27/11/2006
The big water tank experiment - Part Two
Regular viewers will recall the original big water tank experiment which provided some entertainment for Croyde and Myself but failed to produce any worthwhile technical data. Now armed with a more powerful water pump and more efficient chargecooler it was time to have another look.I've created a whole page, as i'm going to document all the pump information that i've collected over the years also.
For all these experiments the system was laid out like so: watertank-->waterpump-->pre-rads-->tempprobe-->chargecooler-->return
Existing Pump flow rates.
I scored a cheap vane style pump from ebay of undetermined age, specification and origin - so first step was to measure and compare its flow rate to my existing Bosch Pump (part no 0 130 002 066) which is used on the Cyclones and Typhoons i believe).
I just timed how long it took to pump water from a tank into a watering can - both free flow and also through the cooler and radiators.
Results
| Free Flow Lpm | Plumbed Flow Lpm | Free Flow Gpm | Plumbed Flow Gpm | Flow loss when plumbed | |
| Bosch Centrifugal Pump | 13 | 7.5 | 2.9 | 1.6 | 43% |
| Vane Type Pump | 20 | 13 | 4.4 | 2.9 | 33% |
Results from Varying the amount of water in a charge cooler system
The results are fairly conclusive with the exception of the existing setup (no extra water - the yellow line) - because this datalog was taken on a day with higher ambient temperatures. I estimate it would of been about 38'c at the end if done on the same day. Using a probe in the water circuit I also calculated and datalogged the chargecooler efficiency, which was around 71% (the overall, air to air figure is lower - usually around 60%)The tests were carried at an ambient temperature of 10'c. The graphs are all taken from logs where the starting temperature and boost duration were the same.
The Green and Blue lines show the comparison between 10 and 20 Litres of water, there is a slight benefit - but not really enough to justify the extra weight.
The Red line is a trace taken with the chargecooler pump switched off - this proves that the chargecooler works - which is nice considering I designed and built this thing from scratch. The car felt more sluggish to drive when i took this log.
The dotted grey line is the turbo outlet temperature, so you can see with no intercooler - your air inlet temp is the same as the turbo outlet (well nearly).
Got heatsoak?
Here's an interesting graph. I had 2 gallons of water and just restarted the car after filling up with petrol.(Click to open in new window)
We see the Red Manifold Inlet Temperature is at 50'c from heatsoak during shutdown. The chargecooler water (white) rapidly rises from 9'c peaking at 24'c after 30 seconds, at the same time the Manifold air temp then comes back down ending at 30c after 50 seconds elapsed time. I know that the pump moves 13 Litres of water in 1 minute and I had 20 Litres on-board in the tank, so I can deduce that the temperature reduction after startup was purely as a result of pumping cold water from the tank, rather than any air moment through the front of the car - something that an intercooler cant do (wahoo!- found a benefit at last..)
Choosing a Chargecooler water pump
So potentially having a faster / more powerful pump could improve things. One school of thought is that by pumping the water slower, it has longer to cool down in the pre-radiators. But i have a theory that pumping a far higher quantity of water will make better use of all the fins both in the radiator and cooler, in other words i believe there's not enough flow to force the water down all of the passages - thereby wasting opportunity to transfer heat.so what pump should you use ? What flow rate? - Here's a selection from my research, my current choice would be the Jabsco 50830. Owners of the Chargecooler equipped Lotus Esprit with its mechanically driven impeller pump may also find my research useful.
Jabsco
I've done quite a bit of searching over the last few years and the one that always gets suggested is the Jabsco Centripuppy Partnumber 18510-0000 or 18510-0021 depending of wether you elect for lip seal or more durable "carbon ceramic seal" which allows higher water temps which i think is unnecessary - my water stays below 30'c.
This pump flows 45L/min which is a huge amount in comparison to my two pumps tested above. Turbonetics used to recommend this pump, stating that it will provide "6-8GPM at the waterside head pressure" found on their coolers. Now, I assume they are talking US gallons, so that equates to 26-35 L/Min - which would indicate a "head" of about 2.5M.
So far so good, but i discovered that the pump is no longer made and is replaced by one of two newer pumps called the Jabsco Cyclone 58030 / 58070 series, there's two styles high and low pressure.
Grainger Pump
Another pump that i've seen suggested is the Grainger 4P062, which is similar to Jabsco pumps - performance wise it sits between the centripuppy and cyclone pumps
Johnson Centrifugal Circulation Pumps
These Centrifugal pumps are potential candidates, the CM10 flows 15L/Min , the CM30 flows 18L/Min and the C090 flows 100L/Min all at 0.1 Bar (1.45psi). The C090 has 38mm hose ports, so way too big. The two smaller ones flow similar to the Grainger pump at the specified pressure. Doesn't come close to the Jabsco unit though.
Johnson Impeller Pumps
The Impeller pumps manage sustained flow rates at higher pressure - although like the Jabsco Waterpuppy (Not the Centripuppy) - flexible impeller pumps are too noisy (the cheap one i bought is an impeller pump - sounds like a washing machine)
LVM Brushless
This is the pump usually supplied on Pace Products Chargecoolers.Pretty weedy in my opinion, at 1.2M head (1.7psi) its completely stalled - whereas a Jabsco is barely breaking a sweat and pumping about 100L/Min
Bosch PCA 12v
Here's a popular Chargecooler pump, Its used as OEM on the Ford F150 Lightning . Several other people sell and recommend them for chargecooler circulation. Lingerfelter use them on their a/w systems. The Bosch part number is 0 392 022 002 and its about £120 in the UK. This flows about half what the Jabsco Cyclone produces and now I cant decide which one to get (they are priced similarly)This is the same pump that is used on the Wortec chargcooler kit used on the the Holden Monaro.
