Repeating Cadillac STS-V Intercooler HX Tests

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I went back to rerun the test on the new Intercooler Heat Exchanger (Flexalite 45321) for confirmation of the original test, Initial IAT2 times with New HX – woops

Here was the test data from that test, suggesting the new HX is not as effective as the original:

My method plan was to rerun the test this weekend after the car has had a week to work the air out of the intercooler loop.

Current configuration:  Flexalite 45321 heat exchanger in the place of the OEM radiator type heat exchanger, no other heat exchanger in the circuit, no inline tank added.

What I found today was that the intercooler IAT2 temp never got below 131F, which is worse than the baseline above.  Unfortunately, test1 today I fumbled the mouse at the end of the test and lost all the test data by accidentally closing VCM Scanner (doh).  The STS-V was heat soaked before the test, starting at 156F for the IAT2, and was able to cool down to 131F and was still dropping slightly on highway runs.  But it was not getting to a steady state of under 120F as the OEM did.

I also got the impression there is some interplay between A/C on or off and intercooler IAT2 temps although I am not clear why.  My intuition is that A/C on would run the radiator fans and improve air flow and so lower IAT2, but on the ‘back’ of the loop where I normally do acceleration runs, I noted that when I turned off the A/C the IAT2s fell 5F quickly.

Now I’m not worried about performance runs for the STS-V when heat-soaked, but this does give us a way to test the efficiency of the intercooler cooling system, since it is presented with the greatest heat load.

After a break I’ll get back on to test2 and try to bring back a data stream this time!  Stay tuned.

UPDATE

Okay, refueled and reran the test loop.  I have added the retest new HX data to the previous data table.  I have also added in some data lines from Jaimie’s STS-V.  Jaime has an 07 STS-V with the 45321 HX in place of the OEM, a Frozen Boost front-mounted heat exchanger, and he has an aftermarket intercooler pump instead of the OEM pump.

Retest of New HX appears to confirm previous test

My conclusion is that my config is still running hotter than I want.  My plan is to return to the OEM intercooler heat exchanger, and add a new ZZP S3 front mounted heat exchanger under the bumper in series with the OEM hx.  So, another install weekend then hopefully more data.

Also, I found on the retest that the area I was in led to a decrease in the IAT2, not turning the A/C off.  The issue is that there is a zone of cooler air at the top of my test loop due to getting off the highway and I saw a drop in IAT2s in that area with the A/C left on during the retest.

 

Team Cadillac Finishes Second, Fourth in Grand Prix of Utah

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  • O’Connell Leads Pilgrim in Driver Points After Four Races
  • Cadillac Leads Manufacturer’s Points Over Porsche
  • O’Connell Leads 10 laps, Pilgrim Nipped at End for Third

TOOELE, Utah  –  For the first 10 laps of Saturday’s PrivacyStar Utah Grand Prix, it appeared that Team Cadillac had a shot at a third victory in four races.

But in the end, the team had to settle for second and fourth places, plus a solid points day toward the Pirelli World Challenge Series championships.

Johnny O’Connell took advantage of a standing-start stumble by polesitter Patrick Long to jump to the lead, edging out a gaggle of cars at the entrance to the super-fast Turn 1. For the next 10 laps, the No. 3 Cadillac CTS-V Coupe driven by O’Connell led the way around the 3.048-mile Miller Motorsports Park course until Long got close enough to challenge.

Long dived to the inside into Turn 1 on Lap 11 and completed the pass through the tricky-fast turn complex and raced away to victory.

“It was a really good race with Patrick,” O’Connell said after the race was over. “With us carrying all the weight, I figured out pretty early that he [Long] was just going to try to wear me down, make me use up my tires and then have his way with me. I actually backed my pace off a little to let him get close. I figured eventually he would make a run at me going into Turn 1.”

He did, but was not successful the first time he tried it. Long actually led Lap 7, but O’Connell kept his foot in it and wound up keeping the top spot for another three laps.

“We raced each other super clean, and I think the fans enjoyed watching that,” O’Connell said. “I was just hoping for traffic that never came. You have to give it to them. They were a little bit stronger today, but shoot, with 144 pounds…we were carrying a lot of weight.”

That weight, called REWARDS weight, came from O’Connell winning at St. Petersburg to open the season and finishing second in the second race at St. Pete and third at Long Beach.

Andy Pilgrim, who was carrying 96 pounds after winning at Long Beach, started fourth, lost a spot in the gaggle at the start, and then advanced to third place by Lap 5, chasing O’Connell and Long.

He made up a ton of time through the middle portion as O’Connell and Long battled for the lead, his No. 8 Cadillac CTS-V Coupe shadowing his teammate and looking for opportunities to advance.

But a hard-charging Mike Skeen came from 13th on the grid to fourth place with a handful of laps remaining and passed Pilgrim on the penultimate lap to knock Team Cadillac out of another double- podium finish.

“It was a good race,” Pilgrim said of his battle with Skeen. “I knew [Skeen] was coming; there was nothing I could do. He didn’t have any weight on his car, and we know the Corvette is good. He was really good through the fast corners.”

Pilgrim got a touch loose on the next-to-last lap and Skeen pounced.

“I got a big slide out of Turn 6 and it killed my momentum for that long straight up to Turn 7,” he said. “He got to the inside and there was nothing I could do. He just accelerated faster than I did. I had to let him go. I couldn’t have turned in, and if I had tried to go around the outside I would have just punched right off the track. There’s a lot of stuff on that corner.”

At the end of the day, O’Connell was pragmatic about the result.

“For me it was very difficult, watching my tires and saving some for the end,” he said. “Right now, I am driving as strong if not stronger than I ever have in my career. It was really hard for me to sit back and manage everything, but I was very proud that I was able to do that.”

For Pilgrim, it was a good result, for the big picture, but not the one he was looking for on Saturday.

“I didn’t want top-five, but when you come into one of these races, you want to come away with top-five points if you’re in the championship. That’s all you want.”

Long’s Porsche beat O’Connell to the flag by 3.032 seconds, and Skeen, Pilgrim and David Welch in a Ferrari rounded out the top five. Randy Pobst headed the second five in his Volvo, with the Porsches of Steve Ott, James Sofronas and Madison Snow seventh through ninth. Tony Gaples rounded out the top 10 in another Corvette.

In the points, it was a banner day for Team Cadillac.  O’Connell now leads the World Challenge GT driver’s points by 49 over Pilgrim, 501-452. Sofronas is a distant third with 354, Lawson Aschenbach is fourth with 342 and Pobst is fifth with 333.

In the Manufacturer’s points, Cadillac leads Porsche by 2, 32-30, after four rounds.

Next action for Team Cadillac and the rest of the Pirelli World Challenge Series competitors will be May 10-11, the Cadillac Sports Car Grand Prix at Laguna Seca Raceway in Monterey, Calif.

The Grand Prix of Utah will be telecast on NBC Sports, Sunday, May 27 at 11 p.m. EDT. View live streaming on www.world-challengeTV.com day of races and continuously on demand after races.

The Cadillac Racing Media Kit is now available online.

Cadillac STS-V RX Performance Products Intercooler Tank Project

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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.