I am new to turbo buick web site even though i have owned one of these cars for several years. My 87 gn is great sold 68 camaro race car for it never looked back. I liked it so much i recently purchased a 89 tta. It i dont know about it will not build boost until 3000 rpms unlike my gn at 1800-2200. It detonates under what i consider to be normal boost for my gn about 17-18 pounds. It has almost the exact same mods my gn does but is alot harder to get a handle on. Does a tta have any special electronics or boost control features my gn doesnt. i did the same spring cleaning i did to my gn and even took the chip out of my gn to no avail. The boost will get greater as you go through the gears. Ex 1st 16 pounds at 4800 rpm, 2nd 18 pounds at 4800 rpm, 3rd 20 pounds at 4800 rmps. My buick will stay at what i set it for through all three gears. Any info you guys and gals could give me would be greatly appreciated. thanks in advance
Stetson
Nothing special with the TTA in regards to boost control, etc.
Sounds like maybe fuel system related (for the knock) and I'm guessing the puck isn't sealing on the wastegate correctly, accounting for the slow spool. Also, it could be a bad wastegate solenoid (so you might want to swap the one off the GN for a quick test).
With some scan tool numbers and scenarios, I'm sure we can help you pin stuff down and get it to be as much fun as the GN!
Just went through this with a local TTA. Had a "new" converter, would NOT build any boost, same as original cat. Removed the flex coupling in front of the converter and got 4-5 psi. Uncoupled the entire exhaust from the downpipe and got 18-20 psi!
The TTA exhaust set-up is much different than a GN.
FWIW, my car doesn't like timing. So I run a Thrasher. All the other chips I have will pull timing. I know others don't have problems but mine always has been like this.
Along with exhaust, there is more load on the car because of the high gearing also, 3.27 vs. 3.42.
Thanks for all the great info. my car doesn't have a cat on it but i pulled the dump pipe and now the turbo preasure is steady and not creeping up each gear. It also eliminated the detination because the boost is not soaring in third gear. Now im ready to take it to the track and tweak it out. My car will still not build boost until about 2800 rpms. Any other info you can give me on this matter would be greatly appreciated. Also where do you get thrasher chips?
I would like to look into them i keep hearing great things about them. Ive been running armstrong chip until now. thanks again Stetson