dfw

**Doug1227** · 07-24-2013, 09:08 PM

YES, a centri isn't getting any cooling effect when not moving, but it's also not generating any real heat like a PD. Granted that the centri isn't cooling anything in the lanes, but neither is the PD. Fluid is circulating, but there's no air movement across the heat exchanger, so the fluid just gets hotter and hotter (heat soak). Heat soak is going to be much more prominent on a PD car than a centri. At least on the centri it starts cooling as you go down the track and you're essentially starting with ambient. On a PD, you're circulating hot ass water as you go down the track! LOL! I've had both and I think a PD makes a LOT more heat, both on the street and the track.

Edit: Obviously, a PD with an A/W with fans, huge reservoir, bag of ice, etc. will cool better, but that's not what ANY of them come with from the manufacturers, so that's a moot point. I'm talking about how they come in the kits.

**TrueStreetMotorSports.com** · 07-25-2013, 12:56 AM

Originally Posted by Doug1227

At least on the centri it starts cooling as you go down the track and you're essentially starting with ambient.

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Not correct, when the pass/race starts you will start to get fresh air across the intercooler but you are in boost heat is even greater from that point on. There is no intercooler, watercooler on the market that will cool off to ambient temps once boost starts. Once in boost Intake air temps will continue to heat up until there is no boost present and air flow is run across the intercooler water or air to air for a giving amount of time.

**KungFuHamster** · 07-25-2013, 10:15 AM

my vortech car ET'ed and MPH'ed the same pass after pass with minimal cool down and no intercooler (on a 2V car 10 years ago). thats centrifugal efficiency.

so if the A/W is so much more efficient, then why do all the factory PD blower cars heat soak so much? the water is still circulating. but once the water heats up, then it can't absorb anymore heat. its the same as the A/A car sitting there with no air flowing over it. I watched a Cadillac CTS-V lose .4 and 7 mph due to heat soak on his 2nd pass. The car was down on power the whole time we were at the track due to heat soak. We all know this...terminators, lightnings, ZL1, etc.

The centrifugals are the more efficient blowers, and while the twin screws are more efficient than the roots and TVS blowers, they still generate more heat per lb of boost. it's always been that way.