{"id":56566,"date":"2018-10-30T14:32:33","date_gmt":"2018-10-30T21:32:33","guid":{"rendered":"https:\/\/www.racingjunk.com\/news\/?p=56566"},"modified":"2018-10-30T14:32:33","modified_gmt":"2018-10-30T21:32:33","slug":"air-density-tuning-elite-16-promods-drag-racing-texas-motorplex-nov-1-3-2018","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/air-density-tuning-elite-16-promods-drag-racing-texas-motorplex-nov-1-3-2018\/","title":{"rendered":"Air Density Tuning Elite 16 ProMods Drag Racing @ Texas Motorplex Nov. 1-3, 2018"},"content":{"rendered":"<p><a href=\"http:\/\/airdensityonline.com\/\">Via Air Density Online<\/a><\/p>\n<p>ProMods and Top Sportsman drag racing cars are the wildest motorsports door slammers around!\u00a0 <a href=\"http:\/\/www.midwestpromodseries.com\/\">Midwest ProMod Racing Series<\/a> (MWPMS) host a crazy event featuring these wild drag racers at the <a href=\"https:\/\/texasmotorplex.com\/\">Texas Motorplex<\/a>, Nov. 1-3, 2018.\u00a0 Top drag racing ProMod racers running power levels well in excess of 2,000 HP, gamble for a $50K purse with air density tuning that is all-important for max performance.\u00a0 In addition, the very entertaining Top Sportsman (TS) racecars also compete for a healthy purse.\u00a0 Power levels are a bit less in many of the TS competitors where predictability is more important than making max power since these cars run within an ET bracket.\u00a0 For some of these participants, ET dial-in adjustments are done from air density changes.\u00a0 For others, engine, launch RPM, or shift RPM changes are made for air density changes to reproduce an elapse time target.\u00a0 In most competition cases, air density knowledge is important!\u00a0 <a href=\"http:\/\/RacingJunk.com\">RacingJunk.com<\/a> is filled with racecars and parts servicing this category of racing.<\/p>\n<p><strong>Bit of Air Density Science<\/strong><\/p>\n<p>That altitude puts a theoretical nominal barometer at about 29.4 inches HG or about 98% air density for STP (standard temperature pressure) weather conditions.\u00a0 That would be for an ideal sea level baseline although those conditions seldom exist in racing.<\/p>\n<p>Back to the science.\u00a0 The air density affects the power output of a racing engine:<\/p>\n<ul>\n<li>less air density &gt;&gt; less oxygen in the air<\/li>\n<li>less oxygen in the air &gt;&gt; less power.<\/li>\n<\/ul>\n<p><strong>Air Density Affects Racing Engine Tuning<\/strong><\/p>\n<p>The following are examples of different weather conditions at Texas Motorplex and how they might affect engine tuning.\u00a0 Track altitude is 515 feet above sea level.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_56568\" aria-describedby=\"caption-attachment-56568\" style=\"width: 640px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"56568\" data-permalink=\"https:\/\/www.racingjunk.com\/news\/air-density-tuning-elite-16-promods-drag-racing-texas-motorplex-nov-1-3-2018\/ado-texasmotorplex-01-925x525\/\" data-orig-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-01-925x525-e1540935112140.jpg\" data-orig-size=\"640,363\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"ado-texasmotorplex-01-925&amp;#215;525\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Screen snapshot from Air Density Online for Texas Motorplex showing an example of air density, density altitude, and grains of water for October 25, 2018.\u00a0 This weather data is used by professional racers for critical race engine tuning.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-01-925x525-300x170.jpg\" data-large-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-01-925x525-e1540935112140.jpg\" class=\"wp-image-56568\" src=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-01-925x525.jpg\" alt=\"\" width=\"640\" height=\"363\" \/><figcaption id=\"caption-attachment-56568\" class=\"wp-caption-text\">Screen snapshot from Air Density Online for Texas Motorplex showing an example of air density, density altitude, and grains of water for October 25, 2018.\u00a0 This weather data is used by professional racers for critical race engine tuning.<\/figcaption><\/figure>\n<p><strong>Air Density the Year Before<\/strong><\/p>\n<p>One year before this 2018 event, on Nov. 1-3, 2017, Texas Motorplex air density was about 97% in the morning and dropped to around 91% in the heat of late afternoon from warm temperatures well over 80 deg F.\u00a0 Humidity was high that also affects the amount of oxygen in the air:<\/p>\n<ul>\n<li>more humidity &gt;&gt; less oxygen in the air<\/li>\n<li>less oxygen in the air &gt;&gt; less power.<\/li>\n<\/ul>\n<p>Fuel system tuning for these kinds of air density changes is more dramatic.<\/p>\n<p><strong>Air Density Forecast for Theoretical Racing Time October 18-20<\/strong><\/p>\n<p>Air density information was re-examined a couple weeks before the event for this year.\u00a0 That is shown in the next screen snapshot from <a href=\"https:\/\/airdensityonline.com\">Air Density Online<\/a> for the <a href=\"https:\/\/texasmotorplex.com\/\">Texas Motorplex<\/a>.