CM30 VS OEM BOSCH, Interesting RESULTS...
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E350 Sport & Rs6
CM30 VS OEM BOSCH, Interesting RESULTS...
OKAY!!!!
Good afternoon MBworld...I hope everyone is having a great day!
WELL....After having an aggresive discusion with our AMG MB master tech, BMW master tech and one Aeronautical engineer. The question was: "Which pump flows more volume of water quicker?"
Video:
BOSCH: http://www.youtube.com/watch?v=FMmWPM8htQ0
CM30: http://www.youtube.com/watch?v=60tzWqriWM0
I decided to go purchase a coolant hose, and start the process to our test.
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00556.jpg)
OEM BOSCH VS. JOHNSON CM30.....
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00557.jpg)
We performed TWO tests; 30 second and 10 second intervals. Which one could move the most volume of water per test.
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00562.jpg)
We started off with 2 buckets of water!
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00558.jpg)
The first test was with the CM30
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00559.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00560.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00561.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00563.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00566.jpg)
The second test was with the BOSCH
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00567.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00568.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00569.jpg)
NOW, THE CONCLUSION:
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00571.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00572.jpg)
Both pumps flowed the same amount of water per test. Not only were the results mind-boggling to our Techs, but I was suprised as well.
My END result:
I am not saying the CM30 pump is a bad buy, I understand the CM30 has other advantages but from our test results, they flow THE SAME!
I just thought I would share this "experiment" with everyone!
The CM30 is great buy but my results prove that they FLOW at the same rate!
I am told the internals are more efficient so that being said it is still a great upgrade if your current BOSCH pump fails!
That's all folks.....Have a great day!
Good afternoon MBworld...I hope everyone is having a great day!
WELL....After having an aggresive discusion with our AMG MB master tech, BMW master tech and one Aeronautical engineer. The question was: "Which pump flows more volume of water quicker?"
Video:
BOSCH: http://www.youtube.com/watch?v=FMmWPM8htQ0
CM30: http://www.youtube.com/watch?v=60tzWqriWM0
I decided to go purchase a coolant hose, and start the process to our test.
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00556.jpg)
OEM BOSCH VS. JOHNSON CM30.....
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00557.jpg)
We performed TWO tests; 30 second and 10 second intervals. Which one could move the most volume of water per test.
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00562.jpg)
We started off with 2 buckets of water!
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00558.jpg)
The first test was with the CM30
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00559.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00560.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00561.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00563.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00566.jpg)
The second test was with the BOSCH
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00567.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00568.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00569.jpg)
NOW, THE CONCLUSION:
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00571.jpg)
![](http://i624.photobucket.com/albums/tt326/Autoscope/DSC00572.jpg)
Both pumps flowed the same amount of water per test. Not only were the results mind-boggling to our Techs, but I was suprised as well.
My END result:
I am not saying the CM30 pump is a bad buy, I understand the CM30 has other advantages but from our test results, they flow THE SAME!
I just thought I would share this "experiment" with everyone!
The CM30 is great buy but my results prove that they FLOW at the same rate!
I am told the internals are more efficient so that being said it is still a great upgrade if your current BOSCH pump fails!
That's all folks.....Have a great day!
Last edited by Autoscope; 05-28-2009 at 01:01 PM.
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Thanks for the taking the time to perform this test...
I just don't trust the Bosch pump.. I have replaced 3 of them in my 2 cars.
So far my CM30 has lasted for over 2 years without a problem.
Now, if we can find an upgrade to both pumps without changing diameter in hoses like the (CM90) it would be ideal.
I just don't trust the Bosch pump.. I have replaced 3 of them in my 2 cars.
So far my CM30 has lasted for over 2 years without a problem.
Now, if we can find an upgrade to both pumps without changing diameter in hoses like the (CM90) it would be ideal.
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E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
One will pump better under a load (head) than the other.
One pump has a much lower electrical draw too.
So if you have a HE sitting around and an amp meter you can determine the best one.
One pump has a much lower electrical draw too.
So if you have a HE sitting around and an amp meter you can determine the best one.
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2003 W211 E55, 2003 W220 S600
So my question is what does the cm30 have that prevents sc shut down, if the flow rate is the same we should experience sc shut down with the cm30 also.
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SL600
I have to admit I'm surprised by the results of the test, I would have thought the Johnson pump would flow better. But even so, I think this is still a valuable upgrade purely from a reliability standpoint. Most people around here have been through several Bosch pumps, but I can't remember hearing about a single Johnson pump crapping out yet.
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AMG E55, Stage 1, Strait Pipe from Primary Cats
Simple: The Johnson doesn't break. That's what shuts the s/c off, the intake temps get too high when the Bosch pump starts crapping out and gets weak, and as a result you get sporadic/intermittent s/c engagement. The johnson pump is a $h!tload more reliable than the Bosch pumps, and that's the real benefit of switching them out.
I have to admit I'm surprised by the results of the test, I would have thought the Johnson pump would flow better. But even so, I think this is still a valuable upgrade purely from a reliability standpoint. Most people around here have been through several Bosch pumps, but I can't remember hearing about a single Johnson pump crapping out yet.
I have to admit I'm surprised by the results of the test, I would have thought the Johnson pump would flow better. But even so, I think this is still a valuable upgrade purely from a reliability standpoint. Most people around here have been through several Bosch pumps, but I can't remember hearing about a single Johnson pump crapping out yet.
