just got a '87 gn, knocks under full throttle

[killahertz]

hey i am new here and i just bought a national and the hose from turbo to intercooler was drawn up and only held on by worm clamps, but the car ran really well had leaky water pump, now replaced,and intercooler cleaned, the throttle body was coated in oil but car does not smoke so i figured turbo needs to be rebuilt and still needs,but after replacing the hose it had a lot more boost than it used to, it has the led style boost meter it goes to the max pressure pretty fast 15psi and is probaly more, and the car starts knocking, like it needs fuel or higher octane. is there a way of modding the stock turbo for more boost, like making waste gate stick or something , this is my first turbo car, and this seems like a lot of boost and not enough fuel or timing or something cause i want to undo it if you can,it also does not seem to have a rev limiter but when it knocks i get out of it but by the time it knocks i am usally at 75 mph rolling start in 2nd gear 30 mph, i am not used to driving it yet and gets crazy in first, and neighbors are'nt keen on tire smoke and loud noise, and i don't really want to run on it because of the vavle noise. HELP please! don't wanna blow

[87 GRANNY]

Check the vacuum hose that goes from the turbo to the control solenoid to the wastegate bellows. This is a special hose with a controlled orifice in the T and substituting any hose will not do. Make positively sure this hose is attached and not oil softened. Sometimes this orifice will get plugged with oil or varnish over. Any hoses with cracks in them will need to be replaced because if the ECM doesn't know what the boost is it cannot control it-I had this same condition on my 87 and a new hose assembly fixed it right up. Make sure the waste gate is moving against some spring pressure inside the bellows. Original wastegate bellows are none adjustable but new one come with a turnbuckle to adjust boost.

[vader87]

Where to start? Hmmm.... first is this a stock setup? Sounds like it is not if you are getting knock at 15 pounds. If you are getting knock, how much? First upgrade I would do is a hotwire and fuel pump upgrade from Caspers, Racetronixs, Fullthrottlespeed, or Ebay. Cost less than $150. Make sure it is a Walboro 340 or equivilant. Check all fuel and vacuum lines and replace (these will kill your motor). Replace your PCV valve. Check all grounds and plug wires. These things must be running perfect to run right. If the turbo is smoking, rebuild it or replace. The next upgrade should be an Alcohol injection kit. New about $500, used from $200. Best upgrade I have! You can find all kind of info at:
www.turbobuick.com and www.turbobuicks.com and www.gnttype.org

Welcome to the world of Turbo Buicks!

[killahertz]

sorry it has been so long since i got back to you guys been real busy trying to change jobs and all and it is a long process. thanks guys, it was vacum hose. i put some synthetic oil in it, changed the vacum hose ran pretty good. have not had the time to play with it. still missing tho and rough idle. i checked the wires and saw i was getting dull fire on rear two so looks like coil pack is going to be needed too.still have a few more hoses to replace as well and the syn let me know about a leak on the rear seal. car is 27900 miles on it and has sat most of its life. all stock i think can't tell yet, stock boost guage goes way red real fast no knock tho, and the fuel pump is not real quite, clues maybe we will have to see. ill get back with you when i put boost guage some wires, plugs and a new pak. o and if i can squeez a airflow meter or a tuning tool in thier i will. thanks for your help

thanks for the welcome