Stock Cadillac STS exhaust flow: 308 CFM

Found this interesting info graphic from a Corsa performance ad on a Lingenfelter site:

Corsa vs Stock Exhaust for Corsa 14157


The graphic shown is for the 14157 system versus the stock 2005 Cadillac STS system. This is particularly interesting for the STS-V since this is the same Corsa system that D3 sells for the STS-V.

The text notes: * Flow bench-tested 42.3 gain in exhaust flow vs. stock muffler.

This I read to mean that the graph is for flow through a single Corsa muffler versus a single stock muffler.  So in other words, the dual Corsa mufflers probably flow around 437 x 2 =874 CFM and the stock mufflers flow around 308 x 2 = 616 CFM.  Recall our target is 2.2 CFM/HP for 0 backpressure, so with a modified STS-V making 500 hp plus S/C load we would need 560 hp of exhaust or 560 x 2.2 = 1232 CFM.

I am guessing that the STS-V stock exhaust flow is similar to the STS stock exhaust flow.

We can see from the numbers then that the stock exhaust flow is insufficient, and that the Corsa’s are an improvement, but there is still some margin for further improvement.


Friday Test Drive: 2007 Cadillac STS 1SE

I popped over to a local Cadillac Dealer to look at a low mileage 2007 Cadillac CTS-V that they had:

2007 Cadillac CTS-V

Unfortunately, another couple was just taking it out for a test drive, then heading to negotiations as I arrived, so I missed meeting that Cadillac.

2007 Cadillac STS 1SE

Meanwhile, I spotted a 2007 Cadillac STS 1SE on the lot with 42k miles.  The 2007 STS has the 320 hp Northstar 4.6L V8 with variable valve timing.  The 1SE designation means that this is a V8 Luxury model, and not the 1SG Performance Model.  These have to be taken as you find them however, because they can be optioned up quite closely to the 1SG.  The feature that the 1SG has that these don’t get is the MR magnetic suspension.  This one has the Navigation with Premium sound system, and Sunroof so it is a reasonably well equipped example.

I have been shopping around between the 2007 CTS-V, the 2008 STS-V, and the 2009 STS Platinum or STS 1SG models.  I wanted to test drive this Cadillac because it models very closely how one might expect the 2009 STS Platinum or 1SG to drive.  Same engine, same transmission, same vehicle except for some option differences and year differences.  This example was Light Platinum exterior, ebony interior.  The dealer has it on the net for $25K.

2007 Cadillac STS 1SE interior with Nav

We took the 2007 STS 1SE out for a test drive, and up on the Tollway for a bit.  In general it felt strong, but not really better performance than my 2005 CTS 3.6L with CAI & Corsa Catback.  Now since my CTS and this STS have similar 0-60 mph performance that was not surprising, but it does confirm the armchair prediction.  The interior features are good on this car, and the car looked good.  The STS received a redesign that improved the exterior styling in 2008, so I would definitely shop for a 2008+ model however.

After driving this STS my feeling is that I will now exclude the STS V8 1SG from my shopping list, and focus on the 08/09 STS-V, or hold out another year for the prices of the 2009 CTS-V sedans to fall closer to my budget.  I suppose a 2009 STS Platinum might be interesting, but is unlikely to fall to my price range.  The STS 4.6L V8 became interesting because I see that they are in my price range.   They are great cars, and offer very good performance.  I really want my next Cadillac to have break-away performance however, so I’ll have to look for the rare 2008 STS-V at a bargain or wait for the 2009 CTS-V to come into range.