Here are some of the results of recent electric intercooler pump testing performed at Lingenfelter Performance Engineering.

We have performed this type of testing before on several of these pumps but, since we recently upgraded our coolant flow measurement equipment to a much higher level of flow meter that allows us to very accurately measure flow over a very wide range of flows with very little to no impact on the system restriction, we felt this was a good time to perform this testing again and to do so on an expanded range of pumps and conditions.

For this testing we tested the pumps in two primary ways:
•fixed known restriction using a ZL1 intercooler (from inside the supercharger assembly) and intercooler radiator with OEM diameter coolant hoses (3/4")
•variable orifice restriction after the pump so that we could simulate any level of restriction that the pump might encounter (depending on the installed application)


We tested several different intercooler pumps including:
•stock OEM ZL1 intercooler pump (this is also the GMPP LSA and LS9 crate engine pump)
•stock OEM Cadillac CTSV/Bosch PCA 1150LPH intercooler pump
•stock OEM ZR1 intercooler pump
•VariMax 410110 DC brushless intercooler pump
•a common aftermarket 20GPM inline electric pump
•a common aftermarket 55GPM inline electric pump
•Stewart-EMP E2512A DC brushless intercooler pump
•Stewart-EMP E2512A pump reprogrammed to raise the current/pump RPM limit (revised pump part # 1030002107 when programmed with this software)

We tested a few other pumps as well but the above pumps are the primary ones we focused on.

During the testing some of the variables we recorded included:

• coolant flow
• outlet pressure
• inlet pressure (positive or negative)
• differential pressure across the pump
• pump voltage
• pump current
• coolant temperature

All tests were repeated multiple times (at least three times), the data checked to make sure we had test to test repeatability and then the results were averaged to produce the data described below.

The Bosch 1150 LPH PCA pump continues to be the baseline standard pump used in many liquid to air intercooler systems in both OEM and aftermarket applications. In the ZL1 system it flowed 3.6 gallons per minute (GPM). This is the same pump used in the 2009-2013 Cadillac CTSV, Cadillac STSV, Cadillac XLRV, 1999-2004 Ford Lightning, Fort GT500 and many other OEM applications. It is also the pump used in Magnuson, Edelbrock, Whipple and many other aftermarket supercharger kits. It is fairly compact, very reliable and has low current draw. It performs fairly well against an outlet restriction but doesn't flow as well as some of the newer, higher output pumps that are available. This same pump has existed for well over 10 years without any major design changes.

As expected from our previous testing, the ZL1 pump flowed more than the Bosch pump (4.8 GPM vs 3.6 GPM) and the VariMax pump (PN TAFX410110) flowed the same as the ZL1 pump when tested in the stock ZL1 intercooler and intercooler radiator circuit. The Varimax pump is the pump that is in our CTSV pump upgrade kit (part # L330030709) that brings the CTSV up to the same pump flow specification as the ZL1. At 3.6 GPM, the Bosch pump flowed 25% less than the ZL1 and the VariMax pumps.

Also as expected, the ZR1 pump performed very well. It flowed 5.7 gpm, 19% more than the stock ZL1 pump. For its size and current draw the ZR1 pump is a very impressive pump as it is no bigger than the ZL1 pump yet flows more than pumps more than twice its size and does so with 3/4" hose fittings in and out. On the other hand it is a fairly expensive pump, with an MSRP of over $1000 and "street price" of not much under that.

The Stewart-EMP E2512A intercooler pump also performed well, matching the ZR1 pump flow when installed in the ZL1 circuit despite the fact that the inlet hose was 3/4", not the recommended 1" inlet. When we reprogrammed the Stewart-EMP pump to raise the internal pump speed and current limit, the flow was significantly increased to 7.7 gpm. That is 60% more than the ZL1 stock pump. This pump performs very well at high pressure drops but the current draw does increase significantly when the pressure across the pump is high (when the restriction is high) so you need to make sure you account for that in your wiring. The Stewart-EMP pump is a pump we have been using for several years in high horsepower supercharged and turbocharged vehicle applications including our 1250RWHP Camaro SS, our white turbo drag Camaro, and numerous 1000-1600+ HP customer builds.

The 20GPM and 55GPM pumps we tested are pumps that are commonly being used and sold as intercooler pumps so we felt we needed to test how these performed compared to the above pumps that we use on a fairly regular basis. When tested with very little restriction these pumps flowed fairly well and used little electrical current to do so. Once the restriction started to increase the flow of these pumps dropped significantly though. Both pumps, when installed in a stock ZL1 intercooler system, flowed less than the stock ZL1 pump and not much more than the Bosch pump. At higher differential pressures (outlet restrictions) even the Bosch pump flowed more as can be seen by the graph of pump flow vs differential pressure. In 2002 when we were developing and testing a turbo Ecotec engine in the NHRA Sport Compact series we had found similar results. The billet housing electric pump that we had purchased and installed in the vehicle that was supposed to be a high flow pump actually flowed less than the Bosch production pump we were using in the low boost, 500 HP supercharged customer street cars at the time. As we found out then, many pumps being sold in the marketplace are being flow rated with no pump restriction and that many of these pumps did not flow nearly as well when tested in an as installed configuration.

Here are the graphs of the test data described above:



Hope this is of interest.

 

GREAT INFO, what is the street price on some of the other pumps. I know the Bosch unit goes for around $110. Figured the ZR1 pump would be pricey but $1000?

 

Thanks Jason!!

