Exotic-metal55

Has anyone figured out what the perfect rate to flow coolant through our I/C system is? Be nice if we could dial this in and come up with a general formula for flowing X amount of coolant per second? I know this has been passed around some over the years but now we have enough data logers and time to maybe come up with a rate.

At the end of the day, most of us will have a different flow rate based on our modified system capacity. Hope to to be able to control our pump flow rate to match our custom system..

My stock system held about 60 ounces of coolant , to the best I could measure. A 5.6 GPM Bocsh would make one full circulation in 10.7 seconds.. Now with an added aux. H/E (System is 100 ounces), 5.6 GPA bosch only makes one full circulation every 17.8 seconds. Has to be way to slow but still lowered average IAT`s 20 deg.

I have ordered a Mezaire pump , that flows 20 GPA and now will make one circulation every 5 seconds. To fast? To slow? Who knows?

I average 17 over ambient cruising on the hwy @ 75mph in 80 deg. temp. Speaking with Shardul, he averages 8-10 over ambient in same conditions. Although are systems are not exact, they are close but he flows water every 5 seconds or so.

What has everyone else found out? Be nice to be able to dial our pumps in to meet our coolant and H/E fin capacity..

MRAMG1

Although I too wish we could have some magical number my friend, as heat soak is my enemey as well. What you are asking for is NOT easily answered. The time in question would vary with outside temperature, IAT temps, cooling efficeintcy of both the IC and the HE, total capacity, amount of heat being displaced, aka BOOST pressure, etc, etc. There are simnply TOO many variables to say, our car needs a flow rate of 5 GPM.

The MAIN thing I would concentrate on is IAT's. I know you already now this, but one could simply use a LARGE pump, aka HIGH GPM, and put a variable resister in series to the pump. This resistor could be mounted inside, and while dat logging, you could adjust your flow rate.

This would be the ONLY way I know of to set it properly.

Otherwise, my old rule of thumb, " Nothing exceeds like excess"

GOOD LUCK

jangy

Also, isn't "optimal" different for some? I am not looking for just making a single pass. I want to be able to do more of circle track looping with lots of WOT. I always assumed that faster flow was better, but data doesn't seem to support that. i think you may be onto something here....

Yacht Master

The thermal loads can be calculated for a maximum and minimum, but to equate to a single flow rate is going to be a compromise. If your coolant is circulated too fast you may lose optimum heat transfer and by the same token too slow and well heat soak etc. Yes we could do the calculations but there may be an easier way.
With this in mind, I think the best solution would be a thermostatic & boost controlled variable speed circulation pump. Having a fixed flow may not keep you in a thermal sweet spot. BTW Has anyone logged the characteristic of the oem power supply to the IC pump?

Exotic-metal55

That is the ticket. I think there may only be 4-5 pumps floating around here and most of us are going by advertised flow rates, so that is also an assumption. It would be nice to find out in general what would work for most systems at one flow rate. That takes care of one crowd. Then we have all the V-12`s, 55`s and custom sytems to dial in to a nats **** (Thermostatic & boost control flow rate pump).. There is a lot of just basic data log info that could just begin to get us closer to cooler IAT`s..

My cruise IAT at 55-75 is about as optimum as it can get, under current mods. 25mph or under (less air flow but same water flow) and they can go up 20 deg. plus...So , when that M6 rolls up , I already am down 20 plus HP! Blasy off,, and I am starting with a 120 IAT , hit 145 deg at 6K and loose another 25hp! This is what happens on a decent system and unkown to many boost drivers, loss of huge power day to day..


Just need more hard input here to start formulating some great flow options.. Anyone with pump flow numbers and IAT info???

As soon I as I jump from a 5.6GPA to a 20GPA next week, I will be able to add more feedback. At least from one extreme to another..

stevebez

One thing you need to keep in mind pump flow rates are rated in a free flowing state. I.e. if you stuck one end in a tub and the flow that came out the pump spout. Now obstruct the output with a radiator hoses etc etc and the flow rate drops ... and it drops alot. Some pump specs give flow rates under different pressure arranagements .. so as you pump the pressure rises and flow drops...

For example a CM90 flows 30gal/min at 0.1 bar and at 0.4 bar flows 10gal/min... so by measuring the line pressure you could work out aprox what your flow rate is. CM30 is 17gal/min and 8 gal/min respectively.

So IMHO the bigger the pump the better... within reason. I cannot see going larger than a CM90 would yield any discernable benefits.

Ali_E55

but witth high pressure, u may damage the ones under the S/C which could lead to a leak there.

shardul

iTrader: (1)

can understand what you are trying to say. the i/c cooling system is a low presure system.

stevebez

Actually an OEM system is a high pressure system as it shares the engine coolant lines ... splitting it turns it into a low pressure system.

lowprofile

Here is some reading material for you. Of particular interest, scroll down to "high output pump" and then click on the link for installation notes. You will see that the poster performed some testing on a Meziere pump to determine his best flow rate.
http://www.timskelton.com/lightning/...ntercooler.htm

TopGun32

good topic.

In my case, I have a 60 ounce HE (stock is around 28ounce) but I have not split my system.

