SL55/63/65/R230 AMG: Pierburg pump
Senior Member
Joined: Dec 2019
Posts: 407
Likes: 137
From: Houston, TX
2005 SL600
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Joined: May 2009
Posts: 1,187
Likes: 239
From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
With 12v applied to the PWM pin, the CWA100 will run at 95% capacity (emergency running mode). Which is probably fine for our purposes.
If you absolutely must have 100%, or any other capacity, you'll have to use a PWM controller. Documentation is here - check the "CWA PWM Info" link near the bottom of the page.
If you want full control, it's not terribly hard or expensive to incorporate a PWM controller. I've got one of these that I'll be using when I install my CWA100 in the next month or two. I'm doing this just because I'm curious to see how my IATs react at various flow capacities. Intercooler systems are tricky things; sometimes higher flow does not result in better heat transfer. I figure for $15 and a little extra wire, why not?
If you absolutely must have 100%, or any other capacity, you'll have to use a PWM controller. Documentation is here - check the "CWA PWM Info" link near the bottom of the page.
If you want full control, it's not terribly hard or expensive to incorporate a PWM controller. I've got one of these that I'll be using when I install my CWA100 in the next month or two. I'm doing this just because I'm curious to see how my IATs react at various flow capacities. Intercooler systems are tricky things; sometimes higher flow does not result in better heat transfer. I figure for $15 and a little extra wire, why not?
Cheers,
Chris
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Joined: Apr 2017
Posts: 92
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Sl55 amg 2002
Senior Member
Joined: Dec 2019
Posts: 407
Likes: 137
From: Houston, TX
2005 SL600
The stock IC pump does not run full time, it only kicks on when IATs exceed a threshold temperature so you'd have to mod the stock circuit to run full-time to use it for the PWM power supply. I'm going by my knowledge of the SL600/65 system; it may be that the SL55 IC pump runs full time. But I doubt it does, because the stock Bosch pump is a standard brush type motor that would wear out relatively quickly running full time. The Pierburg is a brushless motor so it'll last much longer in a full time run configuration.
I'd just run 2 12v+ and 2 ground wires rather than bother with modifying the stock circuit to run full time. While it would be technically OK to run a single 12v+/ground and then splice the additional wires in near the pump location (the PWM pin isn't going to draw any significant amperage), I wouldn't do that 'cause it's difficult to make a splice water-tight and the pump area is down low and so could be exposed to water.
Member
Joined: Apr 2017
Posts: 92
Likes: 4
Sl55 amg 2002
Yes, new wiring to the fusebox. The fuse and wiring for the stock pump is only rated at 7.5A, and the CWA100 will exceed this.
The stock IC pump does not run full time, it only kicks on when IATs exceed a threshold temperature so you'd have to mod the stock circuit to run full-time to use it for the PWM power supply. I'm going by my knowledge of the SL600/65 system; it may be that the SL55 IC pump runs full time. But I doubt it does, because the stock Bosch pump is a standard brush type motor that would wear out relatively quickly running full time. The Pierburg is a brushless motor so it'll last much longer in a full time run configuration.
I'd just run 2 12v+ and 2 ground wires rather than bother with modifying the stock circuit to run full time. While it would be technically OK to run a single 12v+/ground and then splice the additional wires in near the pump location (the PWM pin isn't going to draw any significant amperage), I wouldn't do that 'cause it's difficult to make a splice water-tight and the pump area is down low and so could be exposed to water.
The stock IC pump does not run full time, it only kicks on when IATs exceed a threshold temperature so you'd have to mod the stock circuit to run full-time to use it for the PWM power supply. I'm going by my knowledge of the SL600/65 system; it may be that the SL55 IC pump runs full time. But I doubt it does, because the stock Bosch pump is a standard brush type motor that would wear out relatively quickly running full time. The Pierburg is a brushless motor so it'll last much longer in a full time run configuration.
I'd just run 2 12v+ and 2 ground wires rather than bother with modifying the stock circuit to run full time. While it would be technically OK to run a single 12v+/ground and then splice the additional wires in near the pump location (the PWM pin isn't going to draw any significant amperage), I wouldn't do that 'cause it's difficult to make a splice water-tight and the pump area is down low and so could be exposed to water.
is the 12v that goes to the pwm signal okay to run from the same source and the main 12v source? Eg the ignition circuit? Or does it need to be seperate? If the same source is ok il just run a single cable
then il splice a watertight fitting to the end of that wire and take the 2 wires to pin 3+4
also you saying if i buy a cheap pwm controler like this? I would run 12v and ground to pin 1 and 4 on pump
then run controller motor pins to the cwa signal pins 3+4
then power the pwm controller with normal 12v and that will alow me to play about with the duty cycle/speed?
sorry for the long messages
Senior Member
Joined: Dec 2019
Posts: 407
Likes: 137
From: Houston, TX
2005 SL600
ok cool thanks for the information, so il go with new wires from fusebox, from a fuse that comes on with ignition and run a 12v to the + pins and il just run a ground from pin 1+2 to a close by chassis ground
is the 12v that goes to the pwm signal okay to run from the same source and the main 12v source? Eg the ignition circuit? Or does it need to be seperate? If the same source is ok il just run a single cable
then il splice a watertight fitting to the end of that wire and take the 2 wires to pin 3+4
is the 12v that goes to the pwm signal okay to run from the same source and the main 12v source? Eg the ignition circuit? Or does it need to be seperate? If the same source is ok il just run a single cable
then il splice a watertight fitting to the end of that wire and take the 2 wires to pin 3+4
also you saying if i buy a cheap pwm controler like this? I would run 12v and ground to pin 1 and 4 on pump
then run controller motor pins to the cwa signal pins 3+4
then power the pwm controller with normal 12v and that will alow me to play about with the duty cycle/speed?
sorry for the long messages
then run controller motor pins to the cwa signal pins 3+4
then power the pwm controller with normal 12v and that will alow me to play about with the duty cycle/speed?
sorry for the long messages
Member
Joined: Apr 2017
Posts: 92
Likes: 4
Sl55 amg 2002
when i bench tested mine soon as i hook the power up it takes a few seconds before it makes a noise and comes on
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