95 gt boost problem

i have a vortech v2 s trim super charger. and pretty well stock 5.0. when the engine gets up to 4800 to 52,5300 range the boost is at about 10 but if i hold the throttle stedy the boost drops almost completely. Is this my bypass valve working correctly or is this serious? it runs great. Lately ive been getting so detination and cant seem to correct it with the boost retard of fmu. it did great at the track the first run...r/t .........101
.60.........1.773
330........5.136
1/8.........7.960
mph@1/8.86.82
1000ft....10.402
1/4........12.473
mph.......108.41
this was my first run of the day, my second run pulled a 15!? its not running well under boost im still testing stuff and cant find a vac leak. any help?

Try not using the boost retard and just turn the timing down at the distributor. Set the timing at 0. You should not have any detonation at that setting. If you still get detonation you probably aren't getting enough fuel. What does you fuel system consist of? Are you still using the stock mass air meter? If you keep letting it detonate, you will break something.

I'm not sure I understand your boost question. If you are saying you rev it to 52 or 5300 and then let off the throttle some and just hold it there at that rpm, then yes, your boost will drop.

I have the stock mass air flow and injectors, they are the next thing to go. i bought an autometer air/fuel ratio guage and ill install that this weekend so i can see what is going on.

About my boost problem: i go balls out i dont let off most the time(at the track) but if i get on it, on the highway and let off just a hair i loose all boost. everything else stays steady. but it falls on its face. I dont have platinum plugs because vortech told me that it could ruin my engine, so i use autolite #25 which is stock for that engine. A buddy of mine (and past supercharger owner) told me to get one step colder on the plugs and gap it hotter so the gap is smaller. im going to try that too.