Last update 8 years and 9 months ago!
Since 2012 when I last updated this thread I got married, relocated and had two children. I also got out of the car industry and went back to being an IT guy. Not that it should read I no longer know anything about cars, I'm still learning... as we all are.
I sold my collection of Saabs including this:
and this:
Plus a 900i, another 900 t16 convertible and a 99 turbo.
This video of my gearbox rattling now has not far off 3000 viewings by this stage, people are mean!
So after the gearbox failed the car was off the road waiting for me to get around to fixing it.
I took out the old engine:
I had to admit defeat on the T35 turbocharger, it was too big for a 1985cc motor. It spooled a bit and I was thinking about making an exhaust manifold which I bought the parts for and was going to CAT CAM it and turn it into a 8000rpm sort of setup.
HOWEVER... I came to a realisation which might not go down too well on this website...
It occurred to me that it is unwise to try and make a car into something it was never supposed to be.
I mentioned the 4WD conversion some years back.
I got the chassis from a Saab 900 ready to weld into the back of the 99. This has been done before to make a mid-engined and rear wheel drive Saab 900 but in my case I just wanted the framework to mount the wishbones and driveshafts. With hindsight it probably would've been more sensible to do the conversion the same way people usually do these things by ripping an entire drivetrain from something else like a BMW or a Subaru and transferring it all in.
So I gave up on that idea. Partially motivated by the fact that I had no place to keep a quarter of a Saab 900 after leaving the motortrade and giving up the workshop but also because I changed my view on how these things are supposed to be done.
I think now that making a Saab 99 into a Subaru beater by transplanting a Subaru drivetrain into it is a little haram. If you want a Subaru Impreza buy one. If you want a Saab 99 to be faster than a Subaru Impreza you have to build it according the the principles of the original design or else it is no longer a Saab so what have you really achieved?
I sold the CAT CAMS and the T35 turbo never came back from the turbo rebuilders CR Turbos because they sold my turbo to someone else and then shut down the business.
I started on a new plan for the car. It has always been my intention to finish designing and building the car before I start on the bodywork but the first phase has taken more than a decade!
The new plan for how to build this thing was to try to maximise the Saab-ness of it. To me that means it should be a low RPM high torque turbo monster and not a high RPM screamer. This is going to be hard on the gearbox but I have a steel differential cover, strengthened gearbox casing and the car weighs a lot less than a full fat street going 900 so whilst I am asking for more from the gearbox it is mitigated.
For traction there is a Quaife ATB diff which is the same thing fitted to the Focus RS. This was in the old gearbox as well and works great. I also have what are termed 'type 7 primaries'. These are the chains and sprockets which connect the unusual Saab transmission under the engine to the flywheel. Here you can change the ratios and 'Type 7' will get you to about 50mph in first gear when combined with a 4-speed gearbox like I have in this case. The long ratios mean it isn't trying to rush through the gears and this helps.
Here is the partly built gearbox:
After the gearbox there was a bit of a gap but I decided to flurry a bit and do some more on it.
I deleted the bonnet vent I had added by welding in a piece from another 99 bonnet I had handy:
This leaves just the 4 vents along the front for extracting the air from the radiator and allowing heat off the turbo.
A long long time ago I got into a dialogue with the chaps at Turbotechnics and they had a new thing going on where they were applying the variable geometry turbocharging technology found on almost every diesel car to petrol cars. The difference between petrol and diesel is the heat. Petrol is much hotter in the exhaust and a normal turbo meant for a diesel would never last on a petrol motor. Porsche have since fitted some of their turbocharged 911s with these variable geometry turbos.
So it happened one day I arrived at the Turbotechnics factory at 9am and asked them to build me a turbo. At about 3pm they had finished it. They even had a Saab 16v engine on the shop floor which they could use to trial fit and check the measurements. At the time this unit cost around £1400 which was fairly hefty for a turbo, probably still is?
As you can see it has two actuators. One controls the vane angle inside the exhaust housing and the other is a standard wastegate. As boost pressure builds the vanes pretty quickly fold back so the exhaust isn't restricted but the upshot is this turbo can allegedly make boost at idle RPMs. So it makes a lot more boost a lot sooner than a conventional turbo.
