wc engineering electric chargecooling pump?

[SENNA01]

i am getting an esprit s4 and was wondering if it would be a good idea to put an electric chargecooler pump on it,also could anyone tell me if w.c. engineering are good to deal with,thank you

[pitstopete69]

really good guys as far as i have found. that pump is a good flow rate too.
possibly the best safety mod to do to a chargecooled car too.. that is if u actually want it to be chargecooled, not chargewarmed with a knackered slow std. engine driven pump.

[SENNA01]

thanks for the reply!

[Boosted Ls1]

I had twin chargecoolers on a RV8, I used a caravan pump which had 1/2" bores. It was completely reliable and 2 staged depending on my boost levels. Don't know if this helps.

Boosted.

[bojangles]

with the right tools the original pump is very fast to repair. It is not expensive and has a reasonable life span. I dont see any reason to change it as long as you dont run it broken for a long time.

[cross-eyed-twit]

sometimes though it is hard to determine if it has started to fail, ie the blades have degraded and arent flowing as much. Mine stopped working and all it took was supergluing the shaft back into the impeller which was fine. I changed it anyway and the WC pump works a treat. Plus the oem one runs at engine rpm, the electric one runs more at idle. I think.

[lotusespritworld]

www.lotusespritworld.com/EModifications/ElectricChargeCooler.html

[bojangles]

so look at it this way.. the lotus does 0-60 in 5 seconds..
the charge cooler rad is waaaaaaaaaaaaaaaaaaaaaay up front.. there you are at idle.. and the coolant is flowing slowly up front and getting quite cool cuz it spends a lot of time in the rad up front.. and the trickle of cold water makes it back to the chargcooler where little air is going into the motor..... and the cooler is stone cold


then the light turns green..........

you floor it.............

the air rushes into the intake ( which is cold )

there are several litres of extra cold water suddenly rushing from the rad to the chargecooler...
the intake charge is cold cold cold and your boost gauge stays pegged..


NOW for you maintenance adverse.. electric pump guys... hopefully next to me at the light.. your coolant is zooming aound top speed all the time.. even temperature butnot as cold because you are keeping it all at the average temp not the coldest at the chargecooler.. in fact your chargecooler is a few degrees warmer than mine..

the green light...
you floor it.. the chargecooler has the same rush of air.. but no rush of cold water.... your boost gauge drops a hair at the end of second gear..



ANYONE get this point.. ????
BRuce

[Paula&Marcus]

bojangles said:

so look at it this way.. the lotus does 0-60 in 5 seconds.. the charge cooler rad is waaaaaaaaaaaaaaaaaaaaaay up front.. there you are at idle.. and the coolant is flowing slowly up front and getting quite cool cuz it spends a lot of time in the rad up front.. and the trickle of cold water makes it back to the chargcooler where little air is going into the motor..... and the cooler is stone cold then the light turns green.......... you floor it............. the air rushes into the intake ( which is cold ) there are several litres of extra cold water suddenly rushing from the rad to the chargecooler... the intake charge is cold cold cold and your boost gauge stays pegged.. NOW for you maintenance adverse.. electric pump guys... hopefully next to me at the light.. your coolant is zooming aound top speed all the time.. even temperature butnot as cold because you are keeping it all at the average temp not the coldest at the chargecooler.. in fact your chargecooler is a few degrees warmer than mine.. the green light... you floor it.. the chargecooler has the same rush of air.. but no rush of cold water.... your boost gauge drops a hair at the end of second gear.. ANYONE get this point.. ???? BRuce

Hi Bruce,
Many thanks that you pointed this out so clearly. We already discussed this effect on the Yahoo-turboseprit-list some months ago ...

I personally agree with you 100%

The stock pump flow rate is rpm related and therefore it has some benefit vs. the continuous running electric one, IMHO.

