Saturn S-series as a platform?

I am looking for some info from people experienced with the Saturn S-series, especially in use as a autocross car and relating with handling and overall suitability as a ""racing"" platform, especially pertaining to the 1st generation SL2.

I personally really like the styling, but it seems like it would be a solid start, as it is very light - under 2500 pounds - with a decent amount of horsepower considering the size, and a manual transmission.

I have however heard of issues with oil starvation on long corners and of the dismal aftermarket. Improving handling would be a definite priority, and I have heard Subaru coilovers are often installed, and thicker sway bars from the wagons, but I'm also looking to see what other options are out there and whether they would make a substantial difference.

I am looking for a budget autocross and backroad project "racer" (as much as a Saturn can be) to improve handling and various performance aspects, and it seems with the very low entry point, and general reliability of the 1st gen S-series that it would be a good fit. 

Can't tell you much about their autox prowess, however I have a friend who runs the platform in endurance racing.  He's built several of them.  If you're looking for true performance, they're mediocre at best.  My understanding is that when the engine is treated properly and you keep it oiled and cooled (a challenge for any engine) they are fairly durable.  At the same time, part supplies are slowly drying up and as you said there is really no aftermarket support, besides Autozone and Pep Boys.  I don't know if you'd have enough cornering forces or duration in autox to create significant oil starvation issues, I guess it depends on the course.  Personally, I'd go with a different platform.  In that class, Civic is the easy button.  You'd be surprised what a Corolla can do too.

PSA - don't do backroad racing - that's what race tracks are for.

I owned an autocross-prepped 2002 SC2 for a bit last year, and raced it in the $2000 Challenge. It was a blast. Anything can be an autocross car with enough sticky tire.

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/emergency-backup-saturn-02-sc2k-challenge-car/184437/page1/

The engines are durable, but even the most powerful DOHC version only makes like 120 HP. They are as slow as a NA Miata but with 200 more pounds. I ran a mid-16 1/4 mile with mine. The manual trans are also durable, but LSD was never an option. Supposedly they can lose the spider gear pin if you do too many 1-wheel peels. There aren't many engines that will starve for oil at an autocross, so I wouldn't worry about that unless you track it. They ALL burn oil though, so watch out for that and keep it topped up.

For styling, the 1st gen SC/SC2 coupes up to 1996 are the coolest ones especially with pop-up headlights. If you squint it looks like a 1g DSM. If The 1st gens are also the lightest, but getting hard to find especially with the pop-ups. Many met their fate in dirt track racing. My '02 was the last of the 3rd gens, and the last of the S-series. They are incredibly modular and share a ton of parts across the model lineup. Used OEM parts are still easy to find and cheap. 

Mine had lowering springs, decent shocks, nice wheels with 200tw tires. You won't need coilovers, just more camber. The thing is these cars are just not very powerful for their weight, so you will maximize suspension performance quickly and still probably won't win any autocross classes. 

By modern standards they are pretty slow, but with bolt-ons you should be able to run mid 15s without much effort.  Intake, exhaust, and header and you'll put ~125-130 to the wheels.  With a tuning solution that will be more like 135, maybe 140.

They don't have a ton of room for tire so you cant easily run 9" or 10" wheels like Miatas can.  15x8 with a 205 or 225 is very easy though and fits well.  If you are going to a more prepared class and you can run R compounds you can do the work to make bigger stuff fit.

As mentioned above, the engines are quite durable as long as they have oil in them.

If you want to build a motor, you can make a frankenstein engine from different engine parts throughout the years and make a little more power.  IIRC the intake manifold is the main restriction.  The heads actually flow ok and should be able to make significantly more power than real world results seem to reflect.

They handle boost o.k. but not great.  Not like a BP.  The ringlands aren't very thick, so you have to be careful with your tuning.  There are people that have put down a reliable ~220hp on 7psi or so.  A lot get greedy and turn up the boost eventually and blow stuff up.  If you put forged internals in there obviously you unlock a much higher ceiling.

The trans has a weakness where if you like to do burnouts the diff pin will loosen (case around it expands due to heat) and fall out, grenading it.  If you weld the pin (not a welded diff), they are fairly bulletproof.  Quaife and Mfactory both made helical LSDs, but I doubt they are available anymore.

Regarding suspension:  The stock rear swaybars are all the same (if present).  There are aftermarket ones floating out there, but not sure if any still made - unlikely.  Coilovers work great, but if you cant find them, look for H&R Race springs.  If you can't find those, the stiffest you will find are H&R sport, which are decent, but probably not going to cut it for competitive autox or anything with R compound tires.

The front suspension has a weird swaybar/toe link setup where you can't remove the bar, so you just have to live with it.  It has not-great bumpsteer characteristics.

Overall the biggest weakness is that everything you can do with one you can likely do easier with a different platform where the buy in is only marginally more, and far less time/energy/money than you would need to spend make custom components for a Saturn.

This was my old daily, and I actually miss it quite a bit.  It was a good combo of useful and fun to toss around, reasonable mileage, and zero berks given about it.