Categories
Cars SAAB

Saab 900 Trionic 5.5 Conversion

An ambition of mine for some time now has been to convert Helga to run the Trionic engine control system as fitted to later 9000s and NG900s. This replaces the old distributor ignition setup and the LH2.2 fuel system with fully live-mappable control of ignition and fuelling, coil on plug ignition with ion discharge knock detection and more. There’s plenty of documentation out there on the swap so I’ll not go into too much depth.

I also needed to keep Helga’s downtime as short as possible because she’s my daily car, so I tried to have as much in place as possible while keeping her running.

First, not essential at all for the swap, I relocated the battery to the other side of the bay away from the downpipe. It’s now where the air box would be located.

Saab 900 battery relocation

The hardest part of the swap is sourcing a signal for the crank position sensor. I chose to get a pattern cut into the back of the flywheel. Because my existing flywheel was lightened, there was nothing left to cut the pattern into, so I sourced a standard later 900 flywheel which takes a 228mm clutch.

This was the fourth time I’d had the clutch apart in my ownership, so I removed the lightened 9000 flywheel/240mm clutch setup and fitted the 90-93 900 flywheel cut for T5 by JamSaab with a Sachs 220mm clutch. Annoyingly I ordered what was supposed to be a 228mm clutch and got a 220mm. This turned out to be a problem.

So at this point I fitted everything for the T5 swap bar the actual loom – so the intake temp sensor, 9000 throttle body with different throttle position sensor, crank position sensor, map sensor etc, all sourced from a scrap Saab 9000, were all fitted but left disconnected ready for the actual swap over. I also fitted a braided clutch line while it was apart.

So I drove the car like that for a few weeks still running the old LH2.2 management, including to this year’s Oulton Park Gold Cup:

Saab 900 and Volvo 940

After that it was time for the final step of the T5 swap – splicing in the Saab 9000 loom and fitting the ECU.

Saab 900 T5 wiring loom

I used a combination of the above wiring diagram and guide. The marked colours matched my loom perfectly but I still checked every pin went where I expected on the ECU connector.

The loom I used didn’t have the MAP or boost control valve wiring so they had to be added off the body connector, then it was a case of adding power via the twin relays borrowed from the old loom, the power block on the driver’s side wing and the ignition live pinched from the old coil power wire. Grounds were fastened to the thermostat housing, the speed signal and check engine light spliced into the wires under the dash. All in, removing the old loom and swapping to the new took a little under a day though I had spent another evening marking all of the wires in the new loom. It still could do with taking off again and bundling up properly but for now it’s tie wrapped out of harm’s way.

Impressively it started on first turn of the key with only one hiccup. Where I was told to put the CPS (in the pre-existing hole) was in fact 18 degrees too far advanced. Turned out that the hole we initially drilled in the backplate above that was nearly bang on at only a degree out, checked with a timing gun. I don’t understand what’s gone on with my flywheel milling to require that. Now that’s sorted she’s running nearly as sweet as a nut.

The problem now is that the 220mm clutch can’t handle the power. This is running a 9000 B204L (185bhp) map that I’ve taken to stage one with a bit more boost at the top end and a bit less at lower rpm, as well as the T7 valve mod. I’ve tried shimming the pressure plate 2mm away from the flywheel to increase the pressure from the fingers but despite making the pedal heavier this still hasn’t cured it. In third and up there’s half a second or so blip in revs as the boost hits around 1 bar.

Another problem was the alternator bracket blot sheared itself off in the block(?!). Noticed the bolt holding the adjuster arm to the block was hanging out, and closer inspection with a mirror revealed it had sheared. There’s no space between the block and the firewall to get in with a drill, so for now I’ve made a temporary adjuster bracket off a spare hole above the water pump. I bet that stays that way for a very long time.

Categories
Cars SAAB

Saab 900 Clutch hydraulics

Brought Helga’s overboosting (was going as high as about 1.5 bar, my gauge only goes to 1 and it was well off the end) under control by setting the base boost properly. The wastegate rod had been screwed in a long way. Not got quite the same ferocity but it’s a bit safer for now.

Anyway, since the brake overhaul the clutch bite point has been very variable. It seems there is truth in the myth that bleeding the clutch can hasten it’s demise if it’s on the way out. I got hold of a rebuild kit for the master and a new slave and got to work.

Clutch master cylinder rebuilt

As many people know, the Saab 900’s gearbox setup is really weird, living underneath the engine and driven by chain. The engine is also mounted with the flywheel facing forwards, which all adds up to a really easy clutch change without disturbing the engine or gearbox at all.

However, there’s something missing from this image…

Hadn’t noticed it drop off the slave while I was putting everything back in. Really annoyingly I’d put everything back together and bled it so I started the car to test it. BIG mistake. The lack of release bearing instantly lurched the new slave and dumped the fluid. So, new slave ordered and I thought I’d try to find a new clutch kit while I was at it. Anyone who’s changed the clutch on a 900 before knows that you really need the hydraulics working to get the old clutch out, otherwise you’re using pry bars.