BTW, if you do the math (theory of two heat exchangers) the flow rate itself does not affect the cooling power ! The cooling power is only dependent on the efficiency of the two heat exchangers ...
-> slow circulating = long time in rad and also long time in cooler
-> fast circulating = short time in rad and also short time in cooler

You see the pattern ?

Marcus
www.PUKesprit.de

[cross-eyed-twit]

when you are at the lights there is no airflow over either cars radiator there for the amount of cooling it provides is uniform between the two cars albeit from different initial temps. the flow rate is higher from the elec car so the fluid doesn't have a chance to heat up through heat soak through sitting in the engine bay as long and therefor enters at a lower temp albeit not much. I recon the elctric pump helps in that the longer the longer the fluid stays near a heat soaked engine, the hotter it will be and less able to cool the charge.
Not much time is spent 'at the lights' though so if I am wrong then the advantage would be minimal for the mech pump. They are minimal either way really.

Of course when the cars are running, and this is where it really counts, then the elec car has a very slight advantage (I think) as there is a constant airflow over the radiator/heat exchanger and the faster the coolant is pumped round to it the better.

all imo of course...

[bojangles]

I think for just the short burst of acceleration.. (the stoplight drag strip).. the engine idle time with the slower stock pump will produce a very small reserve of somewhat cooler water in the hoses etc.. then for the 2-3 seconds you need to get up to cruising speed safely (hahahahhaha) you have a slightly cooler blast of water. Slight and after a few litres of water have been pumped, it all changes.

Fun - I like technical message boards... not which chrome wheels have the best spinners...
Bruce

[deecee]

Its a Chargecooler, not a Beer Cooler...

[dknighto]

Hmmm, the RPM related nature of the stock chargecooler pump begs the question, up to what engine RPM does the stock pump work effeciently? Does the flow increase all the way up to redline or does it top out at say 4000 RPM and therefore never actually flow faster than the electric pump? After writing this question I decided to do a quick search online and found the following at Michaels Motorsports:

Pumping capacity estimates for the stock pump are between 1-4 gpm (gallons per minute) at idle and redline respectively.

The electric chargecooler pump runs at a constant 4 gpm to provide optimal cooling of the fluid

[bojangles]

You are missing the entire point.. the cooling is not related to the flow rate.
Please re-read what I wrote..

The general perception is that More is better. for example if you let your hot water tap flow slowly it will bring hot water forever...( american style tank system - not euro on demand system ) the sink will get hot and the drain pipes get hot ...

Now open the tap wide open.. the tank will eventually be cold the heater on continuously. and the water will be cold. the sink wont get hot and neither will the drain pipes. but the amount of HEATING is the same in both cases.

try to imagine the same thing but with cooling... the front rad removing heat.. and the chragecoooler like the sink and drainpipes.

[cross-eyed-twit]

the only way to really prove the point would be to run two cars at idle with no airflow and record the water and air temps before and after the engine and heat exchanger. perhaps freescan could help here.

[dknighto]

The main point I was trying to make is that the RPM driven nature of the stock pump doesn't give you any advantages over an electric one at the top end because it will not flow faster than the electric. When driving on a track, I definately think the Esprit would be better off with the electric pump in light of this fact.

With regards to the drag racing scenario I'm still not sure that the stock pump would work better than the electric pump. It seems to me that:

1. You need the engine to be at 5500 rpm when you drop the clutch to get the ECU into overboost mode. If chargecooled esprits get off the line and only one is on overboost (getting into this mode is the difference between the 4.7 and 5.0+ 0-60mph on the SE+), that guy is winning no matter what pump he has. So before you even launch, the engine is running fast and so is the coolant. Maybe causing you to run all the cool coolant through the system before you even launch and then by the time you're moving you have that "extra" warm coolant that was sitting in the chargecooler before, coming back to the charge cooler a little warmer than normal because it went to the radiator warmer than normal. Either way, the point is that with the slow/fast scenario, timing is key for any sort of benefit, and it may not work out exactly how you think or even the same every single time.