Kurt

 

Here are part numbers and prices (sorry, I don't know how to make a table on this forum):

Product Description [Part #] Retail $
Bosch 1150LPH PCA IC pump [BOS0392-022-002] $ 104.95
Bosch intercooler pump, bracket and harness kit [L330010000] $ 139.95
Varimax intercooler pump w bracket and connector kit [TAFX410110] $ 215.00
VariMax to Bosch/Minitimer intercooler pump connector adapter harness [L480340000] $ 21.95
CTSV intercooler pump upgrade kit, LSA, '09-'13; w VariMax pump, bracket & harness [L330030709] $ 239.95
Stewart-EMP intercooler pump [ST-E2512A] $ 489.95
Stewart-EMP intercooler pump, reprogrammed for higher pump output [ST-1030002107] $ 549.95
ZL1 Camaro intercooler pump [20945282] $255.99*
ZR1 Corvette intercooler pump and bracket assembly [15870574] $974.58*

*ZL1 and ZR1 pump prices are just example prices I found online. We don't inventory those GM OEM pumps so I don't know what we would charge for them.

Note on the ZL1 pump that the mating connector is not available as a service part so if you don't have the GM engine harness or GMPP crate engine harness, a good connector solution doesn't exist.

Also note that in many of the GMPP/Chevy PP parts catalogs and press releases the ZL1 pump is referred to as the LSA and LS9 pump. It is actually only on the LSA in the ZL1 Camaro. The LSA in the CTSV gets the Bosch pump and the LS9 in the ZR1 gets a different pump. The confusion comes from the fast that the GMPP crate engines and crate engine harnesses use the ZL1 pump. I think the ZL1 pump actually comes from the Volt although it may be programmed differently (I haven't checked if the part numbers are the same).

 

Here are pictures of the pumps that were tested to give you an idea of the size etc.:

 

Awesome info. Thanks for sharing!

 

This is great info, I've been wondering what pump to use for a while. This helps a lot.

 

Has anyone taken a BAP designed for a fuel pump and used it to control a intercooler pump?
I know more is not always better as over circulation can actually cause a fluid to heat up.

 

The guys on the CTS-V foums have been using this Jabsco pump:



You can get it for around $180 shipped from here:

http://www.ultimatepassage.com/cgi-bin/up/34531.html

One of the members did a bucket test flowing through the intercooler sustem on the car and it showed about a 30% improvement in flow.

Mike

 

More importantly, which allowed the best charge temps ?

 

Impressive stuff. Really good helpful information.

 

Informative thread. Very interesting results.

 

Great data! Thanks for taking the trouble to do this and post the results.

 

Looks like the Varimax pump is really nice for the price/performance.

Jason do you guys sell this Kit
Varimax intercooler pump w bracket and connector kit [TAFX410110] $ 215.00


I have a custom built 2.9 whipple on my 4th gen Fbody and I am most likely going to add an intercooler, this pump looks like it might be the ticket.

 

Great information. I am curious though if you have ever tested any of the Rule series pumps? I know they are not intended for automotive applications, but I would be very curious how the Rule 10A pump compares and does against restrictions. I am about to purchase a pump and I know many guys are running the Rule 2000 gph pump with good sucess.

 

You could use voltage boosting on some of these pumps to increase the flow. Maybe in a follow up test we will test some of them at 13.5 and then at 16.5 or 17 volts. I would expect to see a bigger difference in the brush type pumps since the voltage should directly impact pump speed while on the DC brushless pumps with a motor controller they may control pump speed and then voltage may not have much of an impact (unless they are limiting current and can achieve a higher RPM for the same current level due to the elevated voltage).

Some of the pumps in this test are variable speed. The Varimax is probably the easiest of the pumps in this test to do external pump speed control on although you could use a PWM control on the brush type DC pumps (I would test that though, some pumps don't like PWM control especially at low duty cycles/low motor RPM).

In general more velocity is more turbulence and that is a good thing for heat transfer.

 

Yes, we sell that pump with bracket and connector. We have them in stock. We also have an adpater harness available to make the Varimax a plug-and-play replacement for the Bosch pump (or any other pump that uses that same Minitimer connector). That harness is our part number L480340000.

FYI the minitimer connector is the old standard fuel injector connector that most of you are probably familiar with from the 1980's and 1990's.

 

Yes, we have tested that pump and a few others that I didn't include in the data. Actually one of our employees use the Rule 2000 pump on his drag racing turbo vehicle.

Here is a line graph with a few of the same pumps as before for reference and then the Rule 2000 pump added. A lot of drag racers use the Rule 2000 as an intercooler pump. In drag racing this pump is usually used in a large coolant reservoir that is filled with ice water. This pump is not designed for automotive coolant temperatures so it should not be used in a street vehicle application that might see higher intercooler fluid temperatures and/or those temperatures under more sustained use. This pump is a submerged bilge pump so it is mounted inside the coolant reservoir so the data for this pump is graphed versus pump outlet pressure (not differential pressure that was used for the other pumps). The inlet pressure is fairly fixed on this pump since it is mounted in the reservoir.

The pump performs pretty well but you want to be careful how much outlet pressure/restriction you have. If it is too high the flow drops off a fair amount. With just one heat exchanger (the intercooler), the amount of pressure drop in drag race applications is often less than if it had to also be pumped into/out of a intercooler radiator. Since every intercooler design can be different, it wouldn't be a bad idea to check outlet pressure in your system. Past around 7 psi and several of the OEM type pumps are better.

 

Great information. I knew that pump had a pretty steep drop off as head pressure went up, but I was not sure how that would translate to psi of pressure. The above graph does a great job of putting it all into perspective. Thank you for sharing this information. Great stuff!

 

Again...I know more water flow is a good thing. But how did it affect actual charge temps ?

How would the Stewart pump perform with 3/4 fittings ?