Unfortunately Helga’s running a 240mm Saab 9000 clutch which is practically unobtainable these days with the necessary 17 splines. The best price I got was £500. So for now the old clutch has gone back in (with release bearing this time) because there’s a bit of wear left in it. I also dropped in a VW 99 relay for the wipers, which adds adjustable intermittency by turning the wipers off and on again with the delay you want to set. A pretty useful drop in upgrade.

While the lower dash is still out I’ve had a prod about at the cruise control and got it working. All it needed was the pedal switches cleaning up. Replaced the vac lines for cruise with silicone as they were looking tired.

Gearbox is continuing to sound pretty whiney at times, but still operating fine. I’ve got another ready, but is there any point in swapping it out before it fails completely, or have I to just sit it out till it gives in? Think I’ve read before that if it’s been ran for long with a whine, it’s beyond repair?

Categories
Cars SAAB

Tidying

Since last update I’ve painted a few panels, all of the aero kit in satin black, fitted 6.5” speakers in the doors to replace the in dash ones, fitted vent covers and some fog lights as well as swapped to the earlier front grill.

The speakers are quite neat, though the door panels were made by the last owner.

Unfortunately I didn’t have time to do all the paint in one go so due to the need to get to work I rocked the extreme rat look for a while…

Pretty surprising I didn’t get pulled. She was perfectly road worthy but didn’t look it

But finally bit by bit I did the painting. I had a lot of trouble with this, and the results are pretty poor, even after rubbing back the orange peel but at least she’s mostly the same colour now. I didn’t paint the driver’s door because they’re both getting replaced with less rotten ones eventually.

Painting the body kit satin black instead of the standard anthracite colour went much better. I think it contrasts better with the bodywork.

1986 Saab 900 turbo
And finally back together. I really like the black aero panels against the Odoardo grey.

She took a few days off sick recently after a brake bleed job went awry. The first circuit bled fine, but then the front left wheel wouldn’t stop spurting bubbles. On closer inspection of the reservoir bubbles were also coming up through that circuit’s port. So off came the master to find seals and bores looking in fine condition. Ordered a new one anyway because I didn’t have time to play, and also some new front pads. Went for Ferodo DS2500 in Mk. 2 Ford Escort fitment, which drop in with only slight modification.

The DS2500 replaced worn out EBC yellowstuff and they feel pretty similar, but with a bit more initial bite especially when cold. I fitted 9000 brakes to my last 900 and they were great but since Helga is a front handbrake model, I don’t fancy converting the front hubs, handbrake mechanism and rear axle to rear handbrake at the moment. So for now I’ve chucked all I can at these brakes to get them as good as they can be.

Categories
Cars SAAB

More welding

Been using Helga regularly for the last few weeks, and all was going well. Fixed a few niggles along the way like the central locking on the boot and making a bushing to take the slack out of the clutch pedal.

Had a bit of a showstopper though, suddenly started getting a knock from the back so I investigated and found the shock has parted company with it’s mount.

Also, there was a hole in the back corner of the boot floor.

So, having just moved into a house with a garage again, I bought myself a 250 amp gas MIG welder and got to work.

Plus there was a patch in the boot floor. All acid etched, seam sealed and shcutz’d now, though I still need to paint the body areas in her Odoardo grey yet and refit the aero panels so she looks very mad max for now.

For a while there’s been a leak between the turbo and it’s elbow, which turns out is because the elbow has pitted quite badly. As a temporary fix I’ve made a thick copper gasket, but ultimately I’d like to do a 3″ downpipe.

Anyway, after all this I took her for a MOT on Monday which after an initial fail and quick tinker, she passed! Which is great news, because it was just in time for the Gold Cup at Oulton Park.

This year it was drama free apart from popping a boost hose yet again while trying to find out who’s fastest in the gang. Amazingly a chap came up who said he used to own Helga!

Other work done lately:

  • Fitted a decor panel (the bit between the rear lights, might take it back off, not sure I’m fussed)
  • Fitted the front seats that I refurbished way back.
  • Fitted a new old stock bonnet release cable – finally I can get my mole grips back
  • Fitted the bigger sump guard from later 900s
  • Fitted a LED running light in place of the broken boot light – bit silly bright but pretty effective.
  • Made a new parcel shelf from ply
This got covered in carpet

She’s running fine, so I’m going to keep using her for now but there’s plenty to do tidying wise. First up I think will be to sort the paint and refit the aero panels. There’s a slight whine in the box so I think at some point that’ll need changing, though it hasn’t got any worse. I’ve got a spare lined up for when the time comes.

Categories
Cars SAAB

Super Inca Wheels

I’m not much of a fan of minilite-style wheels on 900s, so I got hold of some freshly refurbed Super Incas from JamSaab along with super rare locking centre caps. Had some Uniroyal Rain Expert 3’s fitted, and on they went. Annoyingly, the centre caps don’t actually fit – they’re about 1mm too big for the hole. It might just be the thickness of the paint, but I’m not too keen to file them down so they’re staying off for now.

Also – what’s this? A genuine Saab whale tail? I’m still in two minds about it – I think they look great on later slope front cars but I’m not so sure about flat fronts like Helga. I’ll leave it a while before fitting.