\u00a0\u00a0\u00a0 It looked like much cooler temperatures and higher overall air densities than last year if the race was run at this time.<\/p>\n<figure id=\"attachment_56569\" aria-describedby=\"caption-attachment-56569\" style=\"width: 640px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"56569\" data-permalink=\"https:\/\/www.racingjunk.com\/news\/air-density-tuning-elite-16-promods-drag-racing-texas-motorplex-nov-1-3-2018\/ado-texasmotorplex-02-905x720\/\" data-orig-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720.jpg\" data-orig-size=\"905,720\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"ado-texasmotorplex-02-905&amp;#215;720\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Screen snapshot of Air density forecast chart from race track weather for Texas Motorplex showing 3 day forecast of air density, density altitude, and grains of water for October 18-20.\u00a0 The forecast shows vital tuning data used by serious racing tuners.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720-300x239.jpg\" data-large-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720.jpg\" class=\"wp-image-56569\" src=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720.jpg\" alt=\"\" width=\"640\" height=\"509\" srcset=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720.jpg 905w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720-300x239.jpg 300w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720-768x611.jpg 768w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-02-905x720-108x86.jpg 108w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption id=\"caption-attachment-56569\" class=\"wp-caption-text\">Screen snapshot of Air density forecast chart from race track weather for Texas Motorplex showing 3 day forecast of air density, density altitude, and grains of water for October 18-20.\u00a0 The forecast shows vital tuning data used by serious racing tuners.<\/figcaption><\/figure>\n<p><strong>Air Density Variation Effects<\/strong><\/p>\n<p>This particular weather shows good air density that only varies from a high of 99% to a low of 98%.\u00a0 If racing was done during these days:<\/p>\n<ol>\n<li>The first tuning task is to <em>adjust the fuel system<\/em> for this local air density. Essentially the fuel system should be adjusted a comparable amount to the air density change from the racer&#8217;s baseline.\u00a0 That often depends on where the racer came from, which would determine a prior high or low air density baseline standard for that racer&#8217;s tune-up.<\/li>\n<li>Once that is done, <em>tuning would be minimal<\/em>, in this case, <em>because of this narrow air density range throughout this theoretical event time<\/em>. Spark plug readings, as tuning indicators, should remain consistent.\u00a0 The air density simply does not change very much, and fuel system demands would not change very much.<\/li>\n<\/ol>\n<p><strong>Air Density Forecast for Theoretical Racing Time October 25-27 Showing Rain<\/strong><\/p>\n<p>Air density during the week before the upcoming event was further examined.<\/p>\n<p><em>It looks like rain for a few days preceding cooler weather.<\/em><\/p>\n<p>Air density is 98% in the morning going down to about 94% in the warmest afternoon with a temperature of around 60 deg F.\u00a0 That is lower than last year around this same calendar period.\u00a0 This is shown in the next screen snapshot for the Texas Motorplex for October 25-27.<\/p>\n<figure id=\"attachment_56570\" aria-describedby=\"caption-attachment-56570\" style=\"width: 640px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"56570\" data-permalink=\"https:\/\/www.racingjunk.com\/news\/air-density-tuning-elite-16-promods-drag-racing-texas-motorplex-nov-1-3-2018\/ado-texasmotorplex-03-905x725\/\" data-orig-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725.jpg\" data-orig-size=\"905,725\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"ado-texasmotorplex-03-905&amp;#215;725\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Screen snapshot of Air density forecast chart from race track weather for Texas Motorplex showing 3 day forecast of air density, density altitude, and grains of water for October 18-20.\u00a0 The forecast shows vital tuning data used by serious racing tuners.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725-300x240.jpg\" data-large-file=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725.jpg\" class=\"wp-image-56570\" src=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725.jpg\" alt=\"\" width=\"640\" height=\"513\" srcset=\"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725.jpg 905w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725-300x240.jpg 300w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725-768x615.jpg 768w, https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-03-905x725-108x86.jpg 108w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption id=\"caption-attachment-56570\" class=\"wp-caption-text\">Screen snapshot from Air Density Online for US Tracks, specifically the Texas Motorplex showing 3 day forecast of air density,\u00a0 density altitude, and grains of water for race tuning on theoretical event time of October 25-27<\/figcaption><\/figure>\n<p><strong>More Air Density Variation &gt;&gt; More Oxygen Variation, &gt;&gt; More Power Variation<\/strong><\/p>\n<p>Air density varies from a high of 98% to a low of 94%.