I started racing SM this year and I bought a 1990 1.6L before I knew that they weren't competitive past regional races. This car has been raced a long time and I'm sure the motor could be freshened up.
Is it even worth it to freshen a tired 1.6? In 2018 I want to try running a Majors event, but maybe it would be better to sell the car and change to a 1.8 car if I want to get serious. Opinions?
I think what Steve, Dave W and Bench said above are good answers
You might get a laugh out of how I ended up dealing with the same conundrum. I bought a 1.6 that was well prepped by a professional racer and used it as my learner car. I did a lot to the car, new tranny, torsen diff (which I think hurt my lap times but was unbreakable compared to the VLSD), learned how to scale and align it, put in a fuel pressure regulator, played with the AFM clock spring..accumulated boxes of 1/2 used brake pads..hit a spec racer ford..but that's a different story..After a few years of SCCA racing I decided to dyno the thing...got 108 hp SAE corrected on a humid and hot day in FL. Thought, well I'm down on power so may as well put a new motor in. Besides racing I for sure also enjoy the mechanical aspects of working on the car, so I bought a craigslist motor, tore it apart and rebuilt it using the factory manual as a guide..popped the motor in fired her up, broke her in and re dynoed at ...111 hp. ...this after hours on the dyno with tuning the AFM, fuel pressure and the tech shaking his head at me getting excited about 1 hp. I gave up mostly because I got tired of hearing about how I should megasquirt it. OK so now round 3: a pro head ... Guess what ? same hp and maybe a smidge more if we get creative with the dyno calculation. Final round: new car. Oh yes I did, took 14 months and built the whole damn thing using everything Mazda doing all the work myself (including motor) except cage. dyno 123 with the plate...yesss look out on the track... but but wait my times are only marginally improved. WTF? It's the driver stupid (I'm calling myself stupid here) In all that effort I neglected to work on my skills on track.
Now to be clear, I did all that work partly for the satisfaction of saying I could and did and not solely because I thought I would start winning races. Also I have a really reliable car and I know I have minimized it as a limiting factor. So here is what I have learned about SM racing. If you are in a 20+ car field you are likely around some drivers who have spent a lot of time on their skills as well as the car. The drivers who win, can and do outdrive their competition and that is a very difficult thing to learn if you do not have natural talent. What is their secret? Are they cheating?...who knows..? the likely answer is time and effort into themselves as drivers as well as their cars. They are keeping the car as close to the limit as possible in the entry and mid corner phases of the corner...none of which is dependent on what is behind the pedal on the far right but their ability to control the middle pedal along with hand/eye co-ordination. That may translate to only 1 or 2 or 3 mph of difference compared to a driver like me but it translates to a big difference in time by the end of the straightaway. You know that I'm sure, we all know that BUT there is something in human nature that makes us think the answer has to be a different car. Maybe that's true to win major races but not to move up the grid.
If your car is low on HP ( maybe I'm wrong here but if it is closer to 100 hp you probably have a worn motor) you should probably rebuild or put a used good motor in. Even 5-6 K on a pro motor is going to be less than the 20 K you will have to spend to build a new car. Talk to someone who knows what a good number is for a 1.6 and if you are close to a good HP for sure you need to work on skills. In terms of a new car, maybe 17k to 20 k for a good 1999 era car or 20-25 K for some new builds and obviously way more for a known car or one from well known shops. These are rough numbers but as part of a racing budget how much are we including for coaching? Maybe a 5-10 K investment in you car along with another 5-7k in coaching gets you to a better lap time than just buying a 17 K used car. If you are solely interested in answering the question how much skill do you have compared to the front runners, here is something you could do: contact one of the shops that is local to the track you are racing at and pay for a rental at least for a test day or a track event. Spend the day trying to set your best time and compare that to their data or have someone who is a known good driver set the target time for you By the end of the day you will know how much work you have to do on you vs the car. If the car you rented was for sale, then you know, you might just buy it. If you are concerned about wrecking it, think about this: you would have to be really unlucky to total the thing on a test day and if you just buy the car at the end of the day, then you have a project now to fix the damage instead of messing around with a 1.6 motor. Just a thought anyway. Maybe I have given you some laughs and a perspective from someone who has asked the same question. Ultimately you have gotta set a goal for what you want to achieve as a driver and then your path will become clearer. In terms of enjoying it and having fun, that's mandatory. Make some friends this weekend, I hope you enjoy the whole process from loading the car up until you get home.