{"id":10431,"date":"2011-07-07T19:50:31","date_gmt":"2011-07-08T00:50:31","guid":{"rendered":"http:\/\/caddyinfo.com\/wordpress\/?p=10431"},"modified":"2011-07-11T14:37:41","modified_gmt":"2011-07-11T19:37:41","slug":"how-cool-is-this-intercooler-pressure-versus-pump-output-and-flow-motorama","status":"publish","type":"post","link":"http:\/\/www.caddyinfo.com\/wordpress\/how-cool-is-this-intercooler-pressure-versus-pump-output-and-flow-motorama\/","title":{"rendered":"How COOL is THIS: Intercooler Pressure versus Pump Output and Flow @Motorama"},"content":{"rendered":"

Update:<\/h2>\n

Although the info shown is relevant for 4 Laminova cores in series, the Cadillac design does not have 4 in series but rather has A-B in parallel and C-D in parallel flow.\u00a0 I caused some confusion in the way I asked my question of Laminova as it turns out.\u00a0 I am leaving this for consideration, but the pressure head through 2 Laminova cores instead of through 4 cores would be different.<\/span><\/p>\n

 <\/p>\n

Intercooler coolant pumps are at heart 12v water pumps.\u00a0 Extra points if they are light and quiet, and very long lasting.\u00a0 They are rated in gallons per minute, or liters per minute, or liters per hour.\u00a0 However, with pumps one also has to know at what pressure.\u00a0 If an 8 gpm pump is pumping against NO resistance then it can pump 8 gpm of fluid.\u00a0 However, if it is pumping against some resistance, like the four cores of a STS-V intercooler, it has a harder job and the flow rate will drop.<\/p>\n

Laminova was kind enough to send me this graphic showing pressure versus flow through four Laminova cores sized for the Cadillac STS-V application in serial:<\/p>\n

Below is a graph with heat transfer vs. flow rate for a 4 x 39.5 mm cores in 392 mm length, coolant in series over the cores. (calculated with 350g\/s 110\u00baC for the charge air, 30\u00baC coolant with flow from 10 to 35 l\/min). As you can see performance continues to increase with increased flow, but at 35 l\/min you have almost 1,4 bar pressure drop, then add the radiator etc. So be careful when choosing pump, normally there are graphs for flow vs. backpressure for the pumps available.<\/p><\/blockquote>\n

\"\"<\/a>

Laminova Cores bar of pressure vs lpm of flow<\/p><\/div>\n

Let’s examine this graphic.\u00a0 First, a bar of pressure is a bit less than the English atmosphere (A), so 1 atm (atmosphere) = 1.01325 bar.\u00a0 Let’s stay in bar for now, as it is frequently used for discussion of our topic.\u00a0 But when you read bar you can think 14.5 psi if you prefer.\u00a0 A liter per minute is 0.2642 gallons per minute (gpm).<\/p>\n

What the graphic shows is that as the coolant flow increases from 10 lpm (2.6 gpm) to 35 lpm (9 gpm) the pressure required to push the water through the 4 STS-V Laminova intercooler cores increases from 0.15 bar (2.1 psi) to 1.4 bar (20 psi).\u00a0 It takes a LOT of pressure to reach a 9 gpm flow rate.\u00a0 The good news is the heat transfer for the system of cores continues to improve right up to 9 gpm, flattening out after that rate of flow.<\/p>\n

If we could increase the flow rate from 16 lpm (4 gpm) up to 35 lpm (9.2 gpm), the heat transfer will increase from around 16 kw up to around 22 kw, or 38% more intercooling at max rate.<\/p>\n

It is inviting to think then, that the STS-V 8 gpm intercooler pump is about right on the money; unfortunately, that pressure it has to pump against lowers its output quite a bit.\u00a0 Let’s see how much.<\/p>\n

The Cadillac STS-V uses a Bosch sourced 8 gpm (gallon per minute) pump.\u00a0 Here is a diagram of the Bosch pump output:<\/p>\n

\"\"<\/a>

Bosch Intercooler Pump Flow vs Pressure<\/p><\/div>\n

This diagram introduces new units again, but we’ll get through it.\u00a0 Along the x axis we have Volume of flow in liters per hour.\u00a0 Along the y axis we have delta pressure in hPa, which is hectopascals of pressure.\u00a0 1000 hectopascals\u00a0 = 1 bar.<\/p>\n

So this Bosch pump will flow 0 liters per hour at 0.5 bar, and up to 1800 liters per hour (30 lpm, 7.9 gpm) at no pressure.\u00a0 Good, as it is rated for 8 gpm.<\/p>\n

Now, how do we determine how much a Bosch pump in our STS-V would flow against the pressure through the intercooler, hoses, and heat exchanger?\u00a0 We graph them together based on flow rates versus pressure and see where their graphs cross.\u00a0\u00a0 That will be the point where the flow rate of the pump against the resistance in the system is equivalent.<\/p>\n