#14
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Simple: The Johnson doesn't break. That's what shuts the s/c off, the intake temps get too high when the Bosch pump starts crapping out and gets weak, and as a result you get sporadic/intermittent s/c engagement. The johnson pump is a $h!tload more reliable than the Bosch pumps, and that's the real benefit of switching them out.
I have to admit I'm surprised by the results of the test, I would have thought the Johnson pump would flow better. But even so, I think this is still a valuable upgrade purely from a reliability standpoint. Most people around here have been through several Bosch pumps, but I can't remember hearing about a single Johnson pump crapping out yet.
I have to admit I'm surprised by the results of the test, I would have thought the Johnson pump would flow better. But even so, I think this is still a valuable upgrade purely from a reliability standpoint. Most people around here have been through several Bosch pumps, but I can't remember hearing about a single Johnson pump crapping out yet.
Tom
#15
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i thought there were a few claims that the cm30 did flow a tiny bit more than the bosch. regardless, flow rate has never been the reason i switched to the cm30...if it was i would have gone with the cm90.
thanks for the info!
thanks for the info!
#16
MBWorld Fanatic!
well it has also been stated that there was nothing wrong with the revised pump mb had...yet people were swapping it out for the cm30 when they were fine![nix](https://mbworld.org/forums/images/smilies/nixweiss.gif)
Thanks for the tests
![nix](https://mbworld.org/forums/images/smilies/nixweiss.gif)
Thanks for the tests
![Smilie](https://mbworld.org/forums/images/smilies/smile.gif)
#17
This reminds me of the bilge pump debate often had over boat bilge pumps.
They're definitely not all created equal ... the minute the going gets tough ... some stop going ... and with boats that can be real bad.
I have 2 - 2000gph pumps and one 1500gph pumps in my boat. The originals were "Attwoods" that I replaced with RULES. Horizontal rates were the same ... noticeable difference when pushing a head.
They're definitely not all created equal ... the minute the going gets tough ... some stop going ... and with boats that can be real bad.
I have 2 - 2000gph pumps and one 1500gph pumps in my boat. The originals were "Attwoods" that I replaced with RULES. Horizontal rates were the same ... noticeable difference when pushing a head.
#19
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So, since the flow rate is the same, in the past, people kept saying that if you feel "less" power (not a complete s/c shutoff), then upgrade pumps. So, this is not true anymore? In other words, the bosch pump is either ON or OFF, not in between??
#20
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thats the one you want and it has warrently and runs fine, have not heard of any one with it complaining
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So, I was under the impression that everyone wanted the CM30 pump for "extra" flow reasons.
The internals are better and it last longer than the OEM pump? Sounds good to me!!!
Good to know!
What else would you guys like me to test out?
The internals are better and it last longer than the OEM pump? Sounds good to me!!!
Good to know!
What else would you guys like me to test out?
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2006 E55
Mad props for taking the time to do the test. One flaw is that any pump changes flow rate as pressure increases. If you look at published flow rates for fuel pumps they show a chart giving pressure and flow. The pump first has to work to create the pressure to over come the FPR or in this case the intercooler circut before flow begins.
I suspect that the difference will be minimal but it is an unknown variable.
I suspect that the difference will be minimal but it is an unknown variable.
#23
Senior Member
i think both pump curves are available. although in a low restriction test, both pumps may perform the same, as restriction increases (such as through a cooling circuit), i'm curious which one performs better. anybody have both curves? (i remember the stock pump is more efficient)
actually, in another thread
https://mbworld.org/forums/c32-amg-c...p-vs-cm30.html
this shows the OEM pump as being more efficient, although it's unsure what the test method and setup is of the bosch.
however, the OP test with an assumed very low restriction is consistant with the two sets of data - the OEM and CM30 pump characteristics are similar at low restrictions, but the OEM will probably be better at higher restriction (vehicle circuit)
actually, in another thread
https://mbworld.org/forums/c32-amg-c...p-vs-cm30.html
this shows the OEM pump as being more efficient, although it's unsure what the test method and setup is of the bosch.
however, the OP test with an assumed very low restriction is consistant with the two sets of data - the OEM and CM30 pump characteristics are similar at low restrictions, but the OEM will probably be better at higher restriction (vehicle circuit)
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2014 E63, Cobra replica, 68 Camaro, 66 Chevy II SS, Z4 BMW, Honda Element, Birel 125cc Shifter Kart.
I've got an 06 E55 now using the new upgraded Bosch pump. I also have a cm30 sitting in the garage that was on the car for six months. I can feel no difference between the two in performance or reliability.
The dealer "suggested" that I remove the cm30 when they found it on the car while doing an oil change under veiled threats of warranty problems and offered to install the upgraded Bosche under warranty. I said OK and haven't had a problem since.
IMO the cm30 is no better or worse than the Bosch. If you're not having problems, I wouldn 't change it.
The dealer "suggested" that I remove the cm30 when they found it on the car while doing an oil change under veiled threats of warranty problems and offered to install the upgraded Bosche under warranty. I said OK and haven't had a problem since.
IMO the cm30 is no better or worse than the Bosch. If you're not having problems, I wouldn 't change it.
Last edited by speedpeddler; 05-29-2009 at 10:21 AM. Reason: spelling