Hi lads
 
I have a 86 AW11 HT SC that doesnt have ABS and it just seems like it is quite under-braked compared to the stock power it puts out. Has anyone else had this problem?
Any recommendations?

I'd be surprised if anybody had an AW equipped with factory ABS.
 
When you say it is unimpressive in the braking department, can you quantify that? Is the pedal spongy? Does it have long pedal travel?  How hard do you push it - road or track car?  The cure maybe something as simple as a good brake service - check all the pads and rotors, flush the brake fluid, adjust the brake pedal free-play.  Get it back to what the factory designed, then see how it feels . . .

what he said. what is the general condition of the brakes? 
 
good pads and a fluid change go along way to improving brake performance and feel esp if they're on an old somewhat neglected vehicle.

Also a booster brace might be needed too maybe?

Absolutely no problems with my brakes, 88 targa SC. 
 
Don't see a need to get bigger brakes as the right pads, rotors, brake lines, fluids and brake master cylinder stopper combined with decent tyres is more than enough for me.

Even on my worn factory rotors and unknown aftermarket OEM spec pads which are quite worn, but with relatively fresh generic fluid, my 87 SC pulls up fine. My daily has outstanding braking as well (just as good as early 2000 spec WRX brembo's) and I've never had a brown pants moment in the adub.
I've been in a situation where a mate also driving an ADM spec adub in front of me locked his brakes up due to not seeing a car approaching, I locked mine at the same time but pulled up a lot better than him, though his tyres had lost quite a bit of grip after going hard after a track day, whereas mine are nice and fresh rubber.
 
Give the brake rotors/pads a refresh. Also at this age the rubber lines might expand a lot so braided lines will give you a big improvement. Cusco makes a cylinder stopper for the AW11 which everyone raves about as well. Also if you can afford it, consider getting your calipers rebuilt whilst refreshing everything else. All of this isn't cheap but I'd consider it a worthwhile upgrade and investment to your pride and joy. Top performing brakes can also shave seconds off your lap time!

The factory brakes on my 89 Targa SC also stop my car well enough. Even when going hard with the 3sgte it pulls up great.  New pads and fluid I reckon.

whoa! Your responses are all united! Well I come from a background of really good braking cars like my evo, gen 3 mr2, TT soarer etc and in comparison the aw feels very underwhelming. For example in an emergency scenario slam the pedal on any of those cars and it will pull up like viagra. Do that in the aw and it locks and I go sliding.
 
Re-reading that it just seems like Im missing abs. Is there anyway I can install it? Or any suggestions on my braking input in crises situations? Thanks

No AW11 ever had ABS. I think installing an aftermarket universal setup would be tricky if there even is such a thing, but I doubt there is.
 
emergency situations in an AW11 can be tricky. I faced one last year. and the car got smashed even though I did my best. the damage got off pretty light. you can't just mash your brake and expect to pull up, which sounds like what your doing. they do lock, but still takes a bit to make them lock.
 
the only safe way to quickly brake an AW11 is to firstly press down lightly on the brakes to transfer the weight to the front then you can hit the brakes hard.
 
I advise you go to a good driver training centre and do a defensive driving course with someone familiar with the quirks of the MR2. they will give you good advise one things you can do. I did one with Rick bates years ago. a few things that stuck with me was this above, and in am emergency if you can go to the side of the situation always do this over braking. and you don't brake then swerve this trows the car off stability, if you do do it you have to commit and accelerate then swerve, then brake. unlike most other cars where you brake then swerve then brake again. this is what saved my ass a little bit. I hit the brakes initally they locked so I remembered and quickly released, accelerated and swerved. and this was from 100km to 0km and everybody drove their cars away that do so it was a good result
 
 
 

I'll vouch for the stock brakes. Mine were as described when I first got my SC adub. After rebuilding the calipers, new fluid & rebuilding the master, pulled up very nicely & felt sublime. Even with crappy bendix pads.

I have similar expectations to you. From my Gen3 turbo, WRX, Evo TME, IS350, RX8, FD RX7. If I still had my Adub, would not even consider any brake upgrade unless I threw my SW20 5SGTE in or something silly.