\u00a0 If the ProMod racing event was done during these days:<\/p>\n<ol>\n<li>The racecar fuel system should again be adjusted from the racer&#8217;s baseline for a comparable amount of fuel volume change for this increased amount of air density change at the start of racing.<\/li>\n<li>The fuel system should be adjusted for the changing air density at it occurs throughout race day. Changes in spark plug reading become more dramatic as tuning indicators.<\/li>\n<\/ol>\n<p><strong>Humidity Effects on Drag Racecars<\/strong><\/p>\n<p><em>Note 1: The best racetrack surface is usually right after a strong rain storm where the pavement surface is washed clean from the rain.\u00a0 On the chart, rain is likely with a forecast of 100% humidity. <\/em><em>\u00a0<\/em><em>If rain clears on race day, that is then followed by a good coating of traction compound and rubber dragging deposit before the race track.\u00a0 That is key before it gets dirty from dust and oil\/exhaust byproducts from subsequent racecars.\u00a0 Without a prior rain storm, national event preparation often includes manual washing the racetrack surface as clean as possible prior to traction compound application and dragging.\u00a0 Racetrack preparers say when it does not rain ahead of an event, washing is way more work than applying the subsequent traction compound &amp; dragging.\u00a0 Prior pavement cleaning is more critical to maximum traction for a subsequent event.<\/em><\/p>\n<p><em>Note 2: Note the humidity change data.\u00a0 Typically the higher the humidity during an event, the more sensitive the racetrack surface is to loss of traction.\u00a0 Traction is very critical to high powered ProMods and Top Sportman racecars.\u00a0 As the temperature goes down in the evening, the racetrack temperature drops, and humidity goes up.\u00a0 In many events, as long as the event proceeds on a continuous basis, one racecar-after-another keeps &#8216;the traction groove&#8217;.\u00a0 If the event is interrupted from a crash or oil down, sometimes &#8216;the groove&#8217; is lost.\u00a0 Subsequent traction is difficult to achieve, especially in front heavy, high powered ProMods and TS racecars.\u00a0\u00a0 They tend to unload the rear tires when the front end comes down after a wheels-up launch when there is any loss of racetrack traction from humidity or cooler temperature.\u00a0 More free info is in reference 1.<\/em><\/p>\n<p><strong>Different Racers from Higher Altitude Baselines &gt;&gt; Different Tune-ups<\/strong><\/p>\n<p>Competitors from different parts of the country attend this event.\u00a0 Some competitors developed tuning baselines from higher altitude, lower air density such as mountainous regions.\u00a0 Here air densities are often well below 90%.\u00a0 Lean spark plug readings would be common, and the racer must tune-up to the Texas event.<\/p>\n<p><strong>Different Racers from Lower Altitude Baselines &gt;&gt; Different Tune-downs<\/strong><\/p>\n<p>Some competitors developed tuning baselines from lower altitude, higher air densities such as coastal regions with higher air densities than elevated central regions.\u00a0 Rich spark plug readings would be common when the air density is lower as you go to the higher elevation racetracks.\u00a0 The racer who traveled from lower elevation regions must tune-down to warmer afternoon competition when it occurs at this <a href=\"https:\/\/texasmotorplex.com\/\">Texas Motorplex<\/a> location during warm weather.<\/p>\n<p><strong>Air Density Effects on Different Engine Combinations<\/strong><\/p>\n<p>Different racing engine setups are common to ProMod and Top Sportsman.\u00a0 As temperature, humidity, and barometer vary from STP weather conditions, different air densities result that affect engine power levels especially in both the popular <em>carbureted gas mountain motors<\/em> and the <em>blown alcohol competitors<\/em>.\u00a0 With the right fuel adjustments, power goes up or down with air density in either setup.\u00a0 In both setups, fuel amounts should be adjusted in proportion to air density changes from the racer&#8217;s baseline.\u00a0 The proper amount is weight-of-air to weight-of-fuel or air\/fuel ratio.<\/p>\n<p>For <em>nitrous oxide (NOS) assisted engines<\/em>, baseline engine setups &#8220;on-the-motor&#8221; w\/o nitrous are affected equally as much by air density changes as normally aspirated mountain motors.\u00a0 However many competitors simply adjust the NOS for the air density differences.