Here you go: Stock vs 200 cell cats. The car is supercharged and this was a tune we had 2 years ago.

 

Well, that answers the question of whether they increase RWHP on a SC Aston.

 

Agreed Mark.

rmrmd-Was the ECU touched during the addition of the new CATs? I am curious if they altered it for the CATs.

 

ECU not touched between these runs but A/F ratio changed due to exhaust restrictions. Initially I was running Larini CATs then changed back to stock because of frequent CELs. That was the time I did those runs.

 

I'm confused, I thought you were running ours now?

 

I think what he means is that he removed the Larini cats and did a run with the stock cats (for his "stock run") before adding the RSC cats, then did another run to see the difference.

 

I think you can achieve a reasonable approximation of what to expect on a NA Vantage from this information. The gain of just under 24RWHP works out to about 28.7BHP assuming about 20% drivetrain loss, which is consistent with the loss on most of the dynos I have seen.

A bone stock 4.3L Vantage making 304RWHP is making 62.5% of the output of this SC car. That percentage of the same realized gain yields 17.9BHP on that car. A lot of mods are cumulative/synergistic rather than arithmetic 'add-ons', so you would probably see slightly better results from a car which has been ECU remapped, exhaust, filters etc. than from a standalone mod of just cats. For example, if a car had been remapped to say, 405BHP it should see just over 19BHP using the same formula.

 

Hmmm...I don't know. I think with forced induction the benefits are exponential better, not linear.

 

I would agree here. I guess no one has done a dyno to see what the cats do before and after except for my dealer. Too much guess work here.