I have included the Jabsco 50840-12 Cyclone aftermarket intercooler pump for comparison as well, reading off their flow graphic.\u00a0 This is a popular replacement intercooler pump for the STS-V.<\/p>\n\n\n\n\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n
Laminova<\/strong><\/td>\n<\/td>\nSystem<\/strong><\/td>\nCyclone<\/strong><\/td>\n<\/td>\nBosch Pump<\/strong><\/td>\n<\/td>\n<\/tr>\n
FLOW L\/Min<\/td>\nPressure bar<\/td>\n<\/td>\nFlow L\/Min<\/td>\nPressure Bar<\/td>\nFlow L\/Min<\/td>\nPressure bar<\/td>\n<\/tr>\n
10<\/td>\n0.20<\/td>\n0.3<\/td>\n0<\/td>\n0.6<\/td>\n0<\/td>\n0.5<\/td>\n<\/tr>\n
15<\/td>\n0.35<\/td>\n0.45<\/td>\n40<\/td>\n0.42<\/td>\n8.33<\/td>\n0.45<\/td>\n<\/tr>\n
20<\/td>\n0.50<\/td>\n0.6<\/td>\n80<\/td>\n0.2<\/td>\n16.67<\/td>\n0.38<\/td>\n<\/tr>\n
25<\/td>\n0.70<\/td>\n0.8<\/td>\n120<\/td>\n0<\/td>\n25<\/td>\n0.2<\/td>\n<\/tr>\n
30<\/td>\n1.05<\/td>\n1.15<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
35<\/td>\n1.30<\/td>\n1.4<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

This data table shows the resistance through the Laminova cores alone, then an equivalent resistance value for the whole intercooler cooling system.\u00a0 I don’t know a good value for this so I used 0.1 bar or 1.4\u00a0 psi of pressure to represent the intercooler heat exchanger (1 psi), hoses (0.4 psi), etc.\u00a0 We can change it to another more accurate value later, and can model 2 heat exchangers, etc.<\/p>\n

The data is really easy to relate to if we put each set on an XY graph, so let’s do that!<\/p>\n

Calculated Flow Rates:<\/h2>\n
\"\"<\/a>

Cadillac STS-V Intercooler Flow Rate vs Pump Output & Pressure - Bar versus Liters per Minute<\/p><\/div>\n

So reading from the graph, I find this tabular result:<\/p>\n\n\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n
<\/td>\nLiters\/Min<\/td>\n<\/td>\nGallons\/Min<\/td>\n<\/td>\n<\/tr>\n
Pump<\/td>\nCore Only<\/td>\nSystem<\/td>\nCore only<\/td>\nSystem<\/td>\n<\/tr>\n
Bosch<\/td>\n16<\/td>\n13<\/td>\n4.19<\/td>\n3.41<\/td>\n<\/tr>\n
Cyclone<\/td>\n20<\/td>\n18<\/td>\n5.24<\/td>\n4.72<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

In other words,\u00a0 the 8 gpm Bosch pump will pump 4 gpm if it were only pumping through the 4 Laminova cores in serial (theoretical value), or 3.4 gpm through the whole system.<\/p>\n

The higher flow Cyclone pump will or 4.7 gpm through the whole system, or 38% better than the stock pump.<\/p>\n

A second FMHE (front mounted heat exchanger) might cost 1 psi and thus 2 lpm or 0.5 gpm of flow.\u00a0 Also notable is that the Cyclone pump with a 2nd FMHE still probably flows more than the stock pump and single FMHE.\u00a0 Heat transfer probably increases by 0.5 kw, or 38% of the increased flow rate of 1.3 gpm.<\/p>\n

Ideas for further study:<\/h2>\n

Design an experiment to test actual flow rate through the system.\u00a0 Ideal to me would be to add a flow rate indicator (gauge).<\/p>\n

Source a replacement intercooler coolant pump that can pump 9 gpm against a 1.5 bar head pressure in order to optimize intercooler cooling.\u00a0 This is likely to need to be a positive displacement pump rather than a centrifugal pump.<\/p>\n

See an error?\u00a0\u00a0 Applause for the effort?\u00a0 Chime in via the comments section!!<\/p>\n","protected":false},"excerpt":{"rendered":"

Update: Although the info shown is relevant for 4 Laminova cores in series, the Cadillac design does not have 4 in series but rather has A-B in parallel and C-D in parallel flow.\u00a0 I caused some confusion in the way … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,523,189],"tags":[535,541,738,873,737,719],"class_list":["post-10431","post","type-post","status-publish","format-standard","hentry","category-site-info-news","category-sts-v-cadillac-models","category-test-info","tag-bosch","tag-cadillac-sts-v","tag-cyclone","tag-intercooler","tag-intercooler-pump","tag-laminova"],"_links":{"self":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/10431","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/comments?post=10431"}],"version-history":[{"count":52,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/10431\/revisions"}],"predecessor-version":[{"id":10484,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/10431\/revisions\/10484"}],"wp:attachment":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/media?parent=10431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/categories?post=10431"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/tags?post=10431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}