CaddyInfo Cadillac Chat 2015-09-17



  • Platform names
  • Cadillac XT5 — Does Cadillac need a high performance Battery electric vehicle Tesla Competitor?
  • Intercooler coolant temperature control
  • Programming VVT on the Cadillac LC3

After the chat I redid the analysis of cd 0.31 vs cd 0.33 and determined only 1 whp delta, but playing with loading different profiles showed me something was wrong with my default profile.  Here is a comparison showing Tune 6F if the XLR was 0.31 vs 0.33 cd:


xlr comparison of different CD 031 vs 033

What we see here is the Tune 6F at 0.31 coefficient of drag in red, and the same data except CD 0.33 in Blue.  The blue is 1 whp better.  All other setting identical.

Note that with the profile fix or re-ordering, Tune 6F is now registering at 252 whp not 241 whp with the previous default profile.  Unfortunately, now that I reloaded the profiles to get the CD test to work, I can’t ‘go back’ to the broken default profile to understand what was different about it.

Additionally, I created this graph to compare Virtual Dyno output to calculated torque & hp:

XLR Tune 6F Compare Calc HP to VDyno Output corr

The blue and red lines are the calculated torque and hp. The high yellow line is the corrected hp for atmospheric conditions.  The orange and light blue lines are the virtual dyno w-torque and whp.  The Green line is the Virtual Dyno line with a factor applied to move it up to the calculated hp.  The green line is a smoothed line (average of averaged of values) but appears to be a good fit for the calculated hp curve.  This surprises me as I was thinking that the virtual dyno and the calculated hp frequently do not follow one another based off of the detailed data.

There is still some additional losses in both sets of data from running the test in 2nd gear instead of a 1:1 gear.  The XLR doesn’t have a perfect 1:1 gear, but testing in 2nd is a trade between smooth data, safe testing, and mechanical losses.


Nordic Ice and the AVS Intercooler Tank

We receive some meds packed in thermal blankets with Nordic Ice gel packs tucked in to keep them cold.  “freeze and re-use as long-lasting ice packs” they say.  I have a hot intercooler coolant system (most any day).  What happens if we put these two ideas together?


In my intercooler system, coolant flow up from the pump to the intercooler, then down to a heat exchanger, through a reservoir, another heat exchanger, and back to the pump.  Almost none of the system is accessible with the nose of the V in place.

However, if I remove the engine covers and gently pry back the air guides, I can just slot in Nordic ice bags on the AVS aluminum coolant tank.


I had extras so I put them near the filter to try to provide some local A/C.

temps over time

The yellow line is ambient temp in the driveway — yes 100F here in Texas.  The blue line is air into the engine intake — around 120F.  The Red line we would like to see go down to below 100F (wishes).  What we see is that it falls from 148F to a flat steady 138F and stays there regardless of the iced tank.


I did discover that there was radiator air leaking into the filter area near a joined metal location and applied a seal there to block hot air coming to the filter.


The test was not ideal, as no air was flowing over the two heat exchangers since the V was sitting with the engine running in the driveway.  I was hesitant to drive with the Nordic Ice packs just loosely stacked on the AVS tank.  However, I could in a future test add a fan over the heat exchangers.

It would be great to engineer a system to allow ‘transfusion’ of cold intercooler coolant into the system when heat soaked and thus restore it to cold temps for testing.

Meziere 55 gpm intercooler pump?

Meziere 55 gpm intercooler pump sounds even more pumped up than the Jabsco 29 gpm pump.  Torq has a kit for the Camaro ZL1 with the pump mounted to a bracket and ready to bolt in for that app.  They have been doing test and just announced the kit on Camaro5.

Meziere 55 gpm pump

Meziere 55 gpm pump with bracket and wiring

After getting my Jabsco pump experiment together I appreciate that Torq is offering a complete ready to install kit for the ZL1.

The Meziere 55 gpm intercooler pump would be a remote mounted 12v pump like the Meziere Enterprises WP365S.

Meziere 55 gpm intercooler pump

Meziere WP365S

I have emailed Meziere to ask for a pump performance curve, not having found one on their website.  The pump performance curve shows measured output of the pump at various system resistance points.  Considering the curve versus the system resistance curve would let us estimate how the pump would flow in an actual intercooler system.

Assuming that the Meziere 55 gpm intercooler pump has a higher shutoff pressure than the Jabsco pump, and a similar pump curve, it should have higher flow.  Lots too many ifs until we can get a pump performance curve, but if I had to guess I would say that it might do 8-9 gpm in a system.  So with my 2 heat exchanger system, and an inline tank, the OEM 8 gpm pump does 3.5 gpm, the Jabsco 29 gpm pump does 4.5 gpm, and the Meziere 55 gpm intercooler pump might do 8-9 gpm.

Keep in mind that as the flow goes up, the pressure goes up more.  These are centrifugal pumps, so as the pressure goes up they have less flow.  By comparing the system curve and the pump curves we can predict the spot where the pump will work, once we have the pump curve.  I’ll update if Meziere shares that spec.

Summary — Meziere 55 gpm intercooler pump

Torq, in concert with Meziere, is offering an intercooler pump upgrade ready-to-install kit for the Camaro ZL1.   In their bench tests the kit was advantageous.   The kit could be modified to work with the Cadillac STS-V or CTS-V.  I have not tested the Meziere 55 gpm intercooler pump to determine exactly how it would flow in our systems.  This is a more expensive pump, although I have not seen a price quote from Torq yet.

Torq main website