HI,
I just recently bought an '87 Regal T-type (the blacked out version -- someone told me it was a "WE4"). I did the following modifications:
ATR 3" exhaust including 3" downpipe (fitting the stock wastegate)
Adjustable wastegate control-- boost set at ~ 18 to 19 psi
Installed new boost and fuel pressure gauge
Oversized fuel pump
Grossly oversized injectors
K&N air filter for stock air intake
Installed fuel pressure regulator
Red Armstrong 93 octane chip
Here's the problem: the car screams at the low end (it's nearly impossible to grab the road even with wider street tires -- wants to smoke rubber even into the 30-40 mph range) but at speeds above 55 mph or so the power and response tapers off drastically. At these higher speeds, pedal response is only practical up to about one-quarter of the way to the floor. After that I might as well be pressing my foot on a sponge. I have a hunch the problem is something elusive like a malfunctioning sensor or a misadjusted component. Any suggestions or insights would be hugely appreciated.