So, I come from the Subaru world- I have an 05 STi and have modded these cars in the past. One thing is for certain with Subies- you have to tune for everything, doesn't matter how little it is. We all use the Cobb accessport for plug and play and engine management- its easy to use and every region has a good tuner. We have one in central iowa everyone goes to with a good reputation.

My question is, what can I get away with mod-wise on my 1990 Eclipse GST? I might want to look into some bolt-ons and am wondering what kind of tuning options I have? I've heard something about DSM-link- could someone send me a link to a page about that or maybe offer some info? Again sorry if this is a really easy question but I really have no idea how responsive these motors/ECU's are to basic mods.

Some ideas for basic bolt ons would be, intake, exhaust (full, or maybe cat-back)...etc. Do I need to tune for these?

http://www.ecmtuning.com

You pretty much have full control of the ecm with ecmlink. I highly recommend it.

ecmlink is great I've had it, and for a 1g shouldn't be too hard to acquire an eprom if you're car doesn't have one. Evo 8 ecu s have also been swapped into 1g as well but requires a good bit of re wiring ecu harness. I'm a 2g guy so no first hand knowledge with 1g. also maf-t is a solution as well as the old safc if your not going crazy on power. people have gotten away with 550cc injectors and just a 2g maf, some argue but a good bunch say it's a great combo. hopefully I have u some ideas

I think your best bet is to do a bit of searching as this is very vague question that's hard to answer. Long ago, I had a 91 fwd laser and was pretty fast with a full exhaust, intake, 16g turbo and hard intercooler piping. Obviously, the more mods you do to the car the more you'll need to tune it because you are altering the airflow of the engine and the ecu's programming can't factor that in. If you're looking for a no-tune setup, maybe the 2g maf-550cc injector, exhaust-intake 16g-walbro fuel pump is about as far as I'd go.

Yep, keep investigating the ECM link. That's the way to go.

ECM Link is what you want. Google it. Its gonna be the closest thing to Cobb for you. Its a bit more involved than pressing a few buttons. But the good news is, with ECM Link you get access to their forum.

I will probably be making the switch down the road. Right now I use Evo Scan and Ecu Flash (works for subies to go figure). If you've got any expierance with flashing you might try that. I know 1st gens have a few options beyond ECM Link and swapping to a 2g H8 ecu or Evo ecu. Try googling "Jackal 1g DSM" and "Ostrich 1g DSM". I've not messed with either of them, but have heard of them.

I would, again, HIGHLY HIGHLY recommend getting ECM Link (Formerly Called DSM Link) verison 3. 500$-600$ invested you can get more power than any mods besides a MBC will give you, as well as diagnostic and monitoring information that is invaluable. and a premium forum that will teach you tune it yourself.

way back in 2002, Turbo and High Tech Performance Magazine did an awesome series of upgrades to a galant vr4, which has the same 4g63 as your GST. some of the parts are outdated but it serves as a great guide to how much power you get from individual upgrades. It has dyno numbers for each upgrade that was done.
here are links to all 6 parts. or if you don't wanna read all of them the dyno results are at the end of this post.

part 1

part 2

part 3



part 5

part 6

I also highly recommend link. It's one of the best mods for a dsm and well worth the money if you plan on keeping it for a long time. This is my second dsm. First was a 2g with SAFC that worked great but I didn't know a thing about tuning. I've learned so much (since Oct of 2017) with link as there's so much information and research done by our founding fathers... It isn't "necessary" if you're only modding lightly and the car should run fine. But these cars are getting up there in age and if there's a problem, sometimes you'll see the problem right away with link. READ, READ and READ!!

Another important thing to consider... if you just recently purchased the car, put your money in doing maintenance items first. Timing belt replacement is of special important if you do not know when it was last changed. Be sure to use an OEM tensioner when doing so. Also check for boost leaks as well.

After that, ECMlink is the best thing you can buy. You really can't turn up the power on a stock car too far without running into fuel cut issues.