary Konow is very knowledgeable and he gave me a killer deal,
can't hurt!
Fuel pressure regulator
SDS does not recommend the use of rising
rate fuel pressure regulators (RRFPR) because this puts the fuel delivery
in the hands of a mechanical device, rather than the SDS ECU. While
a RRFPR is a good way to trick out the stock system to deliver more fuel,
the reasoning from SDS is sound. In essence, the RRFPR is another
band-aid.
In its place, I now have an AEM universal FPR, purchased for a relatively good deal on Boxing Day 2002! It is certainly nicely machined, and adjustments are pretty simple. They even include a couple different ports for different flow rates. They say it will handle 1000hp.
However, there are a several idiotic things about it. AEM aims for the import market - import cars invariably use metric fasteners - so why the hell did they make the adjustment screw and locknut in SAE?!? Just dumb, and means you have to scramble a bit to look for the right tools. Also, they did not include the return hose barb. Okay, not such a big deal, readily available every where, yes? Not so, at least not around Edmonton, and not for my hose size. The stock return line is 7mm/-5, but try finding this size hose barb. Why not just include one with each FPR? Okay, so perhaps it was the fault of the local dealer, which isn't much of a speed shop chain as a place where posers hang out and sell stereo equipment and foglights. They couldn't get one directly from AEM unless it was with a larger order; AEM wouldn't sell me one directly. Doh. Enough of that anyway.
The good bit about the FPR is that it comes with a port to accept a fuel pressure gauge. Unfortunately, due to how I have it mounted, it wouldn't fit under the hood. Doh! Mounting the FPR also required some fabrication. While it comes with its own mounting bracket, this wouldn't fit the stock location very well. Again I fabricated a bracket to adapt to the AEM bracket. Used more 6061 aluminum. Drill, tap, etc.
Fittings - I was originally going to use the fancy anodized red and blue fittings on some custom lines, but this proved near impossible to do because of the combination of bends required. So I went back to stock, and this required finding a metric to -6AN adaptor for the FPR side. I also had to plug up a couple of the ports as they wouldn't be used. After trying unsuccessfully with aluminum plugs, I finally went to steel. The steel plugs worked, the aluminum ones didn't no matter how much silicone sealant or even hylomar blue I smeared on them.
So, the FPR install took a lot more time to sort out than I anticipated!
You can see the FPR in the picture with the coils and injector resistor pack above.
Fuel injectors
This was the easiest. Literally
plug and play. I went to stangnet.com,
browsed the classifieds, and found the injectors I wanted. I settled
on Accel 55#s to keep things simple - more than enough for my power aims.
Injectors are great deals on stangnet. If one is searching for the
initial injector upgrade for c900s (usually 24#s or 30#s), then stangnet
is the place to go. But from there, it's a slippery slope to more
and more mods, and you can read my thoughts on that elsewhere on this page.
Whatever, the other issue buying injectors from Mustang people is that they only sell in sets of eight (for obvious reasons, unless you find the odd 2.3T SVO guy). But I had no issue cutting my costs with eBay, sold the other four to a guy in the Vancouver area tuning a 2.5L Porsche 944.
And don't worry about compatibility, because Fords use the Bosch style injectors. It's only when you start getting into some of the Japanese stuff that injector styles become a bit different.
I picked up this little toy in Hong Kong during Christmas 2002. The local riceboy shop wanted C$550 for it, plus another C$120 for the g-sensor. I paid about C$240 for the RSM and another C$90 for the g-sensor. Here is a good place to related my experience at the riceboy shop:
I went in there before Christmas with a couple buddies to kill time before a movie. To my surprise they had the RSM, so I took a peek. I start poking through the manual to see what kind of inputs it would need for it to work. Everything looked cool except the speed sensor. Several concerns for me: a) my Saab is a bit old, still uses a mechanical speedo, no electronic speed signal from the gearbox; b) I had removed my original tach with the speed signal for the cruise, as I also removed cruise; c) at any rate, I forgot completely that there was a speed signal for the cruise.
So I ask the guy behind the counter, let's call him Moron 1, about the speed signal requirement.
"What kind of car is it"
"Saab, but I have it on stand alone."
"Reeeaaallly....", sounding dubious and
causing me much offence; this guy is most obviously my automotive inferior.
Moron 1 then calls over another guy at the shop, let's call him...Moron 2.
"Hey, this guy here has stand along ignition system on his Saab, what about the speed signal?"
Moron 2 comes over and says "So it's a Saab....well, Saabs are GM products, so they should have an electronic speed signal."
Oooooo...I could have knocked him over. I then tell him about the speedo cable and such, and how it's on stand alone. Then he says "So it's on stand alone...is it injected?"
Jaysus Christ...."is it injected?". I respond "Of COURSE IT'S INJECTED!!!"
Damn...some people are dumb.
Anyway, I got the RSM just for kicks. The local pricing is horrible, so I snagged it in HK when I saw it was much much cheaper. Basically what it does is measure RPM, speed, acceleration, etc. All that and more, plus some simple datalogging. A good plus is that it has speed or rev related outputs, ie. I can hook up a shiftlight. It's a bit rice looking, but I'm just intrigued with the datalogging, and how it can do lateral g loadings as well. Very cool.
I haven't gotten around to installing it, but will do it sooner or later, when I find some time. I'm going to retrofit an LH2.4 speedo, with a newer type cruise control speed sensor, along with the requisite LH2.4 speedo wire. I think it will work, but time will tell. If not, eBay here I come!