Maybe someone out there knows the answer to this one.
The L69 in the SS was rated at 180hp/225tq while the same engine in a Z28 was rated at 190hp/240tq. GM shows a different PROM for each car (both with AT and 3.73's). If the ratings are right for each car maybe the PROM's make the difference. Any thoughts?
Larry.

 

A glance at the air cleaner might yield a clue

 

Yeh that and maybe the electric fan contributes too. Anybody got an old '85 Z28 L69 PROM they'd like to get rid of? Might be interesting to compare the two.

 

Yea, in some models, with the same engine the Camaro had about 5 more HP than the Firebird due to the air cleaner.. The later 350 TPI engines had 235hp in the Camaro and 230 in the Firebird.

The Camaro drew cold air from the front of the hood.. Because of the lower hood line and aerodynamic snout, the 'Bird couldn't do this and instead it had a long plastic duct with two 90 degree bends going to a round cannister tucked inside the engine bay near the right fender.

 

I guess I am lost, I did not know there was a SS third Gen

John

 

Monte Carlo SS

 

ok, I did not read far enough to the left to see his Vehicle information, my bad.

John

 

What would the effect be if you put an L69 prom chip into an LG4 ?

 

one problem you would have is that the LG4 does not have a knock sensor (at least early ones did not). The L69 computer uses this sensor to aide in having a more aggressive timing curve.

 

I believe both the 86 & 87 LG4 had the knock sensor. My 87 did for sure.

John

 

Perhaps Exhaust Size and bents make a difference.

I heard that GM had quoted that was the difference in the HP in the Camaro LS1 and the Corvette LS1.

Later, Garrett