During this same 'flurry' of activity apart from welding up a hole in the bonnet I started building the replacement engine.
I took the view that I'd approach this by slapping a load of used parts together and seeing how things go, seeing what breaks before spending serious money on all new everything.
I decided to use the 2.1 cylinder block I had. This came from a Saab which was imported from Australia. They never sold the 2.1 Saab in the UK, instead they sold the 145bhp 'LPT' (low pressure turbo) model in that part of the range. Suffice to say a 2.1 cylinder block in the UK is like poor quality wobbly children's play pony droppings. You can make your own by boring out a normal block but that's expensive and my imported parts car was really cheap.
The 2.1 also has a larger intake manifold so I took that as well.
The 2.1 is also higher compression. It's 10:1 instead of 9:1 on the standard turbocharged cars. Sorry to any RS Cosworth readers!
I also upgraded the cylinder head to the highest flowing cylinder head Saab made. In Saab circles this is called a 'T7' head. T7 is the engine management system on the naughties Saabs which were produced while Saab was under GM ownership but any parts from those engines we call 'T7' parts.
The T7 cylinder head has different porting to the earlier heads. It also has much thinner valve stems. The basic school of thought is that no matter how much you modify an earlier head it'll never flow as well as a T7 head, so I picked that.
It has gaps at the timing cover and around the intake ports but I sealed all of those using aluminium sheet and reported the openings on the intake ports to overcome the minor differences. The exhaust manifold fits the same as any Saab head.
With the head, block and turbo selected I then started on the other bits. I decided to move the throttle body under the intake manifold and I used a bigger throttle body instead of the original.
I decided to attach a water/air chargecooler unit to the cylinder block itself as a way of eliminating pipework and it is now a very direct path from the turbo outlet to the intake ports. It couldn't really be much shorter.
Here is the overview of the finished power unit:
I didn't stop there though. But I will stop for tonight as there is a lot more to tell but I don't think I have time!
Since 2012 when I last updated this thread I got married, relocated and had two children. I also got out of the car industry and went back to being an IT guy. Not that it should read I no longer know anything about cars, I'm still learning... as we all are.
I sold my collection of Saabs including this:
and this:
Plus a 900i, another 900 t16 convertible and a 99 turbo.
This video of my gearbox rattling now has not far off 3000 viewings by this stage, people are mean!
So after the gearbox failed the car was off the road waiting for me to get around to fixing it.
I took out the old engine:
I had to admit defeat on the T35 turbocharger, it was too big for a 1985cc motor. It spooled a bit and I was thinking about making an exhaust manifold which I bought the parts for and was going to CAT CAM it and turn it into a 8000rpm sort of setup.
HOWEVER... I came to a realisation which might not go down too well on this website...
It occurred to me that it is unwise to try and make a car into something it was never supposed to be.
I mentioned the 4WD conversion some years back.
I got the chassis from a Saab 900 ready to weld into the back of the 99. This has been done before to make a mid-engined and rear wheel drive Saab 900 but in my case I just wanted the framework to mount the wishbones and driveshafts. With hindsight it probably would've been more sensible to do the conversion the same way people usually do these things by ripping an entire drivetrain from something else like a BMW or a Subaru and transferring it all in.
So I gave up on that idea. Partially motivated by the fact that I had no place to keep a quarter of a Saab 900 after leaving the motortrade and giving up the workshop but also because I changed my view on how these things are supposed to be done.
I think now that making a Saab 99 into a Subaru beater by transplanting a Subaru drivetrain into it is a little haram. If you want a Subaru Impreza buy one. If you want a Saab 99 to be faster than a Subaru Impreza you have to build it according the the principles of the original design or else it is no longer a Saab so what have you really achieved?
I sold the CAT CAMS and the T35 turbo never came back from the turbo rebuilders CR Turbos because they sold my turbo to someone else and then shut down the business.
I started on a new plan for the car. It has always been my intention to finish designing and building the car before I start on the bodywork but the first phase has taken more than a decade!
