Just a personal comment on headers and exhaust systems. If you are trying to increase performance on a budget and considering and almost stock engine in terms of modifications and RPM capability and driven on the street.
Exhaust modifcations rate almost zero in my book as to doing anything except costing money.
And usually they are extremely expensive in comparrison to other things you can do.
'Specially with small engines, specifically the 2 L type 4 cylinder stuff.
But they look cool and sound terrific even if they do next to nothing.
But that is my opinion.

okay i race at a track i have a 95 sc1 and i'm sick of getting beat out by cheaters. what can i do to bring me back to the front of the pack. mods are illeagal so it needs to be discreat. preferably cheap

A 95 SC1 is a single cam engine, built as an economy car and as I remember a bit on the heavy side. I have specifications, I'd have to look them up. I will if you want them.
There is a basic rule when it comes to drag racing. How fast you want to is a basic function of how much money you have to spend. You want cheap? Go slow! You think you are the only one who has the desire to go fast. Stand in line.
The car is heavy, down on power, and rpm limited. Not a good combination. Go fast parts are not available for it Cheap!
I did the exhaust thing on a small engine, drag strip times before and after exactly the same. Except it sounded nice. Dyno numbers say (in my opinion anyway) at best and under the right circumstances 5-10 hp if you are lucky. And most people arn't.
An exhaust system can run an easy 3-500 bucks.
Simplest thing requiring the most work and some money.
Put a cam in it it.
Do some injector work. Putting larger injectors in it will let it pass more fuel, the computor will try to back it off keeping fuel regulation correct but it can't but that is to your benefit because it will self regulate.
But you need the cam to make it work.
There are MMAP sensor adapters, to let the MMAP sensor run in a different curve.
It will deal with changing the timing to something more performance oriented. And will work with Early GM mmap sensors.
There is not a whole lot you can do, and have it be cheap. There is a lot you can do that will not do a whole lot and be expensive. In my opinion exhaust mods and the intake air filter thingy are two of them.
If you want to cheat and try to get away with it, NOS will work, also visible, and not cheat.
I dunno, try bracket racing. If you are good enough at it. You can win.
Stroker McGurk's basic racing rules
1. You can not beat cubic inches.
2. You can not beat cubic money.
Been there, done that, still am. Having fun.
I will stand corrected if some one can state it, I do not think there are computor chips for that computer

One more thought, again not overly expensive but a lot of work. A high stall torque converter if you are running an automatic. Something in the area 2200 rpm or so will give a slightly better launch and shorten the 60 second times. Much more you would be dealing with excessive transmission heat and problems with the lock up function. Can you go more? Yup, do you wanna? Your dime! You said cheap, fixing it ain't cheap.
About $150.00 or so to have one made in my area. Lots of work to get it in. It was good for better than a second when I did it.
On another small engine car.
But again, if you need more rpm to make it work to your advantage, a cam, some injectors and the torque converter, all invisible, all hard to check, and all stock untill proven otherwise and who is going to do the tear down.

And if you are runnng a stock exhaust and a stock intake, all probably adequate for the rpm and the size of the engine, who is going to be triggered to suspect it.