2. While you're sitting at idle and the coolant is trickling through the chargecooler system, the coolant in the radiator is probably staying colder, but at the same time the charge cooler is getting HOT because it is sucking heat off the engine block. The charge doesn't come in direct contact with the coolant, it touches the charge cooler. So if your charge cooler is extra hot, all the extra "cold" in the coolant is just going to cool the chargecooler down.

[Squelch]

Hey guys..
Thought I'd chime in here....

I get e-mails about this all the time and I try to respond to them, but don't always have time.

The simple fact is that in ANY system, be it a coolant system, AC system, plumbing in a house, or whatever. The elimination of variables is the key to a more efficient system.

Let’s look at the charge cooler system.

Variable intake air speed, volume, and pressure
Variable coolant flow through the chargecooler due to variable engine speed.
Variable heat elimination through the front radiator due to variable vehicle speed, AND variable coolant flow.

If you can eliminate any one of these variables, the system WILL be more efficient, simple science, as we all should have learned in grade school.

With the charge cooler system, there is only one variable we can eliminate, the pump.
As for the pump, volume of flow has an effect only to a point. At 1 gpm, the flow is TOO slow to transfer heat effective at idle and the chargecooler heat soaks. On the other end of the scale, pump flows greater that about 4 GPM show no further improvement, only a rise in system pressure.

Next.. yes, I have the data to back this up. K type thermo couples with Omega gauges measuring the Delta t across the charge cooler. An electric pump of at least 4gpm and15psi of head pressure is about 20% more effective than the stock pump across the engines operating range. At idle, it’s over 50% more efficient, (yes.. cold, cold, cold, while at the stop light) other ranges, it’s exactly the same.


I’m not trying to sell you a pump, as a matter of fact, my supplier is getting difficult to get them from. But please use something that is 4gpm and 15psi. You can go higher, and draw more current, but you don’t need to. Also, you don’t need a self priming pump, self priming pumps (like the stock one) tend to destroy themselves if run dry. Besides why would you want that milk shake machine impeller in there anyway?

FACT: The original impellor used in the pump was designed for a milk shake machine, and moving cold fluids, not pumping hot coolant, and not at the rated RPM that the 910 engine drives it at.


Well.. That’s my $0.02… I’m headed back out to the shop… I’ll try to stop back and see how this progresses.

John Welch
WC Engineering LLC

[bojangles]

I am not sure I really care that much, but since I dont like technical errors. i will state the following:

From various posts....

Getting a clean launch with my car from a stop light is all about NOT getting full boost off the line.. if you drop the clutch at 5k rpm my car rips the tires to shreads, the engine hits redline before you can possibly react and then opens the wastegate, cuts spark and fuel and you go nowhere fast... the K cars just pull away cleanly hehe.
TO get a good hook up you need to manage the power very carefully all through first gear. once you are in second you can go hard on the accelerator and probably get some grip.

A simple search of Lotus weak points will tell you a weak point is the gearbox so 5k clutch drops are silly anyway.

next i challenge that simpler is more efficient.

home heating systems used to be simple.. and very inefficent. now they are more complicated and more efficient. Anyone can remember the old oil burners....

for cars... Old carb were simple - and not so efficent. Newer cars measure all sorts of vairable and use them to give better effiency.

I think a fixed pump is good for fixed conditions on any hydraulic machine. A variable pump allows various effiencies. What we dont know is if the variability is matched to the process. I really think that the idea is to not blindly accept that more is better. the flow has to be right to be good. I suspect that there are some special conditions where a changing flow may be better. No measured proof here. I just think that somewhere in the 0-60 run there would be a slightly cooler litre of water passed to the chargecooler

Next on my list is the history of the rubber impeller pump. It has been used for many years in all kinds of applications. I would not agree that it was designed for cold liquids. I think that in design that you choose the material to match the temperaure ( one of many considerations) and that this has been a basic concept for much longer than the pump's history. I am sure there have been many differnt rubber compounds applied to this type of pump for various applicaitons. If some guy has his first recollection of this pump for cold slush, that does not mean the pump was invented for that. It does not mean the lotus pump specification was not reviewed for the temp of the application.
For all we know the pump lasts longer in the coolant than the slush.
Note also that most all ( even the newest ) marine engines use this style of pump for the coolant. These marine engines need self priming, and also they often handle debris from seawater. They need to be easy to service, and reliable.
I think that if the location of the lotus pump was easy to reach, we would all carry a spare, and nobody would even have ever tried an electric pump. It is mostly because of the awkward location that people never want to do the maintenance twice.

