Saab 900 classic lpt what cheap mods??

[stillnotfinished]

Hi all as above its already got an abotts charge cooler, I've heared of mbc but don't know much about them. What else is out there on a budget ? Also it's got a cat so was thinking of a straight through pipe.
Any ideas welcome
Thanks

[thooms]

APC from a T16S would be ideal - an MBC is a bit risky unless you have a way of knowing what the boost actually is. You can't go much over 1bar (14psi) with the Abbott cooler without risking it failing.

So yeah. APC setup (safer but more effort) or MBC + calibrated boost gauge (easier, but you don't have the knock detection of the APC) would be my vote.

What's your power goal?

I'm adding a Trionic 5 setup from a 9000 to mine (have a Google) - but that's a bit more involved. Worth looking at if you're keeping the car for a long time, but a lot of effort for a quick power boost.

Think about the budget and how much power you're shooting for. That'll define where to go with it probably. APC and a few supporting mods will get 200ish with the stock TE05. Above that, I'd be looking at Trionic 5 (I'm going Trionic 5 + TD04-15g + big IC for ~230hp - much more is v hard on the 'box)

[notsoswift]

Bigger bore exhausts are very effective with Turbo's
If you can weld you can rob parts of other cars and unleash some good power from the rejects for very little money.
Start as big as you can of the exhaust housing (like 3") the drop it down at the first expansion box, BTW the perfect expansion box is a knocked out Cat then choose the diameter based on the power anywhere from 2" up, even if it is standard size the freeing up the first part will help a lot.

APC is good, the first knock control, but I think it is standard from about 86 () face lift with the rounded front. Sorry been a long time since my classic 900Turbo, but I did follow up with a 9-3 (curse word) and 9-5 Aero Sportwagon

[stillnotfinished]

Hi thanks you two for the replys ;-)
Not after any huge power increase , as don't want a drag racer or even to blow up the gearbox!
Car is a 92 so last of the line. Don't think it's apc'ed - they are the red boxed ones?? What is involved in changing to the apc system? Not technically minded enough to go for t5, sounds too complicated to me!

[thooms]

The main components of the APC system are a controller (can be black or red - black = 175hp, red = 185hp), a solenoid (this regulates how much of the manifold pressure the actuator sees), pressure transducer (measures manifold pressure...as the name suggests and the knock sensor to tell if there's badness happening.

My car is a '91 LPT, and that had the knock sensor on the block (though not sure if it's the original engine) - but those're the four things you'd need - plus the loom, obviously.

It's pretty straight forward if you can find a loom that has been extracted from a car

[stillnotfinished]

That sounds pretty easy ,where on the engine should the knock sensor be? Be one less thing to worry about if its already fitted

[thooms]

It's under the inlet manifold, just behind the starter - bolted to the block

[stillnotfinished]

Nov 9, 2013 11:21:08 GMT thooms said:

It's under the inlet manifold, just behind the starter - bolted to the block

Can't find it is it easy to spot?!!

[DavidB]

I have a B204R in my Astra from a 2000 Saab 9-3 SE. It's at 260bhp which cost £200. I intend to go to 300bhp with a few things like larger intercooler, injectors, bigger turbo, etc. but won't go any higher. You can get the APC's from 9-3's as well, easy to wire into ECU. I think I may have a spare one.

[thooms]

Pinched this off Google images - it's the little black thing between the middle two cylinders.

[Dorset_Clive]

Nov 12, 2013 20:12:59 GMT DavidB said:

I have a B204R in my Astra from a 2000 Saab 9-3 SE. It's at 260bhp which cost £200. I intend to go to 300bhp with a few things like larger intercooler, injectors, bigger turbo, etc. but won't go any higher. You can get the APC's from 9-3's as well, easy to wire into ECU. I think I may have a spare one.

At risk of hijacking the thread, what did you do/get for your £200 that added 60bhp?

I've got a 2.0 185bhp turbo in my 'vert and am wondering about a little more ommph!

[nelliem]

Dorset_Clive - a straight remap will get you to around 250, after that you need a 3" downpipe which should see you to 270 ish.

As thooms has said, I'd steer clear of the MBC unless you really know what you are doing as it's easy to get it wrong.

[DavidB]

Had the b204r which is 205 bhp, had a remap and larger intercooler and down pipe/s/s exhaust. Remap scan be done for about 30 pounds.
I'm taking my time on the car and have spent quite a bit, with a Vauxhall calibra turbo f28 six speed box as well. A lot of Vauxhall stuff swaps over as the bulkhead forward was based on a mk3 astra.

[ejenner]

Allow me to clear up a bit of confusion.