Around 85F degree day.. I can be around 10-15 over ambient at 70mph. BUt after 1 hard run..my system stays around 15 to 20 over ambient.
After another hard run.. I recover in about 45 secs to 60 secs but I'm still at 20 over ambient.

Since I doubled the size of my HE, I would think increasing flow rate would help. But I will split my system first and then upgrade my pump.

I have plenty of data logging in 90F to 100F degree heat. The worst days for any 55 engine.

Exotic-metal55

Yes, great info. I read the link about the SS and those test are what promted me to start a thread.

TopGun, You doubled your H/E size but also remember that your intercooler and lines hold another 30 ounces or so. So you are at about 115-120 ounces of coolant capacity.. What pump are you running now? Are you still seeing 20 deg. over ambient in 95 deg. temps?

TopGun32

New CM30 about 4 weeks old.

20 over ambient is still my average on 90F degree day once the car warms up and after 1 hard run to about 100mph on the freeway. I spike at around 150 and with in a minute . i'm down to 110ish.. but it won't go any lower

My engine coolant jump from 190 to 210 and probably one reason my IAT's dont come down any lower. I do have the PTE thermo stat, but I do not have the Fan set to come on sooner (-10C Fan mod). According to PTE, its necessary to really help the t-stat.

Its not bad for a 90F degree (3pm run).. evening is a bit better.

On a 70F degree day.. power is perfect.

My goal is to maxime power from 70F to about 90F ambient temp. Anything over those temps.. its not worth racing anybody.

When I split the system, I will do some more testing and then add the faster flowing pump.

shardul

iTrader: (1)

TopGun32, split you system and consider using a Meziere WP136 pump. I am at 8-10 over ambient at freeway speeds and the recovery rate is bloody fast, I had a CM30and my IATs were like yours

320 dreamer

lets go outside the box for a second. im not sure how much room you have in front of your oem radiator. but this is what i used on my slk32. this is a jegs radiator with the inlet and outlet tubes cut off and welded shut. the 2 tubes welded to the pass. side and the pass. side tank split and welded for a dual pass system. with measurements of 26" wide 1" thich and 16" tall this h/e is massive!! it flows like a beast. if you dont want to split the tank you can flow it as a single pass also
just something to think about. cost was 350$
https://mbworld.org/forums/w211-amg/...estions-2.html post 46# as it wont let me load them here

TopGun32

Yup.. thats where I'm going to do next. Actually, I have the list of parts I need to split the system.. but I'm going to visit "Pick Your Parts" to select a Power Steering reservoir. I have a few ideas on locations where I can mount one.

Then I will pick up the Meziere pump and add to the set up as well.

shardul

iTrader: (1)

this is what you will need

3/4 rubbber cap to cover stock T
5/8 to 3/4 hose spice (only if the tube connecting to the reservoir is 5/8 in diameter)
and couple of clamps

TopGun32

System Split is complete.

I stopped by a "pick a part" junk yard and bought a reservoir for $7

I used a Volvo engine coolant reservoir and 3/4" heater hose. The reservoir holds around 40oz and I placed by the dust filter area. Sadly I won't have a dust filter.. which I rarely use.

I ran the car last night, to get the fluids back in order and bleed the IC system once.

Today I plan to data log cruising on the freeway around 70mph

shardul

iTrader: (1)

let us know the results

Exotic-metal55

I would assume that 8-10 over ambient will be about as good as an average system can attain. Baring adding ice.. As long as the stock intercooler is in place under the blower, then there will be the heat culprit..

What I mean by average; is any system with larger or Aux. He, larger pump, seperated system, water wetter, T-stat mod and even a large capacity trunk surge tank..

I sure hope someone has info to tell me I am wrong but that is how I see the accumualtion of info. At the end of the day, 8-10 over ambient is damn good..

TopGun32

its been super hot in here so cal.. so i'm testing under worst conditions. Usually we only have very few weeks this hot.


I have seen Improvement just splitting the system.

On a 105F degree day.. I cruised at 70 for about 30 mins and I was about 10F over ambient. This was without WOT pulls or even pushing the rpms. Just get on the freeway and driving normal.

depending on the speed, the IATs my raise. If I slow down to say 40mph freeway traffic the heat increases slightly.. if I stay around 70.. I can keep my IAT's flat as a board.

I have not been able to do full blast runs.. (well not with my data logger).. but power seems to be a bit more free up top.

My next test will be the IAT spike when reaching 100+ mph and how fast I can recover. This will be done with the current CM30 pump then I will upgrade to a faster flowing pump.

TopGun32

I agree. AT the end of the day its about avoiding the ECU to pull timing at around 140F+ IAT.

Cooler weather.. say 70F. and a good system like Shardul's will almost not have a problem putting all the power down.

I'm almost there.. but the pump will be next.

shardul

iTrader: (1)

get the Meziere Wp136 pump

Exotic-metal55

I plan to put my Meziere on in the AM. I would have put it on today but my high speed boat was screaming for me to take it out!

shardul

iTrader: (1)

seems like you have the need for speed. Fast car, fast boat.. whats next?