Turbo question
 

I just bought a 1999 Saab 9-5 with the 2.3L Turbo.

It has the low pressure turbo installed, is it possible to just replace the low pressure turbo with the high pressure turbo and keep all of the components the same?

I'm not familiar with Saab engines, so don't take my word as gospel, but I'm going to say probably not.

Your entire engine is built around that turbo. Heads, pistons, rings, manifold, it's all designed for that particular setup. The ecu will likely be programmed with it in mind as well, meaning that you'd see (at best, I reckon) a check engine light that doesn't go away.

At worst? Well, we won't get into the gory details. Engines have been destroyed from too much boost and an improper setup before.

I reckon you're better off with the low pressure turbo anyway. From what I've read, the lag on them is practically non-existant. The bigger the turbine, the more lag you get. I absolutely hate turbo lag (I want my power now, dammit!) so to me that's a big turn off. You may feel differently.

What would be a better recommendation to get more horsepower?

I thought upgrading the turbo might work but I'm not sure and I don't really have to money for something to go wrong.

Specs say it should put out 170 and I'd like to get 15-20 more hp -- 200 would be nice.

15-20 more hp isn't all that hard to get out of an engine.. upgrading the turbo is probably the last thing you'd want to do for that.

Start checking into the aftermarket. Less restrictive exhaust is a good start.. headers won't be an option since the turbo's in there, but everything cat back can be replaced. You can also look at new throttle bodies or intakes to try to cram more air into the cylinders.

The other option is to look for an aftermarket ECU chip. They'll use more aggressive timing, which can squeeze more power out of the engine as it is. The factory chips generally have conservative settings, with the theory being that the engine will last longer like that. Between those three modifications you should be able to get at least 15 hp more than you have already. If you do end up swapping the turbo, make sure you look into all the details first. I'd suggest checking online for a Saab forum... there's probably one out there and they'll be able to give you advice specific to your model, which I can't do.

Hmmm, Martin had a good idea...
 

With a turbo car, I figure a K&N and upgraded exhaust would get your 15 WHP...

IF not, a boost controller would work wonders.

-Will

One thing I would HIGHLY caution is that turning up the boost on any motor will require additional fuel and if the ECU can't compensate adequately the motor will run lean and blow up or burn up a piston or valves etc. So do a little research on your particular car to make sure the stock ECU can compensate for turning up the boost a couple psi. If it can, that would get you at least 20 hp more, probably even more. Freeing up the intake and exhaust will in itself allow higher boost. I know my old '95 Saab 9000 w/low pressure turbo didn't have a boost gauge but I never moded it; and for that matter my present '95 Supra turbo didn't either (I put a boost gauge on this one since I run way over factory boost) but a boost gauge is nice/important to have especially if you decide to turn it up. Also, unless you want to get "more involved" than just a slight boost increase, a boost controller isn't what I would recommend for most people; a bleeder tee in the line to the wastegate actuator costs less than $1 and will give you a fixed amount of extra boost but you need a boost gauge to see how much or follow the proven rules for your Saab with that kind of bleeder tee mod.

Word to the wise... I have learned in my experience with turbo cars that the amount of money you put into making the car faster is exponentially proportional to the amount of money you will spend fixing the shit that it eventually fucks up. If it's fun to drive now, leave it alone... Maybe put a K&N and get rid of your cats, that will add some power without hurting your car too much...

Turn up the boost/put in bigger turbo -
?Upgrade/install intercooler (don't want to force a bunch of hot air in)
?Replace all pressure lines connected with turbo system (stock ones will blow off if not replaced with something heavier duty)
?Install more guages that are more accurate (Boost guage and something that tells your Air/Fuel Ratio)
?Install bigger fuel pump (possibly your stock one will do, but be careful)
?Install new Fuel Controller and Injectors (if you have to put a new fuel pump in then you definitely need these)

And that's just for starters, who knows what the extra pressure you're putting on your internals, clutch, transmission, and driveshaft will eventually do to them.

if you cant afford a roasted motor, you really need to keep things simple.

turbo cars respond very well to exhaust systems, and throw in a lower restriction intake and have the manifold/Throttle body ported. this will give you the power that you want without risking any more damage to the engine.

Actually, headers ARE an option. The turbo is seperate from the exhaust manifolds on the four cylinders. A complete exhaust upgrade, combined with a less restrictive intake is definitely the place to start. Saab has decent exhaust from the get go, but you can do better, I'm sure. Getting the heads and intake manifolds ported and polished would help, too. Not sure what is out there for cams, but if you can find aggressive cams, that is always good. Like they said above...fueling will be something to keep an eye on. Make sure that the factory PCM can handle it, OR find someone who can tune it.