Factory Horse Power rating..how accurate?

[ANDYS87]

I recently purchased an '87 Grand National. I know they are factory rated at 245HP. This seems a little low. Did the factory purposely under-rate them for insurance reasons? Didn't a car mag do a test on a stock 87 GN and reported that the actual HP is more like 275??? Just curious......Any info is appreciated

 

[V6POWER]

I think 275 is closer to actual than 245. I have heard they were advertised lower because they didn't want to out do the Corvette.

 

[gbsean]

rear wheel or flywheel hp rating.

 

[Turbo6inKY]

The 1989 TTA engine made 301 on Pontiac's engine dyno. Only significant differences between that one and the '87 Regal's engine was the chip and a slightly better intercooler.

 

[Jerryl]

The heads are also different. The TTA heads have better flow numbers. I will leave it to the experts to chime in with history, or, you can do a search on that.

While the HP ratings were understated, I belief that some underestimate the "Torque" relevance. HP is a GREAT advertising tool but, torque will get you off the line.
I realize you need HP on the top end, but that is just a calculation of Torque anyway. IHMO, the low RPM high torque numbers are what make these cars so potent on the street / stoplight racing. No, I am NOT advocating street racing ………….. DANG, this hole is getting deep …………….. LOL

 

[ANDYS87]

I think the factory measures HP at the flywheel??? That is what I am interested in. Just so i can brag to my friends!

 

[Jerryl]

Why brag when you can have a sleeper? (joke)

 

[scottyb]

Ringer??

 

[XLR8]

Originally posted by Jerryl
Why brag when you can have a sleeper? (joke)

I agree.
I tell people at the track is's just a 235 HP V-6.