so-so compression, now what?
 

So, I've been driving the '90 for 8 months now with no problems. Went from 193K miles to 196K miles.

My daily driver is now paid off in full so I can spend that cash modding the Miata.

Took her to a trustworthy local shop the other day to get a compression checked and leak down test. Leak down was apparently fine.

Compression was 119, 120, 119, 118

Now, from what I gather 130-150+ psi is ideal. The good thing is that they're all nearly identical. According to the last owner (who was a trustworthy old rocket scientist, literally, who'd owned/sold 20 Miatas) his friend had the engine rebuilt at 160K.

So -- if I'm not looking to have more than 8 psi boost or more then 5K miles a year on the car over the next few years -- does anyone foresee a problem? Oh, and the wear and tear of how many autocrosses I can get to every year. Or, should I try to do a swap (1.8 possibly)? Or, should I sell the car what I paid for it (2 grand) and hunt for another? I'm sure I can get what I paid for it if I'm patient.

Anyway, I'm kinda hoping the answer is: "just boost it -- if the motor goes to hell, buy another." I've gotten kind of attached to the car.

thanks

Anyway, I'm kinda hoping the answer is: "just boost it -- if the motor goes to hell, buy another." I've gotten kind of attached to the car.thanks[/QUOTE]

they are cheap motors.there all over from 500-650,i say boost it just have a extra motor.

if they are earing they are wearing really even. the leakdown test would prove the best test and if that was good I dont see the problem.

Seems low to be that even. Get your own tester and go ahead and boost it.

Was the car stone cold when tested? My 1.6 showed numbers like that cold, but once warmed up would rise 30psi.

I'm starting to wonder that! Maybe the guy didn't warm it up.

The car really hates cold weather starts in general, but runs great after one minute of warmup. I should have taught myself how to do a proper compression test.

Bottom line is, it's a 2000 dollar car that hasn't let me down in 8 months. (Well, I did replace a bad thermostat myself.) I'm throwing 250 dollars worth of Falken Azenis on it this Saturday. Next is a thousand dollar turbo kit and a few hundred in suspension and catback. Then we'll go from there! :)

Thanks for the advice, I'll be around.

Good decision on the tires, a good performance tire was my absolute favorite mod on the miata.

Sweet! Looking forward to it. I'm just putting the 195/60/14's on my stock 14 inchers... which will soon be painted gunmetal.

I weighed the pros and cons. I thought about getting lightweight 15 inchers and 205/50 Azenis but it wasn't going to save much weight if any. The sidewall is already stiff.... couldn't justify the extra cost for the little bit of width. It's not just an autocross tire for me, I want to feel them everytime I drive. I think I've read you can get a lot of miles (relatively) from them anyway.

Maybe one day I'll upgrade to proper wide and light wheels but I'm cool with the sleeper look.