Spectre Intake: boxes on the doorstep

Boxes arrived with the Spectre Performance intake system for the Cadillac STS-V LC3 4.4L Supercharged V8 today (Monday).   Sorry for the camera phone pics, but grabbed the snap while bringing my Wife home and running back to my next appointment.

Spectre Performance Intake

Spectre Performance Intake

The system is offered in two parts, the ‘bottom’ end from MAF to filter (?) and the ‘top’ end from throttle body to MAF.  I ordered both parts, so two boxes from StreetSideAuto.

Friday is the dyno/install/dyno test day at True Street Motorsports in McKinney.

@Cadillac STS-V Supercharger & Intercooler Ideas #Motorama

The Cadillac STS-V (2006-2009) featured the 4.4L DOHC VVT LC3 V8 with a custom Eaton M122 Supercharger and integrated intercooler.

This photo shows the Cadillac LC3 engine without the ‘beauty cover’, looking from the rear of the engine — so the front of the Cadillac would be right and away.

Air flows in the black tubes at the top of the engine to the ‘back’ of the engine, and into the supercharger.  Note the noise baffles in the intake tubing intended to isolate the whine of the supercharger.

This view is of the supercharger+intercooler from the back:


and the next view is the reverse angle or ‘front facing’ shot of the coolant in/out tubes flowing to the intercooler (black part).  The ‘snout’ is the drive for the supercharger.  A belt runs from a pulley below to turn the Supercharger, pressurizing the incoming air.

Once you open and separate the supercharger and intercooler they look like this — note the intercooler is flipped upside down here, as if you simply removed it by ‘opening it up’:

STS-V Intercooler removed from Supercharger

The intercooler is an air to water system, and features Laminova laminar flow heat exchange tubes.

The air flows into the back of the supercharger through the long intake.  Then it is pumped up from the center of the supercharger through the intercooler past the Laminova tubes, and then it flows down the sides of the intercooler casing and the supercharger casing and into the engine.

Each of the four Laminova tubes look like this up close:

Laminova STS-V Intercooler Tubes

The science of the Laminova design is to create huge surface area with minimal air flow restriction.  The very thin fins, 0.2 mm each, along each Laminova tube collect the heat from the air passing through the 0.3 mm gaps between the fins.  The surface area presented to the air flow is approximately 5 times greater than a conventional plate-style intercooler according to Laminova, as well as reducing noise and pulsation.

The heat is conducted to channels surrounding the solid core of each Laminova tube, where liquid coolant is passing through to remove it.

It appears that the coolant flows into the intercooler, circulates through all 4 Laminova intercooler tubes, and then flows back to the intercooler heat exchanger.  The heat exchanger is like a small radiator.  The intercooler coolant system is completely separate from the engine cooling system/radiator.

The advantage of the Laminova design is that they have a very good efficiency with low pressure disruption and light weight.   A disadvantage is cost.

The CTS-V LSA engine uses a finned box air to water intercooler:

This shot shows the CTS-V LSA intercooler upside down.

How can the STS-V intercooler be improved?

An interesting ‘science project’ for the STS-V intercooler would be to replace the intercooler endcaps that direct coolant flow through one Laminova core after another with a custom endcap that directed coolant flow in parallel with all 4 Laminova cores and out after one pass.

One expert mentions that it is helpful to ‘index’ the 4 Laminova cores, so that the large fins are facing the air flow.  I am not clear looking at the images what is intended, as the Laminova cores appear to be uniform and symmetrical, unless the intent is to rotate the ‘sleeves’ the cores are contained in?

Owners are also experimenting with larger heat exchangers at the other end of the system, larger fluid reservoirs to allow more fluid to circulate and absorb heat, and higher capacity intercooler coolant pumps to circulate fluid.

On the slots that allow flow across the Laminova tubes, are the cross-pieces structurally needed?  If removed, so that the slots were just continuous single slots — flow would be increased.

