My local AutoX club has its own set of classing and my ‘90 has a fully maxed out suspension, but I still have 2 points to spare before going up a class. It already has an FM cat/mid pipe/axle back. The logical mods are intake, headers, ECU, but each costs a point. So if you can only choose two, which do you choose:
1) Randall intake, RB header
2) MSASM intake + Speeduino
3) RB header + FM Randall intake

Thanks.

 

Whichever choice has the ECU. That will be the single best thing you can do. You'll pick up 10-15hp across the whole rev range with a good tune.

 

Also the 1.6 has a decent header from the factory so probably some sort of intake would also be good

 

With a tuned CAS on factory ECU, you’ll pick up hp above 6000 with a MS by removing the AFM, 5, maybe 10hp. Not 10-15 across the whole rev range though.

personally I’d do a header and exhaust, and wait for intake until I switched to a 1.8 thermostat neck, ditched the AFM, and did a decent intake+ECU.

 

ECU and then intake if you can use it to get rid of the AFM.

The big difference for the ECU on my car (even with a junk street tune while I was learning to tune it) was the way quicker throttle response and a huge pickup in torque before 4000rpm. Made a huge difference pulling out of slow corners in 2nd gear at autocross. I managed to make 100.6rwhp on 87 with a junk tune, AFM replaced by a piece of 2.5" conduit with the GMIAT in it and an ebay cat back. I could (slowly but surely) reel in stock NA8s in the straights on track.

 

Personally, I'd vote for the intake + ECU.

while my NA still had the 1.6, an ECU, AFM delete and Intake was the first power adder I did to it. Everything else on the car was still stock. I have no numbers to compare it with but there was a noticeable bump in power in all areas. I don't know that I'd call it 10-15 though.

 

Intake and ECU to ditch the restrictive MAF and get a cooler air source. Then tune spark and fuel for power rather than economy.

And doing the intake and exhaust without an ECU won't help you much because you won't be able to tune fuel for any additional airflow.

 

It looks like my post didn't make it through.
Based off of what you said, I think the best mods as far as power is concerned would be an ecu and an intake mod. The advantage of the ecu mod is that you can remove the AFM which is the intake restriction so those mods go hand in hand.
I would suggest the 3d printed intake that Alec Moody developed and posted in a thread here and on the website thingiverse for all of use to download and use on our personal cars. I have one in my miata and I am satisfied with the results.

The 3d intake can be used on a 1.6 engine. Attached is a picture of my engine bay back when I had my 1.6 engine.



https://www.thingiverse.com/thing:3001440

 

Yes, that's the intake that I'll use if I go w/ the ECU+intake. I just priced one out on Xometry and it was $62 for Nylon 12 SLS. I will use your wrapping for some extra integrity and sealing.

Thanks for the info.

Matt.