THe performance is just a discussion. And there is nothing proven.

The reason I am on this rant is that people just assume that more is better and that is what i am trying to avoid.. dont assume.. use logic. I am trying to make us think logically a little more. My opinion is that society does not do enough of that.

[Squelch]

Excellent info..

Except for one point. Take the part number off of the Jabsco impellor that comes from the factory installed in the charge cooler pump and look it up on Jabsco's database.

It's for a milk shake machine.


I could give you the part number, but then people would question weather it's the real number, or one that I pulled from Jabsco to make a point.

[chi-loti]

Dear Mr. Bojangles,
Sir - Thank you for the laughs! I have passed this post around my Engineering office and everyone has enjoyed it greatly. I have only one question: Are you in Marketing or Sales?

So here are my comments:

bojangles said:

next i challenge that simpler is more efficient. home heating systems used to be simple.. and very inefficent. now they are more complicated and more efficient. Anyone can remember the old oil burners.... for cars... Old carb were simple - and not so efficent. Newer cars measure all sorts of vairable and use them to give better effiency.

So... basically... you're saying more complex things are better. This is great, terribly misguided - but great. All good engineering lives under the K.I.S.S. rule (Keep it simple - stupid). More complex things will, by nature, have a lower MTBF (mean time between failures) simply because there are more things that can go wrong. The reason why home heating systems and fuel injection work better than their older counterparts is because they are simpler. You just lack the understanding of electrical systems. Really, it's ok - most people just don't understand modern electronics. But once you do, you will see that a single 10,000 gate FPGA on a Printed wire board (supported by an oscillator, a couple of caps, a resister here and there, and maybe a cheap microcontroller) can do much more things, in much less space, at a much lower cost, with many few parts, and with better accuracy over time than what it would take to create the same system mechanically.

It's not more complex - You just happen to exist behind the curve.

bojangles said:

I think a fixed pump is good for fixed conditions on any hydraulic machine. A variable pump allows various effiencies. What we dont know is if the variability is matched to the process.

Yes we do. Easily calculated.
Also, your previous argument started on the idea that once the car reached a steady state - either pump would work the same. Therefore, an electric pump is not needed. And this point is 100% Correct! Unfortunately, a car is rarely at a steady state. An electric pump would allow the system to work more closely to a steady state condition at all times by maintaining an optimum head pressure and flow rate.

bojangles said:

I think that if the location of the lotus pump was easy to reach, we would all carry a spare, and nobody would even have ever tried an electric pump. It is mostly because of the awkward location that people never want to do the maintenance twice.

Ah. So here you're saying that the only reason people don’t like the original pump is because it's difficult to fix when it breaks down.
...
How about this as a thought: People don't like the original pump because it breaks down. Why does it break down? Poor design. Period. (Btw, it was a great idea. But like most English engineering originating from the pre 90’s, the execution was miserable.)

bojangles said:

THe performance is just a discussion. And there is nothing proven.

Um... did you read the last post? He selected the pump after doing quite a bit of testing and measurement. Nothing says "proven" better than data.

bojangles said:

...dont assume.. use logic. I am trying to make us think logically a little more. My opinion is that society does not do enough of that.

Excellent idea. And apparently spoken by a member of society.

Enjoy,



P.S. Your name wouldn't happen to be Larry M. would it?


>> Edited by chi-loti on Thursday 30th March 11:18