The first Saab's with APC (automatic performance control) came out in around 1981. The idea was to allow the engines to run high compression and a turbo at the same time. So when some turbo engines were running 6.5:1 CR the Saabs were doing 8.5:1, then 9:1 and then 9.5:1 in the latest 9-5s

The first APCs were grey and had fewer pins on the interface connector. This is an old photo from when I first got my 99T16 showing where the guy who originally built the car mounted two APCs. The APC units are the two grey boxes under the glove-box. He had two because he wanted two different levels of tune. Sort of missing the point!



The picture of the grey cylinder block above shows the knock sensor mounted incorrectly on the block. It should point towards the bottom left of the picture rather than the bottom right.

After the grey boxes came the later versions with the 25-pin connector and black case. An optional accessory from the sports catalogue was the red box which added 10hp. Saab made some special addition models which had the red box included.

Saab being Saab meant that all boxes right from early grey to the latest versions of black or red were adjustable and moddable.

The model of car mentioned at the beginning of this thread has no APC. That's because the car is a LPT (low pressure turbo) the idea was to have a turbo you didn't know was there. Just giving a little bit of assistance. It's a wastegate-only setup which relies on the wastegate spring and length of the actuator rod to control boost. The actuator hose is connected directly to the compressor housing. As soon as the compressor is making enough boost the actuator will start to open the wastegate.

Personally... I feel the LPT is a totally flawed concept. You have poor MPG and poor off boost performance because it's a low(er) compression engine and then no big performance hit later on to compensate. Luckily there is a lot you can do to remedy this.

A further point of confusion is the phasing-out of APC.

The 900 always had APC. The later ng900 never had APC. The 9000 had DI+APC (direct ignition... Saabs computer controlled ignition system) in 1985 meaning there were 3 ECUs on the car. One for fuel, one for APC and one for Direct Ignition. Saab quickly rationalised that setup and by about 1988 they were fitting DI/APC - where the APC and DI unit were housed within one box. They improved this again and by about 1992 they introduced Trionic 5.2 which put all three functions in one box. From 1994 onwards an improved version of Trionic was introduced - version 5.5 - that is what is fitted to the Vauxhall Astra shown above.

As for what to do with your LPT Saab 900? By far the best advice on here is to convert it to Trionic 5.5 - that costs about £1000 if you pay someone (like me) to do it for you or if you want to do it yourself then between £250-£500 worth of parts and a fair bit of time. Trionic gives more than just access to power. It also gives better fuel economy, easier starting, reliable performance (as well as good performance) steadier and more adaptable idle speed, the ability to adapt to different kinds of fuel and differences in climate and loads of other stuff. It is also DIY tuneable using the freely available Trionic Suite software.

If you don't want to fit T5 then probably the best thing you can do is fit the APC controller and use it one of two ways. You can either complete the full OEM installation so the APC can control boost or you can use the APC just as a knock detection device. For the latter you require very minimal wiring and you end up with a dash mounted LED bulb which flickers if the APC detects knock. That way you know to either back-off the throttle or tune down your boost so it does not knock.

As your car is an LPT it will have the Lucas ECU and that is a hard one to tune. I don't know of anyone who has although have heard it is possible. On the upside... it is able to compensate well for increases in boost so you can just leave it as it is and tune the stuff you can control. That is boost and ignition advance.

Probably the ideal configuration is a nice tight actuator from Forge (with the spring kit, so you can choose which spring fits best) a manual boost controller and the APC box fitted just for detecting knock to give you peace of mind so you know you're not risking your engine. Then advance your ignition timing as much as you can for any given boost setting and that is the best you'll be able to get out of that setup. You would get your 230hp easy. Just a matter of understanding what you're doing and refining everything until it's nice. You could have a fully functional APC and tune the box so that you get more boost but it would be a lot more effort and you’d have to learn a lot more about how the APC works (i.e. everything)

Personally I wouldn't bother messing about with the exhaust. The Saab exhaust is already pretty big. It's about 2.5 or 2.25 inch anyway. I know some will try and convince you .5 of an inch makes a lot of difference but TBH... those guys have problems.

This is what I managed with the standard turbo. I've driven much slower feeling cars with dyno figures over 200hp so this one must have been around the 250 mark. Standard exhaust, standard intercooler, APC detects no knock. Then I upgraded the turbo to a hybrid version which used to cause a lot of knock with the boost gauge going off the end of the red section. Now it has been T5-ed and is for sale.

[stillnotfinished]

Ejenna thanks for that great reply :-)
Wasn't looking for any particular bhp hike, just think there will be some easy mods out there I could use. Ill read through your thoughts again (and again)! As I said on first post it already has an abotts charge cooler fitted before I got the car ( it may have other mods too, the downpipe looks huge, and there is no middle box but maybe they all are like this on a late 900 ) so will have about 185. As its on type 6 primary's ( for now) don't want gearbox problems from a huge power hike.
Ill look into getting the forge stuff - how much are they and are they easy to fit, and will Probberly get rid of the cat
Cheers for now