The new plan for how to build this thing was to try to maximise the Saab-ness of it. To me that means it should be a low RPM high torque turbo monster and not a high RPM screamer. This is going to be hard on the gearbox but I have a steel differential cover, strengthened gearbox casing and the car weighs a lot less than a full fat street going 900 so whilst I am asking for more from the gearbox it is mitigated.
For traction there is a Quaife ATB diff which is the same thing fitted to the Focus RS. This was in the old gearbox as well and works great. I also have what are termed 'type 7 primaries'. These are the chains and sprockets which connect the unusual Saab transmission under the engine to the flywheel. Here you can change the ratios and 'Type 7' will get you to about 50mph in first gear when combined with a 4-speed gearbox like I have in this case. The long ratios mean it isn't trying to rush through the gears and this helps.
Here is the partly built gearbox:
After the gearbox there was a bit of a gap but I decided to flurry a bit and do some more on it.
I deleted the bonnet vent I had added by welding in a piece from another 99 bonnet I had handy:
This leaves just the 4 vents along the front for extracting the air from the radiator and allowing heat off the turbo.
A long long time ago I got into a dialogue with the chaps at Turbotechnics and they had a new thing going on where they were applying the variable geometry turbocharging technology found on almost every diesel car to petrol cars. The difference between petrol and diesel is the heat. Petrol is much hotter in the exhaust and a normal turbo meant for a diesel would never last on a petrol motor. Porsche have since fitted some of their turbocharged 911s with these variable geometry turbos.
So it happened one day I arrived at the Turbotechnics factory at 9am and asked them to build me a turbo. At about 3pm they had finished it. They even had a Saab 16v engine on the shop floor which they could use to trial fit and check the measurements. At the time this unit cost around £1400 which was fairly hefty for a turbo, probably still is?
As you can see it has two actuators. One controls the vane angle inside the exhaust housing and the other is a standard wastegate. As boost pressure builds the vanes pretty quickly fold back so the exhaust isn't restricted but the upshot is this turbo can allegedly make boost at idle RPMs. So it makes a lot more boost a lot sooner than a conventional turbo.
During this same 'flurry' of activity apart from welding up a hole in the bonnet I started building the replacement engine.
I took the view that I'd approach this by slapping a load of used parts together and seeing how things go, seeing what breaks before spending serious money on all new everything.
I decided to use the 2.1 cylinder block I had. This came from a Saab which was imported from Australia. They never sold the 2.1 Saab in the UK, instead they sold the 145bhp 'LPT' (low pressure turbo) model in that part of the range. Suffice to say a 2.1 cylinder block in the UK is like poor quality wobbly children's play pony droppings. You can make your own by boring out a normal block but that's expensive and my imported parts car was really cheap.
The 2.1 also has a larger intake manifold so I took that as well.
The 2.1 is also higher compression. It's 10:1 instead of 9:1 on the standard turbocharged cars. Sorry to any RS Cosworth readers!
I also upgraded the cylinder head to the highest flowing cylinder head Saab made. In Saab circles this is called a 'T7' head. T7 is the engine management system on the naughties Saabs which were produced while Saab was under GM ownership but any parts from those engines we call 'T7' parts.
The T7 cylinder head has different porting to the earlier heads. It also has much thinner valve stems. The basic school of thought is that no matter how much you modify an earlier head it'll never flow as well as a T7 head, so I picked that.
It has gaps at the timing cover and around the intake ports but I sealed all of those using aluminium sheet and reported the openings on the intake ports to overcome the minor differences. The exhaust manifold fits the same as any Saab head.
With the head, block and turbo selected I then started on the other bits. I decided to move the throttle body under the intake manifold and I used a bigger throttle body instead of the original.
I decided to attach a water/air chargecooler unit to the cylinder block itself as a way of eliminating pipework and it is now a very direct path from the turbo outlet to the intake ports. It couldn't really be much shorter.
Here is the overview of the finished power unit:
I didn't stop there though. But I will stop for tonight as there is a lot more to tell but I don't think I have time!
