87TAairlineyard

After 11 years, I finally got around to buying the Trans Am I always wanted- 1987 TA with the 5.0L TPI V8, automatic, t-tops, WS6; the works. I have a question concerning the horsepower ratings given for the 5.0L TPI. I understand that in 1987 they were rated 190 hp with the automatic, 205 with the 5 speed stick. However, in 1986 all TPI engines were rated 210 hp, which was the horsepower rating for the newly introduced 5.7L in 1987. My question is: are there really any differences between an 86 5.0L TPI and an 87 TPI that would account for the 20 horsepower reduction? Was there a real change in the engine or was this simply GM's way of fiddling with the horsepower figures so that the 5.7 L would fit into the marketing program? We all know how they underrated the 5.7L to not get too close to the Corvette's claimed 230 hp. Is it possible that GM "downgraded" the 5.0L to make room for the 5.7L?

In an unrelated question, I was going through my build sheet the other day and realized that my car, although a WS6, has rear drum brakes, not four wheel discs. I thought all WS6 cars had four wheel disc brakes standard.

urbanhunter44

iTrader: (3)

I know in 85 the LB9 got the L98 cam and made 215 hp, then in '86 it got the peanut cam and made 190.

in 87 the hotter cam returned to the LB9 but was only available with a stick combo. In an auto it was still the smaller cam.

And no, 4 wheel disk wasnt standard with WS6 from what I've seen.

ajmclean

may be the chnaged the cam to meet emission control regulations,

and in 1987 the 305 was 190 for auto and most of them were autos so it was a big difference from
350 TPI whichwas rated at 225hp ,but the 350 TPI difference
from "manual 305 TPI" was in torque,which was 330 compared to 295 in 305

in 1987 the 4 discs where optional in camaro iroc-z28 unlike
previous years, but i think the same goes for the WS6 trans-am
but im not sure about that

Guest

They're all numbers out of a hat anyway. Rest assured though that its not much by today's standards.

If you have an auto, you need to plan on changing the cam sometime in the future. Its small.

In 86 the rear discs became an option that WS6 didnt necessarily come with.

89IrocZ350TPI

85 was rated at 215, 86 models got the lg4 cam yuck! -25 hp