\u00a0 Adjustments for nitrous oxide amount, fuel amount, and bottle temperature are the ones to compensate for air density effects on these very high power racing engines, with many that are well over 2,000 horsepower.<\/p>\n<p><em>EFI and centrifugal superchargers<\/em> are a combination also affected by air density.\u00a0 With closed loop control using oxygen sensors, the fuel is automatically regulated by the fuel map to maintain air\/fuel ratios for air density changes.\u00a0\u00a0 However, power goes up or down with air density.<\/p>\n<p><em>Carburetors and centrifugal superchargers<\/em> are another combination affected by air density.\u00a0 Carburetor re-jetting or other changes such as power valves or float bowl pressure are necessary to chase the air as air density goes up or down.\u00a0 Because of high boost, carburetor tuning may be more vital than in normally aspirated engines with carburetors.\u00a0 At high boost, great power or bad problems may be amplified without proper fuel system adjustment.<\/p>\n<p><em>EFI and turbochargers<\/em> are also one of the ProMod combinations.\u00a0 They are less affected from air density changes since the exhaust waste gate(s) regulate boost to a target value, regardless of air density changes.\u00a0 These setups, commonly running closed loop with oxygen sensors, automatically adjust the fuel as well.\u00a0 That is again done according to the electronic controller fuel map properly matched to a constant boost that is regulated by the waste gate(s).<\/p>\n<p>That logic would apply to a <em>carburetor and turbocharger setup<\/em> as well.\u00a0 Waste gates tend to keep everything the same, and tuning for air density changes from a good baseline may be minimal.<\/p>\n<p><strong>Most Engine Combos and Air Density Tuning<\/strong><\/p>\n<p>For any of the racing engine combinations that do not run NOS, the oxygen from the air supports the combustion process.\u00a0 The amount of oxygen in the air determines the amount of fuel.\u00a0 The proper air\/fuel ratio determines the amount of power.\u00a0 Higher or lower air density affects the amount of oxygen in the air and subsequently the amount of power.<\/p>\n<p><em>Note: Top Sportsman setups that use a blower can change the blower overdrive to compensate for a change in oxygen in the air from air density changes.<\/em><\/p>\n<p>Our <a href=\"https:\/\/airdensityonline.com\/procalc\/\">ProCalc fuel injection jetting calculator<\/a> is a tool to determine the amount of overdrive change to compensate for air density changes to reproduce a power level for racing mechanical fuel injection.<\/p>\n<p>ProMod engine tuners who their engines at the blower overdrive limits specified by the event rules cannot make this change.\u00a0 Fuel system adjustments are needed instead.\u00a0 The effect on air density from changes in temperature, humidity, or barometer is outlined in reference 2 &amp; 3 and illustrated with math in these free references.\u00a0 <a href=\"https:\/\/airdensityonline.com\/procalc\/\">ProCalc<\/a> is again a tool to determine fuel system changes for air density changes in racing mechanical fuel injection setups.<\/p>\n<p><strong>Air Density Effect on Horsepower Corrections<\/strong><\/p>\n<p>ProMod competitors strive for max power.\u00a0 Other than the turbocharged racecars with boost controlled exhaust waste gates with relatively constant fuel systems, air density affects the fuel delivery needs (tuning) in the other engine combinations.<\/p>\n<p><em>Air density changes also affect the horsepower<\/em><\/p>\n<p><em>but in a different amount than the fuel delivery needs.<\/em><\/p>\n<p>The effects are quite complex.\u00a0 Changes to temperature, humidity, and air pressure (barometer) each have different effects on horsepower.\u00a0 This is illustrated in the next example.<\/p>\n<p><em>Example: Assume a <\/em>dramatic temperature change<em> by itself that causes a 5% change in air density.\u00a0 That would necessitate a 5% change in fuel delivery needs from a baseline.\u00a0 Now assume a different racing location where a <\/em>dramatic barometer change<em> by itself causes a 5% change in air density.\u00a0 That would necessitate the same 5% change in fuel delivery needs from the same baseline.\u00a0 Even though the air density change would be the same in both cases and the fuel system change would be the same, the horsepower correction would be different.<\/em><\/p>\n<ol>\n<li><em>Temperature changes have one effect on horsepower.<\/em><\/li>\n<li><em>Barometric pressure changes have a different effect on horsepower, even though the engine fuel system may be the same in both cases.<\/em><\/li>\n<\/ol>\n<p><strong>More Information about Horsepower Corrections<\/strong><\/p>\n<p>Reference 4 highlights the science behind horsepower corrections.\u00a0 This source illustrates an example where an air density of 98% was achieved with a specific combination of the three weather values.