Do you see other avenues to explore?


Aftermarket Cadillac Modifications: Power

Once you purchase a pre-packaged sport tuned V-Series Cadillac, has the Factory pushed the vehicle as far as it can go, or is there some left on the table?  Is there anything else that could be done to these V-Series Cadillacs that would make them faster?

In a word, YES.  Like most tuning however, it is very good to start with a goal usage and power level in mind, and tune to those goals.  A classic hot-rodding question is: How much money do you have, and how fast do you want to go?

First of all, it depends on which V-Series Cadillac you focus on.  The STS-V and XLR-V have more in common with each other than the 2004-2007 CTS-V or the 2009+ CTS-V.

The STS-V and XLR-V are powered by the LC3 Supercharged 4.4L Northstar and make 440-469 hp stock depending on the model.

The 2004-2005 CTS-V was powered by the 5.7L V8 LS6 engine making 400 hp.

The 2006-2007 CTS-V was powered by the 6.0L V8 LS2 engine making 400 hp.

The newest V, the 2009+ CTS-V is powered by the Supercharged and Intercooled 6.2L V8 LSA engine making 556 hp.

LC3 4.4L Supercharged Northstar Tuning

For the STS-V and XLR-V the aftermarket offers re-tuning / re-calibration of the computer, cold air intakes, and performance exhausts.  Together these can net around 40 RWHP, or rear wheel horsepower.

LS6 or LS2 V8 Tuning (~400hp stock)

There is a rich suite of tuning options available for the LS6 or LS2, because they share a great deal of aftermarket development with ongoing LSx performance engine development.

Best bang for the buck items include:

  • Cam shaft — best done along with ported heads.  Cam/heads can add as much as 90 hp at the crankshaft for $2500 plus installation
  • Headers — long tube headers will cost around $1600 and add 20-30 RWHP
  • Supercharger — around 140 RWHP for US$6-7K
  • Dyno Tuning — results vary based on the other modifications on the vehicle, but give the best opportunity for gains from modifications.  Some level of custom tuning will be required with most changes.
  • LS7 Conversion — replace the LS2 or LS6 with a 505hp LS7
  • L92 heads / L76 Intake — To make the LS3 engine GM added the L92 heads to the LS2, so this is a known power combo. The 4.00-inch bore of the LS2 enables it to use LS1/LS6 heads, as well as L92-style heads (including LS3, LS9 and LSA engines).  The L76 intake allows the combo to fit under the hood.  For confusion, the L94 Engine in the current Escalade is an updated variant of the L92.

As an aside, not all adders are additive.  So while you might see 25 hp from adder A and 20 hp from Adder B on a stock setup, you might only reach +30hp from both together.

Second, to some extent a Supercharger works by “forcing” better breathing.  So if you plan to get a Supercharger, I would start with that.  If you want to stay all-motor, go with cam and heads and headers which all act to free up the engine’s breathing.

LSA Supercharged V8 Tuning (556 hp stock)

The LSA engine can be considered a Supercharged LS3 engine, with a steel crankshaft.  The LSA has rectangular port heads like the LS9 or L92 (Escalade engine) instead of Cathedral port heads like the LS2.  The rectangular port heads in the LSA flow a bit better than the cathedral port heads in the LS2.

Although the Supercharged LSA V8 is relatively new, the aftermarket offers include:

  • New supercharger snout to raise boost: with tuning around +74 hp for $2,500.
  • Dyno Tuning
  • Upgrade to the LS9’s Supercharger – Complete packages that include tuning, exhaust quote up to 700 hp, so +150 hp.
  • Upgrade the engine to the LS9:  The LS9 engine makes 638 hp stock.  LS9 Engine around $22K, so pricey
  • Headers with Tuning can produce around 50 RWHP for $2K
  • L92 Heads and Cam package – around 70 RWHP for $2,500 plus installation
  • Cold Air Induction kit

Cadillac Tuner pages: