Category Archives: Cadillac Performance Mods

Cadillac Performance modifications

Cadillac STS-V RX Performance Products Intercooler Tank Project

Posted on by
2

I have been exchanging fitment photos and details with RX Performance Products in Florida regarding a variant of their new Cadillac CTS-V intercooler expansion tank for the Cadillac STS-V.

Cadillac CTS-V supercharger expansion tank from RX Performance Products Image by RX Performance Products

On the Cadillac CTS-V and the Cadillac STS-V there is an air escape (bleed) from the intercooler coolant system at a Tee-fitting, and this is where coolant may be added to the system when needed.  The idea RX Performance Products has had is to replace the T-fitting with a small tank and fittings.  This part of the intercooler coolant flow is on a ‘side-track’ to the main coolant loop.  If the intercooler coolant pump can’t pull fluid from its normal intake, for example when there is air in the system, it can pull coolant down this side-track and the air can escape up the side-track.

STS-V T-fitting fill tube

When one does need to add coolant to the system, the T-fitting tube will only accept a tube full, or under a pint of fluid.  Once the intercooler pump pulls that into the system you can add a bit more, rinse, repeat.  Each time even with a funnel there is some spillage during the add process.

With the small tank — the CTS-V tank is 1 quart– it will be easier to add fluid, and “overfill” the system a bit so that as the system does bleed air there is plenty of coolant to replace it.

The CTS-V T fitting is slightly different from the STS-V T-fitting; the CTS-V one has the same size in and out flow fittings, while the STS-V has a larger in than out.

I have emailed images along to RX Performance Products of my STS-V engine bay with various measures in order to help them to fab a tank for the STS-V.   In this photo I cut a granola box to 4″ x 4″ x 10.5″ to try to model what size tank might fit under the strut brace on the STS-V where the T-fitting is.

RX Performance Products
2200 US Hwy 301N
Ste 6
Palmetto, FL 34221

Based on the pictures and measurements we are hoping to size a tank for the STS-V similar to the CTS-V tank.  Stay Tuned.

Cadillac STS-V Intercooler cooling – gathering more parts

Posted on by
3

Tim C keeps working on his STS-V — he has done a turbo kit then returned it to stock at this point.  His product offerings include a front mounted heat exchanger, an upper supercharger pulley service, and a new product on the way, a cold air intake.  He has a new website coming for sales and info; stay tuned.

As the next experiment in my intercooler cooling quest I have decided to try the ZZP S3 front mounted heat exchanger.

ZZP S3 Intercooler Front-Mounted Heat Exchanger

Here is the ZZP info on this part:

Intercooler heat exchanger (radiator) for your liquid to air intercooler system. This HE is the largest most well thought out radiator we’ve produced to date. With a 1.8 liter fluid capacity, it holds more liquid than any HE in the Redline/Cobalt market and with 4000 sqare inches of fin area it cools better than anything currently available!

  • All aluminum construction
  • Drill 4 holes into existing bumper support
  • Overall measurements of 32.5×6.5×2.25
  • Core measurements of 28×6.5×2.25
  • 2 row, dual pass
  • Maximum cooling, minimum weight, fully tig welded and pressure tested
  • 2 stainless bolts and nuts
  • Includes 2 fittings and 4 hose clamps
  • 49″ of 3/4″ hose
  • 6.4 pounds

Here is a link to a tech article ZZP did on the S3 comparing to OEM and a competitor.  Their conclusion was that almost any 2nd HX works about the same, but it is a nice write-up nonetheless.

A different popular choice would be the Frozen Boost 101, but I really like the ZZP info and research, and I like that Tim is doing so much experimentation on what works for these cars, so I would like to test out the S3 on my STS-V.

I’ll have to decide whether to put the OEM HX back in and then use the S3, or stay with the 45321 and S3.  Best would be to test each set, but I am not sure I am up for those installs; we’ll see.

My current tests suggested the system is at a higher equilibrium temperature with the 45321 than it was with the OEM HX.  This week I am continuing to monitor the fluid level and then hope to retest after it has burped air for the week.

Initial IAT2 times with New HX – woops

Posted on by
11

Initial IAT2 trends with the new Intercooler Heat Exchanger appear to be somewhat worse than the OEM intercooler heat exchanger.

This is disappointing since tuners have reported improvements with similar heat exchangers.  There may be more variables at play here, but my first tests suggest the new HX as installed is not performing better than the OEM HX.

To compare the two I considered HP Tuners VCM Scanner data captures for the OEM heat exchanger on a hot day (heat soaked) to a similar run with my replacement heat exchanger (a flexalite 45321).  IAT1 temps, which is air at the MAF, were similar for each run, but the runs were certainly on different days etc.  Thanks to HP Tuners for updating their comma delimited export capability to make this easier!

The first chart shows overall trend over time for my normal data capture run.  The spikes are acceleration runs.  The X axis is actually the sample time for the scan, which runs from 0-65K so I simply left it off for clarity.  The Y axis is IAT2 temps in degrees F.

 

The new HX appears to reach constant IAT2 around 127F.  The OEM HX reached constant IAT2 around 117F.

This is a comparison side by side over time during a 0-60 mph run with each:

The OEM HX starts at a lower temp, but the two HX’s appear to show similar trends for the expected increase in IAT2’s during hard acceleration.

It is possible that the system is still not air-free, and I will retest after a week of continued monitoring.