\u00a0 An engine with 2,200 horsepower was reduced to 2,165 horsepower from this weather combination.\u00a0\u00a0 The illustration shows that different weather combinations with the same air density could have different horsepower corrections.<\/p>\n<p><strong>Humidity vs. Water Grains<\/strong><\/p>\n<p>The previous charts show both humidity and water grains.\u00a0 Many racers pay more attention to water grains.\u00a0 That is because the relative humidity % changes with temperature, and water grains do not.\u00a0 They stay relatively constant regardless of a temperature and relative humidity % changes that may occur throughout a racing day.\u00a0 They may change from a weather front that may be moving in, but not from regional effects, especially where the wind speed is low.<\/p>\n<p><strong>Humidity Effects on Horsepower<\/strong><\/p>\n<ul>\n<li>Years ago, I was told to ignore humidity in tuning because its effects were minimal.<\/li>\n<li>I was also told that more humidity made more power because of detonation retarding.<\/li>\n<li>I was also told that it made more power from cooling of the air.<\/li>\n<\/ul>\n<p>That is really not the case.\u00a0 More humidity displaces oxygen in the air making less power.\u00a0 Reference 5 illustrates an example where 50% relative humidity by itself reduces the air density (and oxygen content in the air) by over 2%.\u00a0 That would be a reduction in fuel system delivery by over 2% to maintain an optimum air\/fuel ratio, just from low vs muggy humidity.\u00a0 That would be a comparable reduction in power.<\/p>\n<p><strong>ProMod at <a href=\"http:\/\/www.midwestpromodseries.com\/\">MWPMS<\/a> and HP Correction<\/strong><\/p>\n<p>The performance change of the ProMod in changing air densities does not exactly follow the air density percentage line event though the fuel system correction may.\u00a0 These racecars can overpower the tires, at will, almost anywhere on the racetrack.\u00a0 Horsepower corrections from the weather value combinations become a vital part of the tuning data base to try to avoid tire spin.<\/p>\n<p><strong>Top Sportsman at <a href=\"http:\/\/www.midwestpromodseries.com\/\">MWPMS<\/a> and HP Correction<\/strong><\/p>\n<p>The performance change from different weather value combinations in Top Sportsman may be more critical.\u00a0 Tuning with air density changes to control a target ET dial-in really depends on the specific combination of weather values.\u00a0 One weather value combination affects horsepower correction and the ET.\u00a0 Another weather value combination even with the same air density affects horsepower corrections and the ET in a different manner.<\/p>\n<p><strong>In Summary<\/strong><\/p>\n<ul>\n<li>Air density forecasts are available through <a href=\"https:\/\/airdensityonline.com\">Air Density Online<\/a> for racetracks all over the US.<\/li>\n<li>Current air density for international tracks all around the world are listed as well, and metric units for weather conversions are provided for these.<\/li>\n<li>Air density is key to fuel system tuning in most high performance racing engines.<\/li>\n<li>Fuel system tuning goes up and down with air density.<\/li>\n<li>Engine horsepower corrections go up and down as well but at a more complex rate.<\/li>\n<li>Several air density and horsepower corrections results were provided from several references.<\/li>\n<li>Air density tuning is a vital part of motorsports setups bought or sold through <a href=\"http:\/\/racingjunk.com\">com<\/a>.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>Air Density Online gives racers a very important tool when it comes to fuel system tuning. <\/p>\n<\/div>","protected":false},"author":17,"featured_media":56568,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5028,5008,17,3470,22],"tags":[6370,2,41,674,515,404],"class_list":["post-56566","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fuel-delivery","category-engine","category-guest-column","category-news","category-event-coverage","tag-air-density-online","tag-drag-racing","tag-news","tag-texas-motor-speedway","tag-texas-motorplex","tag-tuning"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2018\/10\/ado-texasmotorplex-01-925x525-e1540935112140.jpg","jetpack_shortlink":"https:\/\/wp.me\/p42YSK-eIm","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/56566","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/comments?post=56566"}],"version-history":[{"count":5,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/56566\/revisions"}],"predecessor-version":[{"id":56574,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/56566\/revisions\/56574"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media\/56568"}],"wp:attachment":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media?parent=56566"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/categories?post=56566"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/tags?post=56566"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}