got an 88 supra turbo
upgraded the turbo an fule system 550 cc inj lexus maf
walbro and fpr
safc2 and acv-r
my problem is i am hitting some sort of fuel cut at .4 kg cm2 or 6 psi
any ideas

Make certain you dont have a boost leak somewhere. If the system has no leaks check your AFC settings. If you add fuel with the AFC you will bring fuel cut in sooner..if you remove fuel you will push fuel cut up to higher boost levels.

Have you had the car on a dyno with a wide band 02 sensor?

the stock ecu in a mkiv is electronicly controlled on the ammount of boost you run. To rectify the problem we buy a bcc which eliminates the problem. Not sure if it's the same on your models but it might be your problem

7mgte uses mechanical boost control...